fix(material/button-toggle): Add checkmark indicators with hideSingleSelectionIndicator and hideMultipleSelectionIndicator input and config options

Author: amysorto

src/dev-app/button-toggle/button-toggle-demo.html

@@ -6,10 +6,18 @@
   <mat-checkbox (change)="isDisabled = $event.checked">Disable Button Toggle Items</mat-checkbox>
 </p>
 
+<p>
+  <mat-checkbox (change)="hideSingleSelectionIndicator = $event.checked">Hide Single Selection Indicator</mat-checkbox>
+</p>
+
+<p>
+  <mat-checkbox (change)="hideMultipleSelectionIndicator = $event.checked">Hide Multiple Selection Indicator</mat-checkbox>
+</p>
+
 <h1>Exclusive Selection</h1>
 
 <section>
-  <mat-button-toggle-group name="alignment" [vertical]="isVertical">
+  <mat-button-toggle-group name="alignment" [vertical]="isVertical" [hideSingleSelectionIndicator]="hideSingleSelectionIndicator">
     <mat-button-toggle value="left" [disabled]="isDisabled">
       <mat-icon>format_align_left</mat-icon>
     </mat-button-toggle>
@@ -26,7 +34,7 @@ <h1>Exclusive Selection</h1>
 </section>
 
 <section>
-  <mat-button-toggle-group appearance="legacy" name="alignment" [vertical]="isVertical">
+  <mat-button-toggle-group appearance="legacy" name="alignment" [vertical]="isVertical" [hideSingleSelectionIndicator]="hideSingleSelectionIndicator">
     <mat-button-toggle value="left" [disabled]="isDisabled">
       <mat-icon>format_align_left</mat-icon>
     </mat-button-toggle>
@@ -45,7 +53,7 @@ <h1>Exclusive Selection</h1>
 <h1>Disabled Group</h1>
 
 <section>
-  <mat-button-toggle-group name="checkbox" [vertical]="isVertical" [disabled]="isDisabled">
+  <mat-button-toggle-group name="checkbox" [vertical]="isVertical" [disabled]="isDisabled" [hideSingleSelectionIndicator]="hideSingleSelectionIndicator">
     <mat-button-toggle value="bold">
       <mat-icon>format_bold</mat-icon>
     </mat-button-toggle>
@@ -60,15 +68,15 @@ <h1>Disabled Group</h1>
 
 <h1>Multiple Selection</h1>
 <section>
-  <mat-button-toggle-group multiple [vertical]="isVertical">
+  <mat-button-toggle-group multiple [vertical]="isVertical" [hideMultipleSelectionIndicator]="hideMultipleSelectionIndicator">
     <mat-button-toggle>Flour</mat-button-toggle>
     <mat-button-toggle>Eggs</mat-button-toggle>
     <mat-button-toggle>Sugar</mat-button-toggle>
     <mat-button-toggle [disabled]="isDisabled">Milk</mat-button-toggle>
   </mat-button-toggle-group>
 </section>
 <section>
-  <mat-button-toggle-group appearance="legacy" multiple [vertical]="isVertical">
+  <mat-button-toggle-group appearance="legacy" multiple [vertical]="isVertical" [hideMultipleSelectionIndicator]="hideMultipleSelectionIndicator">
     <mat-button-toggle>Flour</mat-button-toggle>
     <mat-button-toggle>Eggs</mat-button-toggle>
     <mat-button-toggle>Sugar</mat-button-toggle>
@@ -82,7 +90,7 @@ <h1>Single Toggle</h1>
 
 <h1>Dynamic Exclusive Selection</h1>
 <section>
-  <mat-button-toggle-group name="pies" [(ngModel)]="favoritePie" [vertical]="isVertical">
+  <mat-button-toggle-group name="pies" [(ngModel)]="favoritePie" [vertical]="isVertical" [hideSingleSelectionIndicator]="hideSingleSelectionIndicator">
     @for (pie of pieOptions; track pie) {
       <mat-button-toggle [value]="pie">{{pie}}</mat-button-toggle>
     }

src/dev-app/button-toggle/button-toggle-demo.ts

@@ -23,6 +23,8 @@ import {MatIconModule} from '@angular/material/icon';
 export class ButtonToggleDemo {
   isVertical = false;
   isDisabled = false;
+  hideSingleSelectionIndicator = false;
+  hideMultipleSelectionIndicator = false;
   favoritePie = 'Apple';
   pieOptions = ['Apple', 'Cherry', 'Pecan', 'Lemon'];
 }

