source: trip-planner-front/node_modules/@angular/cdk/fesm2015/drag-drop.js

import * as i0 from '@angular/core';
import { Injectable, NgZone, Inject, InjectionToken, Directive, Input, EventEmitter, ElementRef, ChangeDetectorRef, Optional, SkipSelf, Output, TemplateRef, ViewContainerRef, Self, ContentChildren, ContentChild, NgModule } from '@angular/core';
import * as i1 from '@angular/common';
import { DOCUMENT } from '@angular/common';
import * as i2 from '@angular/cdk/scrolling';
import { ViewportRuler, ScrollDispatcher, CdkScrollableModule } from '@angular/cdk/scrolling';
import { _getEventTarget, normalizePassiveListenerOptions, _getShadowRoot } from '@angular/cdk/platform';
import { coerceBooleanProperty, coerceElement, coerceArray, coerceNumberProperty } from '@angular/cdk/coercion';
import { isFakeTouchstartFromScreenReader, isFakeMousedownFromScreenReader } from '@angular/cdk/a11y';
import { Subject, Subscription, interval, animationFrameScheduler, Observable, merge } from 'rxjs';
import { takeUntil, startWith, map, take, tap, switchMap } from 'rxjs/operators';
import { Directionality } from '@angular/cdk/bidi';

