select-animations.ts

/**
 * @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
 */

import {
  animate,
  AnimationTriggerMetadata,
  state,
  style,
  transition,
  trigger,
  query,
  animateChild,
  group,
} from '@angular/animations';

/**
 * The following are all the animations for the mat-select component, with each
 * const containing the metadata for one animation.
 *
 * The values below match the implementation of the AngularJS Material mat-select animation.
 */
export const matSelectAnimations: {
  readonly transformPanel: AnimationTriggerMetadata;
  readonly fadeInContent: AnimationTriggerMetadata;
} = {
  /**
   * This animation transforms the select's overlay panel on and off the page.
   *
   * When the panel is attached to the DOM, it expands its width by the amount of padding, scales it
   * up to 100% on the Y axis, fades in its border, and translates slightly up and to the
   * side to ensure the option text correctly overlaps the trigger text.
   *
   * When the panel is removed from the DOM, it simply fades out linearly.
   */
  transformPanel: trigger('transformPanel', [
    state('void', style({
      transform: 'scaleY(0)',
      minWidth: '100%',
      opacity: 0
    })),
    state('showing', style({
      opacity: 1,
      minWidth: 'calc(100% + 32px)', // 32px = 2 * 16px padding
      transform: 'scaleY(1)'
    })),
    state('showing-multiple', style({
      opacity: 1,
      minWidth: 'calc(100% + 64px)', // 64px = 48px padding on the left + 16px padding on the right
      transform: 'scaleY(1)'
    })),
    transition('void => *', group([
      query('@fadeInContent', animateChild()),
      animate('150ms cubic-bezier(0.25, 0.8, 0.25, 1)')
    ])),
    transition('* => void', [
      animate('250ms 100ms linear', style({opacity: 0}))
    ])
  ]),

  /**
   * This animation fades in the background color and text content of the
   * select's options. It is time delayed to occur 100ms after the overlay
   * panel has transformed in.
   */
  fadeInContent: trigger('fadeInContent', [
    state('showing', style({opacity: 1})),
    transition('void => showing', [
      style({opacity: 0}),
      animate('150ms 100ms cubic-bezier(0.55, 0, 0.55, 0.2)')
    ])
  ])
};


/**
 * @deprecated
 * @deletion-target 7.0.0
 */
export const transformPanel = matSelectAnimations.transformPanel;

/**
 * @deprecated
 * @deletion-target 7.0.0
 */
export const fadeInContent = matSelectAnimations.fadeInContent;