(function (global, factory) {
    typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports, require('@angular/cdk/coercion'), require('@angular/core'), require('rxjs'), require('rxjs/operators')) :
    typeof define === 'function' && define.amd ? define('@angular/cdk/observers', ['exports', '@angular/cdk/coercion', '@angular/core', 'rxjs', 'rxjs/operators'], factory) :
    (global = typeof globalThis !== 'undefined' ? globalThis : global || self, factory((global.ng = global.ng || {}, global.ng.cdk = global.ng.cdk || {}, global.ng.cdk.observers = {}), global.ng.cdk.coercion, global.ng.core, global.rxjs, global.rxjs.operators));
}(this, (function (exports, coercion, i0, rxjs, operators) { 'use strict';

    function _interopNamespace(e) {
        if (e && e.__esModule) return e;
        var n = Object.create(null);
        if (e) {
            Object.keys(e).forEach(function (k) {
                if (k !== 'default') {
                    var d = Object.getOwnPropertyDescriptor(e, k);
                    Object.defineProperty(n, k, d.get ? d : {
                        enumerable: true,
                        get: function () {
                            return e[k];
                        }
                    });
                }
            });
        }
        n['default'] = e;
        return Object.freeze(n);
    }

    var i0__namespace = /*#__PURE__*/_interopNamespace(i0);

