sass-references/angular-material/material/autocomplete/autocomplete-trigger.ts

1104 lines
41 KiB
TypeScript

/**
* @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.dev/license
*/
import {addAriaReferencedId, removeAriaReferencedId} from '@angular/cdk/a11y';
import {Directionality} from '@angular/cdk/bidi';
import {DOWN_ARROW, ENTER, ESCAPE, TAB, UP_ARROW, hasModifierKey} from '@angular/cdk/keycodes';
import {BreakpointObserver, Breakpoints} from '@angular/cdk/layout';
import {
ConnectedPosition,
FlexibleConnectedPositionStrategy,
Overlay,
OverlayConfig,
OverlayRef,
PositionStrategy,
ScrollStrategy,
} from '@angular/cdk/overlay';
import {_getEventTarget} from '@angular/cdk/platform';
import {TemplatePortal} from '@angular/cdk/portal';
import {ViewportRuler} from '@angular/cdk/scrolling';
import {DOCUMENT} from '@angular/common';
import {
AfterViewInit,
ChangeDetectorRef,
Directive,
ElementRef,
InjectionToken,
Injector,
Input,
NgZone,
OnChanges,
OnDestroy,
SimpleChanges,
ViewContainerRef,
afterNextRender,
booleanAttribute,
forwardRef,
inject,
} from '@angular/core';
import {ControlValueAccessor, NG_VALUE_ACCESSOR} from '@angular/forms';
import {
MatOption,
MatOptionSelectionChange,
_countGroupLabelsBeforeOption,
_getOptionScrollPosition,
} from '@angular/material/core';
import {MAT_FORM_FIELD, MatFormField} from '@angular/material/form-field';
import {Observable, Subject, Subscription, defer, fromEvent, merge, of as observableOf} from 'rxjs';
import {delay, filter, map, startWith, switchMap, take, tap} from 'rxjs/operators';
import {
MAT_AUTOCOMPLETE_DEFAULT_OPTIONS,
MatAutocomplete,
MatAutocompleteDefaultOptions,
} from './autocomplete';
import {MatAutocompleteOrigin} from './autocomplete-origin';
/**
* Provider that allows the autocomplete to register as a ControlValueAccessor.
* @docs-private
*/
export const MAT_AUTOCOMPLETE_VALUE_ACCESSOR: any = {
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => MatAutocompleteTrigger),
multi: true,
};
/**
* Creates an error to be thrown when attempting to use an autocomplete trigger without a panel.
* @docs-private
*/
export function getMatAutocompleteMissingPanelError(): Error {
return Error(
'Attempting to open an undefined instance of `mat-autocomplete`. ' +
'Make sure that the id passed to the `matAutocomplete` is correct and that ' +
"you're attempting to open it after the ngAfterContentInit hook.",
);
}
/** Injection token that determines the scroll handling while the autocomplete panel is open. */
export const MAT_AUTOCOMPLETE_SCROLL_STRATEGY = new InjectionToken<() => ScrollStrategy>(
'mat-autocomplete-scroll-strategy',
{
providedIn: 'root',
factory: () => {
const overlay = inject(Overlay);
return () => overlay.scrollStrategies.reposition();
},
},
);
/** @docs-private */
export function MAT_AUTOCOMPLETE_SCROLL_STRATEGY_FACTORY(overlay: Overlay): () => ScrollStrategy {
return () => overlay.scrollStrategies.reposition();
}
/** @docs-private */
export const MAT_AUTOCOMPLETE_SCROLL_STRATEGY_FACTORY_PROVIDER = {
provide: MAT_AUTOCOMPLETE_SCROLL_STRATEGY,
deps: [Overlay],
useFactory: MAT_AUTOCOMPLETE_SCROLL_STRATEGY_FACTORY,
};
/** Base class with all of the `MatAutocompleteTrigger` functionality. */
@Directive({
selector: `input[matAutocomplete], textarea[matAutocomplete]`,
host: {
'class': 'mat-mdc-autocomplete-trigger',
'[attr.autocomplete]': 'autocompleteAttribute',
'[attr.role]': 'autocompleteDisabled ? null : "combobox"',
'[attr.aria-autocomplete]': 'autocompleteDisabled ? null : "list"',
'[attr.aria-activedescendant]': '(panelOpen && activeOption) ? activeOption.id : null',
'[attr.aria-expanded]': 'autocompleteDisabled ? null : panelOpen.toString()',
'[attr.aria-controls]': '(autocompleteDisabled || !panelOpen) ? null : autocomplete?.id',
'[attr.aria-haspopup]': 'autocompleteDisabled ? null : "listbox"',
// Note: we use `focusin`, as opposed to `focus`, in order to open the panel
// a little earlier. This avoids issues where IE delays the focusing of the input.