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Shallow-extends a stylesheet object with another stylesheet-like object.
 * Note that the keys in `source` have to be dash-cased.
 * @docs-private
 */
function extendStyles(dest, source, importantProperties) {
    for (let key in source) {
        if (source.hasOwnProperty(key)) {
            const value = source[key];
            if (value) {
                dest.setProperty(key, value, (importantProperties === null || importantProperties === void 0 ? void 0 : importantProperties.has(key)) ? 'important' : '');
            }
            else {
                dest.removeProperty(key);
            }
        }
    }
    return dest;
}
/**
 * Toggles whether the native drag interactions should be enabled for an element.
 * @param element Element on which to toggle the drag interactions.
 * @param enable Whether the drag interactions should be enabled.
 * @docs-private
 */
function toggleNativeDragInteractions(element, enable) {
    const userSelect = enable ? '' : 'none';
    extendStyles(element.style, {
        'touch-action': enable ? '' : 'none',
        '-webkit-user-drag': enable ? '' : 'none',
        '-webkit-tap-highlight-color': enable ? '' : 'transparent',
        'user-select': userSelect,
        '-ms-user-select': userSelect,
        '-webkit-user-select': userSelect,
        '-moz-user-select': userSelect
    });
}
/**
 * Toggles whether an element is visible while preserving its dimensions.
 * @param element Element whose visibility to toggle
 * @param enable Whether the element should be visible.
 * @param importantProperties Properties to be set as `!important`.
 * @docs-private
 */
function toggleVisibility(element, enable, importantProperties) {
    extendStyles(element.style, {
        position: enable ? '' : 'fixed',
        top: enable ? '' : '0',
        opacity: enable ? '' : '0',
        left: enable ? '' : '-999em'
    }, importantProperties);
}
/**
 * Combines a transform string with an optional other transform
 * that exited before the base transform was applied.
 */
function combineTransforms(transform, initialTransform) {
    return initialTransform && initialTransform != 'none' ?
        (transform + ' ' + initialTransform) :
        transform;
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Parses a CSS time value to milliseconds. */
function parseCssTimeUnitsToMs(value) {
    // Some browsers will return it in seconds, whereas others will return milliseconds.
    const multiplier = value.toLowerCase().indexOf('ms') > -1 ? 1 : 1000;
    return parseFloat(value) * multiplier;
}
/** Gets the transform transition duration, including the delay, of an element in milliseconds. */
function getTransformTransitionDurationInMs(element) {
    const computedStyle = getComputedStyle(element);
    const transitionedProperties = parseCssPropertyValue(computedStyle, 'transition-property');
    const property = transitionedProperties.find(prop => prop === 'transform' || prop === 'all');
    // If there's no transition for `all` or `transform`, we shouldn't do anything.
    if (!property) {
        return 0;
    }
    // Get the index of the property that we're interested in and match
    // it up to the same index in `transition-delay` and `transition-duration`.
    const propertyIndex = transitionedProperties.indexOf(property);
    const rawDurations = parseCssPropertyValue(computedStyle, 'transition-duration');
    const rawDelays = parseCssPropertyValue(computedStyle, 'transition-delay');
    return parseCssTimeUnitsToMs(rawDurations[propertyIndex]) +
        parseCssTimeUnitsToMs(rawDelays[propertyIndex]);
}
/** Parses out multiple values from a computed style into an array. */
function parseCssPropertyValue(computedStyle, name) {
    const value = computedStyle.getPropertyValue(name);
    return value.split(',').map(part => part.trim());
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Gets a mutable version of an element's bounding `ClientRect`. */
function getMutableClientRect(element) {
    const clientRect = element.getBoundingClientRect();
    // We need to clone the `clientRect` here, because all the values on it are readonly
    // and we need to be able to update them. Also we can't use a spread here, because
    // the values on a `ClientRect` aren't own properties. See:
    // https://developer.mozilla.org/en-US/docs/Web/API/Element/getBoundingClientRect#Notes
    return {
        top: clientRect.top,
        right: clientRect.right,
        bottom: clientRect.bottom,
        left: clientRect.left,
        width: clientRect.width,
        height: clientRect.height
    };
}
/**
 * Checks whether some coordinates are within a `ClientRect`.
 * @param clientRect ClientRect that is being checked.
 * @param x Coordinates along the X axis.
 * @param y Coordinates along the Y axis.
 */
function isInsideClientRect(clientRect, x, y) {
    const { top, bottom, left, right } = clientRect;
    return y >= top && y <= bottom && x >= left && x <= right;
}
/**
 * Updates the top/left positions of a `ClientRect`, as well as their bottom/right counterparts.
 * @param clientRect `ClientRect` that should be updated.
 * @param top Amount to add to the `top` position.
 * @param left Amount to add to the `left` position.
 */
function adjustClientRect(clientRect, top, left) {
    clientRect.top += top;
    clientRect.bottom = clientRect.top + clientRect.height;
    clientRect.left += left;
    clientRect.right = clientRect.left + clientRect.width;
}
/**
 * Checks whether the pointer coordinates are close to a ClientRect.
 * @param rect ClientRect to check against.
 * @param threshold Threshold around the ClientRect.
 * @param pointerX Coordinates along the X axis.
 * @param pointerY Coordinates along the Y axis.
 */
function isPointerNearClientRect(rect, threshold, pointerX, pointerY) {
    const { top, right, bottom, left, width, height } = rect;
    const xThreshold = width * threshold;
    const yThreshold = height * threshold;
    return pointerY > top - yThreshold && pointerY < bottom + yThreshold &&
        pointerX > left - xThreshold && pointerX < right + xThreshold;
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Keeps track of the scroll position and dimensions of the parents of an element. */
class ParentPositionTracker {
    constructor(_document, _viewportRuler) {
        this._document = _document;
        this._viewportRuler = _viewportRuler;
        /** Cached positions of the scrollable parent elements. */
        this.positions = new Map();
    }
    /** Clears the cached positions. */
    clear() {
        this.positions.clear();
    }
    /** Caches the positions. Should be called at the beginning of a drag sequence. */
    cache(elements) {
        this.clear();
        this.positions.set(this._document, {
            scrollPosition: this._viewportRuler.getViewportScrollPosition(),
        });
        elements.forEach(element => {
            this.positions.set(element, {
                scrollPosition: { top: element.scrollTop, left: element.scrollLeft },
                clientRect: getMutableClientRect(element)
            });
        });
    }
    /** Handles scrolling while a drag is taking place. */
    handleScroll(event) {
        const target = _getEventTarget(event);
        const cachedPosition = this.positions.get(target);
        if (!cachedPosition) {
            return null;
        }
        // Used when figuring out whether an element is inside the scroll parent. If the scrolled
        // parent is the `document`, we use the `documentElement`, because IE doesn't support
        // `contains` on the `document`.
        const scrolledParentNode = target === this._document ? target.documentElement : target;
        const scrollPosition = cachedPosition.scrollPosition;
        let newTop;
        let newLeft;
        if (target === this._document) {
            const viewportScrollPosition = this._viewportRuler.getViewportScrollPosition();
            newTop = viewportScrollPosition.top;
            newLeft = viewportScrollPosition.left;
        }
        else {
            newTop = target.scrollTop;
            newLeft = target.scrollLeft;
        }
        const topDifference = scrollPosition.top - newTop;
        const leftDifference = scrollPosition.left - newLeft;
        // Go through and update the cached positions of the scroll
        // parents that are inside the element that was scrolled.
        this.positions.forEach((position, node) => {
            if (position.clientRect && target !== node && scrolledParentNode.contains(node)) {
                adjustClientRect(position.clientRect, topDifference, leftDifference);
            }
        });
        scrollPosition.top = newTop;
        scrollPosition.left = newLeft;
        return { top: topDifference, left: leftDifference };
    }
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Creates a deep clone of an element. */
function deepCloneNode(node) {
    const clone = node.cloneNode(true);
    const descendantsWithId = clone.querySelectorAll('[id]');
    const nodeName = node.nodeName.toLowerCase();
    // Remove the `id` to avoid having multiple elements with the same id on the page.
    clone.removeAttribute('id');
    for (let i = 0; i < descendantsWithId.length; i++) {
        descendantsWithId[i].removeAttribute('id');
    }
    if (nodeName === 'canvas') {
        transferCanvasData(node, clone);
    }
    else if (nodeName === 'input' || nodeName === 'select' || nodeName === 'textarea') {
        transferInputData(node, clone);
    }
    transferData('canvas', node, clone, transferCanvasData);
    transferData('input, textarea, select', node, clone, transferInputData);
    return clone;
}
/** Matches elements between an element and its clone and allows for their data to be cloned. */
function transferData(selector, node, clone, callback) {
    const descendantElements = node.querySelectorAll(selector);
    if (descendantElements.length) {
        const cloneElements = clone.querySelectorAll(selector);
        for (let i = 0; i < descendantElements.length; i++) {
            callback(descendantElements[i], cloneElements[i]);
        }
    }
}
// Counter for unique cloned radio button names.
let cloneUniqueId = 0;
/** Transfers the data of one input element to another. */
function transferInputData(source, clone) {
    // Browsers throw an error when assigning the value of a file input programmatically.
    if (clone.type !== 'file') {
        clone.value = source.value;
    }
    // Radio button `name` attributes must be unique for radio button groups
    // otherwise original radio buttons can lose their checked state
    // once the clone is inserted in the DOM.
    if (clone.type === 'radio' && clone.name) {
        clone.name = `mat-clone-${clone.name}-${cloneUniqueId++}`;
    }
}
/** Transfers the data of one canvas element to another. */
function transferCanvasData(source, clone) {
    const context = clone.getContext('2d');
    if (context) {
        // In some cases `drawImage` can throw (e.g. if the canvas size is 0x0).
        // We can't do much about it so just ignore the error.
        try {
            context.drawImage(source, 0, 0);
        }
        catch (_a) { }
    }
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Options that can be used to bind a passive event listener. */
const passiveEventListenerOptions = normalizePassiveListenerOptions({ passive: true });
/** Options that can be used to bind an active event listener. */
const activeEventListenerOptions = normalizePassiveListenerOptions({ passive: false });
/**
 * Time in milliseconds for which to ignore mouse events, after
 * receiving a touch event. Used to avoid doing double work for
 * touch devices where the browser fires fake mouse events, in
 * addition to touch events.
 */
const MOUSE_EVENT_IGNORE_TIME = 800;
/** Inline styles to be set as `!important` while dragging. */
const dragImportantProperties = new Set([
    // Needs to be important, because some `mat-table` sets `position: sticky !important`. See #22781.
    'position'
]);
/**
 * Reference to a draggable item. Used to manipulate or dispose of the item.
 */
class DragRef {
    constructor(element, _config, _document, _ngZone, _viewportRuler, _dragDropRegistry) {
        this._config = _config;
        this._document = _document;
        this._ngZone = _ngZone;
        this._viewportRuler = _viewportRuler;
        this._dragDropRegistry = _dragDropRegistry;
        /**
         * CSS `transform` applied to the element when it isn't being dragged. We need a
         * passive transform in order for the dragged element to retain its new position
         * after the user has stopped dragging and because we need to know the relative
         * position in case they start dragging again. This corresponds to `element.style.transform`.
         */
        this._passiveTransform = { x: 0, y: 0 };
        /** CSS `transform` that is applied to the element while it's being dragged. */
        this._activeTransform = { x: 0, y: 0 };
        /**
         * Whether the dragging sequence has been started. Doesn't
         * necessarily mean that the element has been moved.
         */
        this._hasStartedDragging = false;
        /** Emits when the item is being moved. */
        this._moveEvents = new Subject();
        /** Subscription to pointer movement events. */
        this._pointerMoveSubscription = Subscription.EMPTY;
        /** Subscription to the event that is dispatched when the user lifts their pointer. */
        this._pointerUpSubscription = Subscription.EMPTY;
        /** Subscription to the viewport being scrolled. */
        this._scrollSubscription = Subscription.EMPTY;
        /** Subscription to the viewport being resized. */
        this._resizeSubscription = Subscription.EMPTY;
        /** Cached reference to the boundary element. */
        this._boundaryElement = null;
        /** Whether the native dragging interactions have been enabled on the root element. */
        this._nativeInteractionsEnabled = true;
        /** Elements that can be used to drag the draggable item. */
        this._handles = [];
        /** Registered handles that are currently disabled. */
        this._disabledHandles = new Set();
        /** Layout direction of the item. */
        this._direction = 'ltr';
        /**
         * Amount of milliseconds to wait after the user has put their
         * pointer down before starting to drag the element.
         */
        this.dragStartDelay = 0;
        this._disabled = false;
        /** Emits as the drag sequence is being prepared. */
        this.beforeStarted = new Subject();
        /** Emits when the user starts dragging the item. */
        this.started = new Subject();
        /** Emits when the user has released a drag item, before any animations have started. */
        this.released = new Subject();
        /** Emits when the user stops dragging an item in the container. */
        this.ended = new Subject();
        /** Emits when the user has moved the item into a new container. */
        this.entered = new Subject();
        /** Emits when the user removes the item its container by dragging it into another container. */
        this.exited = new Subject();
        /** Emits when the user drops the item inside a container. */
        this.dropped = new Subject();
        /**
         * Emits as the user is dragging the item. Use with caution,
         * because this event will fire for every pixel that the user has dragged.
         */
        this.moved = this._moveEvents;
        /** Handler for the `mousedown`/`touchstart` events. */
        this._pointerDown = (event) => {
            this.beforeStarted.next();
            // Delegate the event based on whether it started from a handle or the element itself.
            if (this._handles.length) {
                const targetHandle = this._handles.find(handle => {
                    const target = _getEventTarget(event);
                    return !!target && (target === handle || handle.contains(target));
                });
                if (targetHandle && !this._disabledHandles.has(targetHandle) && !this.disabled) {
                    this._initializeDragSequence(targetHandle, event);
                }
            }
            else if (!this.disabled) {
                this._initializeDragSequence(this._rootElement, event);
            }
        };
        /** Handler that is invoked when the user moves their pointer after they've initiated a drag. */
        this._pointerMove = (event) => {
            const pointerPosition = this._getPointerPositionOnPage(event);
            if (!this._hasStartedDragging) {
                const distanceX = Math.abs(pointerPosition.x - this._pickupPositionOnPage.x);
                const distanceY = Math.abs(pointerPosition.y - this._pickupPositionOnPage.y);
                const isOverThreshold = distanceX + distanceY >= this._config.dragStartThreshold;
                // Only start dragging after the user has moved more than the minimum distance in either
                // direction. Note that this is preferrable over doing something like `skip(minimumDistance)`
                // in the `pointerMove` subscription, because we're not guaranteed to have one move event
                // per pixel of movement (e.g. if the user moves their pointer quickly).
                if (isOverThreshold) {
                    const isDelayElapsed = Date.now() >= this._dragStartTime + this._getDragStartDelay(event);
                    const container = this._dropContainer;
                    if (!isDelayElapsed) {
                        this._endDragSequence(event);
                        return;
                    }
                    // Prevent other drag sequences from starting while something in the container is still
                    // being dragged. This can happen while we're waiting for the drop animation to finish
                    // and can cause errors, because some elements might still be moving around.
                    if (!container || (!container.isDragging() && !container.isReceiving())) {
                        // Prevent the default action as soon as the dragging sequence is considered as
                        // "started" since waiting for the next event can allow the device to begin scrolling.
                        event.preventDefault();
                        this._hasStartedDragging = true;
                        this._ngZone.run(() => this._startDragSequence(event));
                    }
                }
                return;
            }
            // We only need the preview dimensions if we have a boundary element.
            if (this._boundaryElement) {
                // Cache the preview element rect if we haven't cached it already or if
                // we cached it too early before the element dimensions were computed.
                if (!this._previewRect || (!this._previewRect.width && !this._previewRect.height)) {
                    this._previewRect = (this._preview || this._rootElement).getBoundingClientRect();
                }
            }
            // We prevent the default action down here so that we know that dragging has started. This is
            // important for touch devices where doing this too early can unnecessarily block scrolling,
            // if there's a dragging delay.
            event.preventDefault();
            const constrainedPointerPosition = this._getConstrainedPointerPosition(pointerPosition);
            this._hasMoved = true;
            this._lastKnownPointerPosition = pointerPosition;
            this._updatePointerDirectionDelta(constrainedPointerPosition);
            if (this._dropContainer) {
                this._updateActiveDropContainer(constrainedPointerPosition, pointerPosition);
            }
            else {
                const activeTransform = this._activeTransform;
                activeTransform.x =
                    constrainedPointerPosition.x - this._pickupPositionOnPage.x + this._passiveTransform.x;
                activeTransform.y =
                    constrainedPointerPosition.y - this._pickupPositionOnPage.y + this._passiveTransform.y;
                this._applyRootElementTransform(activeTransform.x, activeTransform.y);
                // Apply transform as attribute if dragging and svg element to work for IE
                if (typeof SVGElement !== 'undefined' && this._rootElement instanceof SVGElement) {
                    const appliedTransform = `translate(${activeTransform.x} ${activeTransform.y})`;
                    this._rootElement.setAttribute('transform', appliedTransform);
                }
            }
            // Since this event gets fired for every pixel while dragging, we only
            // want to fire it if the consumer opted into it. Also we have to
            // re-enter the zone because we run all of the events on the outside.
            if (this._moveEvents.observers.length) {
                this._ngZone.run(() => {
                    this._moveEvents.next({
                        source: this,
                        pointerPosition: constrainedPointerPosition,
                        event,
                        distance: this._getDragDistance(constrainedPointerPosition),
                        delta: this._pointerDirectionDelta
                    });
                });
            }
        };
        /** Handler that is invoked when the user lifts their pointer up, after initiating a drag. */
        this._pointerUp = (event) => {
            this._endDragSequence(event);
        };
        this.withRootElement(element).withParent(_config.parentDragRef || null);
        this._parentPositions = new ParentPositionTracker(_document, _viewportRuler);
        _dragDropRegistry.registerDragItem(this);
    }
    /** Whether starting to drag this element is disabled. */
    get disabled() {
        return this._disabled || !!(this._dropContainer && this._dropContainer.disabled);
    }
    set disabled(value) {
        const newValue = coerceBooleanProperty(value);
        if (newValue !== this._disabled) {
            this._disabled = newValue;
            this._toggleNativeDragInteractions();
            this._handles.forEach(handle => toggleNativeDragInteractions(handle, newValue));
        }
    }
    /**
     * Returns the element that is being used as a placeholder
     * while the current element is being dragged.
     */
    getPlaceholderElement() {
        return this._placeholder;
    }
    /** Returns the root draggable element. */
    getRootElement() {
        return this._rootElement;
    }
    /**
     * Gets the currently-visible element that represents the drag item.
     * While dragging this is the placeholder, otherwise it's the root element.
     */
    getVisibleElement() {
        return this.isDragging() ? this.getPlaceholderElement() : this.getRootElement();
    }
    /** Registers the handles that can be used to drag the element. */
    withHandles(handles) {
        this._handles = handles.map(handle => coerceElement(handle));
        this._handles.forEach(handle => toggleNativeDragInteractions(handle, this.disabled));
        this._toggleNativeDragInteractions();
        // Delete any lingering disabled handles that may have been destroyed. Note that we re-create
        // the set, rather than iterate over it and filter out the destroyed handles, because while
        // the ES spec allows for sets to be modified while they're being iterated over, some polyfills
        // use an array internally which may throw an error.
        const disabledHandles = new Set();
        this._disabledHandles.forEach(handle => {
            if (this._handles.indexOf(handle) > -1) {
                disabledHandles.add(handle);
            }
        });
        this._disabledHandles = disabledHandles;
        return this;
    }
    /**
     * Registers the template that should be used for the drag preview.
     * @param template Template that from which to stamp out the preview.
     */
    withPreviewTemplate(template) {
        this._previewTemplate = template;
        return this;
    }
    /**
     * Registers the template that should be used for the drag placeholder.
     * @param template Template that from which to stamp out the placeholder.
     */
    withPlaceholderTemplate(template) {
        this._placeholderTemplate = template;
        return this;
    }
    /**
     * Sets an alternate drag root element. The root element is the element that will be moved as
     * the user is dragging. Passing an alternate root element is useful when trying to enable
     * dragging on an element that you might not have access to.
     */
    withRootElement(rootElement) {
        const element = coerceElement(rootElement);
        if (element !== this._rootElement) {
            if (this._rootElement) {
                this._removeRootElementListeners(this._rootElement);
            }
            this._ngZone.runOutsideAngular(() => {
                element.addEventListener('mousedown', this._pointerDown, activeEventListenerOptions);
                element.addEventListener('touchstart', this._pointerDown, passiveEventListenerOptions);
            });
            this._initialTransform = undefined;
            this._rootElement = element;
        }
        if (typeof SVGElement !== 'undefined' && this._rootElement instanceof SVGElement) {
            this._ownerSVGElement = this._rootElement.ownerSVGElement;
        }
        return this;
    }
    /**
     * Element to which the draggable's position will be constrained.
     */
    withBoundaryElement(boundaryElement) {
        this._boundaryElement = boundaryElement ? coerceElement(boundaryElement) : null;
        this._resizeSubscription.unsubscribe();
        if (boundaryElement) {
            this._resizeSubscription = this._viewportRuler
                .change(10)
                .subscribe(() => this._containInsideBoundaryOnResize());
        }
        return this;
    }
    /** Sets the parent ref that the ref is nested in.  */
    withParent(parent) {
        this._parentDragRef = parent;
        return this;
    }
    /** Removes the dragging functionality from the DOM element. */
    dispose() {
        this._removeRootElementListeners(this._rootElement);
        // Do this check before removing from the registry since it'll
        // stop being considered as dragged once it is removed.
        if (this.isDragging()) {
            // Since we move out the element to the end of the body while it's being
            // dragged, we have to make sure that it's removed if it gets destroyed.
            removeNode(this._rootElement);
        }
        removeNode(this._anchor);
        this._destroyPreview();
        this._destroyPlaceholder();
        this._dragDropRegistry.removeDragItem(this);
        this._removeSubscriptions();
        this.beforeStarted.complete();
        this.started.complete();
        this.released.complete();
        this.ended.complete();
        this.entered.complete();
        this.exited.complete();
        this.dropped.complete();
        this._moveEvents.complete();
        this._handles = [];
        this._disabledHandles.clear();
        this._dropContainer = undefined;
        this._resizeSubscription.unsubscribe();
        this._parentPositions.clear();
        this._boundaryElement = this._rootElement = this._ownerSVGElement = this._placeholderTemplate =
            this._previewTemplate = this._anchor = this._parentDragRef = null;
    }
    /** Checks whether the element is currently being dragged. */
    isDragging() {
        return this._hasStartedDragging && this._dragDropRegistry.isDragging(this);
    }
    /** Resets a standalone drag item to its initial position. */
    reset() {
        this._rootElement.style.transform = this._initialTransform || '';
        this._activeTransform = { x: 0, y: 0 };
        this._passiveTransform = { x: 0, y: 0 };
    }
    /**
     * Sets a handle as disabled. While a handle is disabled, it'll capture and interrupt dragging.
     * @param handle Handle element that should be disabled.
     */
    disableHandle(handle) {
        if (!this._disabledHandles.has(handle) && this._handles.indexOf(handle) > -1) {
            this._disabledHandles.add(handle);
            toggleNativeDragInteractions(handle, true);
        }
    }
    /**
     * Enables a handle, if it has been disabled.
     * @param handle Handle element to be enabled.
     */
    enableHandle(handle) {
        if (this._disabledHandles.has(handle)) {
            this._disabledHandles.delete(handle);
            toggleNativeDragInteractions(handle, this.disabled);
        }
    }
    /** Sets the layout direction of the draggable item. */
    withDirection(direction) {
        this._direction = direction;
        return this;
    }
    /** Sets the container that the item is part of. */
    _withDropContainer(container) {
        this._dropContainer = container;
    }
    /**
     * Gets the current position in pixels the draggable outside of a drop container.
     */
    getFreeDragPosition() {
        const position = this.isDragging() ? this._activeTransform : this._passiveTransform;
        return { x: position.x, y: position.y };
    }
    /**
     * Sets the current position in pixels the draggable outside of a drop container.
     * @param value New position to be set.
     */
    setFreeDragPosition(value) {
        this._activeTransform = { x: 0, y: 0 };
        this._passiveTransform.x = value.x;
        this._passiveTransform.y = value.y;
        if (!this._dropContainer) {
            this._applyRootElementTransform(value.x, value.y);
        }
        return this;
    }
    /**
     * Sets the container into which to insert the preview element.
     * @param value Container into which to insert the preview.
     */
    withPreviewContainer(value) {
        this._previewContainer = value;
        return this;
    }
    /** Updates the item's sort order based on the last-known pointer position. */
    _sortFromLastPointerPosition() {
        const position = this._lastKnownPointerPosition;
        if (position && this._dropContainer) {
            this._updateActiveDropContainer(this._getConstrainedPointerPosition(position), position);
        }
    }
    /** Unsubscribes from the global subscriptions. */
    _removeSubscriptions() {
        this._pointerMoveSubscription.unsubscribe();
        this._pointerUpSubscription.unsubscribe();
        this._scrollSubscription.unsubscribe();
    }
    /** Destroys the preview element and its ViewRef. */
    _destroyPreview() {
        if (this._preview) {
            removeNode(this._preview);
        }
        if (this._previewRef) {
            this._previewRef.destroy();
        }
        this._preview = this._previewRef = null;
    }
    /** Destroys the placeholder element and its ViewRef. */
    _destroyPlaceholder() {
        if (this._placeholder) {
            removeNode(this._placeholder);
        }
        if (this._placeholderRef) {
            this._placeholderRef.destroy();
        }
        this._placeholder = this._placeholderRef = null;
    }
    /**
     * Clears subscriptions and stops the dragging sequence.
     * @param event Browser event object that ended the sequence.
     */
    _endDragSequence(event) {
        // Note that here we use `isDragging` from the service, rather than from `this`.
        // The difference is that the one from the service reflects whether a dragging sequence
        // has been initiated, whereas the one on `this` includes whether the user has passed
        // the minimum dragging threshold.
        if (!this._dragDropRegistry.isDragging(this)) {
            return;
        }
        this._removeSubscriptions();
        this._dragDropRegistry.stopDragging(this);
        this._toggleNativeDragInteractions();
        if (this._handles) {
            this._rootElement.style.webkitTapHighlightColor = this._rootElementTapHighlight;
        }
        if (!this._hasStartedDragging) {
            return;
        }
        this.released.next({ source: this });
        if (this._dropContainer) {
            // Stop scrolling immediately, instead of waiting for the animation to finish.
            this._dropContainer._stopScrolling();
            this._animatePreviewToPlaceholder().then(() => {
                this._cleanupDragArtifacts(event);
                this._cleanupCachedDimensions();
                this._dragDropRegistry.stopDragging(this);
            });
        }
        else {
            // Convert the active transform into a passive one. This means that next time
            // the user starts dragging the item, its position will be calculated relatively
            // to the new passive transform.
            this._passiveTransform.x = this._activeTransform.x;
            const pointerPosition = this._getPointerPositionOnPage(event);
            this._passiveTransform.y = this._activeTransform.y;
            this._ngZone.run(() => {
                this.ended.next({
                    source: this,
                    distance: this._getDragDistance(pointerPosition),
                    dropPoint: pointerPosition
                });
            });
            this._cleanupCachedDimensions();
            this._dragDropRegistry.stopDragging(this);
        }
    }
    /** Starts the dragging sequence. */
    _startDragSequence(event) {
        if (isTouchEvent(event)) {
            this._lastTouchEventTime = Date.now();
        }
        this._toggleNativeDragInteractions();
        const dropContainer = this._dropContainer;
        if (dropContainer) {
            const element = this._rootElement;
            const parent = element.parentNode;
            const placeholder = this._placeholder = this._createPlaceholderElement();
            const anchor = this._anchor = this._anchor || this._document.createComment('');
            // Needs to happen before the root element is moved.
            const shadowRoot = this._getShadowRoot();
            // Insert an anchor node so that we can restore the element's position in the DOM.
            parent.insertBefore(anchor, element);
            // There's no risk of transforms stacking when inside a drop container so
            // we can keep the initial transform up to date any time dragging starts.
            this._initialTransform = element.style.transform || '';
            // Create the preview after the initial transform has
            // been cached, because it can be affected by the transform.
            this._preview = this._createPreviewElement();
            // We move the element out at the end of the body and we make it hidden, because keeping it in
            // place will throw off the consumer's `:last-child` selectors. We can't remove the element
            // from the DOM completely, because iOS will stop firing all subsequent events in the chain.
            toggleVisibility(element, false, dragImportantProperties);
            this._document.body.appendChild(parent.replaceChild(placeholder, element));
            this._getPreviewInsertionPoint(parent, shadowRoot).appendChild(this._preview);
            this.started.next({ source: this }); // Emit before notifying the container.
            dropContainer.start();
            this._initialContainer = dropContainer;
            this._initialIndex = dropContainer.getItemIndex(this);
        }
        else {
            this.started.next({ source: this });
            this._initialContainer = this._initialIndex = undefined;
        }
        // Important to run after we've called `start` on the parent container
        // so that it has had time to resolve its scrollable parents.
        this._parentPositions.cache(dropContainer ? dropContainer.getScrollableParents() : []);
    }
    /**
     * Sets up the different variables and subscriptions
     * that will be necessary for the dragging sequence.
     * @param referenceElement Element that started the drag sequence.
     * @param event Browser event object that started the sequence.
     */
    _initializeDragSequence(referenceElement, event) {
        // Stop propagation if the item is inside another
        // draggable so we don't start multiple drag sequences.
        if (this._parentDragRef) {
            event.stopPropagation();
        }
        const isDragging = this.isDragging();
        const isTouchSequence = isTouchEvent(event);
        const isAuxiliaryMouseButton = !isTouchSequence && event.button !== 0;
        const rootElement = this._rootElement;
        const target = _getEventTarget(event);
        const isSyntheticEvent = !isTouchSequence && this._lastTouchEventTime &&
            this._lastTouchEventTime + MOUSE_EVENT_IGNORE_TIME > Date.now();
        const isFakeEvent = isTouchSequence ? isFakeTouchstartFromScreenReader(event) :
            isFakeMousedownFromScreenReader(event);
        // If the event started from an element with the native HTML drag&drop, it'll interfere
        // with our own dragging (e.g. `img` tags do it by default). Prevent the default action
        // to stop it from happening. Note that preventing on `dragstart` also seems to work, but
        // it's flaky and it fails if the user drags it away quickly. Also note that we only want
        // to do this for `mousedown` since doing the same for `touchstart` will stop any `click`
        // events from firing on touch devices.
        if (target && target.draggable && event.type === 'mousedown') {
            event.preventDefault();
        }
        // Abort if the user is already dragging or is using a mouse button other than the primary one.
        if (isDragging || isAuxiliaryMouseButton || isSyntheticEvent || isFakeEvent) {
            return;
        }
        // If we've got handles, we need to disable the tap highlight on the entire root element,
        // otherwise iOS will still add it, even though all the drag interactions on the handle
        // are disabled.
        if (this._handles.length) {
            this._rootElementTapHighlight = rootElement.style.webkitTapHighlightColor || '';
            rootElement.style.webkitTapHighlightColor = 'transparent';
        }
        this._hasStartedDragging = this._hasMoved = false;
        // Avoid multiple subscriptions and memory leaks when multi touch
        // (isDragging check above isn't enough because of possible temporal and/or dimensional delays)
        this._removeSubscriptions();
        this._pointerMoveSubscription = this._dragDropRegistry.pointerMove.subscribe(this._pointerMove);
        this._pointerUpSubscription = this._dragDropRegistry.pointerUp.subscribe(this._pointerUp);
        this._scrollSubscription = this._dragDropRegistry
            .scrolled(this._getShadowRoot())
            .subscribe(scrollEvent => this._updateOnScroll(scrollEvent));
        if (this._boundaryElement) {
            this._boundaryRect = getMutableClientRect(this._boundaryElement);
        }
        // If we have a custom preview we can't know ahead of time how large it'll be so we position
        // it next to the cursor. The exception is when the consumer has opted into making the preview
        // the same size as the root element, in which case we do know the size.
        const previewTemplate = this._previewTemplate;
        this._pickupPositionInElement = previewTemplate && previewTemplate.template &&