    /**
     * @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
     */
    /**
     * Factory that creates a new MutationObserver and allows us to stub it out in unit tests.
     * @docs-private
     */
    var MutationObserverFactory = /** @class */ (function () {
        function MutationObserverFactory() {
        }
        MutationObserverFactory.prototype.create = function (callback) {
            return typeof MutationObserver === 'undefined' ? null : new MutationObserver(callback);
        };
        return MutationObserverFactory;
    }());
    MutationObserverFactory.ɵprov = i0__namespace.ɵɵdefineInjectable({ factory: function MutationObserverFactory_Factory() { return new MutationObserverFactory(); }, token: MutationObserverFactory, providedIn: "root" });
    MutationObserverFactory.decorators = [
        { type: i0.Injectable, args: [{ providedIn: 'root' },] }
    ];
    /** An injectable service that allows watching elements for changes to their content. */
    var ContentObserver = /** @class */ (function () {
        function ContentObserver(_mutationObserverFactory) {
            this._mutationObserverFactory = _mutationObserverFactory;
            /** Keeps track of the existing MutationObservers so they can be reused. */
            this._observedElements = new Map();
        }
        ContentObserver.prototype.ngOnDestroy = function () {
            var _this = this;
            this._observedElements.forEach(function (_, element) { return _this._cleanupObserver(element); });
        };
        ContentObserver.prototype.observe = function (elementOrRef) {
            var _this = this;
            var element = coercion.coerceElement(elementOrRef);
            return new rxjs.Observable(function (observer) {
                var stream = _this._observeElement(element);
                var subscription = stream.subscribe(observer);
                return function () {
                    subscription.unsubscribe();
                    _this._unobserveElement(element);
                };
            });
        };
        /**
         * Observes the given element by using the existing MutationObserver if available, or creating a
         * new one if not.
         */
        ContentObserver.prototype._observeElement = function (element) {
            if (!this._observedElements.has(element)) {
                var stream_1 = new rxjs.Subject();
                var observer = this._mutationObserverFactory.create(function (mutations) { return stream_1.next(mutations); });
                if (observer) {
                    observer.observe(element, {
                        characterData: true,
                        childList: true,
                        subtree: true
                    });
                }
                this._observedElements.set(element, { observer: observer, stream: stream_1, count: 1 });
            }
            else {
                this._observedElements.get(element).count++;
            }
            return this._observedElements.get(element).stream;
        };
        /**
         * Un-observes the given element and cleans up the underlying MutationObserver if nobody else is
         * observing this element.
         */
        ContentObserver.prototype._unobserveElement = function (element) {
            if (this._observedElements.has(element)) {
                this._observedElements.get(element).count--;
                if (!this._observedElements.get(element).count) {
                    this._cleanupObserver(element);
                }
            }
        };
        /** Clean up the underlying MutationObserver for the specified element. */
        ContentObserver.prototype._cleanupObserver = function (element) {
            if (this._observedElements.has(element)) {
                var _b = this._observedElements.get(element), observer = _b.observer, stream = _b.stream;
                if (observer) {
                    observer.disconnect();
                }
                stream.complete();
                this._observedElements.delete(element);
            }
        };
        return ContentObserver;
    }());
    ContentObserver.ɵprov = i0__namespace.ɵɵdefineInjectable({ factory: function ContentObserver_Factory() { return new ContentObserver(i0__namespace.ɵɵinject(MutationObserverFactory)); }, token: ContentObserver, providedIn: "root" });
    ContentObserver.decorators = [
        { type: i0.Injectable, args: [{ providedIn: 'root' },] }
    ];
    ContentObserver.ctorParameters = function () { return [
        { type: MutationObserverFactory }
    ]; };
    /**
     * Directive that triggers a callback whenever the content of
     * its associated element has changed.
     */
    var CdkObserveContent = /** @class */ (function () {
        function CdkObserveContent(_contentObserver, _elementRef, _ngZone) {
            this._contentObserver = _contentObserver;
            this._elementRef = _elementRef;
            this._ngZone = _ngZone;
            /** Event emitted for each change in the element's content. */
            this.event = new i0.EventEmitter();
            this._disabled = false;
            this._currentSubscription = null;
        }
        Object.defineProperty(CdkObserveContent.prototype, "disabled", {
            /**
             * Whether observing content is disabled. This option can be used
             * to disconnect the underlying MutationObserver until it is needed.
             */
            get: function () { return this._disabled; },
            set: function (value) {
                this._disabled = coercion.coerceBooleanProperty(value);
                this._disabled ? this._unsubscribe() : this._subscribe();
            },
            enumerable: false,
            configurable: true
        });
        Object.defineProperty(CdkObserveContent.prototype, "debounce", {
            /** Debounce interval for emitting the changes. */
            get: function () { return this._debounce; },
            set: function (value) {
                this._debounce = coercion.coerceNumberProperty(value);
                this._subscribe();
            },
            enumerable: false,
            configurable: true
        });
        CdkObserveContent.prototype.ngAfterContentInit = function () {
            if (!this._currentSubscription && !this.disabled) {
                this._subscribe();
            }
        };
        CdkObserveContent.prototype.ngOnDestroy = function () {
            this._unsubscribe();
        };
        CdkObserveContent.prototype._subscribe = function () {
            var _this = this;
            this._unsubscribe();
            var stream = this._contentObserver.observe(this._elementRef);
            // TODO(mmalerba): We shouldn't be emitting on this @Output() outside the zone.
            // Consider brining it back inside the zone next time we're making breaking changes.
            // Bringing it back inside can cause things like infinite change detection loops and changed
            // after checked errors if people's code isn't handling it properly.
            this._ngZone.runOutsideAngular(function () {
                _this._currentSubscription =
                    (_this.debounce ? stream.pipe(operators.debounceTime(_this.debounce)) : stream).subscribe(_this.event);
            });
        };
        CdkObserveContent.prototype._unsubscribe = function () {
            var _a;
            (_a = this._currentSubscription) === null || _a === void 0 ? void 0 : _a.unsubscribe();
        };
        return CdkObserveContent;
    }());
    CdkObserveContent.decorators = [
        { type: i0.Directive, args: [{
                    selector: '[cdkObserveContent]',
                    exportAs: 'cdkObserveContent',
                },] }
    ];
    CdkObserveContent.ctorParameters = function () { return [
        { type: ContentObserver },
        { type: i0.ElementRef },
        { type: i0.NgZone }
    ]; };
    CdkObserveContent.propDecorators = {
        event: [{ type: i0.Output, args: ['cdkObserveContent',] }],
        disabled: [{ type: i0.Input, args: ['cdkObserveContentDisabled',] }],
        debounce: [{ type: i0.Input }]
    };
    var ObserversModule = /** @class */ (function () {
        function ObserversModule() {
        }
        return ObserversModule;
    }());
    ObserversModule.decorators = [
        { type: i0.NgModule, args: [{
                    exports: [CdkObserveContent],
                    declarations: [CdkObserveContent],
                    providers: [MutationObserverFactory]
                },] }
    ];

    /**
     * @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.
     */

    exports.CdkObserveContent = CdkObserveContent;
    exports.ContentObserver = ContentObserver;
    exports.MutationObserverFactory = MutationObserverFactory;
    exports.ObserversModule = ObserversModule;

    Object.defineProperty(exports, '__esModule', { value: true });

})));
//# sourceMappingURL=cdk-observers.umd.js.map