'(focusin)': '_handleFocus()',
'(blur)': '_onTouched()',
'(input)': '_handleInput($event)',
'(keydown)': '_handleKeydown($event)',
'(click)': '_handleClick()',
},
exportAs: 'matAutocompleteTrigger',
providers: [MAT_AUTOCOMPLETE_VALUE_ACCESSOR],
})
export class MatAutocompleteTrigger
implements ControlValueAccessor, AfterViewInit, OnChanges, OnDestroy
{
private _element = inject<ElementRef<HTMLInputElement>>(ElementRef);
private _overlay = inject(Overlay);
private _viewContainerRef = inject(ViewContainerRef);
private _zone = inject(NgZone);
private _changeDetectorRef = inject(ChangeDetectorRef);
private _dir = inject(Directionality, {optional: true});
private _formField = inject<MatFormField | null>(MAT_FORM_FIELD, {optional: true, host: true});
private _document = inject(DOCUMENT);
private _viewportRuler = inject(ViewportRuler);
private _defaults = inject<MatAutocompleteDefaultOptions | null>(
MAT_AUTOCOMPLETE_DEFAULT_OPTIONS,
{optional: true},
);
private _overlayRef: OverlayRef | null;
private _portal: TemplatePortal;
private _componentDestroyed = false;
private _scrollStrategy = inject(MAT_AUTOCOMPLETE_SCROLL_STRATEGY);
private _keydownSubscription: Subscription | null;
private _outsideClickSubscription: Subscription | null;
/** Old value of the native input. Used to work around issues with the `input` event on IE. */
private _previousValue: string | number | null;
/** Value of the input element when the panel was attached (even if there are no options). */
private _valueOnAttach: string | number | null;
/** Value on the previous keydown event. */
private _valueOnLastKeydown: string | null;
/** Strategy that is used to position the panel. */
private _positionStrategy: FlexibleConnectedPositionStrategy;
/** Whether or not the label state is being overridden. */
private _manuallyFloatingLabel = false;
/** The subscription for closing actions (some are bound to document). */
private _closingActionsSubscription: Subscription;
/** Subscription to viewport size changes. */
private _viewportSubscription = Subscription.EMPTY;
/** Implements BreakpointObserver to be used to detect handset landscape */
private _breakpointObserver = inject(BreakpointObserver);
private _handsetLandscapeSubscription = Subscription.EMPTY;
/**
* Whether the autocomplete can open the next time it is focused. Used to prevent a focused,
* closed autocomplete from being reopened if the user switches to another browser tab and then
* comes back.
*/
private _canOpenOnNextFocus = true;
/** Value inside the input before we auto-selected an option. */
private _valueBeforeAutoSelection: string | undefined;
/**
* Current option that we have auto-selected as the user is navigating,
* but which hasn't been propagated to the model value yet.
*/
private _pendingAutoselectedOption: MatOption | null;
/** Stream of keyboard events that can close the panel. */
private readonly _closeKeyEventStream = new Subject<void>();
/**
* Event handler for when the window is blurred. Needs to be an
* arrow function in order to preserve the context.
*/
private _windowBlurHandler = () => {
// If the user blurred the window while the autocomplete is focused, it means that it'll be
// refocused when they come back. In this case we want to skip the first focus event, if the
// pane was closed, in order to avoid reopening it unintentionally.
this._canOpenOnNextFocus =
this._document.activeElement !== this._element.nativeElement || this.panelOpen;
};
/** `View -> model callback called when value changes` */
_onChange: (value: any) => void = () => {};
/** `View -> model callback called when autocomplete has been touched` */
_onTouched = () => {};
/** The autocomplete panel to be attached to this trigger. */
@Input('matAutocomplete') autocomplete: MatAutocomplete;
/**
* Position of the autocomplete panel relative to the trigger element. A position of `auto`
* will render the panel underneath the trigger if there is enough space for it to fit in
* the viewport, otherwise the panel will be shown above it. If the position is set to
* `above` or `below`, the panel will always be shown above or below the trigger. no matter
* whether it fits completely in the viewport.
*/
@Input('matAutocompletePosition') position: 'auto' | 'above' | 'below' = 'auto';
/**
* Reference relative to which to position the autocomplete panel.
* Defaults to the autocomplete trigger element.
*/
@Input('matAutocompleteConnectedTo') connectedTo: MatAutocompleteOrigin;
/**
* `autocomplete` attribute to be set on the input element.
* @docs-private
*/
@Input('autocomplete') autocompleteAttribute: string = 'off';
/**
* Whether the autocomplete is disabled. When disabled, the element will
* act as a regular input and the user won't be able to open the panel.