            !previewTemplate.matchSize ? { x: 0, y: 0 } :
            this._getPointerPositionInElement(referenceElement, event);
        const pointerPosition = this._pickupPositionOnPage = this._lastKnownPointerPosition =
            this._getPointerPositionOnPage(event);
        this._pointerDirectionDelta = { x: 0, y: 0 };
        this._pointerPositionAtLastDirectionChange = { x: pointerPosition.x, y: pointerPosition.y };
        this._dragStartTime = Date.now();
        this._dragDropRegistry.startDragging(this, event);
    }
    /** Cleans up the DOM artifacts that were added to facilitate the element being dragged. */
    _cleanupDragArtifacts(event) {
        // Restore the element's visibility and insert it at its old position in the DOM.
        // It's important that we maintain the position, because moving the element around in the DOM
        // can throw off `NgFor` which does smart diffing and re-creates elements only when necessary,
        // while moving the existing elements in all other cases.
        toggleVisibility(this._rootElement, true, dragImportantProperties);
        this._anchor.parentNode.replaceChild(this._rootElement, this._anchor);
        this._destroyPreview();
        this._destroyPlaceholder();
        this._boundaryRect = this._previewRect = this._initialTransform = undefined;
        // Re-enter the NgZone since we bound `document` events on the outside.
        this._ngZone.run(() => {
            const container = this._dropContainer;
            const currentIndex = container.getItemIndex(this);
            const pointerPosition = this._getPointerPositionOnPage(event);
            const distance = this._getDragDistance(pointerPosition);
            const isPointerOverContainer = container._isOverContainer(pointerPosition.x, pointerPosition.y);
            this.ended.next({ source: this, distance, dropPoint: pointerPosition });
            this.dropped.next({
                item: this,
                currentIndex,
                previousIndex: this._initialIndex,
                container: container,
                previousContainer: this._initialContainer,
                isPointerOverContainer,
                distance,
                dropPoint: pointerPosition
            });
            container.drop(this, currentIndex, this._initialIndex, this._initialContainer, isPointerOverContainer, distance, pointerPosition);
            this._dropContainer = this._initialContainer;
        });
    }
    /**
     * Updates the item's position in its drop container, or moves it
     * into a new one, depending on its current drag position.
     */
    _updateActiveDropContainer({ x, y }, { x: rawX, y: rawY }) {
        // Drop container that draggable has been moved into.
        let newContainer = this._initialContainer._getSiblingContainerFromPosition(this, x, y);
        // If we couldn't find a new container to move the item into, and the item has left its
        // initial container, check whether the it's over the initial container. This handles the
        // case where two containers are connected one way and the user tries to undo dragging an
        // item into a new container.
        if (!newContainer && this._dropContainer !== this._initialContainer &&
            this._initialContainer._isOverContainer(x, y)) {
            newContainer = this._initialContainer;
        }
        if (newContainer && newContainer !== this._dropContainer) {
            this._ngZone.run(() => {
                // Notify the old container that the item has left.
                this.exited.next({ item: this, container: this._dropContainer });
                this._dropContainer.exit(this);
                // Notify the new container that the item has entered.
                this._dropContainer = newContainer;
                this._dropContainer.enter(this, x, y, newContainer === this._initialContainer &&
                    // If we're re-entering the initial container and sorting is disabled,
                    // put item the into its starting index to begin with.
                    newContainer.sortingDisabled ? this._initialIndex : undefined);
                this.entered.next({
                    item: this,
                    container: newContainer,
                    currentIndex: newContainer.getItemIndex(this)
                });
            });
        }
        // Dragging may have been interrupted as a result of the events above.
        if (this.isDragging()) {
            this._dropContainer._startScrollingIfNecessary(rawX, rawY);
            this._dropContainer._sortItem(this, x, y, this._pointerDirectionDelta);
            this._applyPreviewTransform(x - this._pickupPositionInElement.x, y - this._pickupPositionInElement.y);
        }
    }
    /**
     * Creates the element that will be rendered next to the user's pointer
     * and will be used as a preview of the element that is being dragged.
     */
    _createPreviewElement() {
        const previewConfig = this._previewTemplate;
        const previewClass = this.previewClass;
        const previewTemplate = previewConfig ? previewConfig.template : null;
        let preview;
        if (previewTemplate && previewConfig) {
            // Measure the element before we've inserted the preview
            // since the insertion could throw off the measurement.
            const rootRect = previewConfig.matchSize ? this._rootElement.getBoundingClientRect() : null;
            const viewRef = previewConfig.viewContainer.createEmbeddedView(previewTemplate, previewConfig.context);
            viewRef.detectChanges();
            preview = getRootNode(viewRef, this._document);
            this._previewRef = viewRef;
            if (previewConfig.matchSize) {
                matchElementSize(preview, rootRect);
            }
            else {
                preview.style.transform =
                    getTransform(this._pickupPositionOnPage.x, this._pickupPositionOnPage.y);
            }
        }
        else {
            const element = this._rootElement;
            preview = deepCloneNode(element);
            matchElementSize(preview, element.getBoundingClientRect());
            if (this._initialTransform) {
                preview.style.transform = this._initialTransform;
            }
        }
        extendStyles(preview.style, {
            // It's important that we disable the pointer events on the preview, because
            // it can throw off the `document.elementFromPoint` calls in the `CdkDropList`.
            'pointer-events': 'none',
            // We have to reset the margin, because it can throw off positioning relative to the viewport.
            'margin': '0',
            'position': 'fixed',
            'top': '0',
            'left': '0',
            'z-index': `${this._config.zIndex || 1000}`
        }, dragImportantProperties);
        toggleNativeDragInteractions(preview, false);
        preview.classList.add('cdk-drag-preview');
        preview.setAttribute('dir', this._direction);
        if (previewClass) {
            if (Array.isArray(previewClass)) {
                previewClass.forEach(className => preview.classList.add(className));
            }
            else {
                preview.classList.add(previewClass);
            }
        }
        return preview;
    }
    /**
     * Animates the preview element from its current position to the location of the drop placeholder.
     * @returns Promise that resolves when the animation completes.
     */
    _animatePreviewToPlaceholder() {
        // If the user hasn't moved yet, the transitionend event won't fire.
        if (!this._hasMoved) {
            return Promise.resolve();
        }
        const placeholderRect = this._placeholder.getBoundingClientRect();
        // Apply the class that adds a transition to the preview.
        this._preview.classList.add('cdk-drag-animating');
        // Move the preview to the placeholder position.
        this._applyPreviewTransform(placeholderRect.left, placeholderRect.top);
        // If the element doesn't have a `transition`, the `transitionend` event won't fire. Since
        // we need to trigger a style recalculation in order for the `cdk-drag-animating` class to
        // apply its style, we take advantage of the available info to figure out whether we need to
        // bind the event in the first place.
        const duration = getTransformTransitionDurationInMs(this._preview);
        if (duration === 0) {
            return Promise.resolve();
        }
        return this._ngZone.runOutsideAngular(() => {
            return new Promise(resolve => {
                const handler = ((event) => {
                    var _a;
                    if (!event || (_getEventTarget(event) === this._preview &&
                        event.propertyName === 'transform')) {
                        (_a = this._preview) === null || _a === void 0 ? void 0 : _a.removeEventListener('transitionend', handler);
                        resolve();
                        clearTimeout(timeout);
                    }
                });
                // If a transition is short enough, the browser might not fire the `transitionend` event.
                // Since we know how long it's supposed to take, add a timeout with a 50% buffer that'll
                // fire if the transition hasn't completed when it was supposed to.
                const timeout = setTimeout(handler, duration * 1.5);
                this._preview.addEventListener('transitionend', handler);
            });
        });
    }
    /** Creates an element that will be shown instead of the current element while dragging. */
    _createPlaceholderElement() {
        const placeholderConfig = this._placeholderTemplate;
        const placeholderTemplate = placeholderConfig ? placeholderConfig.template : null;
        let placeholder;
        if (placeholderTemplate) {
            this._placeholderRef = placeholderConfig.viewContainer.createEmbeddedView(placeholderTemplate, placeholderConfig.context);
            this._placeholderRef.detectChanges();
            placeholder = getRootNode(this._placeholderRef, this._document);
        }
        else {
            placeholder = deepCloneNode(this._rootElement);
        }
        placeholder.classList.add('cdk-drag-placeholder');
        return placeholder;
    }
    /**
     * Figures out the coordinates at which an element was picked up.
     * @param referenceElement Element that initiated the dragging.
     * @param event Event that initiated the dragging.
     */
    _getPointerPositionInElement(referenceElement, event) {
        const elementRect = this._rootElement.getBoundingClientRect();
        const handleElement = referenceElement === this._rootElement ? null : referenceElement;
        const referenceRect = handleElement ? handleElement.getBoundingClientRect() : elementRect;
        const point = isTouchEvent(event) ? event.targetTouches[0] : event;
        const scrollPosition = this._getViewportScrollPosition();
        const x = point.pageX - referenceRect.left - scrollPosition.left;
        const y = point.pageY - referenceRect.top - scrollPosition.top;
        return {
            x: referenceRect.left - elementRect.left + x,
            y: referenceRect.top - elementRect.top + y
        };
    }
    /** Determines the point of the page that was touched by the user. */
    _getPointerPositionOnPage(event) {
        const scrollPosition = this._getViewportScrollPosition();
        const point = isTouchEvent(event) ?
            // `touches` will be empty for start/end events so we have to fall back to `changedTouches`.
            // Also note that on real devices we're guaranteed for either `touches` or `changedTouches`
            // to have a value, but Firefox in device emulation mode has a bug where both can be empty
            // for `touchstart` and `touchend` so we fall back to a dummy object in order to avoid
            // throwing an error. The value returned here will be incorrect, but since this only
            // breaks inside a developer tool and the value is only used for secondary information,
            // we can get away with it. See https://bugzilla.mozilla.org/show_bug.cgi?id=1615824.
            (event.touches[0] || event.changedTouches[0] || { pageX: 0, pageY: 0 }) : event;
        const x = point.pageX - scrollPosition.left;
        const y = point.pageY - scrollPosition.top;
        // if dragging SVG element, try to convert from the screen coordinate system to the SVG
        // coordinate system
        if (this._ownerSVGElement) {
            const svgMatrix = this._ownerSVGElement.getScreenCTM();
            if (svgMatrix) {
                const svgPoint = this._ownerSVGElement.createSVGPoint();
                svgPoint.x = x;
                svgPoint.y = y;
                return svgPoint.matrixTransform(svgMatrix.inverse());
            }
        }
        return { x, y };
    }
    /** Gets the pointer position on the page, accounting for any position constraints. */
    _getConstrainedPointerPosition(point) {
        const dropContainerLock = this._dropContainer ? this._dropContainer.lockAxis : null;
        let { x, y } = this.constrainPosition ? this.constrainPosition(point, this) : point;
        if (this.lockAxis === 'x' || dropContainerLock === 'x') {
            y = this._pickupPositionOnPage.y;
        }
        else if (this.lockAxis === 'y' || dropContainerLock === 'y') {
            x = this._pickupPositionOnPage.x;
        }
        if (this._boundaryRect) {
            const { x: pickupX, y: pickupY } = this._pickupPositionInElement;
            const boundaryRect = this._boundaryRect;
            const previewRect = this._previewRect;
            const minY = boundaryRect.top + pickupY;
            const maxY = boundaryRect.bottom - (previewRect.height - pickupY);
            const minX = boundaryRect.left + pickupX;
            const maxX = boundaryRect.right - (previewRect.width - pickupX);
            x = clamp$1(x, minX, maxX);
            y = clamp$1(y, minY, maxY);
        }
        return { x, y };
    }
    /** Updates the current drag delta, based on the user's current pointer position on the page. */
    _updatePointerDirectionDelta(pointerPositionOnPage) {
        const { x, y } = pointerPositionOnPage;
        const delta = this._pointerDirectionDelta;
        const positionSinceLastChange = this._pointerPositionAtLastDirectionChange;
        // Amount of pixels the user has dragged since the last time the direction changed.
        const changeX = Math.abs(x - positionSinceLastChange.x);
        const changeY = Math.abs(y - positionSinceLastChange.y);
        // Because we handle pointer events on a per-pixel basis, we don't want the delta
        // to change for every pixel, otherwise anything that depends on it can look erratic.
        // To make the delta more consistent, we track how much the user has moved since the last
        // delta change and we only update it after it has reached a certain threshold.
        if (changeX > this._config.pointerDirectionChangeThreshold) {
            delta.x = x > positionSinceLastChange.x ? 1 : -1;
            positionSinceLastChange.x = x;
        }
        if (changeY > this._config.pointerDirectionChangeThreshold) {
            delta.y = y > positionSinceLastChange.y ? 1 : -1;
            positionSinceLastChange.y = y;
        }
        return delta;
    }
    /** Toggles the native drag interactions, based on how many handles are registered. */
    _toggleNativeDragInteractions() {
        if (!this._rootElement || !this._handles) {
            return;
        }
        const shouldEnable = this._handles.length > 0 || !this.isDragging();
        if (shouldEnable !== this._nativeInteractionsEnabled) {
            this._nativeInteractionsEnabled = shouldEnable;
            toggleNativeDragInteractions(this._rootElement, shouldEnable);
        }
    }
    /** Removes the manually-added event listeners from the root element. */
    _removeRootElementListeners(element) {
        element.removeEventListener('mousedown', this._pointerDown, activeEventListenerOptions);
        element.removeEventListener('touchstart', this._pointerDown, passiveEventListenerOptions);
    }
    /**
     * Applies a `transform` to the root element, taking into account any existing transforms on it.
     * @param x New transform value along the X axis.
     * @param y New transform value along the Y axis.
     */
    _applyRootElementTransform(x, y) {
        const transform = getTransform(x, y);
        // Cache the previous transform amount only after the first drag sequence, because
        // we don't want our own transforms to stack on top of each other.
        // Should be excluded none because none + translate3d(x, y, x) is invalid css
        if (this._initialTransform == null) {
            this._initialTransform = this._rootElement.style.transform
                && this._rootElement.style.transform != 'none'
                ? this._rootElement.style.transform
                : '';
        }
        // Preserve the previous `transform` value, if there was one. Note that we apply our own
        // transform before the user's, because things like rotation can affect which direction
        // the element will be translated towards.
        this._rootElement.style.transform = combineTransforms(transform, this._initialTransform);
    }
    /**
     * Applies a `transform` to the preview, taking into account any existing transforms on it.
     * @param x New transform value along the X axis.
     * @param y New transform value along the Y axis.
     */
    _applyPreviewTransform(x, y) {
        var _a;
        // Only apply the initial transform if the preview is a clone of the original element, otherwise
        // it could be completely different and the transform might not make sense anymore.
        const initialTransform = ((_a = this._previewTemplate) === null || _a === void 0 ? void 0 : _a.template) ? undefined : this._initialTransform;
        const transform = getTransform(x, y);
        this._preview.style.transform = combineTransforms(transform, initialTransform);
    }
    /**
     * Gets the distance that the user has dragged during the current drag sequence.
     * @param currentPosition Current position of the user's pointer.
     */
    _getDragDistance(currentPosition) {
        const pickupPosition = this._pickupPositionOnPage;
        if (pickupPosition) {
            return { x: currentPosition.x - pickupPosition.x, y: currentPosition.y - pickupPosition.y };
        }
        return { x: 0, y: 0 };
    }
    /** Cleans up any cached element dimensions that we don't need after dragging has stopped. */
    _cleanupCachedDimensions() {
        this._boundaryRect = this._previewRect = undefined;
        this._parentPositions.clear();
    }
    /**
     * Checks whether the element is still inside its boundary after the viewport has been resized.
     * If not, the position is adjusted so that the element fits again.
     */
    _containInsideBoundaryOnResize() {
        let { x, y } = this._passiveTransform;
        if ((x === 0 && y === 0) || this.isDragging() || !this._boundaryElement) {
            return;
        }
        const boundaryRect = this._boundaryElement.getBoundingClientRect();
        const elementRect = this._rootElement.getBoundingClientRect();
        // It's possible that the element got hidden away after dragging (e.g. by switching to a
        // different tab). Don't do anything in this case so we don't clear the user's position.
        if ((boundaryRect.width === 0 && boundaryRect.height === 0) ||
            (elementRect.width === 0 && elementRect.height === 0)) {
            return;
        }
        const leftOverflow = boundaryRect.left - elementRect.left;
        const rightOverflow = elementRect.right - boundaryRect.right;
        const topOverflow = boundaryRect.top - elementRect.top;
        const bottomOverflow = elementRect.bottom - boundaryRect.bottom;
        // If the element has become wider than the boundary, we can't
        // do much to make it fit so we just anchor it to the left.
        if (boundaryRect.width > elementRect.width) {
            if (leftOverflow > 0) {
                x += leftOverflow;
            }
            if (rightOverflow > 0) {
                x -= rightOverflow;
            }
        }
        else {
            x = 0;
        }
        // If the element has become taller than the boundary, we can't
        // do much to make it fit so we just anchor it to the top.
        if (boundaryRect.height > elementRect.height) {
            if (topOverflow > 0) {
                y += topOverflow;
            }
            if (bottomOverflow > 0) {
                y -= bottomOverflow;
            }
        }
        else {
            y = 0;
        }
        if (x !== this._passiveTransform.x || y !== this._passiveTransform.y) {
            this.setFreeDragPosition({ y, x });
        }
    }
    /** Gets the drag start delay, based on the event type. */
    _getDragStartDelay(event) {
        const value = this.dragStartDelay;
        if (typeof value === 'number') {
            return value;
        }
        else if (isTouchEvent(event)) {
            return value.touch;
        }
        return value ? value.mouse : 0;
    }
    /** Updates the internal state of the draggable element when scrolling has occurred. */
    _updateOnScroll(event) {
        const scrollDifference = this._parentPositions.handleScroll(event);
        if (scrollDifference) {
            const target = _getEventTarget(event);
            // ClientRect dimensions are based on the scroll position of the page and its parent node so
            // we have to update the cached boundary ClientRect if the user has scrolled. Check for
            // the `document` specifically since IE doesn't support `contains` on it.
            if (this._boundaryRect && (target === this._document ||
                (target !== this._boundaryElement && target.contains(this._boundaryElement)))) {
                adjustClientRect(this._boundaryRect, scrollDifference.top, scrollDifference.left);
            }
            this._pickupPositionOnPage.x += scrollDifference.left;
            this._pickupPositionOnPage.y += scrollDifference.top;
            // If we're in free drag mode, we have to update the active transform, because
            // it isn't relative to the viewport like the preview inside a drop list.
            if (!this._dropContainer) {
                this._activeTransform.x -= scrollDifference.left;
                this._activeTransform.y -= scrollDifference.top;
                this._applyRootElementTransform(this._activeTransform.x, this._activeTransform.y);
            }
        }
    }
    /** Gets the scroll position of the viewport. */
    _getViewportScrollPosition() {
        const cachedPosition = this._parentPositions.positions.get(this._document);
        return cachedPosition ? cachedPosition.scrollPosition :
            this._viewportRuler.getViewportScrollPosition();
    }
    /**
     * Lazily resolves and returns the shadow root of the element. We do this in a function, rather
     * than saving it in property directly on init, because we want to resolve it as late as possible
     * in order to ensure that the element has been moved into the shadow DOM. Doing it inside the
     * constructor might be too early if the element is inside of something like `ngFor` or `ngIf`.
     */
    _getShadowRoot() {
        if (this._cachedShadowRoot === undefined) {
            this._cachedShadowRoot = _getShadowRoot(this._rootElement);
        }
        return this._cachedShadowRoot;
    }
    /** Gets the element into which the drag preview should be inserted. */
    _getPreviewInsertionPoint(initialParent, shadowRoot) {
        const previewContainer = this._previewContainer || 'global';
        if (previewContainer === 'parent') {
            return initialParent;
        }
        if (previewContainer === 'global') {
            const documentRef = this._document;
            // We can't use the body if the user is in fullscreen mode,
            // because the preview will render under the fullscreen element.
            // TODO(crisbeto): dedupe this with the `FullscreenOverlayContainer` eventually.
            return shadowRoot ||
                documentRef.fullscreenElement ||
                documentRef.webkitFullscreenElement ||
                documentRef.mozFullScreenElement ||
                documentRef.msFullscreenElement ||
                documentRef.body;
        }
        return coerceElement(previewContainer);
    }
}
/**
 * Gets a 3d `transform` that can be applied to an element.
 * @param x Desired position of the element along the X axis.
 * @param y Desired position of the element along the Y axis.
 */
function getTransform(x, y) {
    // Round the transforms since some browsers will
    // blur the elements for sub-pixel transforms.
    return `translate3d(${Math.round(x)}px, ${Math.round(y)}px, 0)`;
}
/** Clamps a value between a minimum and a maximum. */
function clamp$1(value, min, max) {
    return Math.max(min, Math.min(max, value));
}
/**
 * Helper to remove a node from the DOM and to do all the necessary null checks.
 * @param node Node to be removed.
 */
function removeNode(node) {
    if (node && node.parentNode) {
        node.parentNode.removeChild(node);
    }
}
/** Determines whether an event is a touch event. */
function isTouchEvent(event) {
    // This function is called for every pixel that the user has dragged so we need it to be
    // as fast as possible. Since we only bind mouse events and touch events, we can assume
    // that if the event's name starts with `t`, it's a touch event.
    return event.type[0] === 't';
}
/**
 * Gets the root HTML element of an embedded view.
 * If the root is not an HTML element it gets wrapped in one.
 */
function getRootNode(viewRef, _document) {
    const rootNodes = viewRef.rootNodes;
    if (rootNodes.length === 1 && rootNodes[0].nodeType === _document.ELEMENT_NODE) {
        return rootNodes[0];
    }
    const wrapper = _document.createElement('div');
    rootNodes.forEach(node => wrapper.appendChild(node));
    return wrapper;
}
/**
 * Matches the target element's size to the source's size.
 * @param target Element that needs to be resized.
 * @param sourceRect Dimensions of the source element.
 */
function matchElementSize(target, sourceRect) {
    target.style.width = `${sourceRect.width}px`;
    target.style.height = `${sourceRect.height}px`;
    target.style.transform = getTransform(sourceRect.left, sourceRect.top);
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Moves an item one index in an array to another.
 * @param array Array in which to move the item.
 * @param fromIndex Starting index of the item.
 * @param toIndex Index to which the item should be moved.
 */
function moveItemInArray(array, fromIndex, toIndex) {
    const from = clamp(fromIndex, array.length - 1);
    const to = clamp(toIndex, array.length - 1);
    if (from === to) {
        return;
    }
    const target = array[from];
    const delta = to < from ? -1 : 1;
    for (let i = from; i !== to; i += delta) {
        array[i] = array[i + delta];
    }
    array[to] = target;
}
/**
 * Moves an item from one array to another.
 * @param currentArray Array from which to transfer the item.
 * @param targetArray Array into which to put the item.
 * @param currentIndex Index of the item in its current array.
 * @param targetIndex Index at which to insert the item.
 */
function transferArrayItem(currentArray, targetArray, currentIndex, targetIndex) {
    const from = clamp(currentIndex, currentArray.length - 1);
    const to = clamp(targetIndex, targetArray.length);
    if (currentArray.length) {
        targetArray.splice(to, 0, currentArray.splice(from, 1)[0]);
    }
}
/**
 * Copies an item from one array to another, leaving it in its
 * original position in current array.
 * @param currentArray Array from which to copy the item.
 * @param targetArray Array into which is copy the item.
 * @param currentIndex Index of the item in its current array.
 * @param targetIndex Index at which to insert the item.
 *
 */
function copyArrayItem(currentArray, targetArray, currentIndex, targetIndex) {
    const to = clamp(targetIndex, targetArray.length);
    if (currentArray.length) {
        targetArray.splice(to, 0, currentArray[currentIndex]);
    }
}
/** Clamps a number between zero and a maximum. */
function clamp(value, max) {
    return Math.max(0, Math.min(max, value));
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Proximity, as a ratio to width/height, at which a
 * dragged item will affect the drop container.
 */
const DROP_PROXIMITY_THRESHOLD = 0.05;
/**
 * Proximity, as a ratio to width/height at which to start auto-scrolling the drop list or the
 * viewport. The value comes from trying it out manually until it feels right.
 */
const SCROLL_PROXIMITY_THRESHOLD = 0.05;
/**
 * Reference to a drop list. Used to manipulate or dispose of the container.
 */
class DropListRef {
    constructor(element, _dragDropRegistry, _document, _ngZone, _viewportRuler) {
        this._dragDropRegistry = _dragDropRegistry;
        this._ngZone = _ngZone;
        this._viewportRuler = _viewportRuler;
        /** Whether starting a dragging sequence from this container is disabled. */
        this.disabled = false;
        /** Whether sorting items within the list is disabled. */
        this.sortingDisabled = false;
        /**
         * Whether auto-scrolling the view when the user
         * moves their pointer close to the edges is disabled.
         */
        this.autoScrollDisabled = false;
        /** Number of pixels to scroll for each frame when auto-scrolling an element. */
        this.autoScrollStep = 2;
        /**
         * Function that is used to determine whether an item
         * is allowed to be moved into a drop container.
         */
        this.enterPredicate = () => true;
        /** Functions that is used to determine whether an item can be sorted into a particular index. */
        this.sortPredicate = () => true;
        /** Emits right before dragging has started. */
        this.beforeStarted = new Subject();
        /**
         * Emits when the user has moved a new drag item into this container.
         */
        this.entered = new Subject();
        /**
         * Emits when the user removes an item from the container
         * by dragging it into another container.
         */
        this.exited = new Subject();
        /** Emits when the user drops an item inside the container. */
        this.dropped = new Subject();
        /** Emits as the user is swapping items while actively dragging. */
        this.sorted = new Subject();
        /** Whether an item in the list is being dragged. */
        this._isDragging = false;
        /** Cache of the dimensions of all the items inside the container. */
        this._itemPositions = [];
        /**
         * Keeps track of the item that was last swapped with the dragged item, as well as what direction
         * the pointer was moving in when the swap occured and whether the user's pointer continued to
         * overlap with the swapped item after the swapping occurred.
         */
        this._previousSwap = { drag: null, delta: 0, overlaps: false };
        /** Draggable items in the container. */
        this._draggables = [];
        /** Drop lists that are connected to the current one. */
        this._siblings = [];
        /** Direction in which the list is oriented. */
        this._orientation = 'vertical';
        /** Connected siblings that currently have a dragged item. */
        this._activeSiblings = new Set();
        /** Layout direction of the drop list. */
        this._direction = 'ltr';
        /** Subscription to the window being scrolled. */
        this._viewportScrollSubscription = Subscription.EMPTY;
        /** Vertical direction in which the list is currently scrolling. */
        this._verticalScrollDirection = 0 /* NONE */;
        /** Horizontal direction in which the list is currently scrolling. */
        this._horizontalScrollDirection = 0 /* NONE */;
        /** Used to signal to the current auto-scroll sequence when to stop. */
        this._stopScrollTimers = new Subject();
        /** Shadow root of the current element. Necessary for `elementFromPoint` to resolve correctly. */
        this._cachedShadowRoot = null;
        /** Starts the interval that'll auto-scroll the element. */
        this._startScrollInterval = () => {
            this._stopScrolling();
            interval(0, animationFrameScheduler)
                .pipe(takeUntil(this._stopScrollTimers))
                .subscribe(() => {
                const node = this._scrollNode;
                const scrollStep = this.autoScrollStep;
                if (this._verticalScrollDirection === 1 /* UP */) {
                    incrementVerticalScroll(node, -scrollStep);
                }
                else if (this._verticalScrollDirection === 2 /* DOWN */) {
                    incrementVerticalScroll(node, scrollStep);
                }
                if (this._horizontalScrollDirection === 1 /* LEFT */) {
                    incrementHorizontalScroll(node, -scrollStep);
                }
                else if (this._horizontalScrollDirection === 2 /* RIGHT */) {
                    incrementHorizontalScroll(node, scrollStep);
                }
            });
        };
        this.element = coerceElement(element);
        this._document = _document;
        this.withScrollableParents([this.element]);
        _dragDropRegistry.registerDropContainer(this);
        this._parentPositions = new ParentPositionTracker(_document, _viewportRuler);
    }
    /** Removes the drop list functionality from the DOM element. */
    dispose() {
        this._stopScrolling();
        this._stopScrollTimers.complete();
        this._viewportScrollSubscription.unsubscribe();
        this.beforeStarted.complete();
        this.entered.complete();
        this.exited.complete();
        this.dropped.complete();
        this.sorted.complete();
        this._activeSiblings.clear();
        this._scrollNode = null;
        this._parentPositions.clear();
        this._dragDropRegistry.removeDropContainer(this);
    }
    /** Whether an item from this list is currently being dragged. */
    isDragging() {
        return this._isDragging;
    }
    /** Starts dragging an item. */
    start() {
        this._draggingStarted();
        this._notifyReceivingSiblings();
    }
    /**
     * Emits an event to indicate that the user moved an item into the container.
     * @param item Item that was moved into the container.
     * @param pointerX Position of the item along the X axis.
     * @param pointerY Position of the item along the Y axis.
     * @param index Index at which the item entered. If omitted, the container will try to figure it
     *   out automatically.
     */
    enter(item, pointerX, pointerY, index) {
        this._draggingStarted();
        // If sorting is disabled, we want the item to return to its starting
        // position if the user is returning it to its initial container.
        let newIndex;
        if (index == null) {
            newIndex = this.sortingDisabled ? this._draggables.indexOf(item) : -1;
            if (newIndex === -1) {
                // We use the coordinates of where the item entered the drop
                // zone to figure out at which index it should be inserted.
                newIndex = this._getItemIndexFromPointerPosition(item, pointerX, pointerY);
            }
        }
        else {
            newIndex = index;
        }
        const activeDraggables = this._activeDraggables;
        const currentIndex = activeDraggables.indexOf(item);
        const placeholder = item.getPlaceholderElement();
        let newPositionReference = activeDraggables[newIndex];
        // If the item at the new position is the same as the item that is being dragged,
        // it means that we're trying to restore the item to its initial position. In this
        // case we should use the next item from the list as the reference.
        if (newPositionReference === item) {
            newPositionReference = activeDraggables[newIndex + 1];
        }
        // Since the item may be in the `activeDraggables` already (e.g. if the user dragged it
        // into another container and back again), we have to ensure that it isn't duplicated.
        if (currentIndex > -1) {
            activeDraggables.splice(currentIndex, 1);
        }
        // Don't use items that are being dragged as a reference, because
        // their element has been moved down to the bottom of the body.
        if (newPositionReference && !this._dragDropRegistry.isDragging(newPositionReference)) {
            const element = newPositionReference.getRootElement();
            element.parentElement.insertBefore(placeholder, element);
            activeDraggables.splice(newIndex, 0, item);
        }
        else if (this._shouldEnterAsFirstChild(pointerX, pointerY)) {
            const reference = activeDraggables[0].getRootElement();
            reference.parentNode.insertBefore(placeholder, reference);
            activeDraggables.unshift(item);
        }
        else {
            coerceElement(this.element).appendChild(placeholder);
            activeDraggables.push(item);
        }
        // The transform needs to be cleared so it doesn't throw off the measurements.
        placeholder.style.transform = '';
        // Note that the positions were already cached when we called `start` above,
        // but we need to refresh them since the amount of items has changed and also parent rects.
        this._cacheItemPositions();
        this._cacheParentPositions();
        // Notify siblings at the end so that the item has been inserted into the `activeDraggables`.
        this._notifyReceivingSiblings();
        this.entered.next({ item, container: this, currentIndex: this.getItemIndex(item) });
    }
    /**
     * Removes an item from the container after it was dragged into another container by the user.
     * @param item Item that was dragged out.
     */
    exit(item) {
        this._reset();
        this.exited.next({ item, container: this });
    }
    /**
     * Drops an item into this container.
     * @param item Item being dropped into the container.
     * @param currentIndex Index at which the item should be inserted.
     * @param previousIndex Index of the item when dragging started.
     * @param previousContainer Container from which the item got dragged in.
     * @param isPointerOverContainer Whether the user's pointer was over the
     *    container when the item was dropped.
     * @param distance Distance the user has dragged since the start of the dragging sequence.
     */
    drop(item, currentIndex, previousIndex, previousContainer, isPointerOverContainer, distance, dropPoint) {
        this._reset();
        this.dropped.next({
            item,
            currentIndex,
            previousIndex,
            container: this,
            previousContainer,
            isPointerOverContainer,
            distance,
            dropPoint
        });
    }
    /**
     * Sets the draggable items that are a part of this list.
     * @param items Items that are a part of this list.
