import { coerceElement, coerceBooleanProperty, coerceNumberProperty } from '@angular/cdk/coercion';
import * as i0 from '@angular/core';
import { Injectable, EventEmitter, Directive, Output, Input, NgModule } from '@angular/core';
import { Observable, Subject } from 'rxjs';
import { debounceTime } from 'rxjs/operators';

/**
 * Factory that creates a new MutationObserver and allows us to stub it out in unit tests.
 * @docs-private
 */
class MutationObserverFactory {
    create(callback) {
        return typeof MutationObserver === 'undefined' ? null : new MutationObserver(callback);
    }
    static { this.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: MutationObserverFactory, deps: [], target: i0.ɵɵFactoryTarget.Injectable }); }
    static { this.ɵprov = i0.ɵɵngDeclareInjectable({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: MutationObserverFactory, providedIn: 'root' }); }
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: MutationObserverFactory, decorators: [{
            type: Injectable,
            args: [{ providedIn: 'root' }]
        }] });
/** An injectable service that allows watching elements for changes to their content. */
class ContentObserver {
    constructor(_mutationObserverFactory) {
        this._mutationObserverFactory = _mutationObserverFactory;
        /** Keeps track of the existing MutationObservers so they can be reused. */
        this._observedElements = new Map();
    }
    ngOnDestroy() {
        this._observedElements.forEach((_, element) => this._cleanupObserver(element));
    }
    observe(elementOrRef) {
        const element = coerceElement(elementOrRef);
        return new Observable((observer) => {
            const stream = this._observeElement(element);
            const subscription = stream.subscribe(observer);
            return () => {
                subscription.unsubscribe();
                this._unobserveElement(element);
            };
        });
    }
    /**
     * Observes the given element by using the existing MutationObserver if available, or creating a
     * new one if not.
     */
    _observeElement(element) {
        if (!this._observedElements.has(element)) {
            const stream = new Subject();
            const observer = this._mutationObserverFactory.create(mutations => stream.next(mutations));
            if (observer) {
                observer.observe(element, {
                    characterData: true,
                    childList: true,
                    subtree: true,
                });
            }
            this._observedElements.set(element, { observer, stream, 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.
     */
    _unobserveElement(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. */
    _cleanupObserver(element) {
        if (this._observedElements.has(element)) {
            const { observer, stream } = this._observedElements.get(element);
            if (observer) {
                observer.disconnect();
            }
            stream.complete();
            this._observedElements.delete(element);
        }
    }
    static { this.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: ContentObserver, deps: [{ token: MutationObserverFactory }], target: i0.ɵɵFactoryTarget.Injectable }); }
    static { this.ɵprov = i0.ɵɵngDeclareInjectable({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: ContentObserver, providedIn: 'root' }); }
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: ContentObserver, decorators: [{
            type: Injectable,
            args: [{ providedIn: 'root' }]
        }], ctorParameters: function () { return [{ type: MutationObserverFactory }]; } });
/**
 * Directive that triggers a callback whenever the content of
 * its associated element has changed.
 */
class CdkObserveContent {
    /**
     * Whether observing content is disabled. This option can be used
     * to disconnect the underlying MutationObserver until it is needed.
     */
    get disabled() {
        return this._disabled;
    }
    set disabled(value) {
        this._disabled = coerceBooleanProperty(value);
        this._disabled ? this._unsubscribe() : this._subscribe();
    }
    /** Debounce interval for emitting the changes. */
    get debounce() {
        return this._debounce;
    }
    set debounce(value) {
        this._debounce = coerceNumberProperty(value);
        this._subscribe();
    }
    constructor(_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 EventEmitter();
        this._disabled = false;
        this._currentSubscription = null;
    }
    ngAfterContentInit() {
        if (!this._currentSubscription && !this.disabled) {
            this._subscribe();
        }
    }
    ngOnDestroy() {
        this._unsubscribe();
    }
    _subscribe() {
        this._unsubscribe();
        const 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(() => {
            this._currentSubscription = (this.debounce ? stream.pipe(debounceTime(this.debounce)) : stream).subscribe(this.event);
        });
    }
    _unsubscribe() {
        this._currentSubscription?.unsubscribe();
    }
    static { this.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: CdkObserveContent, deps: [{ token: ContentObserver }, { token: i0.ElementRef }, { token: i0.NgZone }], target: i0.ɵɵFactoryTarget.Directive }); }
    static { this.ɵdir = i0.ɵɵngDeclareDirective({ minVersion: "14.0.0", version: "16.1.1", type: CdkObserveContent, selector: "[cdkObserveContent]", inputs: { disabled: ["cdkObserveContentDisabled", "disabled"], debounce: "debounce" }, outputs: { event: "cdkObserveContent" }, exportAs: ["cdkObserveContent"], ngImport: i0 }); }
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: CdkObserveContent, decorators: [{
            type: Directive,
            args: [{
                    selector: '[cdkObserveContent]',
                    exportAs: 'cdkObserveContent',
                }]
        }], ctorParameters: function () { return [{ type: ContentObserver }, { type: i0.ElementRef }, { type: i0.NgZone }]; }, propDecorators: { event: [{
                type: Output,
                args: ['cdkObserveContent']
            }], disabled: [{
                type: Input,
                args: ['cdkObserveContentDisabled']
            }], debounce: [{
                type: Input
            }] } });
class ObserversModule {
    static { this.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: ObserversModule, deps: [], target: i0.ɵɵFactoryTarget.NgModule }); }
    static { this.ɵmod = i0.ɵɵngDeclareNgModule({ minVersion: "14.0.0", version: "16.1.1", ngImport: i0, type: ObserversModule, declarations: [CdkObserveContent], exports: [CdkObserveContent] }); }
    static { this.ɵinj = i0.ɵɵngDeclareInjector({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: ObserversModule, providers: [MutationObserverFactory] }); }
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "16.1.1", ngImport: i0, type: ObserversModule, decorators: [{
            type: NgModule,
            args: [{
                    exports: [CdkObserveContent],
                    declarations: [CdkObserveContent],
                    providers: [MutationObserverFactory],
                }]
        }] });

/**
 * Generated bundle index. Do not edit.
 */

export { CdkObserveContent, ContentObserver, MutationObserverFactory, ObserversModule };
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