feat(cdk-experimental/column-resize): Support column size persistance…

src/cdk-experimental/column-resize/column-resize.ts

@@ -44,7 +44,6 @@ export const COLUMN_RESIZE_OPTIONS = new InjectionToken<ColumnResizeOptions>(
  */
 @Directive()
 export abstract class ColumnResize implements AfterViewInit, OnDestroy {
-  private _idGenerator = inject(_IdGenerator);
   protected readonly destroyed = new Subject<void>();
 
   /* Publicly accessible interface for triggering and being notified of resizes. */
@@ -58,7 +57,7 @@ export abstract class ColumnResize implements AfterViewInit, OnDestroy {
   protected abstract readonly notifier: ColumnResizeNotifierSource;
 
   /** Unique ID for this table instance. */
-  protected readonly selectorId = this._idGenerator.getId('cdk-column-resize-');
+  protected readonly selectorId = inject(_IdGenerator).getId('cdk-column-resize-');
 
   /** The id attribute of the table, if specified. */
   id?: string;
@@ -88,6 +87,11 @@ export abstract class ColumnResize implements AfterViewInit, OnDestroy {
     return this.selectorId;
   }
 
+  /** Gets the ID for this table used for column size persistance. */
+  getTableId(): string {
+    return String(this.elementRef.nativeElement.id);
+  }
+
   /** Called when a column in the table is resized. Applies a css class to the table element. */
   setResized() {
     this.elementRef.nativeElement!.classList.add(WITH_RESIZED_COLUMN_CLASS);

src/cdk-experimental/column-resize/column-size-store.ts

@@ -7,15 +7,16 @@
  */
 
 import {Injectable} from '@angular/core';
+import {Observable} from 'rxjs';
 
 /**
  * Can be provided by the host application to enable persistence of column resize state.
  */
 @Injectable()
 export abstract class ColumnSizeStore {
   /** Returns the persisted size of the specified column in the specified table. */
-  abstract getSize(tableId: string, columnId: string): number;
+  abstract getSize(tableId: string, columnId: string): Observable<number | null> | null;
 
   /** Persists the size of the specified column in the specified table. */
-  abstract setSize(tableId: string, columnId: string): void;
+  abstract setSize(tableId: string, columnId: string, sizePx: number): void;
 }

src/cdk-experimental/column-resize/resizable.ts

@@ -10,6 +10,7 @@ import {
   AfterViewInit,
   Directive,
   ElementRef,
+  inject,
   Injector,
   NgZone,
   OnDestroy,
@@ -22,14 +23,15 @@ import {ComponentPortal} from '@angular/cdk/portal';
 import {Overlay, OverlayRef} from '@angular/cdk/overlay';
 import {CdkColumnDef, _CoalescedStyleScheduler} from '@angular/cdk/table';
 import {merge, Subject} from 'rxjs';
-import {filter, takeUntil} from 'rxjs/operators';
+import {distinctUntilChanged, filter, take, takeUntil} from 'rxjs/operators';
 
 import {_closest} from '@angular/cdk-experimental/popover-edit';
 
 import {HEADER_ROW_SELECTOR} from './selectors';
 import {ResizeOverlayHandle} from './overlay-handle';
 import {ColumnResize} from './column-resize';
 import {ColumnSizeAction, ColumnResizeNotifierSource} from './column-resize-notifier';
+import {ColumnSizeStore} from './column-size-store';
 import {HeaderRowEventDispatcher} from './event-dispatcher';
 import {ResizeRef} from './resize-ref';
 import {ResizeStrategy} from './resize-strategy';
@@ -66,6 +68,8 @@ export abstract class Resizable<HandleComponent extends ResizeOverlayHandle>
   protected abstract readonly viewContainerRef: ViewContainerRef;
   protected abstract readonly changeDetectorRef: ChangeDetectorRef;
 
+  protected readonly columnSizeStore = inject(ColumnSizeStore, {optional: true});
+
   private _viewInitialized = false;
   private _isDestroyed = false;
 
@@ -105,6 +109,15 @@ export abstract class Resizable<HandleComponent extends ResizeOverlayHandle>
       this._viewInitialized = true;
       this._applyMinWidthPx();
       this._applyMaxWidthPx();
+      this.columnSizeStore
+        ?.getSize(this.columnResize.getTableId(), this.columnDef.name)
+        ?.pipe(take(1), takeUntil(this.destroyed))
+        .subscribe(size => {
+          if (size == null) {
+            return;
+          }
+          this._applySize(size);
+        });
     });
   }
 
@@ -195,6 +208,20 @@ export abstract class Resizable<HandleComponent extends ResizeOverlayHandle>
       .subscribe(columnSize => {
         this._cleanUpAfterResize(columnSize);
       });
+
+    this.resizeNotifier.resizeCompleted
+      .pipe(
+        filter(sizeUpdate => sizeUpdate.columnId === this.columnDef.name),
+        distinctUntilChanged((a, b) => a.size === b.size),
+        takeUntil(this.destroyed),
+      )
+      .subscribe(sizeUpdate => {
+        this.columnSizeStore?.setSize(
+          this.columnResize.getTableId(),
+          this.columnDef.name,
+          sizeUpdate.size,
+        );
+      });
   }
 
   private _completeResizeOperation(): void {

src/material-experimental/column-resize/column-resize.spec.ts

@@ -1,13 +1,20 @@
 import {BidiModule} from '@angular/cdk/bidi';
 import {DataSource} from '@angular/cdk/collections';
 import {ESCAPE} from '@angular/cdk/keycodes';
-import {ChangeDetectionStrategy, Component, Directive, ElementRef, ViewChild} from '@angular/core';
+import {
+  ChangeDetectionStrategy,
+  Component,
+  Directive,
+  ElementRef,
+  Injectable,
+  ViewChild,
+} from '@angular/core';
 import {ComponentFixture, TestBed, fakeAsync, flush} from '@angular/core/testing';
 import {MatTableModule} from '@angular/material/table';
-import {BehaviorSubject} from 'rxjs';
+import {BehaviorSubject, Observable, ReplaySubject} from 'rxjs';
 import {dispatchKeyboardEvent} from '../../cdk/testing/private';
 