     */
    withItems(items) {
        const previousItems = this._draggables;
        this._draggables = items;
        items.forEach(item => item._withDropContainer(this));
        if (this.isDragging()) {
            const draggedItems = previousItems.filter(item => item.isDragging());
            // If all of the items being dragged were removed
            // from the list, abort the current drag sequence.
            if (draggedItems.every(item => items.indexOf(item) === -1)) {
                this._reset();
            }
            else {
                this._cacheItems();
            }
        }
        return this;
    }
    /** Sets the layout direction of the drop list. */
    withDirection(direction) {
        this._direction = direction;
        return this;
    }
    /**
     * Sets the containers that are connected to this one. When two or more containers are
     * connected, the user will be allowed to transfer items between them.
     * @param connectedTo Other containers that the current containers should be connected to.
     */
    connectedTo(connectedTo) {
        this._siblings = connectedTo.slice();
        return this;
    }
    /**
     * Sets the orientation of the container.
     * @param orientation New orientation for the container.
     */
    withOrientation(orientation) {
        this._orientation = orientation;
        return this;
    }
    /**
     * Sets which parent elements are can be scrolled while the user is dragging.
     * @param elements Elements that can be scrolled.
     */
    withScrollableParents(elements) {
        const element = coerceElement(this.element);
        // We always allow the current element to be scrollable
        // so we need to ensure that it's in the array.
        this._scrollableElements =
            elements.indexOf(element) === -1 ? [element, ...elements] : elements.slice();
        return this;
    }
    /** Gets the scrollable parents that are registered with this drop container. */
    getScrollableParents() {
        return this._scrollableElements;
    }
    /**
     * Figures out the index of an item in the container.
     * @param item Item whose index should be determined.
     */
    getItemIndex(item) {
        if (!this._isDragging) {
            return this._draggables.indexOf(item);
        }
        // Items are sorted always by top/left in the cache, however they flow differently in RTL.
        // The rest of the logic still stands no matter what orientation we're in, however
        // we need to invert the array when determining the index.
        const items = this._orientation === 'horizontal' && this._direction === 'rtl' ?
            this._itemPositions.slice().reverse() : this._itemPositions;
        return findIndex(items, currentItem => currentItem.drag === item);
    }
    /**
     * Whether the list is able to receive the item that
     * is currently being dragged inside a connected drop list.
     */
    isReceiving() {
        return this._activeSiblings.size > 0;
    }
    /**
     * Sorts an item inside the container based on its position.
     * @param item Item to be sorted.
     * @param pointerX Position of the item along the X axis.
     * @param pointerY Position of the item along the Y axis.
     * @param pointerDelta Direction in which the pointer is moving along each axis.
     */
    _sortItem(item, pointerX, pointerY, pointerDelta) {
        // Don't sort the item if sorting is disabled or it's out of range.
        if (this.sortingDisabled || !this._clientRect ||
            !isPointerNearClientRect(this._clientRect, DROP_PROXIMITY_THRESHOLD, pointerX, pointerY)) {
            return;
        }
        const siblings = this._itemPositions;
        const newIndex = this._getItemIndexFromPointerPosition(item, pointerX, pointerY, pointerDelta);
        if (newIndex === -1 && siblings.length > 0) {
            return;
        }
        const isHorizontal = this._orientation === 'horizontal';
        const currentIndex = findIndex(siblings, currentItem => currentItem.drag === item);
        const siblingAtNewPosition = siblings[newIndex];
        const currentPosition = siblings[currentIndex].clientRect;
        const newPosition = siblingAtNewPosition.clientRect;
        const delta = currentIndex > newIndex ? 1 : -1;
        // How many pixels the item's placeholder should be offset.
        const itemOffset = this._getItemOffsetPx(currentPosition, newPosition, delta);
        // How many pixels all the other items should be offset.
        const siblingOffset = this._getSiblingOffsetPx(currentIndex, siblings, delta);
        // Save the previous order of the items before moving the item to its new index.
        // We use this to check whether an item has been moved as a result of the sorting.
        const oldOrder = siblings.slice();
        // Shuffle the array in place.
        moveItemInArray(siblings, currentIndex, newIndex);
        this.sorted.next({
            previousIndex: currentIndex,
            currentIndex: newIndex,
            container: this,
            item
        });
        siblings.forEach((sibling, index) => {
            // Don't do anything if the position hasn't changed.
            if (oldOrder[index] === sibling) {
                return;
            }
            const isDraggedItem = sibling.drag === item;
            const offset = isDraggedItem ? itemOffset : siblingOffset;
            const elementToOffset = isDraggedItem ? item.getPlaceholderElement() :
                sibling.drag.getRootElement();
            // Update the offset to reflect the new position.
            sibling.offset += offset;
            // Since we're moving the items with a `transform`, we need to adjust their cached
            // client rects to reflect their new position, as well as swap their positions in the cache.
            // Note that we shouldn't use `getBoundingClientRect` here to update the cache, because the
            // elements may be mid-animation which will give us a wrong result.
            if (isHorizontal) {
                // Round the transforms since some browsers will
                // blur the elements, for sub-pixel transforms.
                elementToOffset.style.transform = combineTransforms(`translate3d(${Math.round(sibling.offset)}px, 0, 0)`, sibling.initialTransform);
                adjustClientRect(sibling.clientRect, 0, offset);
            }
            else {
                elementToOffset.style.transform = combineTransforms(`translate3d(0, ${Math.round(sibling.offset)}px, 0)`, sibling.initialTransform);
                adjustClientRect(sibling.clientRect, offset, 0);
            }
        });
        // Note that it's important that we do this after the client rects have been adjusted.
        this._previousSwap.overlaps = isInsideClientRect(newPosition, pointerX, pointerY);
        this._previousSwap.drag = siblingAtNewPosition.drag;
        this._previousSwap.delta = isHorizontal ? pointerDelta.x : pointerDelta.y;
    }
    /**
     * Checks whether the user's pointer is close to the edges of either the
     * viewport or the drop list and starts the auto-scroll sequence.
     * @param pointerX User's pointer position along the x axis.
     * @param pointerY User's pointer position along the y axis.
     */
    _startScrollingIfNecessary(pointerX, pointerY) {
        if (this.autoScrollDisabled) {
            return;
        }
        let scrollNode;
        let verticalScrollDirection = 0 /* NONE */;
        let horizontalScrollDirection = 0 /* NONE */;
        // Check whether we should start scrolling any of the parent containers.
        this._parentPositions.positions.forEach((position, element) => {
            // We have special handling for the `document` below. Also this would be
            // nicer with a  for...of loop, but it requires changing a compiler flag.
            if (element === this._document || !position.clientRect || scrollNode) {
                return;
            }
            if (isPointerNearClientRect(position.clientRect, DROP_PROXIMITY_THRESHOLD, pointerX, pointerY)) {
                [verticalScrollDirection, horizontalScrollDirection] = getElementScrollDirections(element, position.clientRect, pointerX, pointerY);
                if (verticalScrollDirection || horizontalScrollDirection) {
                    scrollNode = element;
                }
            }
        });
        // Otherwise check if we can start scrolling the viewport.
        if (!verticalScrollDirection && !horizontalScrollDirection) {
            const { width, height } = this._viewportRuler.getViewportSize();
            const clientRect = { width, height, top: 0, right: width, bottom: height, left: 0 };
            verticalScrollDirection = getVerticalScrollDirection(clientRect, pointerY);
            horizontalScrollDirection = getHorizontalScrollDirection(clientRect, pointerX);
            scrollNode = window;
        }
        if (scrollNode && (verticalScrollDirection !== this._verticalScrollDirection ||
            horizontalScrollDirection !== this._horizontalScrollDirection ||
            scrollNode !== this._scrollNode)) {
            this._verticalScrollDirection = verticalScrollDirection;
            this._horizontalScrollDirection = horizontalScrollDirection;
            this._scrollNode = scrollNode;
            if ((verticalScrollDirection || horizontalScrollDirection) && scrollNode) {
                this._ngZone.runOutsideAngular(this._startScrollInterval);
            }
            else {
                this._stopScrolling();
            }
        }
    }
    /** Stops any currently-running auto-scroll sequences. */
    _stopScrolling() {
        this._stopScrollTimers.next();
    }
    /** Starts the dragging sequence within the list. */
    _draggingStarted() {
        const styles = coerceElement(this.element).style;
        this.beforeStarted.next();
        this._isDragging = true;
        // We need to disable scroll snapping while the user is dragging, because it breaks automatic
        // scrolling. The browser seems to round the value based on the snapping points which means
        // that we can't increment/decrement the scroll position.
        this._initialScrollSnap = styles.msScrollSnapType || styles.scrollSnapType || '';
        styles.scrollSnapType = styles.msScrollSnapType = 'none';
        this._cacheItems();
        this._viewportScrollSubscription.unsubscribe();
        this._listenToScrollEvents();
    }
    /** Caches the positions of the configured scrollable parents. */
    _cacheParentPositions() {
        const element = coerceElement(this.element);
        this._parentPositions.cache(this._scrollableElements);
        // The list element is always in the `scrollableElements`
        // so we can take advantage of the cached `ClientRect`.
        this._clientRect = this._parentPositions.positions.get(element).clientRect;
    }
    /** Refreshes the position cache of the items and sibling containers. */
    _cacheItemPositions() {
        const isHorizontal = this._orientation === 'horizontal';
        this._itemPositions = this._activeDraggables.map(drag => {
            const elementToMeasure = drag.getVisibleElement();
            return {
                drag,
                offset: 0,
                initialTransform: elementToMeasure.style.transform || '',
                clientRect: getMutableClientRect(elementToMeasure),
            };
        }).sort((a, b) => {
            return isHorizontal ? a.clientRect.left - b.clientRect.left :
                a.clientRect.top - b.clientRect.top;
        });
    }
    /** Resets the container to its initial state. */
    _reset() {
        this._isDragging = false;
        const styles = coerceElement(this.element).style;
        styles.scrollSnapType = styles.msScrollSnapType = this._initialScrollSnap;
        // TODO(crisbeto): may have to wait for the animations to finish.
        this._activeDraggables.forEach(item => {
            var _a;
            const rootElement = item.getRootElement();
            if (rootElement) {
                const initialTransform = (_a = this._itemPositions
                    .find(current => current.drag === item)) === null || _a === void 0 ? void 0 : _a.initialTransform;
                rootElement.style.transform = initialTransform || '';
            }
        });
        this._siblings.forEach(sibling => sibling._stopReceiving(this));
        this._activeDraggables = [];
        this._itemPositions = [];
        this._previousSwap.drag = null;
        this._previousSwap.delta = 0;
        this._previousSwap.overlaps = false;
        this._stopScrolling();
        this._viewportScrollSubscription.unsubscribe();
        this._parentPositions.clear();
    }
    /**
     * Gets the offset in pixels by which the items that aren't being dragged should be moved.
     * @param currentIndex Index of the item currently being dragged.
     * @param siblings All of the items in the list.
     * @param delta Direction in which the user is moving.
     */
    _getSiblingOffsetPx(currentIndex, siblings, delta) {
        const isHorizontal = this._orientation === 'horizontal';
        const currentPosition = siblings[currentIndex].clientRect;
        const immediateSibling = siblings[currentIndex + delta * -1];
        let siblingOffset = currentPosition[isHorizontal ? 'width' : 'height'] * delta;
        if (immediateSibling) {
            const start = isHorizontal ? 'left' : 'top';
            const end = isHorizontal ? 'right' : 'bottom';
            // Get the spacing between the start of the current item and the end of the one immediately
            // after it in the direction in which the user is dragging, or vice versa. We add it to the
            // offset in order to push the element to where it will be when it's inline and is influenced
            // by the `margin` of its siblings.
            if (delta === -1) {
                siblingOffset -= immediateSibling.clientRect[start] - currentPosition[end];
            }
            else {
                siblingOffset += currentPosition[start] - immediateSibling.clientRect[end];
            }
        }
        return siblingOffset;
    }
    /**
     * Gets the offset in pixels by which the item that is being dragged should be moved.
     * @param currentPosition Current position of the item.
     * @param newPosition Position of the item where the current item should be moved.
     * @param delta Direction in which the user is moving.
     */
    _getItemOffsetPx(currentPosition, newPosition, delta) {
        const isHorizontal = this._orientation === 'horizontal';
        let itemOffset = isHorizontal ? newPosition.left - currentPosition.left :
            newPosition.top - currentPosition.top;
        // Account for differences in the item width/height.
        if (delta === -1) {
            itemOffset += isHorizontal ? newPosition.width - currentPosition.width :
                newPosition.height - currentPosition.height;
        }
        return itemOffset;
    }
    /**
     * Checks if pointer is entering in the first position
     * @param pointerX Position of the user's pointer along the X axis.
     * @param pointerY Position of the user's pointer along the Y axis.
     */
    _shouldEnterAsFirstChild(pointerX, pointerY) {
        if (!this._activeDraggables.length) {
            return false;
        }
        const itemPositions = this._itemPositions;
        const isHorizontal = this._orientation === 'horizontal';
        // `itemPositions` are sorted by position while `activeDraggables` are sorted by child index
        // check if container is using some sort of "reverse" ordering (eg: flex-direction: row-reverse)
        const reversed = itemPositions[0].drag !== this._activeDraggables[0];
        if (reversed) {
            const lastItemRect = itemPositions[itemPositions.length - 1].clientRect;
            return isHorizontal ? pointerX >= lastItemRect.right : pointerY >= lastItemRect.bottom;
        }
        else {
            const firstItemRect = itemPositions[0].clientRect;
            return isHorizontal ? pointerX <= firstItemRect.left : pointerY <= firstItemRect.top;
        }
    }
    /**
     * Gets the index of an item in the drop container, based on the position of the user's pointer.
     * @param item Item that is being sorted.
     * @param pointerX Position of the user's pointer along the X axis.
     * @param pointerY Position of the user's pointer along the Y axis.
     * @param delta Direction in which the user is moving their pointer.
     */
    _getItemIndexFromPointerPosition(item, pointerX, pointerY, delta) {
        const isHorizontal = this._orientation === 'horizontal';
        const index = findIndex(this._itemPositions, ({ drag, clientRect }, _, array) => {
            if (drag === item) {
                // If there's only one item left in the container, it must be
                // the dragged item itself so we use it as a reference.
                return array.length < 2;
            }
            if (delta) {
                const direction = isHorizontal ? delta.x : delta.y;
                // If the user is still hovering over the same item as last time, their cursor hasn't left
                // the item after we made the swap, and they didn't change the direction in which they're
                // dragging, we don't consider it a direction swap.
                if (drag === this._previousSwap.drag && this._previousSwap.overlaps &&
                    direction === this._previousSwap.delta) {
                    return false;
                }
            }
            return isHorizontal ?
                // Round these down since most browsers report client rects with
                // sub-pixel precision, whereas the pointer coordinates are rounded to pixels.
                pointerX >= Math.floor(clientRect.left) && pointerX < Math.floor(clientRect.right) :
                pointerY >= Math.floor(clientRect.top) && pointerY < Math.floor(clientRect.bottom);
        });
        return (index === -1 || !this.sortPredicate(index, item, this)) ? -1 : index;
    }
    /** Caches the current items in the list and their positions. */
    _cacheItems() {
        this._activeDraggables = this._draggables.slice();
        this._cacheItemPositions();
        this._cacheParentPositions();
    }
    /**
     * Checks whether the user's pointer is positioned over the container.
     * @param x Pointer position along the X axis.
     * @param y Pointer position along the Y axis.
     */
    _isOverContainer(x, y) {
        return this._clientRect != null && isInsideClientRect(this._clientRect, x, y);
    }
    /**
     * Figures out whether an item should be moved into a sibling
     * drop container, based on its current position.
     * @param item Drag item that is being moved.
     * @param x Position of the item along the X axis.
     * @param y Position of the item along the Y axis.
     */
    _getSiblingContainerFromPosition(item, x, y) {
        return this._siblings.find(sibling => sibling._canReceive(item, x, y));
    }
    /**
     * Checks whether the drop list can receive the passed-in item.
     * @param item Item that is being dragged into the list.
     * @param x Position of the item along the X axis.
     * @param y Position of the item along the Y axis.
     */
    _canReceive(item, x, y) {
        if (!this._clientRect || !isInsideClientRect(this._clientRect, x, y) ||
            !this.enterPredicate(item, this)) {
            return false;
        }
        const elementFromPoint = this._getShadowRoot().elementFromPoint(x, y);
        // If there's no element at the pointer position, then
        // the client rect is probably scrolled out of the view.
        if (!elementFromPoint) {
            return false;
        }
        const nativeElement = coerceElement(this.element);
        // The `ClientRect`, that we're using to find the container over which the user is
        // hovering, doesn't give us any information on whether the element has been scrolled
        // out of the view or whether it's overlapping with other containers. This means that
        // we could end up transferring the item into a container that's invisible or is positioned
        // below another one. We use the result from `elementFromPoint` to get the top-most element
        // at the pointer position and to find whether it's one of the intersecting drop containers.
        return elementFromPoint === nativeElement || nativeElement.contains(elementFromPoint);
    }
    /**
     * Called by one of the connected drop lists when a dragging sequence has started.
     * @param sibling Sibling in which dragging has started.
     */
    _startReceiving(sibling, items) {
        const activeSiblings = this._activeSiblings;
        if (!activeSiblings.has(sibling) && items.every(item => {
            // Note that we have to add an exception to the `enterPredicate` for items that started off
            // in this drop list. The drag ref has logic that allows an item to return to its initial
            // container, if it has left the initial container and none of the connected containers
            // allow it to enter. See `DragRef._updateActiveDropContainer` for more context.
            return this.enterPredicate(item, this) || this._draggables.indexOf(item) > -1;
        })) {
            activeSiblings.add(sibling);
            this._cacheParentPositions();
            this._listenToScrollEvents();
        }
    }
    /**
     * Called by a connected drop list when dragging has stopped.
     * @param sibling Sibling whose dragging has stopped.
     */
    _stopReceiving(sibling) {
        this._activeSiblings.delete(sibling);
        this._viewportScrollSubscription.unsubscribe();
    }
    /**
     * Starts listening to scroll events on the viewport.
     * Used for updating the internal state of the list.
     */
    _listenToScrollEvents() {
        this._viewportScrollSubscription = this._dragDropRegistry
            .scrolled(this._getShadowRoot())
            .subscribe(event => {
            if (this.isDragging()) {
                const scrollDifference = this._parentPositions.handleScroll(event);
                if (scrollDifference) {
                    // Since we know the amount that the user has scrolled we can shift all of the
                    // client rectangles ourselves. This is cheaper than re-measuring everything and
                    // we can avoid inconsistent behavior where we might be measuring the element before
                    // its position has changed.
                    this._itemPositions.forEach(({ clientRect }) => {
                        adjustClientRect(clientRect, scrollDifference.top, scrollDifference.left);
                    });
                    // We need two loops for this, because we want all of the cached
                    // positions to be up-to-date before we re-sort the item.
                    this._itemPositions.forEach(({ drag }) => {
                        if (this._dragDropRegistry.isDragging(drag)) {
                            // We need to re-sort the item manually, because the pointer move
                            // events won't be dispatched while the user is scrolling.
                            drag._sortFromLastPointerPosition();
                        }
                    });
                }
            }
            else if (this.isReceiving()) {
                this._cacheParentPositions();
            }
        });
    }
    /**
     * Lazily resolves and returns the shadow root of the element. We do this in a function, rather
     * than saving it in property directly on init, because we want to resolve it as late as possible
     * in order to ensure that the element has been moved into the shadow DOM. Doing it inside the
     * constructor might be too early if the element is inside of something like `ngFor` or `ngIf`.
     */
    _getShadowRoot() {
        if (!this._cachedShadowRoot) {
            const shadowRoot = _getShadowRoot(coerceElement(this.element));
            this._cachedShadowRoot = shadowRoot || this._document;
        }
        return this._cachedShadowRoot;
    }
    /** Notifies any siblings that may potentially receive the item. */
    _notifyReceivingSiblings() {
        const draggedItems = this._activeDraggables.filter(item => item.isDragging());
        this._siblings.forEach(sibling => sibling._startReceiving(this, draggedItems));
    }
}
/**
 * Finds the index of an item that matches a predicate function. Used as an equivalent
 * of `Array.prototype.findIndex` which isn't part of the standard Google typings.
 * @param array Array in which to look for matches.
 * @param predicate Function used to determine whether an item is a match.
 */
function findIndex(array, predicate) {
    for (let i = 0; i < array.length; i++) {
        if (predicate(array[i], i, array)) {
            return i;
        }
    }
    return -1;
}
/**
 * Increments the vertical scroll position of a node.
 * @param node Node whose scroll position should change.
 * @param amount Amount of pixels that the `node` should be scrolled.
 */
function incrementVerticalScroll(node, amount) {
    if (node === window) {
        node.scrollBy(0, amount);
    }
    else {
        // Ideally we could use `Element.scrollBy` here as well, but IE and Edge don't support it.
        node.scrollTop += amount;
    }
}
/**
 * Increments the horizontal scroll position of a node.
 * @param node Node whose scroll position should change.
 * @param amount Amount of pixels that the `node` should be scrolled.
 */
function incrementHorizontalScroll(node, amount) {
    if (node === window) {
        node.scrollBy(amount, 0);
    }
    else {
        // Ideally we could use `Element.scrollBy` here as well, but IE and Edge don't support it.
        node.scrollLeft += amount;
    }
}
/**
 * Gets whether the vertical auto-scroll direction of a node.
 * @param clientRect Dimensions of the node.
 * @param pointerY Position of the user's pointer along the y axis.
 */
function getVerticalScrollDirection(clientRect, pointerY) {
    const { top, bottom, height } = clientRect;
    const yThreshold = height * SCROLL_PROXIMITY_THRESHOLD;
    if (pointerY >= top - yThreshold && pointerY <= top + yThreshold) {
        return 1 /* UP */;
    }
    else if (pointerY >= bottom - yThreshold && pointerY <= bottom + yThreshold) {
        return 2 /* DOWN */;
    }
    return 0 /* NONE */;
}
/**
 * Gets whether the horizontal auto-scroll direction of a node.
 * @param clientRect Dimensions of the node.
 * @param pointerX Position of the user's pointer along the x axis.
 */
function getHorizontalScrollDirection(clientRect, pointerX) {
    const { left, right, width } = clientRect;
    const xThreshold = width * SCROLL_PROXIMITY_THRESHOLD;
    if (pointerX >= left - xThreshold && pointerX <= left + xThreshold) {
        return 1 /* LEFT */;
    }
    else if (pointerX >= right - xThreshold && pointerX <= right + xThreshold) {
        return 2 /* RIGHT */;
    }
    return 0 /* NONE */;
}
/**
 * Gets the directions in which an element node should be scrolled,
 * assuming that the user's pointer is already within it scrollable region.
 * @param element Element for which we should calculate the scroll direction.
 * @param clientRect Bounding client rectangle of the element.
 * @param pointerX Position of the user's pointer along the x axis.
 * @param pointerY Position of the user's pointer along the y axis.
 */
function getElementScrollDirections(element, clientRect, pointerX, pointerY) {
    const computedVertical = getVerticalScrollDirection(clientRect, pointerY);
    const computedHorizontal = getHorizontalScrollDirection(clientRect, pointerX);
    let verticalScrollDirection = 0 /* NONE */;
    let horizontalScrollDirection = 0 /* NONE */;
    // Note that we here we do some extra checks for whether the element is actually scrollable in
    // a certain direction and we only assign the scroll direction if it is. We do this so that we
    // can allow other elements to be scrolled, if the current element can't be scrolled anymore.
    // This allows us to handle cases where the scroll regions of two scrollable elements overlap.
    if (computedVertical) {
        const scrollTop = element.scrollTop;
        if (computedVertical === 1 /* UP */) {
            if (scrollTop > 0) {
                verticalScrollDirection = 1 /* UP */;
            }
        }
        else if (element.scrollHeight - scrollTop > element.clientHeight) {
            verticalScrollDirection = 2 /* DOWN */;
        }
    }
    if (computedHorizontal) {
        const scrollLeft = element.scrollLeft;
        if (computedHorizontal === 1 /* LEFT */) {
            if (scrollLeft > 0) {
                horizontalScrollDirection = 1 /* LEFT */;
            }
        }
        else if (element.scrollWidth - scrollLeft > element.clientWidth) {
            horizontalScrollDirection = 2 /* RIGHT */;
        }
    }
    return [verticalScrollDirection, horizontalScrollDirection];
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Event options that can be used to bind an active, capturing event. */
const activeCapturingEventOptions = normalizePassiveListenerOptions({
    passive: false,
    capture: true
});
/**
 * Service that keeps track of all the drag item and drop container
 * instances, and manages global event listeners on the `document`.
 * @docs-private
 */
// Note: this class is generic, rather than referencing CdkDrag and CdkDropList directly, in order
// to avoid circular imports. If we were to reference them here, importing the registry into the
// classes that are registering themselves will introduce a circular import.
class DragDropRegistry {
    constructor(_ngZone, _document) {
        this._ngZone = _ngZone;
        /** Registered drop container instances. */
        this._dropInstances = new Set();
        /** Registered drag item instances. */
        this._dragInstances = new Set();
        /** Drag item instances that are currently being dragged. */
        this._activeDragInstances = [];
        /** Keeps track of the event listeners that we've bound to the `document`. */
        this._globalListeners = new Map();
        /**
         * Predicate function to check if an item is being dragged.  Moved out into a property,
         * because it'll be called a lot and we don't want to create a new function every time.
         */
        this._draggingPredicate = (item) => item.isDragging();
        /**
         * Emits the `touchmove` or `mousemove` events that are dispatched
         * while the user is dragging a drag item instance.
         */
        this.pointerMove = new Subject();
        /**
         * Emits the `touchend` or `mouseup` events that are dispatched
         * while the user is dragging a drag item instance.
         */
        this.pointerUp = new Subject();
        /**
         * Emits when the viewport has been scrolled while the user is dragging an item.
         * @deprecated To be turned into a private member. Use the `scrolled` method instead.
         * @breaking-change 13.0.0
         */
        this.scroll = new Subject();
        /**
         * Event listener that will prevent the default browser action while the user is dragging.
         * @param event Event whose default action should be prevented.
         */
        this._preventDefaultWhileDragging = (event) => {
            if (this._activeDragInstances.length > 0) {
                event.preventDefault();
            }
        };
        /** Event listener for `touchmove` that is bound even if no dragging is happening. */
        this._persistentTouchmoveListener = (event) => {
            if (this._activeDragInstances.length > 0) {
                // Note that we only want to prevent the default action after dragging has actually started.
                // Usually this is the same time at which the item is added to the `_activeDragInstances`,
                // but it could be pushed back if the user has set up a drag delay or threshold.
                if (this._activeDragInstances.some(this._draggingPredicate)) {
                    event.preventDefault();
                }
                this.pointerMove.next(event);
            }
        };
        this._document = _document;
    }
    /** Adds a drop container to the registry. */
    registerDropContainer(drop) {
        if (!this._dropInstances.has(drop)) {
            this._dropInstances.add(drop);
        }
    }
    /** Adds a drag item instance to the registry. */
    registerDragItem(drag) {
        this._dragInstances.add(drag);
        // The `touchmove` event gets bound once, ahead of time, because WebKit
        // won't preventDefault on a dynamically-added `touchmove` listener.
        // See https://bugs.webkit.org/show_bug.cgi?id=184250.
        if (this._dragInstances.size === 1) {
            this._ngZone.runOutsideAngular(() => {
                // The event handler has to be explicitly active,
                // because newer browsers make it passive by default.
                this._document.addEventListener('touchmove', this._persistentTouchmoveListener, activeCapturingEventOptions);
            });
        }
    }
    /** Removes a drop container from the registry. */
    removeDropContainer(drop) {
        this._dropInstances.delete(drop);
    }
    /** Removes a drag item instance from the registry. */
    removeDragItem(drag) {
        this._dragInstances.delete(drag);
        this.stopDragging(drag);
        if (this._dragInstances.size === 0) {
            this._document.removeEventListener('touchmove', this._persistentTouchmoveListener, activeCapturingEventOptions);
        }
    }
    /**
     * Starts the dragging sequence for a drag instance.
     * @param drag Drag instance which is being dragged.
     * @param event Event that initiated the dragging.
     */
    startDragging(drag, event) {
        // Do not process the same drag twice to avoid memory leaks and redundant listeners
        if (this._activeDragInstances.indexOf(drag) > -1) {
            return;
        }
        this._activeDragInstances.push(drag);
        if (this._activeDragInstances.length === 1) {
            const isTouchEvent = event.type.startsWith('touch');
            // We explicitly bind __active__ listeners here, because newer browsers will default to
            // passive ones for `mousemove` and `touchmove`. The events need to be active, because we
            // use `preventDefault` to prevent the page from scrolling while the user is dragging.
            this._globalListeners
                .set(isTouchEvent ? 'touchend' : 'mouseup', {
                handler: (e) => this.pointerUp.next(e),
                options: true
            })
                .set('scroll', {
                handler: (e) => this.scroll.next(e),
                // Use capturing so that we pick up scroll changes in any scrollable nodes that aren't
                // the document. See https://github.com/angular/components/issues/17144.
                options: true
            })
                // Preventing the default action on `mousemove` isn't enough to disable text selection
                // on Safari so we need to prevent the selection event as well. Alternatively this can
                // be done by setting `user-select: none` on the `body`, however it has causes a style
                // recalculation which can be expensive on pages with a lot of elements.
                .set('selectstart', {
                handler: this._preventDefaultWhileDragging,
                options: activeCapturingEventOptions
            });
            // We don't have to bind a move event for touch drag sequences, because
            // we already have a persistent global one bound from `registerDragItem`.
            if (!isTouchEvent) {
                this._globalListeners.set('mousemove', {
                    handler: (e) => this.pointerMove.next(e),
                    options: activeCapturingEventOptions
                });
            }
            this._ngZone.runOutsideAngular(() => {
                this._globalListeners.forEach((config, name) => {
                    this._document.addEventListener(name, config.handler, config.options);
                });
            });
        }
    }
    /** Stops dragging a drag item instance. */
    stopDragging(drag) {
        const index = this._activeDragInstances.indexOf(drag);
        if (index > -1) {
            this._activeDragInstances.splice(index, 1);
            if (this._activeDragInstances.length === 0) {
                this._clearGlobalListeners();
            }
        }
    }
    /** Gets whether a drag item instance is currently being dragged. */
    isDragging(drag) {
        return this._activeDragInstances.indexOf(drag) > -1;
    }
    /**
     * Gets a stream that will emit when any element on the page is scrolled while an item is being
     * dragged.
     * @param shadowRoot Optional shadow root that the current dragging sequence started from.
     *   Top-level listeners won't pick up events coming from the shadow DOM so this parameter can
     *   be used to include an additional top-level listener at the shadow root level.
     */
    scrolled(shadowRoot) {
        const streams = [this.scroll];
        if (shadowRoot && shadowRoot !== this._document) {
            // Note that this is basically the same as `fromEvent` from rjxs, but we do it ourselves,
            // because we want to guarantee that the event is bound outside of the `NgZone`. With
            // `fromEvent` it'll only happen if the subscription is outside the `NgZone`.
            streams.push(new Observable((observer) => {
                return this._ngZone.runOutsideAngular(() => {
                    const eventOptions = true;
                    const callback = (event) => {
                        if (this._activeDragInstances.length) {
                            observer.next(event);
                        }
                    };
                    shadowRoot.addEventListener('scroll', callback, eventOptions);
                    return () => {
                        shadowRoot.removeEventListener('scroll', callback, eventOptions);
                    };
                });
            }));
        }
        return merge(...streams);
    }
    ngOnDestroy() {
        this._dragInstances.forEach(instance => this.removeDragItem(instance));
        this._dropInstances.forEach(instance => this.removeDropContainer(instance));
        this._clearGlobalListeners();
        this.pointerMove.complete();
        this.pointerUp.complete();
    }
    /** Clears out the global event listeners from the `document`. */
    _clearGlobalListeners() {
        this._globalListeners.forEach((config, name) => {
            this._document.removeEventListener(name, config.handler, config.options);
        });
        this._globalListeners.clear();
    }
}
DragDropRegistry.ɵprov = i0.ɵɵdefineInjectable({ factory: function DragDropRegistry_Factory() { return new DragDropRegistry(i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(i1.DOCUMENT)); }, token: DragDropRegistry, providedIn: "root" });
DragDropRegistry.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
DragDropRegistry.ctorParameters = () => [
    { type: NgZone },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] }
];