*/
@Input({alias: 'matAutocompleteDisabled', transform: booleanAttribute})
autocompleteDisabled: boolean;
private _initialized = new Subject();
private _injector = inject(Injector);
constructor(...args: unknown[]);
constructor() {}
/** Class to apply to the panel when it's above the input. */
private _aboveClass = 'mat-mdc-autocomplete-panel-above';
ngAfterViewInit() {
this._initialized.next();
this._initialized.complete();
const window = this._getWindow();
if (typeof window !== 'undefined') {
this._zone.runOutsideAngular(() => window.addEventListener('blur', this._windowBlurHandler));
}
}
ngOnChanges(changes: SimpleChanges) {
if (changes['position'] && this._positionStrategy) {
this._setStrategyPositions(this._positionStrategy);
if (this.panelOpen) {
this._overlayRef!.updatePosition();
}
}
}
ngOnDestroy() {
const window = this._getWindow();
if (typeof window !== 'undefined') {
window.removeEventListener('blur', this._windowBlurHandler);
}
this._handsetLandscapeSubscription.unsubscribe();
this._viewportSubscription.unsubscribe();
this._componentDestroyed = true;
this._destroyPanel();
this._closeKeyEventStream.complete();
this._clearFromModal();
}
/** Whether or not the autocomplete panel is open. */
get panelOpen(): boolean {
return this._overlayAttached && this.autocomplete.showPanel;
}
private _overlayAttached: boolean = false;
/** Opens the autocomplete suggestion panel. */
openPanel(): void {
this._openPanelInternal();
}
/** Closes the autocomplete suggestion panel. */
closePanel(): void {
this._resetLabel();
if (!this._overlayAttached) {
return;
}
if (this.panelOpen) {
// Only emit if the panel was visible.
// `afterNextRender` always runs outside of the Angular zone, so all the subscriptions from
// `_subscribeToClosingActions()` are also outside of the Angular zone.
// We should manually run in Angular zone to update UI after panel closing.
this._zone.run(() => {
this.autocomplete.closed.emit();
});
}
// Only reset if this trigger is the latest one that opened the
// autocomplete since another may have taken it over.
if (this.autocomplete._latestOpeningTrigger === this) {
this.autocomplete._isOpen = false;
this.autocomplete._latestOpeningTrigger = null;
}
this._overlayAttached = false;
this._pendingAutoselectedOption = null;
if (this._overlayRef && this._overlayRef.hasAttached()) {
this._overlayRef.detach();
this._closingActionsSubscription.unsubscribe();
}
this._updatePanelState();
// Note that in some cases this can end up being called after the component is destroyed.
// Add a check to ensure that we don't try to run change detection on a destroyed view.
if (!this._componentDestroyed) {
// We need to trigger change detection manually, because
// `fromEvent` doesn't seem to do it at the proper time.
// This ensures that the label is reset when the
// user clicks outside.
this._changeDetectorRef.detectChanges();
}
// Remove aria-owns attribute when the autocomplete is no longer visible.
if (this._trackedModal) {
removeAriaReferencedId(this._trackedModal, 'aria-owns', this.autocomplete.id);
}
}
/**
* Updates the position of the autocomplete suggestion panel to ensure that it fits all options
* within the viewport.
*/
updatePosition(): void {
if (this._overlayAttached) {
this._overlayRef!.updatePosition();
}
}
/**
* A stream of actions that should close the autocomplete panel, including
* when an option is selected, on blur, and when TAB is pressed.
*/
get panelClosingActions(): Observable<MatOptionSelectionChange | null> {
return merge(
this.optionSelections,
this.autocomplete._keyManager.tabOut.pipe(filter(() => this._overlayAttached)),
this._closeKeyEventStream,
this._getOutsideClickStream(),
this._overlayRef
? this._overlayRef.detachments().pipe(filter(() => this._overlayAttached))
: observableOf(),
).pipe(
// Normalize the output so we return a consistent type.
map(event => (event instanceof MatOptionSelectionChange ? event : null)),
);
}
/** Stream of changes to the selection state of the autocomplete options. */
readonly optionSelections: Observable<MatOptionSelectionChange> = defer(() => {
const options = this.autocomplete ? this.autocomplete.options : null;
if (options) {
return options.changes.pipe(
startWith(options),
switchMap(() => merge(...options.map(option => option.onSelectionChange))),
);
}
// If there are any subscribers before `ngAfterViewInit`, the `autocomplete` will be undefined.
