@use '../../../cdk/a11y';

@mixin ripple() {
  // The host element of an mat-ripple directive should always have a position of "absolute" or
  // "relative" so that the ripples inside are correctly positioned relatively to the container.
  .mat-ripple {
    overflow: hidden;

    // By default, every ripple container should have position: relative in favor of creating an
    // easy API for developers using the MatRipple directive.
    position: relative;

    // Promote containers that have ripples to a new layer. We want to target `:not(:empty)`,
    // because we don't want all ripple containers to have their own layer since they're used in a
    // lot of places and the layer is only relevant while animating. Note that ideally we'd use
    // the `contain` property here (see #13175), because `:empty` can be broken by having extra
    // text inside the element, but it isn't very well supported yet.
    &:not(:empty) {
      transform: translateZ(0);
    }
  }

  .mat-ripple.mat-ripple-unbounded {
    overflow: visible;
  }

  .mat-ripple-element {
    position: absolute;
    border-radius: 50%;
    pointer-events: none;

    transition: opacity, transform 0ms cubic-bezier(0, 0, 0.2, 1);
    transform: scale(0);

    // In high contrast mode the ripple is opaque, causing it to obstruct the content.
    @include a11y.high-contrast(active, off) {
      display: none;
    }
  }
}