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Default configuration to be used when creating a `DragRef`. */
const DEFAULT_CONFIG = {
    dragStartThreshold: 5,
    pointerDirectionChangeThreshold: 5
};
/**
 * Service that allows for drag-and-drop functionality to be attached to DOM elements.
 */
class DragDrop {
    constructor(_document, _ngZone, _viewportRuler, _dragDropRegistry) {
        this._document = _document;
        this._ngZone = _ngZone;
        this._viewportRuler = _viewportRuler;
        this._dragDropRegistry = _dragDropRegistry;
    }
    /**
     * Turns an element into a draggable item.
     * @param element Element to which to attach the dragging functionality.
     * @param config Object used to configure the dragging behavior.
     */
    createDrag(element, config = DEFAULT_CONFIG) {
        return new DragRef(element, config, this._document, this._ngZone, this._viewportRuler, this._dragDropRegistry);
    }
    /**
     * Turns an element into a drop list.
     * @param element Element to which to attach the drop list functionality.
     */
    createDropList(element) {
        return new DropListRef(element, this._dragDropRegistry, this._document, this._ngZone, this._viewportRuler);
    }
}
DragDrop.ɵprov = i0.ɵɵdefineInjectable({ factory: function DragDrop_Factory() { return new DragDrop(i0.ɵɵinject(i1.DOCUMENT), i0.ɵɵinject(i0.NgZone), i0.ɵɵinject(i2.ViewportRuler), i0.ɵɵinject(DragDropRegistry)); }, token: DragDrop, providedIn: "root" });
DragDrop.decorators = [
    { type: Injectable, args: [{ providedIn: 'root' },] }
];
DragDrop.ctorParameters = () => [
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] },
    { type: NgZone },
    { type: ViewportRuler },
    { type: DragDropRegistry }
];

