fix(material/autocomplete): switch away from animations module (angular#30356)

Switches the autocomplete away from the animations module. The animations are implemented using CSS instead.

Author: crisbeto

src/material/autocomplete/animations.ts

@@ -736,13 +736,7 @@ export class MatAutocompleteTrigger
     ) {
       this._clearPreviousSelectedOption(null);
       this._assignOptionValue(null);
-      // Wait for the animation to finish before clearing the form control value, otherwise
-      // the options might change while the animation is running which looks glitchy.
-      if (panel._animationDone) {
-        panel._animationDone.pipe(take(1)).subscribe(() => this._onChange(null));
-      } else {
-        this._onChange(null);
-      }
+      this._onChange(null);
     }
 
     this.closePanel();

src/material/autocomplete/autocomplete-trigger.ts

@@ -6,13 +6,12 @@
     [class]="_classList"
     [class.mat-mdc-autocomplete-visible]="showPanel"
     [class.mat-mdc-autocomplete-hidden]="!showPanel"
+    [class.mat-autocomplete-panel-animations-enabled]="!_animationsDisabled"
     [class.mat-primary]="_color === 'primary'"
     [class.mat-accent]="_color === 'accent'"
     [class.mat-warn]="_color === 'warn'"
     [attr.aria-label]="ariaLabel || null"
     [attr.aria-labelledby]="_getPanelAriaLabelledby(formFieldId)"
-    [@panelAnimation]="isOpen ? 'visible' : 'hidden'"
-    (@panelAnimation.done)="_animationDone.next($event)"
     #panel>
     <ng-content></ng-content>
   </div>

src/material/autocomplete/autocomplete.html

@@ -50,6 +50,25 @@ div.mat-mdc-autocomplete-panel {
   }
 }
 
+@keyframes _mat-autocomplete-enter {
+  from {
+    opacity: 0;
+    transform: scaleY(0.8);
+  }
+
+  to {
+    opacity: 1;
+    transform: none;
+  }
+}
+
+// Note: the autocomplete intentionally only implements an enter animation.
+// The exit animation can look glitchy, because usually selecting an option
+// causes the list to change and jump around while it's animating.
+.mat-autocomplete-panel-animations-enabled {
+  animation: _mat-autocomplete-enter 120ms cubic-bezier(0, 0, 0.2, 1);
+}
+
 // Prevent the overlay host node from affecting its surrounding layout.
 mat-autocomplete {
   display: none;

src/material/autocomplete/autocomplete.scss

@@ -3849,6 +3849,8 @@ describe('MatAutocomplete', () => {
 
       dispatchFakeEvent(document.querySelector('mat-option')!, 'click');
       fixture.detectChanges();
+      fixture.componentInstance.trigger.openPanel();
+      fixture.detectChanges();
 
       const selectedOption = document.querySelector('mat-option[aria-selected="true"]');
       expect(selectedOption).withContext('Expected an option to be selected.').not.toBeNull();
@@ -3875,6 +3877,8 @@ describe('MatAutocomplete', () => {
 
       dispatchFakeEvent(document.querySelector('mat-option')!, 'click');
       fixture.detectChanges();
+      fixture.componentInstance.trigger.openPanel();
+      fixture.detectChanges();
 
       const selectedOption = document.querySelector('mat-option[aria-selected="true"]');
       expect(selectedOption).withContext('Expected an option to be selected.').not.toBeNull();

src/material/autocomplete/autocomplete.spec.ts

@@ -7,6 +7,7 @@
  */
 
 import {
+  ANIMATION_MODULE_TYPE,
   AfterContentInit,
   ChangeDetectionStrategy,
   ChangeDetectorRef,
@@ -25,7 +26,6 @@ import {
   booleanAttribute,
   inject,
 } from '@angular/core';
-import {AnimationEvent} from '@angular/animations';
 import {
   MAT_OPTGROUP,
   MAT_OPTION_PARENT_COMPONENT,
@@ -35,7 +35,6 @@ import {
 } from '@angular/material/core';
 import {_IdGenerator, ActiveDescendantKeyManager} from '@angular/cdk/a11y';
 import {Platform} from '@angular/cdk/platform';
-import {panelAnimation} from './animations';
 import {Subscription} from 'rxjs';
 
 /** Event object that is emitted when an autocomplete option is selected. */
@@ -109,18 +108,15 @@ export function MAT_AUTOCOMPLETE_DEFAULT_OPTIONS_FACTORY(): MatAutocompleteDefau
     'class': 'mat-mdc-autocomplete',
   },
   providers: [{provide: MAT_OPTION_PARENT_COMPONENT, useExisting: MatAutocomplete}],
-  animations: [panelAnimation],
 })
 export class MatAutocomplete implements AfterContentInit, OnDestroy {
   private _changeDetectorRef = inject(ChangeDetectorRef);
   private _elementRef = inject<ElementRef<HTMLElement>>(ElementRef);
   protected _defaults = inject<MatAutocompleteDefaultOptions>(MAT_AUTOCOMPLETE_DEFAULT_OPTIONS);
-
+  protected _animationsDisabled =
+    inject(ANIMATION_MODULE_TYPE, {optional: true}) === 'NoopAnimations';
   private _activeOptionChanges = Subscription.EMPTY;
 
-  /** Emits when the panel animation is done. Null if the panel doesn't animate. */
-  _animationDone = new EventEmitter<AnimationEvent>();
-
   /** Manages active item in option list based on key events. */
   _keyManager: ActiveDescendantKeyManager<MatOption>;
 
@@ -282,7 +278,6 @@ export class MatAutocomplete implements AfterContentInit, OnDestroy {
   ngOnDestroy() {
     this._keyManager?.destroy();
     this._activeOptionChanges.unsubscribe();
-    this._animationDone.complete();
   }
 
   /**

src/material/autocomplete/autocomplete.ts

@@ -7,7 +7,6 @@
 import { ActiveDescendantKeyManager } from '@angular/cdk/a11y';
 import { AfterContentInit } from '@angular/core';
 import { AfterViewInit } from '@angular/core';
-import { AnimationEvent as AnimationEvent_2 } from '@angular/animations';
 import { ControlValueAccessor } from '@angular/forms';
 import { ElementRef } from '@angular/core';
 import { EventEmitter } from '@angular/core';
@@ -57,7 +56,8 @@ export const MAT_AUTOCOMPLETE_VALUE_ACCESSOR: any;
 // @public
 export class MatAutocomplete implements AfterContentInit, OnDestroy {
     constructor(...args: unknown[]);
-    _animationDone: EventEmitter<AnimationEvent_2>;
+    // (undocumented)
+    protected _animationsDisabled: boolean;
     ariaLabel: string;
     ariaLabelledby: string;
     autoActiveFirstOption: boolean;