// Return a stream that we'll replace with the real one once everything is in place.
return this._initialized.pipe(switchMap(() => this.optionSelections));
}) as Observable<MatOptionSelectionChange>;
/** The currently active option, coerced to MatOption type. */
get activeOption(): MatOption | null {
if (this.autocomplete && this.autocomplete._keyManager) {
return this.autocomplete._keyManager.activeItem;
}
return null;
}
/** Stream of clicks outside of the autocomplete panel. */
private _getOutsideClickStream(): Observable<any> {
return merge(
fromEvent(this._document, 'click') as Observable<MouseEvent>,
fromEvent(this._document, 'auxclick') as Observable<MouseEvent>,
fromEvent(this._document, 'touchend') as Observable<TouchEvent>,
).pipe(
filter(event => {
// If we're in the Shadow DOM, the event target will be the shadow root, so we have to
// fall back to check the first element in the path of the click event.
const clickTarget = _getEventTarget<HTMLElement>(event)!;
const formField = this._formField
? this._formField.getConnectedOverlayOrigin().nativeElement
: null;
const customOrigin = this.connectedTo ? this.connectedTo.elementRef.nativeElement : null;
return (
this._overlayAttached &&
clickTarget !== this._element.nativeElement &&
// Normally focus moves inside `mousedown` so this condition will almost always be
// true. Its main purpose is to handle the case where the input is focused from an
// outside click which propagates up to the `body` listener within the same sequence
// and causes the panel to close immediately (see #3106).
this._document.activeElement !== this._element.nativeElement &&
(!formField || !formField.contains(clickTarget)) &&
(!customOrigin || !customOrigin.contains(clickTarget)) &&
!!this._overlayRef &&
!this._overlayRef.overlayElement.contains(clickTarget)
);
}),
);
}
// Implemented as part of ControlValueAccessor.
writeValue(value: any): void {
Promise.resolve(null).then(() => this._assignOptionValue(value));
}
// Implemented as part of ControlValueAccessor.
registerOnChange(fn: (value: any) => {}): void {
this._onChange = fn;
}
// Implemented as part of ControlValueAccessor.
registerOnTouched(fn: () => {}) {
this._onTouched = fn;
}
// Implemented as part of ControlValueAccessor.
setDisabledState(isDisabled: boolean) {
this._element.nativeElement.disabled = isDisabled;
}
_handleKeydown(event: KeyboardEvent): void {
const keyCode = event.keyCode;
const hasModifier = hasModifierKey(event);
// Prevent the default action on all escape key presses. This is here primarily to bring IE
// in line with other browsers. By default, pressing escape on IE will cause it to revert
// the input value to the one that it had on focus, however it won't dispatch any events
// which means that the model value will be out of sync with the view.
if (keyCode === ESCAPE && !hasModifier) {
event.preventDefault();
}
this._valueOnLastKeydown = this._element.nativeElement.value;
if (this.activeOption && keyCode === ENTER && this.panelOpen && !hasModifier) {
this.activeOption._selectViaInteraction();
this._resetActiveItem();
event.preventDefault();
} else if (this.autocomplete) {
const prevActiveItem = this.autocomplete._keyManager.activeItem;
const isArrowKey = keyCode === UP_ARROW || keyCode === DOWN_ARROW;
if (keyCode === TAB || (isArrowKey && !hasModifier && this.panelOpen)) {
this.autocomplete._keyManager.onKeydown(event);
} else if (isArrowKey && this._canOpen()) {
this._openPanelInternal(this._valueOnLastKeydown);
}
if (isArrowKey || this.autocomplete._keyManager.activeItem !== prevActiveItem) {
this._scrollToOption(this.autocomplete._keyManager.activeItemIndex || 0);
if (this.autocomplete.autoSelectActiveOption && this.activeOption) {
if (!this._pendingAutoselectedOption) {
this._valueBeforeAutoSelection = this._valueOnLastKeydown;
}
this._pendingAutoselectedOption = this.activeOption;
this._assignOptionValue(this.activeOption.value);
}
}
}
}
_handleInput(event: KeyboardEvent): void {
let target = event.target as HTMLInputElement;
let value: number | string | null = target.value;
// Based on `NumberValueAccessor` from forms.
if (target.type === 'number') {
value = value == '' ? null : parseFloat(value);
}
// If the input has a placeholder, IE will fire the `input` event on page load,
// focus and blur, in addition to when the user actually changed the value. To
// filter out all of the extra events, we save the value on focus and between
// `input` events, and we check whether it changed.
// See: https://connect.microsoft.com/IE/feedback/details/885747/
if (this._previousValue !== value) {
this._previousValue = value;
this._pendingAutoselectedOption = null;
// If selection is required we don't write to the CVA while the user is typing.