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Injection token that can be used for a `CdkDrag` to provide itself as a parent to the
 * drag-specific child directive (`CdkDragHandle`, `CdkDragPreview` etc.). Used primarily
 * to avoid circular imports.
 * @docs-private
 */
const CDK_DRAG_PARENT = new InjectionToken('CDK_DRAG_PARENT');

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Injection token that can be used to reference instances of `CdkDropListGroup`. It serves as
 * alternative token to the actual `CdkDropListGroup` class which could cause unnecessary
 * retention of the class and its directive metadata.
 */
const CDK_DROP_LIST_GROUP = new InjectionToken('CdkDropListGroup');
/**
 * Declaratively connects sibling `cdkDropList` instances together. All of the `cdkDropList`
 * elements that are placed inside a `cdkDropListGroup` will be connected to each other
 * automatically. Can be used as an alternative to the `cdkDropListConnectedTo` input
 * from `cdkDropList`.
 */
class CdkDropListGroup {
    constructor() {
        /** Drop lists registered inside the group. */
        this._items = new Set();
        this._disabled = false;
    }
    /** Whether starting a dragging sequence from inside this group is disabled. */
    get disabled() { return this._disabled; }
    set disabled(value) {
        this._disabled = coerceBooleanProperty(value);
    }
    ngOnDestroy() {
        this._items.clear();
    }
}
CdkDropListGroup.decorators = [
    { type: Directive, args: [{
                selector: '[cdkDropListGroup]',
                exportAs: 'cdkDropListGroup',
                providers: [{ provide: CDK_DROP_LIST_GROUP, useExisting: CdkDropListGroup }],
            },] }
];
CdkDropListGroup.propDecorators = {
    disabled: [{ type: Input, args: ['cdkDropListGroupDisabled',] }]
};

