refactor(cdk/scrolling): switch to input transforms

Switches inputs in cdk/scrolling to use transforms instead of getters/setters.

Author: crisbeto

src/cdk/scrolling/virtual-for-of.ts

@@ -34,7 +34,7 @@ import {
   TrackByFunction,
   ViewContainerRef,
 } from '@angular/core';
-import {coerceNumberProperty, NumberInput} from '@angular/cdk/coercion';
+import {NumberInput, coerceNumberProperty} from '@angular/cdk/coercion';
 import {Observable, Subject, of as observableOf, isObservable} from 'rxjs';
 import {pairwise, shareReplay, startWith, switchMap, takeUntil} from 'rxjs/operators';
 import {CdkVirtualScrollRepeater} from './virtual-scroll-repeater';

src/cdk/scrolling/virtual-scroll-viewport.ts

@@ -9,6 +9,7 @@
 import {Directionality} from '@angular/cdk/bidi';
 import {ListRange} from '@angular/cdk/collections';
 import {
+  booleanAttribute,
   ChangeDetectionStrategy,
   ChangeDetectorRef,
   Component,
@@ -39,7 +40,6 @@ import {CdkScrollable, ExtendedScrollToOptions} from './scrollable';
 import {VIRTUAL_SCROLL_STRATEGY, VirtualScrollStrategy} from './virtual-scroll-strategy';
 import {ViewportRuler} from './viewport-ruler';
 import {CdkVirtualScrollRepeater} from './virtual-scroll-repeater';
-import {BooleanInput, coerceBooleanProperty} from '@angular/cdk/coercion';
 import {CdkVirtualScrollable, VIRTUAL_SCROLLABLE} from './virtual-scrollable';
 
 /** Checks if the given ranges are equal. */
@@ -106,14 +106,7 @@ export class CdkVirtualScrollViewport extends CdkVirtualScrollable implements On
    * Whether rendered items should persist in the DOM after scrolling out of view. By default, items
    * will be removed.
    */
-  @Input()
-  get appendOnly(): boolean {
-    return this._appendOnly;
-  }
-  set appendOnly(value: BooleanInput) {
-    this._appendOnly = coerceBooleanProperty(value);
-  }
-  private _appendOnly = false;
+  @Input({transform: booleanAttribute}) appendOnly: boolean = false;
 
   // Note: we don't use the typical EventEmitter here because we need to subscribe to the scroll
   // strategy lazily (i.e. only if the user is actually listening to the events). We do this because

tools/public_api_guard/cdk/scrolling.md

@@ -4,7 +4,6 @@
 
 ```ts
 
-import { BooleanInput } from '@angular/cdk/coercion';
 import { ChangeDetectorRef } from '@angular/core';
 import { CollectionViewer } from '@angular/cdk/collections';
 import { DataSource } from '@angular/cdk/collections';
@@ -186,8 +185,7 @@ export interface CdkVirtualScrollRepeater<T> {
 // @public
 export class CdkVirtualScrollViewport extends CdkVirtualScrollable implements OnInit, OnDestroy {
     constructor(elementRef: ElementRef<HTMLElement>, _changeDetectorRef: ChangeDetectorRef, ngZone: NgZone, _scrollStrategy: VirtualScrollStrategy, dir: Directionality, scrollDispatcher: ScrollDispatcher, viewportRuler: ViewportRuler, scrollable: CdkVirtualScrollable);
-    get appendOnly(): boolean;
-    set appendOnly(value: BooleanInput);
+    appendOnly: boolean;
     attach(forOf: CdkVirtualScrollRepeater<any>): void;
     checkViewportSize(): void;
     _contentWrapper: ElementRef<HTMLElement>;
@@ -205,6 +203,8 @@ export class CdkVirtualScrollViewport extends CdkVirtualScrollable implements On
     measureScrollOffset(from?: 'top' | 'left' | 'right' | 'bottom' | 'start' | 'end'): number;
     measureViewportOffset(from?: 'top' | 'left' | 'right' | 'bottom' | 'start' | 'end'): number;
     // (undocumented)
+    static ngAcceptInputType_appendOnly: unknown;
+    // (undocumented)
     ngOnDestroy(): void;
     // (undocumented)
     ngOnInit(): void;