// At the end of the selection either the user will have picked something
// or we'll reset the value back to null.
if (!this.autocomplete || !this.autocomplete.requireSelection) {
this._onChange(value);
}
if (!value) {
this._clearPreviousSelectedOption(null, false);
} else if (this.panelOpen && !this.autocomplete.requireSelection) {
// Note that we don't reset this when `requireSelection` is enabled,
// because the option will be reset when the panel is closed.
const selectedOption = this.autocomplete.options?.find(option => option.selected);
if (selectedOption) {
const display = this._getDisplayValue(selectedOption.value);
if (value !== display) {
selectedOption.deselect(false);
}
}
}
if (this._canOpen() && this._document.activeElement === event.target) {
// When the `input` event fires, the input's value will have already changed. This means
// that if we take the `this._element.nativeElement.value` directly, it'll be one keystroke
// behind. This can be a problem when the user selects a value, changes a character while
// the input still has focus and then clicks away (see #28432). To work around it, we
// capture the value in `keydown` so we can use it here.
const valueOnAttach = this._valueOnLastKeydown ?? this._element.nativeElement.value;
this._valueOnLastKeydown = null;
this._openPanelInternal(valueOnAttach);
}
}
}
_handleFocus(): void {
if (!this._canOpenOnNextFocus) {
this._canOpenOnNextFocus = true;
} else if (this._canOpen()) {
this._previousValue = this._element.nativeElement.value;
this._attachOverlay(this._previousValue);
this._floatLabel(true);
}
}
_handleClick(): void {
if (this._canOpen() && !this.panelOpen) {
this._openPanelInternal();
}
}
/**
* In "auto" mode, the label will animate down as soon as focus is lost.
* This causes the value to jump when selecting an option with the mouse.
* This method manually floats the label until the panel can be closed.
* @param shouldAnimate Whether the label should be animated when it is floated.
*/
private _floatLabel(shouldAnimate = false): void {
if (this._formField && this._formField.floatLabel === 'auto') {
if (shouldAnimate) {
this._formField._animateAndLockLabel();
} else {
this._formField.floatLabel = 'always';
}
this._manuallyFloatingLabel = true;
}
}
/** If the label has been manually elevated, return it to its normal state. */
private _resetLabel(): void {
if (this._manuallyFloatingLabel) {
if (this._formField) {
this._formField.floatLabel = 'auto';
}
this._manuallyFloatingLabel = false;
}
}
/**
* This method listens to a stream of panel closing actions and resets the
* stream every time the option list changes.
*/
private _subscribeToClosingActions(): Subscription {
const initialRender = new Observable(subscriber => {
afterNextRender(
() => {
subscriber.next();
},
{injector: this._injector},
);
});
const optionChanges = this.autocomplete.options.changes.pipe(
tap(() => this._positionStrategy.reapplyLastPosition()),
// Defer emitting to the stream until the next tick, because changing
// bindings in here will cause "changed after checked" errors.
delay(0),
);
// When the options are initially rendered, and when the option list changes...
return (
merge(initialRender, optionChanges)
.pipe(
// create a new stream of panelClosingActions, replacing any previous streams
// that were created, and flatten it so our stream only emits closing events...
switchMap(() =>
this._zone.run(() => {
// `afterNextRender` always runs outside of the Angular zone, thus we have to re-enter
// the Angular zone. This will lead to change detection being called outside of the Angular
// zone and the `autocomplete.opened` will also emit outside of the Angular.
const wasOpen = this.panelOpen;
this._resetActiveItem();
this._updatePanelState();
this._changeDetectorRef.detectChanges();
if (this.panelOpen) {
this._overlayRef!.updatePosition();
}
if (wasOpen !== this.panelOpen) {
// If the `panelOpen` state changed, we need to make sure to emit the `opened` or
// `closed` event, because we may not have emitted it. This can happen
// - if the users opens the panel and there are no options, but the
// options come in slightly later or as a result of the value changing,
// - if the panel is closed after the user entered a string that did not match any
// of the available options,
// - if a valid string is entered after an invalid one.
if (this.panelOpen) {
this._emitOpened();
} else {
this.autocomplete.closed.emit();
}
}
return this.panelClosingActions;
}),
),
// when the first closing event occurs...
take(1),
)
// set the value, close the panel, and complete.
.subscribe(event => this._setValueAndClose(event))
);
}
/**
* Emits the opened event once it's known that the panel will be shown and stores
* the state of the trigger right before the opening sequence was finished.
*/
private _emitOpened() {
this.autocomplete.opened.emit();
}
/** Destroys the autocomplete suggestion panel. */
private _destroyPanel(): void {
if (this._overlayRef) {
this.closePanel();
this._overlayRef.dispose();
this._overlayRef = null;
}
}
/** Given a value, returns the string that should be shown within the input. */
private _getDisplayValue<T>(value: T): T | string {
const autocomplete = this.autocomplete;
return autocomplete && autocomplete.displayWith ? autocomplete.displayWith(value) : value;
}
private _assignOptionValue(value: any): void {
const toDisplay = this._getDisplayValue(value);
if (value == null) {
this._clearPreviousSelectedOption(null, false);
}
// Simply falling back to an empty string if the display value is falsy does not work properly.