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Injection token that can be used to configure the
 * behavior of the drag&drop-related components.
 */
const CDK_DRAG_CONFIG = new InjectionToken('CDK_DRAG_CONFIG');

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Asserts that a particular node is an element.
 * @param node Node to be checked.
 * @param name Name to attach to the error message.
 */
function assertElementNode(node, name) {
    if (node.nodeType !== 1) {
        throw Error(`${name} must be attached to an element node. ` +
            `Currently attached to "${node.nodeName}".`);
    }
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/** Counter used to generate unique ids for drop zones. */
let _uniqueIdCounter = 0;
/**
 * Injection token that can be used to reference instances of `CdkDropList`. It serves as
 * alternative token to the actual `CdkDropList` class which could cause unnecessary
 * retention of the class and its directive metadata.
 */
const CDK_DROP_LIST = new InjectionToken('CdkDropList');
const ɵ0 = undefined;
/** Container that wraps a set of draggable items. */
class CdkDropList {
    constructor(
    /** Element that the drop list is attached to. */
    element, dragDrop, _changeDetectorRef, _scrollDispatcher, _dir, _group, config) {
        this.element = element;
        this._changeDetectorRef = _changeDetectorRef;
        this._scrollDispatcher = _scrollDispatcher;
        this._dir = _dir;
        this._group = _group;
        /** Emits when the list has been destroyed. */
        this._destroyed = new Subject();
        /**
         * Other draggable containers that this container is connected to and into which the
         * container's items can be transferred. Can either be references to other drop containers,
         * or their unique IDs.
         */
        this.connectedTo = [];
        /**
         * Unique ID for the drop zone. Can be used as a reference
         * in the `connectedTo` of another `CdkDropList`.
         */
        this.id = `cdk-drop-list-${_uniqueIdCounter++}`;
        /**
         * Function that is used to determine whether an item
         * is allowed to be moved into a drop container.
         */
        this.enterPredicate = () => true;
        /** Functions that is used to determine whether an item can be sorted into a particular index. */
        this.sortPredicate = () => true;
        /** Emits when the user drops an item inside the container. */
        this.dropped = new EventEmitter();
        /**
         * Emits when the user has moved a new drag item into this container.
         */
        this.entered = new EventEmitter();
        /**
         * Emits when the user removes an item from the container
         * by dragging it into another container.
         */
        this.exited = new EventEmitter();
        /** Emits as the user is swapping items while actively dragging. */
        this.sorted = new EventEmitter();
        /**
         * Keeps track of the items that are registered with this container. Historically we used to
         * do this with a `ContentChildren` query, however queries don't handle transplanted views very
         * well which means that we can't handle cases like dragging the headers of a `mat-table`
         * correctly. What we do instead is to have the items register themselves with the container
         * and then we sort them based on their position in the DOM.
         */
        this._unsortedItems = new Set();
        if (typeof ngDevMode === 'undefined' || ngDevMode) {
            assertElementNode(element.nativeElement, 'cdkDropList');
        }
        this._dropListRef = dragDrop.createDropList(element);
        this._dropListRef.data = this;
        if (config) {
            this._assignDefaults(config);
        }
        this._dropListRef.enterPredicate = (drag, drop) => {
            return this.enterPredicate(drag.data, drop.data);
        };
        this._dropListRef.sortPredicate =
            (index, drag, drop) => {
                return this.sortPredicate(index, drag.data, drop.data);
            };
        this._setupInputSyncSubscription(this._dropListRef);
        this._handleEvents(this._dropListRef);
        CdkDropList._dropLists.push(this);
        if (_group) {
            _group._items.add(this);
        }
    }
    /** Whether starting a dragging sequence from this container is disabled. */
    get disabled() {
        return this._disabled || (!!this._group && this._group.disabled);
    }
    set disabled(value) {
        // Usually we sync the directive and ref state right before dragging starts, in order to have
        // a single point of failure and to avoid having to use setters for everything. `disabled` is
        // a special case, because it can prevent the `beforeStarted` event from firing, which can lock
        // the user in a disabled state, so we also need to sync it as it's being set.
        this._dropListRef.disabled = this._disabled = coerceBooleanProperty(value);
    }
    /** Registers an items with the drop list. */
    addItem(item) {
        this._unsortedItems.add(item);
        if (this._dropListRef.isDragging()) {
            this._syncItemsWithRef();
        }
    }
    /** Removes an item from the drop list. */
    removeItem(item) {
        this._unsortedItems.delete(item);
        if (this._dropListRef.isDragging()) {
            this._syncItemsWithRef();
        }
    }
    /** Gets the registered items in the list, sorted by their position in the DOM. */
    getSortedItems() {
        return Array.from(this._unsortedItems).sort((a, b) => {
            const documentPosition = a._dragRef.getVisibleElement().compareDocumentPosition(b._dragRef.getVisibleElement());
            // `compareDocumentPosition` returns a bitmask so we have to use a bitwise operator.
            // https://developer.mozilla.org/en-US/docs/Web/API/Node/compareDocumentPosition
            // tslint:disable-next-line:no-bitwise
            return documentPosition & Node.DOCUMENT_POSITION_FOLLOWING ? -1 : 1;
        });
    }
    ngOnDestroy() {
        const index = CdkDropList._dropLists.indexOf(this);
        if (index > -1) {
            CdkDropList._dropLists.splice(index, 1);
        }
        if (this._group) {
            this._group._items.delete(this);
        }
        this._unsortedItems.clear();
        this._dropListRef.dispose();
        this._destroyed.next();
        this._destroyed.complete();
    }
    /** Syncs the inputs of the CdkDropList with the options of the underlying DropListRef. */
    _setupInputSyncSubscription(ref) {
        if (this._dir) {
            this._dir.change
                .pipe(startWith(this._dir.value), takeUntil(this._destroyed))
                .subscribe(value => ref.withDirection(value));
        }
        ref.beforeStarted.subscribe(() => {
            const siblings = coerceArray(this.connectedTo).map(drop => {
                if (typeof drop === 'string') {
                    const correspondingDropList = CdkDropList._dropLists.find(list => list.id === drop);
                    if (!correspondingDropList && (typeof ngDevMode === 'undefined' || ngDevMode)) {
                        console.warn(`CdkDropList could not find connected drop list with id "${drop}"`);
                    }
                    return correspondingDropList;
                }
                return drop;
            });
            if (this._group) {
                this._group._items.forEach(drop => {
                    if (siblings.indexOf(drop) === -1) {
                        siblings.push(drop);
                    }
                });
            }
            // Note that we resolve the scrollable parents here so that we delay the resolution
            // as long as possible, ensuring that the element is in its final place in the DOM.
            if (!this._scrollableParentsResolved) {
                const scrollableParents = this._scrollDispatcher
                    .getAncestorScrollContainers(this.element)
                    .map(scrollable => scrollable.getElementRef().nativeElement);
                this._dropListRef.withScrollableParents(scrollableParents);
                // Only do this once since it involves traversing the DOM and the parents
                // shouldn't be able to change without the drop list being destroyed.
                this._scrollableParentsResolved = true;
            }
            ref.disabled = this.disabled;
            ref.lockAxis = this.lockAxis;
            ref.sortingDisabled = coerceBooleanProperty(this.sortingDisabled);
            ref.autoScrollDisabled = coerceBooleanProperty(this.autoScrollDisabled);
            ref.autoScrollStep = coerceNumberProperty(this.autoScrollStep, 2);
            ref
                .connectedTo(siblings.filter(drop => drop && drop !== this).map(list => list._dropListRef))
                .withOrientation(this.orientation);
        });
    }
    /** Handles events from the underlying DropListRef. */
    _handleEvents(ref) {
        ref.beforeStarted.subscribe(() => {
            this._syncItemsWithRef();
            this._changeDetectorRef.markForCheck();
        });
        ref.entered.subscribe(event => {
            this.entered.emit({
                container: this,
                item: event.item.data,
                currentIndex: event.currentIndex
            });
        });
        ref.exited.subscribe(event => {
            this.exited.emit({
                container: this,
                item: event.item.data
            });
            this._changeDetectorRef.markForCheck();
        });
        ref.sorted.subscribe(event => {
            this.sorted.emit({
                previousIndex: event.previousIndex,
                currentIndex: event.currentIndex,
                container: this,
                item: event.item.data
            });
        });
        ref.dropped.subscribe(event => {
            this.dropped.emit({
                previousIndex: event.previousIndex,
                currentIndex: event.currentIndex,
                previousContainer: event.previousContainer.data,
                container: event.container.data,
                item: event.item.data,
                isPointerOverContainer: event.isPointerOverContainer,
                distance: event.distance,
                dropPoint: event.dropPoint
            });
            // Mark for check since all of these events run outside of change
            // detection and we're not guaranteed for something else to have triggered it.
            this._changeDetectorRef.markForCheck();
        });
    }
    /** Assigns the default input values based on a provided config object. */
    _assignDefaults(config) {
        const { lockAxis, draggingDisabled, sortingDisabled, listAutoScrollDisabled, listOrientation } = config;
        this.disabled = draggingDisabled == null ? false : draggingDisabled;
        this.sortingDisabled = sortingDisabled == null ? false : sortingDisabled;
        this.autoScrollDisabled = listAutoScrollDisabled == null ? false : listAutoScrollDisabled;
        this.orientation = listOrientation || 'vertical';
        if (lockAxis) {
            this.lockAxis = lockAxis;
        }
    }
    /** Syncs up the registered drag items with underlying drop list ref. */
    _syncItemsWithRef() {
        this._dropListRef.withItems(this.getSortedItems().map(item => item._dragRef));
    }
}
/** Keeps track of the drop lists that are currently on the page. */
CdkDropList._dropLists = [];
CdkDropList.decorators = [
    { type: Directive, args: [{
                selector: '[cdkDropList], cdk-drop-list',
                exportAs: 'cdkDropList',
                providers: [
                    // Prevent child drop lists from picking up the same group as their parent.
                    { provide: CDK_DROP_LIST_GROUP, useValue: ɵ0 },
                    { provide: CDK_DROP_LIST, useExisting: CdkDropList },
                ],
                host: {
                    'class': 'cdk-drop-list',
                    '[attr.id]': 'id',
                    '[class.cdk-drop-list-disabled]': 'disabled',
                    '[class.cdk-drop-list-dragging]': '_dropListRef.isDragging()',
                    '[class.cdk-drop-list-receiving]': '_dropListRef.isReceiving()',
                }
            },] }
];
CdkDropList.ctorParameters = () => [
    { type: ElementRef },
    { type: DragDrop },
    { type: ChangeDetectorRef },
    { type: ScrollDispatcher },
    { type: Directionality, decorators: [{ type: Optional }] },
    { type: CdkDropListGroup, decorators: [{ type: Optional }, { type: Inject, args: [CDK_DROP_LIST_GROUP,] }, { type: SkipSelf }] },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [CDK_DRAG_CONFIG,] }] }
];
CdkDropList.propDecorators = {
    connectedTo: [{ type: Input, args: ['cdkDropListConnectedTo',] }],
    data: [{ type: Input, args: ['cdkDropListData',] }],
    orientation: [{ type: Input, args: ['cdkDropListOrientation',] }],
    id: [{ type: Input }],
    lockAxis: [{ type: Input, args: ['cdkDropListLockAxis',] }],
    disabled: [{ type: Input, args: ['cdkDropListDisabled',] }],
    sortingDisabled: [{ type: Input, args: ['cdkDropListSortingDisabled',] }],
    enterPredicate: [{ type: Input, args: ['cdkDropListEnterPredicate',] }],
    sortPredicate: [{ type: Input, args: ['cdkDropListSortPredicate',] }],
    autoScrollDisabled: [{ type: Input, args: ['cdkDropListAutoScrollDisabled',] }],
    autoScrollStep: [{ type: Input, args: ['cdkDropListAutoScrollStep',] }],
    dropped: [{ type: Output, args: ['cdkDropListDropped',] }],
    entered: [{ type: Output, args: ['cdkDropListEntered',] }],
    exited: [{ type: Output, args: ['cdkDropListExited',] }],
    sorted: [{ type: Output, args: ['cdkDropListSorted',] }]
};

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Injection token that can be used to reference instances of `CdkDragHandle`. It serves as
 * alternative token to the actual `CdkDragHandle` class which could cause unnecessary
 * retention of the class and its directive metadata.
 */
const CDK_DRAG_HANDLE = new InjectionToken('CdkDragHandle');
/** Handle that can be used to drag a CdkDrag instance. */
class CdkDragHandle {
    constructor(element, parentDrag) {
        this.element = element;
        /** Emits when the state of the handle has changed. */
        this._stateChanges = new Subject();
        this._disabled = false;
        if (typeof ngDevMode === 'undefined' || ngDevMode) {
            assertElementNode(element.nativeElement, 'cdkDragHandle');
        }
        this._parentDrag = parentDrag;
    }
    /** Whether starting to drag through this handle is disabled. */
    get disabled() { return this._disabled; }
    set disabled(value) {
        this._disabled = coerceBooleanProperty(value);
        this._stateChanges.next(this);
    }
    ngOnDestroy() {
        this._stateChanges.complete();
    }
}
CdkDragHandle.decorators = [
    { type: Directive, args: [{
                selector: '[cdkDragHandle]',
                host: {
                    'class': 'cdk-drag-handle'
                },
                providers: [{ provide: CDK_DRAG_HANDLE, useExisting: CdkDragHandle }],
            },] }
];
CdkDragHandle.ctorParameters = () => [
    { type: ElementRef },
    { type: undefined, decorators: [{ type: Inject, args: [CDK_DRAG_PARENT,] }, { type: Optional }, { type: SkipSelf }] }
];
CdkDragHandle.propDecorators = {
    disabled: [{ type: Input, args: ['cdkDragHandleDisabled',] }]
};

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Injection token that can be used to reference instances of `CdkDragPlaceholder`. It serves as
 * alternative token to the actual `CdkDragPlaceholder` class which could cause unnecessary
 * retention of the class and its directive metadata.
 */
const CDK_DRAG_PLACEHOLDER = new InjectionToken('CdkDragPlaceholder');
/**
 * Element that will be used as a template for the placeholder of a CdkDrag when
 * it is being dragged. The placeholder is displayed in place of the element being dragged.
 */
class CdkDragPlaceholder {
    constructor(templateRef) {
        this.templateRef = templateRef;
    }
}
CdkDragPlaceholder.decorators = [
    { type: Directive, args: [{
                selector: 'ng-template[cdkDragPlaceholder]',
                providers: [{ provide: CDK_DRAG_PLACEHOLDER, useExisting: CdkDragPlaceholder }],
            },] }
];
CdkDragPlaceholder.ctorParameters = () => [
    { type: TemplateRef }
];
CdkDragPlaceholder.propDecorators = {
    data: [{ type: Input }]
};

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
/**
 * Injection token that can be used to reference instances of `CdkDragPreview`. It serves as
 * alternative token to the actual `CdkDragPreview` class which could cause unnecessary
 * retention of the class and its directive metadata.
 */
const CDK_DRAG_PREVIEW = new InjectionToken('CdkDragPreview');
/**
 * Element that will be used as a template for the preview
 * of a CdkDrag when it is being dragged.
 */
class CdkDragPreview {
    constructor(templateRef) {
        this.templateRef = templateRef;
        this._matchSize = false;
    }
    /** Whether the preview should preserve the same size as the item that is being dragged. */
    get matchSize() { return this._matchSize; }
    set matchSize(value) { this._matchSize = coerceBooleanProperty(value); }
}
CdkDragPreview.decorators = [
    { type: Directive, args: [{
                selector: 'ng-template[cdkDragPreview]',
                providers: [{ provide: CDK_DRAG_PREVIEW, useExisting: CdkDragPreview }],
            },] }
];
CdkDragPreview.ctorParameters = () => [
    { type: TemplateRef }
];
CdkDragPreview.propDecorators = {
    data: [{ type: Input }],
    matchSize: [{ type: Input }]
};