-import {ColumnSize} from '@angular/cdk-experimental/column-resize';
+import {ColumnSize, ColumnSizeStore} from '@angular/cdk-experimental/column-resize';
 import {AbstractMatColumnResize} from './column-resize-directives/common';
 import {
   MatColumnResize,
@@ -52,7 +59,7 @@ function getTableTemplate(defaultEnabled: boolean) {
         }
       </style>
       <div #table [dir]="direction">
-        <table ${directives.table} mat-table [dataSource]="dataSource"
+        <table ${directives.table} mat-table [dataSource]="dataSource" id="theTable"
             style="table-layout: fixed;">
           <!-- Position Column -->
           <ng-container matColumnDef="position" sticky>
@@ -109,7 +116,7 @@ function getFlexTemplate(defaultEnabled: boolean) {
         }
       </style>
       <div #table [dir]="direction">
-        <mat-table ${directives.table} [dataSource]="dataSource">
+        <mat-table ${directives.table} [dataSource]="dataSource" id="theTable">
           <!-- Position Column -->
           <ng-container matColumnDef="position" sticky>
             <mat-header-cell *matHeaderCellDef
@@ -628,6 +635,63 @@ describe('Material Popover Edit', () => {
       }));
     });
   }
+
+  describe('ColumnSizeStore (persistance)', () => {
+    let component: BaseTestComponent;
+    let fixture: ComponentFixture<BaseTestComponent>;
+    let columnSizeStore: FakeColumnSizeStore;
+
+    beforeEach(fakeAsync(() => {
+      jasmine.addMatchers(approximateMatcher);
+
+      TestBed.configureTestingModule({
+        imports: [BidiModule, MatTableModule, MatColumnResizeModule],
+        providers: [
+          FakeColumnSizeStore,
+          {provide: ColumnSizeStore, useExisting: FakeColumnSizeStore},
+        ],
+        declarations: [MatResizeOnPushTest],
+      });
+      fixture = TestBed.createComponent(MatResizeOnPushTest);
+      component = fixture.componentInstance;
+      columnSizeStore = TestBed.inject(FakeColumnSizeStore);
+      fixture.detectChanges();
+      flush();
+    }));
+
+    it('applies the persisted size', fakeAsync(() => {
+      (expect(component.getColumnWidth(1)).not as any).isApproximately(300);
+
+      columnSizeStore.emitSize('theTable', 'name', 300);
+
+      flush();
+
+      (expect(component.getColumnWidth(1)) as any).isApproximately(300);
+    }));
+
+    it('persists the user-triggered size update', fakeAsync(() => {
+      const initialColumnWidth = component.getColumnWidth(1);
+
+      component.triggerHoverState();
+      fixture.detectChanges();
+
+      component.resizeColumnWithMouse(1, 5);
+      fixture.detectChanges();
+      flush();
+
+      component.completeResizeWithMouseInProgress(1);
+      flush();
+
+      component.endHoverState();
+      fixture.detectChanges();
+
+      expect(columnSizeStore.setSizeCalls.length).toBe(1);
+      const {tableId, columnId, sizePx} = columnSizeStore.setSizeCalls[0];
+      expect(tableId).toBe('theTable');
+      expect(columnId).toBe('name');
+      (expect(sizePx) as any).isApproximately(initialColumnWidth + 5);
+    }));
+  });
 });
 
 function createElementData() {
@@ -639,3 +703,38 @@ function createElementData() {
     {position: 5, name: 'Boron', weight: 10.811, symbol: 'B'},
   ];
 }
+
+@Injectable()
+class FakeColumnSizeStore extends ColumnSizeStore {
+  readonly emitStore = new Map<string, ReplaySubject<number>>();
+  readonly setSizeCalls: {tableId: string; columnId: string; sizePx: number}[] = [];
+
+  /** Returns an observable that will emit values from emitSize(). */
+  override getSize(tableId: string, columnId: string): Observable<number> | null {
+    return this._getOrAdd(tableId, columnId);
+  }
+
+  /**
+   * Adds an entry to setSizeCalls.
+   * Note: Does not affect values returned from getSize.
+   */
+  override setSize(tableId: string, columnId: string, sizePx: number): void {
+    this.setSizeCalls.push({tableId, columnId, sizePx});
+  }
+
+  /** Call this in test code to simulate persisted column sizes. */
+  emitSize(tableId: string, columnId: string, sizePx: number) {
+    const stored = this._getOrAdd(tableId, columnId);
+    stored.next(sizePx);
+  }
+
+  private _getOrAdd(tableId: string, columnId: string): ReplaySubject<number> {
+    const key = `tableId----columnId`;
+    let stored = this.emitStore.get(key);
+    if (!stored) {
+      stored = new ReplaySubject<number>(1);
+      this.emitStore.set(key, stored);
+    }
+    return stored;
+  }
+}

src/material-experimental/column-resize/public-api.ts

@@ -16,4 +16,4 @@ export * from './resizable-directives/resizable';
 export * from './resize-strategy';
 export * from './overlay-handle';
 export type {ColumnResizeOptions} from '@angular/cdk-experimental/column-resize';
-export {COLUMN_RESIZE_OPTIONS} from '@angular/cdk-experimental/column-resize';
+export {COLUMN_RESIZE_OPTIONS, ColumnSizeStore} from '@angular/cdk-experimental/column-resize';