// The display value can also be the number zero and shouldn't fall back to an empty string.
this._updateNativeInputValue(toDisplay != null ? toDisplay : '');
}
private _updateNativeInputValue(value: string): void {
// If it's used within a `MatFormField`, we should set it through the property so it can go
// through change detection.
if (this._formField) {
this._formField._control.value = value;
} else {
this._element.nativeElement.value = value;
}
this._previousValue = value;
}
/**
* This method closes the panel, and if a value is specified, also sets the associated
* control to that value. It will also mark the control as dirty if this interaction
* stemmed from the user.
*/
private _setValueAndClose(event: MatOptionSelectionChange | null): void {
const panel = this.autocomplete;
const toSelect = event ? event.source : this._pendingAutoselectedOption;
if (toSelect) {
this._clearPreviousSelectedOption(toSelect);
this._assignOptionValue(toSelect.value);
// TODO(crisbeto): this should wait until the animation is done, otherwise the value
// gets reset while the panel is still animating which looks glitchy. It'll likely break
// some tests to change it at this point.
this._onChange(toSelect.value);
panel._emitSelectEvent(toSelect);
this._element.nativeElement.focus();
} else if (
panel.requireSelection &&
this._element.nativeElement.value !== this._valueOnAttach
) {
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.closePanel();
}
/**
* Clear any previous selected option and emit a selection change event for this option
*/
private _clearPreviousSelectedOption(skip: MatOption | null, emitEvent?: boolean) {
// Null checks are necessary here, because the autocomplete
// or its options may not have been assigned yet.
this.autocomplete?.options?.forEach(option => {
if (option !== skip && option.selected) {
option.deselect(emitEvent);
}
});
}
private _openPanelInternal(valueOnAttach = this._element.nativeElement.value) {
this._attachOverlay(valueOnAttach);
this._floatLabel();
// Add aria-owns attribute when the autocomplete becomes visible.
if (this._trackedModal) {
const panelId = this.autocomplete.id;
addAriaReferencedId(this._trackedModal, 'aria-owns', panelId);
}
}
private _attachOverlay(valueOnAttach: string): void {
if (!this.autocomplete && (typeof ngDevMode === 'undefined' || ngDevMode)) {
throw getMatAutocompleteMissingPanelError();
}
let overlayRef = this._overlayRef;
if (!overlayRef) {
this._portal = new TemplatePortal(this.autocomplete.template, this._viewContainerRef, {
id: this._formField?.getLabelId(),
});
overlayRef = this._overlay.create(this._getOverlayConfig());
this._overlayRef = overlayRef;
this._viewportSubscription = this._viewportRuler.change().subscribe(() => {
if (this.panelOpen && overlayRef) {
overlayRef.updateSize({width: this._getPanelWidth()});
}
});
// Subscribe to the breakpoint events stream to detect when screen is in
// handsetLandscape.
this._handsetLandscapeSubscription = this._breakpointObserver
.observe(Breakpoints.HandsetLandscape)
.subscribe(result => {
const isHandsetLandscape = result.matches;
// Check if result.matches Breakpoints.HandsetLandscape. Apply HandsetLandscape
// settings to prevent overlay cutoff in that breakpoint. Fixes b/284148377
if (isHandsetLandscape) {
this._positionStrategy
.withFlexibleDimensions(true)
.withGrowAfterOpen(true)
.withViewportMargin(8);
} else {
this._positionStrategy
.withFlexibleDimensions(false)
.withGrowAfterOpen(false)
.withViewportMargin(0);
}
});
} else {
// Update the trigger, panel width and direction, in case anything has changed.
this._positionStrategy.setOrigin(this._getConnectedElement());
overlayRef.updateSize({width: this._getPanelWidth()});
}
if (overlayRef && !overlayRef.hasAttached()) {
overlayRef.attach(this._portal);
this._valueOnAttach = valueOnAttach;
this._valueOnLastKeydown = null;
this._closingActionsSubscription = this._subscribeToClosingActions();
}
const wasOpen = this.panelOpen;
this.autocomplete._isOpen = this._overlayAttached = true;
this.autocomplete._latestOpeningTrigger = this;
this.autocomplete._setColor(this._formField?.color);
this._updatePanelState();
this._applyModalPanelOwnership();
// We need to do an extra `panelOpen` check in here, because the
// autocomplete won't be shown if there are no options.
if (this.panelOpen && wasOpen !== this.panelOpen) {
this._emitOpened();
}
}
/** Handles keyboard events coming from the overlay panel. */
private _handlePanelKeydown = (event: KeyboardEvent) => {
// Close when pressing ESCAPE or ALT + UP_ARROW, based on the a11y guidelines.