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
const DRAG_HOST_CLASS = 'cdk-drag';
/** Element that can be moved inside a CdkDropList container. */
class CdkDrag {
    constructor(
    /** Element that the draggable is attached to. */
    element, 
    /** Droppable container that the draggable is a part of. */
    dropContainer, 
    /**
     * @deprecated `_document` parameter no longer being used and will be removed.
     * @breaking-change 12.0.0
     */
    _document, _ngZone, _viewContainerRef, config, _dir, dragDrop, _changeDetectorRef, _selfHandle, _parentDrag) {
        this.element = element;
        this.dropContainer = dropContainer;
        this._ngZone = _ngZone;
        this._viewContainerRef = _viewContainerRef;
        this._dir = _dir;
        this._changeDetectorRef = _changeDetectorRef;
        this._selfHandle = _selfHandle;
        this._parentDrag = _parentDrag;
        this._destroyed = new Subject();
        /** Emits when the user starts dragging the item. */
        this.started = new EventEmitter();
        /** Emits when the user has released a drag item, before any animations have started. */
        this.released = new EventEmitter();
        /** Emits when the user stops dragging an item in the container. */
        this.ended = new EventEmitter();
        /** Emits when the user has moved the item into a new container. */
        this.entered = new EventEmitter();
        /** Emits when the user removes the item its container by dragging it into another container. */
        this.exited = new EventEmitter();
        /** Emits when the user drops the item inside a container. */
        this.dropped = new EventEmitter();
        /**
         * Emits as the user is dragging the item. Use with caution,
         * because this event will fire for every pixel that the user has dragged.
         */
        this.moved = new Observable((observer) => {
            const subscription = this._dragRef.moved.pipe(map(movedEvent => ({
                source: this,
                pointerPosition: movedEvent.pointerPosition,
                event: movedEvent.event,
                delta: movedEvent.delta,
                distance: movedEvent.distance
            }))).subscribe(observer);
            return () => {
                subscription.unsubscribe();
            };
        });
        this._dragRef = dragDrop.createDrag(element, {
            dragStartThreshold: config && config.dragStartThreshold != null ?
                config.dragStartThreshold : 5,
            pointerDirectionChangeThreshold: config && config.pointerDirectionChangeThreshold != null ?
                config.pointerDirectionChangeThreshold : 5,
            zIndex: config === null || config === void 0 ? void 0 : config.zIndex,
        });
        this._dragRef.data = this;
        // We have to keep track of the drag instances in order to be able to match an element to
        // a drag instance. We can't go through the global registry of `DragRef`, because the root
        // element could be different.
        CdkDrag._dragInstances.push(this);
        if (config) {
            this._assignDefaults(config);
        }
        // Note that usually the container is assigned when the drop list is picks up the item, but in
        // some cases (mainly transplanted views with OnPush, see #18341) we may end up in a situation
        // where there are no items on the first change detection pass, but the items get picked up as
        // soon as the user triggers another pass by dragging. This is a problem, because the item would
        // have to switch from standalone mode to drag mode in the middle of the dragging sequence which
        // is too late since the two modes save different kinds of information. We work around it by
        // assigning the drop container both from here and the list.
        if (dropContainer) {
            this._dragRef._withDropContainer(dropContainer._dropListRef);
            dropContainer.addItem(this);
        }
        this._syncInputs(this._dragRef);
        this._handleEvents(this._dragRef);
    }
    /** Whether starting to drag this element is disabled. */
    get disabled() {
        return this._disabled || (this.dropContainer && this.dropContainer.disabled);
    }
    set disabled(value) {
        this._disabled = coerceBooleanProperty(value);
        this._dragRef.disabled = this._disabled;
    }
    /**
     * Returns the element that is being used as a placeholder
     * while the current element is being dragged.
     */
    getPlaceholderElement() {
        return this._dragRef.getPlaceholderElement();
    }
    /** Returns the root draggable element. */
    getRootElement() {
        return this._dragRef.getRootElement();
    }
    /** Resets a standalone drag item to its initial position. */
    reset() {
        this._dragRef.reset();
    }
    /**
     * Gets the pixel coordinates of the draggable outside of a drop container.
     */
    getFreeDragPosition() {
        return this._dragRef.getFreeDragPosition();
    }
    ngAfterViewInit() {
        // Normally this isn't in the zone, but it can cause major performance regressions for apps
        // using `zone-patch-rxjs` because it'll trigger a change detection when it unsubscribes.
        this._ngZone.runOutsideAngular(() => {
            // We need to wait for the zone to stabilize, in order for the reference
            // element to be in the proper place in the DOM. This is mostly relevant
            // for draggable elements inside portals since they get stamped out in
            // their original DOM position and then they get transferred to the portal.
            this._ngZone.onStable
                .pipe(take(1), takeUntil(this._destroyed))
                .subscribe(() => {
                this._updateRootElement();
                this._setupHandlesListener();
                if (this.freeDragPosition) {
                    this._dragRef.setFreeDragPosition(this.freeDragPosition);
                }
            });
        });
    }
    ngOnChanges(changes) {
        const rootSelectorChange = changes['rootElementSelector'];
        const positionChange = changes['freeDragPosition'];
        // We don't have to react to the first change since it's being
        // handled in `ngAfterViewInit` where it needs to be deferred.
        if (rootSelectorChange && !rootSelectorChange.firstChange) {
            this._updateRootElement();
        }
        // Skip the first change since it's being handled in `ngAfterViewInit`.
        if (positionChange && !positionChange.firstChange && this.freeDragPosition) {
            this._dragRef.setFreeDragPosition(this.freeDragPosition);
        }
    }
    ngOnDestroy() {
        if (this.dropContainer) {
            this.dropContainer.removeItem(this);
        }
        const index = CdkDrag._dragInstances.indexOf(this);
        if (index > -1) {
            CdkDrag._dragInstances.splice(index, 1);
        }
        // Unnecessary in most cases, but used to avoid extra change detections with `zone-paths-rxjs`.
        this._ngZone.runOutsideAngular(() => {
            this._destroyed.next();
            this._destroyed.complete();
            this._dragRef.dispose();
        });
    }
    /** Syncs the root element with the `DragRef`. */
    _updateRootElement() {
        const element = this.element.nativeElement;
        const rootElement = this.rootElementSelector ?
            getClosestMatchingAncestor(element, this.rootElementSelector) : element;
        if (rootElement && (typeof ngDevMode === 'undefined' || ngDevMode)) {
            assertElementNode(rootElement, 'cdkDrag');
        }
        this._dragRef.withRootElement(rootElement || element);
    }
    /** Gets the boundary element, based on the `boundaryElement` value. */
    _getBoundaryElement() {
        const boundary = this.boundaryElement;
        if (!boundary) {
            return null;
        }
        if (typeof boundary === 'string') {
            return getClosestMatchingAncestor(this.element.nativeElement, boundary);
        }
        const element = coerceElement(boundary);
        if ((typeof ngDevMode === 'undefined' || ngDevMode) &&
            !element.contains(this.element.nativeElement)) {
            throw Error('Draggable element is not inside of the node passed into cdkDragBoundary.');
        }
        return element;
    }
    /** Syncs the inputs of the CdkDrag with the options of the underlying DragRef. */
    _syncInputs(ref) {
        ref.beforeStarted.subscribe(() => {
            if (!ref.isDragging()) {
                const dir = this._dir;
                const dragStartDelay = this.dragStartDelay;
                const placeholder = this._placeholderTemplate ? {
                    template: this._placeholderTemplate.templateRef,
                    context: this._placeholderTemplate.data,
                    viewContainer: this._viewContainerRef
                } : null;
                const preview = this._previewTemplate ? {
                    template: this._previewTemplate.templateRef,
                    context: this._previewTemplate.data,
                    matchSize: this._previewTemplate.matchSize,
                    viewContainer: this._viewContainerRef
                } : null;
                ref.disabled = this.disabled;
                ref.lockAxis = this.lockAxis;
                ref.dragStartDelay = (typeof dragStartDelay === 'object' && dragStartDelay) ?
                    dragStartDelay : coerceNumberProperty(dragStartDelay);
                ref.constrainPosition = this.constrainPosition;
                ref.previewClass = this.previewClass;
                ref
                    .withBoundaryElement(this._getBoundaryElement())
                    .withPlaceholderTemplate(placeholder)
                    .withPreviewTemplate(preview)
                    .withPreviewContainer(this.previewContainer || 'global');
                if (dir) {
                    ref.withDirection(dir.value);
                }
            }
        });
        // This only needs to be resolved once.
        ref.beforeStarted.pipe(take(1)).subscribe(() => {
            var _a, _b;
            // If we managed to resolve a parent through DI, use it.
            if (this._parentDrag) {
                ref.withParent(this._parentDrag._dragRef);
                return;
            }
            // Otherwise fall back to resolving the parent by looking up the DOM. This can happen if
            // the item was projected into another item by something like `ngTemplateOutlet`.
            let parent = this.element.nativeElement.parentElement;
            while (parent) {
                // `classList` needs to be null checked, because IE doesn't have it on some elements.
                if ((_a = parent.classList) === null || _a === void 0 ? void 0 : _a.contains(DRAG_HOST_CLASS)) {
                    ref.withParent(((_b = CdkDrag._dragInstances.find(drag => {
                        return drag.element.nativeElement === parent;
                    })) === null || _b === void 0 ? void 0 : _b._dragRef) || null);
                    break;
                }
                parent = parent.parentElement;
            }
        });
    }
    /** Handles the events from the underlying `DragRef`. */
    _handleEvents(ref) {
        ref.started.subscribe(() => {
            this.started.emit({ source: this });
            // Since all of these events run outside of change detection,
            // we need to ensure that everything is marked correctly.
            this._changeDetectorRef.markForCheck();
        });
        ref.released.subscribe(() => {
            this.released.emit({ source: this });
        });
        ref.ended.subscribe(event => {
            this.ended.emit({
                source: this,
                distance: event.distance,
                dropPoint: event.dropPoint
            });
            // Since all of these events run outside of change detection,
            // we need to ensure that everything is marked correctly.
            this._changeDetectorRef.markForCheck();
        });
        ref.entered.subscribe(event => {
            this.entered.emit({
                container: event.container.data,
                item: this,
                currentIndex: event.currentIndex
            });
        });
        ref.exited.subscribe(event => {
            this.exited.emit({
                container: event.container.data,
                item: this
            });
        });
        ref.dropped.subscribe(event => {
            this.dropped.emit({
                previousIndex: event.previousIndex,
                currentIndex: event.currentIndex,
                previousContainer: event.previousContainer.data,
                container: event.container.data,
                isPointerOverContainer: event.isPointerOverContainer,
                item: this,
                distance: event.distance,
                dropPoint: event.dropPoint
            });
        });
    }
    /** Assigns the default input values based on a provided config object. */
    _assignDefaults(config) {
        const { lockAxis, dragStartDelay, constrainPosition, previewClass, boundaryElement, draggingDisabled, rootElementSelector, previewContainer } = config;
        this.disabled = draggingDisabled == null ? false : draggingDisabled;
        this.dragStartDelay = dragStartDelay || 0;
        if (lockAxis) {
            this.lockAxis = lockAxis;
        }
        if (constrainPosition) {
            this.constrainPosition = constrainPosition;
        }
        if (previewClass) {
            this.previewClass = previewClass;
        }
        if (boundaryElement) {
            this.boundaryElement = boundaryElement;
        }
        if (rootElementSelector) {
            this.rootElementSelector = rootElementSelector;
        }
        if (previewContainer) {
            this.previewContainer = previewContainer;
        }
    }
    /** Sets up the listener that syncs the handles with the drag ref. */
    _setupHandlesListener() {
        // Listen for any newly-added handles.
        this._handles.changes.pipe(startWith(this._handles), 
        // Sync the new handles with the DragRef.
        tap((handles) => {
            const childHandleElements = handles
                .filter(handle => handle._parentDrag === this)
                .map(handle => handle.element);
            // Usually handles are only allowed to be a descendant of the drag element, but if
            // the consumer defined a different drag root, we should allow the drag element
            // itself to be a handle too.
            if (this._selfHandle && this.rootElementSelector) {
                childHandleElements.push(this.element);
            }
            this._dragRef.withHandles(childHandleElements);
        }), 
        // Listen if the state of any of the handles changes.
        switchMap((handles) => {
            return merge(...handles.map(item => {
                return item._stateChanges.pipe(startWith(item));
            }));
        }), takeUntil(this._destroyed)).subscribe(handleInstance => {
            // Enabled/disable the handle that changed in the DragRef.
            const dragRef = this._dragRef;
            const handle = handleInstance.element.nativeElement;
            handleInstance.disabled ? dragRef.disableHandle(handle) : dragRef.enableHandle(handle);
        });
    }
}
CdkDrag._dragInstances = [];
CdkDrag.decorators = [
    { type: Directive, args: [{
                selector: '[cdkDrag]',
                exportAs: 'cdkDrag',
                host: {
                    'class': DRAG_HOST_CLASS,
                    '[class.cdk-drag-disabled]': 'disabled',
                    '[class.cdk-drag-dragging]': '_dragRef.isDragging()',
                },
                providers: [{ provide: CDK_DRAG_PARENT, useExisting: CdkDrag }]
            },] }
];
CdkDrag.ctorParameters = () => [
    { type: ElementRef },
    { type: undefined, decorators: [{ type: Inject, args: [CDK_DROP_LIST,] }, { type: Optional }, { type: SkipSelf }] },
    { type: undefined, decorators: [{ type: Inject, args: [DOCUMENT,] }] },
    { type: NgZone },
    { type: ViewContainerRef },
    { type: undefined, decorators: [{ type: Optional }, { type: Inject, args: [CDK_DRAG_CONFIG,] }] },
    { type: Directionality, decorators: [{ type: Optional }] },
    { type: DragDrop },
    { type: ChangeDetectorRef },
    { type: CdkDragHandle, decorators: [{ type: Optional }, { type: Self }, { type: Inject, args: [CDK_DRAG_HANDLE,] }] },
    { type: CdkDrag, decorators: [{ type: Optional }, { type: SkipSelf }, { type: Inject, args: [CDK_DRAG_PARENT,] }] }
];
CdkDrag.propDecorators = {
    _handles: [{ type: ContentChildren, args: [CDK_DRAG_HANDLE, { descendants: true },] }],
    _previewTemplate: [{ type: ContentChild, args: [CDK_DRAG_PREVIEW,] }],
    _placeholderTemplate: [{ type: ContentChild, args: [CDK_DRAG_PLACEHOLDER,] }],
    data: [{ type: Input, args: ['cdkDragData',] }],
    lockAxis: [{ type: Input, args: ['cdkDragLockAxis',] }],
    rootElementSelector: [{ type: Input, args: ['cdkDragRootElement',] }],
    boundaryElement: [{ type: Input, args: ['cdkDragBoundary',] }],
    dragStartDelay: [{ type: Input, args: ['cdkDragStartDelay',] }],
    freeDragPosition: [{ type: Input, args: ['cdkDragFreeDragPosition',] }],
    disabled: [{ type: Input, args: ['cdkDragDisabled',] }],
    constrainPosition: [{ type: Input, args: ['cdkDragConstrainPosition',] }],
    previewClass: [{ type: Input, args: ['cdkDragPreviewClass',] }],
    previewContainer: [{ type: Input, args: ['cdkDragPreviewContainer',] }],
    started: [{ type: Output, args: ['cdkDragStarted',] }],
    released: [{ type: Output, args: ['cdkDragReleased',] }],
    ended: [{ type: Output, args: ['cdkDragEnded',] }],
    entered: [{ type: Output, args: ['cdkDragEntered',] }],
    exited: [{ type: Output, args: ['cdkDragExited',] }],
    dropped: [{ type: Output, args: ['cdkDragDropped',] }],
    moved: [{ type: Output, args: ['cdkDragMoved',] }]
};
/** Gets the closest ancestor of an element that matches a selector. */
function getClosestMatchingAncestor(element, selector) {
    let currentElement = element.parentElement;
    while (currentElement) {
        // IE doesn't support `matches` so we have to fall back to `msMatchesSelector`.
        if (currentElement.matches ? currentElement.matches(selector) :
            currentElement.msMatchesSelector(selector)) {
            return currentElement;
        }
        currentElement = currentElement.parentElement;
    }
    return null;
}

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
class DragDropModule {
}
DragDropModule.decorators = [
    { type: NgModule, args: [{
                declarations: [
                    CdkDropList,
                    CdkDropListGroup,
                    CdkDrag,
                    CdkDragHandle,
                    CdkDragPreview,
                    CdkDragPlaceholder,
                ],
                exports: [
                    CdkScrollableModule,
                    CdkDropList,
                    CdkDropListGroup,
                    CdkDrag,
                    CdkDragHandle,
                    CdkDragPreview,
                    CdkDragPlaceholder,
                ],
                providers: [
                    DragDrop,
                ]
            },] }
];

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

/**
 * Generated bundle index. Do not edit.
 */

export { CDK_DRAG_CONFIG, CDK_DRAG_HANDLE, CDK_DRAG_PARENT, CDK_DRAG_PLACEHOLDER, CDK_DRAG_PREVIEW, CDK_DROP_LIST, CDK_DROP_LIST_GROUP, CdkDrag, CdkDragHandle, CdkDragPlaceholder, CdkDragPreview, CdkDropList, CdkDropListGroup, DragDrop, DragDropModule, DragDropRegistry, DragRef, DropListRef, copyArrayItem, moveItemInArray, transferArrayItem };
//# sourceMappingURL=drag-drop.js.map