src/material/button-toggle/button-toggle.html

@@ -9,6 +9,24 @@
         [attr.aria-labelledby]="ariaLabelledby"
         (click)="_onButtonClick()">
   <span class="mat-button-toggle-label-content">
+    <!-- Render checkmark at the beginning for single-selection. -->
+    @if (buttonToggleGroup && checked && !buttonToggleGroup.multiple && !buttonToggleGroup.hideSingleSelectionIndicator) {
+      <mat-pseudo-checkbox
+          class="mat-mdc-option-pseudo-checkbox"
+          [disabled]="disabled"
+          state="checked"
+          aria-hidden="true"
+          appearance="minimal"></mat-pseudo-checkbox>
+    }
+    <!-- Render checkmark at the beginning for multiple-selection. -->
+    @if (buttonToggleGroup && checked && buttonToggleGroup.multiple && !buttonToggleGroup.hideMultipleSelectionIndicator) {
+      <mat-pseudo-checkbox
+          class="mat-mdc-option-pseudo-checkbox"
+          [disabled]="disabled"
+          state="checked"
+          aria-hidden="true"
+          appearance="minimal"></mat-pseudo-checkbox>
+    }
     <ng-content></ng-content>
   </span>
 </button>

src/material/button-toggle/button-toggle.scss

@@ -9,6 +9,7 @@
 
 $standard-padding: 0 12px !default;
 $legacy-padding: 0 16px !default;
+$checkmark-padding: 12px !default;
 
 // TODO(crisbeto): these variables aren't used anymore and should be removed.
 $legacy-height: 36px !default;
@@ -90,6 +91,14 @@ $_standard-tokens: (
   .mat-icon svg {
     vertical-align: top;
   }
+
+  .mat-pseudo-checkbox {
+    margin-right: $checkmark-padding;
+    [dir='rtl'] & {
+      margin-right: 0;
+      margin-left: $checkmark-padding;
+    }
+  }
 }
 
 .mat-button-toggle-checked {

src/material/button-toggle/button-toggle.spec.ts

@@ -1,12 +1,22 @@
-import {dispatchMouseEvent} from '@angular/cdk/testing/private';
-import {Component, DebugElement, QueryList, ViewChild, ViewChildren} from '@angular/core';
+import {dispatchFakeEvent, dispatchMouseEvent} from '@angular/cdk/testing/private';
+import {
+  Component,
+  DebugElement,
+  Provider,
+  QueryList,
+  Type,
+  ViewChild,
+  ViewChildren,
+} from '@angular/core';
 import {CommonModule} from '@angular/common';
 import {ComponentFixture, fakeAsync, flush, TestBed, tick} from '@angular/core/testing';
 import {FormControl, FormsModule, NgModel, ReactiveFormsModule} from '@angular/forms';
 import {By} from '@angular/platform-browser';
 import {
+  MAT_BUTTON_TOGGLE_DEFAULT_OPTIONS,
   MatButtonToggle,
   MatButtonToggleChange,
+  MatButtonToggleDefaultOptions,
   MatButtonToggleGroup,
   MatButtonToggleModule,
 } from './index';
@@ -546,6 +556,13 @@ describe('MatButtonToggle without forms', () => {
       expect(groupInstance.value).toBeFalsy();
       expect(groupInstance.selected).toBeFalsy();
     }));
+
+    it('should show checkmark indicator by default', () => {
+      buttonToggleLabelElements[0].click();
+      fixture.detectChanges();
+
+      expect(document.querySelectorAll('.mat-pseudo-checkbox').length).toBe(1);
+    });
   });
 
   describe('with initial value and change event', () => {
@@ -701,6 +718,14 @@ describe('MatButtonToggle without forms', () => {
         groupInstance.value = 'not-an-array';
       }).toThrowError(/Value must be an array/);
     });
+
+    it('should show checkmark indicator by default', () => {
+      buttonToggleLabelElements[0].click();
+      buttonToggleLabelElements[1].click();
+      fixture.detectChanges();
+
+      expect(document.querySelectorAll('.mat-pseudo-checkbox').length).toBe(2);
+    });
   });
 
   describe('as standalone', () => {
@@ -876,6 +901,52 @@ describe('MatButtonToggle without forms', () => {
     });
   });
 