// See: https://www.w3.org/TR/wai-aria-practices-1.1/#textbox-keyboard-interaction
if (
(event.keyCode === ESCAPE && !hasModifierKey(event)) ||
(event.keyCode === UP_ARROW && hasModifierKey(event, 'altKey'))
) {
// If the user had typed something in before we autoselected an option, and they decided
// to cancel the selection, restore the input value to the one they had typed in.
if (this._pendingAutoselectedOption) {
this._updateNativeInputValue(this._valueBeforeAutoSelection ?? '');
this._pendingAutoselectedOption = null;
}
this._closeKeyEventStream.next();
this._resetActiveItem();
// We need to stop propagation, otherwise the event will eventually
// reach the input itself and cause the overlay to be reopened.
event.stopPropagation();
event.preventDefault();
}
};
/** Updates the panel's visibility state and any trigger state tied to id. */
private _updatePanelState() {
this.autocomplete._setVisibility();
// Note that here we subscribe and unsubscribe based on the panel's visiblity state,
// because the act of subscribing will prevent events from reaching other overlays and
// we don't want to block the events if there are no options.
if (this.panelOpen) {
const overlayRef = this._overlayRef!;
if (!this._keydownSubscription) {
// Use the `keydownEvents` in order to take advantage of
// the overlay event targeting provided by the CDK overlay.
this._keydownSubscription = overlayRef.keydownEvents().subscribe(this._handlePanelKeydown);
}
if (!this._outsideClickSubscription) {
// Subscribe to the pointer events stream so that it doesn't get picked up by other overlays.
// TODO(crisbeto): we should switch `_getOutsideClickStream` eventually to use this stream,
// but the behvior isn't exactly the same and it ends up breaking some internal tests.
this._outsideClickSubscription = overlayRef.outsidePointerEvents().subscribe();
}
} else {
this._keydownSubscription?.unsubscribe();
this._outsideClickSubscription?.unsubscribe();
this._keydownSubscription = this._outsideClickSubscription = null;
}
}
private _getOverlayConfig(): OverlayConfig {
return new OverlayConfig({
positionStrategy: this._getOverlayPosition(),
scrollStrategy: this._scrollStrategy(),
width: this._getPanelWidth(),
direction: this._dir ?? undefined,
panelClass: this._defaults?.overlayPanelClass,
});
}
private _getOverlayPosition(): PositionStrategy {
// Set default Overlay Position
const strategy = this._overlay
.position()
.flexibleConnectedTo(this._getConnectedElement())
.withFlexibleDimensions(false)
.withPush(false);
this._setStrategyPositions(strategy);
this._positionStrategy = strategy;
return strategy;
}
/** Sets the positions on a position strategy based on the directive's input state. */
private _setStrategyPositions(positionStrategy: FlexibleConnectedPositionStrategy) {
// Note that we provide horizontal fallback positions, even though by default the dropdown
// width matches the input, because consumers can override the width. See #18854.
const belowPositions: ConnectedPosition[] = [
{originX: 'start', originY: 'bottom', overlayX: 'start', overlayY: 'top'},
{originX: 'end', originY: 'bottom', overlayX: 'end', overlayY: 'top'},
];
// The overlay edge connected to the trigger should have squared corners, while
// the opposite end has rounded corners. We apply a CSS class to swap the
// border-radius based on the overlay position.
const panelClass = this._aboveClass;
const abovePositions: ConnectedPosition[] = [
{originX: 'start', originY: 'top', overlayX: 'start', overlayY: 'bottom', panelClass},
{originX: 'end', originY: 'top', overlayX: 'end', overlayY: 'bottom', panelClass},
];
let positions: ConnectedPosition[];
if (this.position === 'above') {
positions = abovePositions;
} else if (this.position === 'below') {
positions = belowPositions;
} else {
positions = [...belowPositions, ...abovePositions];
}
positionStrategy.withPositions(positions);
}
private _getConnectedElement(): ElementRef<HTMLElement> {
if (this.connectedTo) {
return this.connectedTo.elementRef;
}
return this._formField ? this._formField.getConnectedOverlayOrigin() : this._element;
}
private _getPanelWidth(): number | string {
return this.autocomplete.panelWidth || this._getHostWidth();
}
/** Returns the width of the input element, so the panel width can match it. */
private _getHostWidth(): number {
return this._getConnectedElement().nativeElement.getBoundingClientRect().width;
}
/**
* Reset the active item to -1. This is so that pressing arrow keys will activate the correct
* option.
*
* If the consumer opted-in to automatically activatating the first option, activate the first
* *enabled* option.
*/
private _resetActiveItem(): void {
const autocomplete = this.autocomplete;
if (autocomplete.autoActiveFirstOption) {
// Find the index of the first *enabled* option. Avoid calling `_keyManager.setActiveItem`
// because it activates the first option that passes the skip predicate, rather than the
// first *enabled* option.
let firstEnabledOptionIndex = -1;
for (let index = 0; index < autocomplete.options.length; index++) {
const option = autocomplete.options.get(index)!;
if (!option.disabled) {
firstEnabledOptionIndex = index;
break;
}
}
autocomplete._keyManager.setActiveItem(firstEnabledOptionIndex);
} else {
autocomplete._keyManager.setActiveItem(-1);
}
}
/** Determines whether the panel can be opened. */
private _canOpen(): boolean {
const element = this._element.nativeElement;
return !element.readOnly && !element.disabled && !this.autocompleteDisabled;
}
/** Use defaultView of injected document if available or fallback to global window reference */
private _getWindow(): Window {
return this._document?.defaultView || window;
}
/** Scrolls to a particular option in the list. */
private _scrollToOption(index: number): void {
// Given that we are not actually focusing active options, we must manually adjust scroll
// to reveal options below the fold. First, we find the offset of the option from the top
// of the panel. If that offset is below the fold, the new scrollTop will be the offset -
// the panel height + the option height, so the active option will be just visible at the
// bottom of the panel. If that offset is above the top of the visible panel, the new scrollTop
// will become the offset. If that offset is visible within the panel already, the scrollTop is
// not adjusted.
const autocomplete = this.autocomplete;
const labelCount = _countGroupLabelsBeforeOption(
index,
autocomplete.options,
autocomplete.optionGroups,
);
if (index === 0 && labelCount === 1) {
// If we've got one group label before the option and we're at the top option,
// scroll the list to the top. This is better UX than scrolling the list to the
// top of the option, because it allows the user to read the top group's label.
autocomplete._setScrollTop(0);
} else if (autocomplete.panel) {
const option = autocomplete.options.toArray()[index];
if (option) {
const element = option._getHostElement();
const newScrollPosition = _getOptionScrollPosition(
element.offsetTop,
element.offsetHeight,
autocomplete._getScrollTop(),
autocomplete.panel.nativeElement.offsetHeight,
);
autocomplete._setScrollTop(newScrollPosition);
}
}
}
/**
* Track which modal we have modified the `aria-owns` attribute of. When the combobox trigger is
* inside an aria-modal, we apply aria-owns to the parent modal with the `id` of the options
* panel. Track the modal we have changed so we can undo the changes on destroy.
*/
private _trackedModal: Element | null = null;
/**
* If the autocomplete trigger is inside of an `aria-modal` element, connect
* that modal to the options panel with `aria-owns`.
*
* For some browser + screen reader combinations, when navigation is inside
* of an `aria-modal` element, the screen reader treats everything outside
* of that modal as hidden or invisible.
*
* This causes a problem when the combobox trigger is _inside_ of a modal, because the
* options panel is rendered _outside_ of that modal, preventing screen reader navigation
* from reaching the panel.
*
* We can work around this issue by applying `aria-owns` to the modal with the `id` of
* the options panel. This effectively communicates to assistive technology that the
* options panel is part of the same interaction as the modal.
*
* At time of this writing, this issue is present in VoiceOver.
* See https://github.com/angular/components/issues/20694
*/
private _applyModalPanelOwnership() {
// TODO(http://github.com/angular/components/issues/26853): consider de-duplicating this with
// the `LiveAnnouncer` and any other usages.
//
// Note that the selector here is limited to CDK overlays at the moment in order to reduce the
// section of the DOM we need to look through. This should cover all the cases we support, but
// the selector can be expanded if it turns out to be too narrow.
const modal = this._element.nativeElement.closest(
'body > .cdk-overlay-container [aria-modal="true"]',
);
if (!modal) {
// Most commonly, the autocomplete trigger is not inside a modal.
return;
}
const panelId = this.autocomplete.id;
if (this._trackedModal) {
removeAriaReferencedId(this._trackedModal, 'aria-owns', panelId);
}
addAriaReferencedId(modal, 'aria-owns', panelId);
this._trackedModal = modal;
}
/** Clears the references to the listbox overlay element from the modal it was added to. */
private _clearFromModal() {
if (this._trackedModal) {
const panelId = this.autocomplete.id;
removeAriaReferencedId(this._trackedModal, 'aria-owns', panelId);
this._trackedModal = null;
}
}
}