+  describe('with tokens to hide checkmark selection indicators', () => {
+    beforeEach(() => {
+      TestBed.configureTestingModule({
+        imports: [
+          MatButtonToggleModule,
+          ButtonTogglesInsideButtonToggleGroup,
+          ButtonTogglesInsideButtonToggleGroupMultiple,
+        ],
+        providers: [
+          {
+            provide: MAT_BUTTON_TOGGLE_DEFAULT_OPTIONS,
+            useValue: {
+              hideSingleSelectionIndicator: true,
+              hideMultipleSelectionIndicator: true,
+            },
+          },
+        ],
+      });
+
+      TestBed.compileComponents();
+    });
+
+    it('should hide checkmark indicator for single selection', () => {
+      const fixture = TestBed.createComponent(ButtonTogglesInsideButtonToggleGroup);
+      fixture.detectChanges();
+
+      fixture.debugElement.query(By.css('button')).nativeElement.click();
+      fixture.detectChanges();
+
+      expect(document.querySelectorAll('.mat-pseudo-checkbox').length).toBe(0);
+    });
+
+    it('should hide checkmark indicator for multiple selection', () => {
+      const fixture = TestBed.createComponent(ButtonTogglesInsideButtonToggleGroupMultiple);
+      fixture.detectChanges();
+
+      // Check all button toggles in the group
+      fixture.debugElement
+        .queryAll(By.css('button'))
+        .forEach(toggleButton => toggleButton.nativeElement.click());
+      fixture.detectChanges();
+
+      expect(document.querySelectorAll('.mat-pseudo-checkbox').length).toBe(0);
+    });
+  });
+
   it('should not throw on init when toggles are repeated and there is an initial value', () => {
     const fixture = TestBed.createComponent(RepeatedButtonTogglesWithPreselectedValue);
 

src/material/button-toggle/button-toggle.ts

@@ -33,7 +33,7 @@ import {
   booleanAttribute,
 } from '@angular/core';
 import {ControlValueAccessor, NG_VALUE_ACCESSOR} from '@angular/forms';
-import {MatRipple} from '@angular/material/core';
+import {MatRipple, MatPseudoCheckbox} from '@angular/material/core';
 
 /**
  * @deprecated No longer used.
@@ -54,6 +54,10 @@ export interface MatButtonToggleDefaultOptions {
    * setting an appearance on a button toggle or group.
    */
   appearance?: MatButtonToggleAppearance;
+  /** Whetehr icon indicators should be hidden for single-selection button toggle groups. */
+  hideSingleSelectionIndicator?: boolean;
+  /** Whether icon indicators should be hidden for multiple-selection button toggle groups. */
+  hideMultipleSelectionIndicator?: boolean;
 }
 
 /**
@@ -62,8 +66,19 @@ export interface MatButtonToggleDefaultOptions {
  */
 export const MAT_BUTTON_TOGGLE_DEFAULT_OPTIONS = new InjectionToken<MatButtonToggleDefaultOptions>(
   'MAT_BUTTON_TOGGLE_DEFAULT_OPTIONS',
+  {
+    providedIn: 'root',
+    factory: MAT_BUTTON_TOGGLE_GROUP_DEFAULT_OPTIONS_FACTORY,
+  },
 );
 
+export function MAT_BUTTON_TOGGLE_GROUP_DEFAULT_OPTIONS_FACTORY(): MatButtonToggleDefaultOptions {
+  return {
+    hideSingleSelectionIndicator: false,
+    hideMultipleSelectionIndicator: false,
+  };
+}
+
 /**
  * Injection token that can be used to reference instances of `MatButtonToggleGroup`.
  * It serves as alternative token to the actual `MatButtonToggleGroup` class which
@@ -215,6 +230,28 @@ export class MatButtonToggleGroup implements ControlValueAccessor, OnInit, After
   @Output() readonly change: EventEmitter<MatButtonToggleChange> =
     new EventEmitter<MatButtonToggleChange>();
 
+  /** Whether checkmark indicator for single-selection button toggle groups is hidden. */
+  @Input({transform: booleanAttribute})
+  get hideSingleSelectionIndicator(): boolean {
+    return this._hideSingleSelectionIndicator;
+  }
+  set hideSingleSelectionIndicator(value: boolean) {
+    this._hideSingleSelectionIndicator = value;
+    this._markButtonsForCheck();
+  }
+  private _hideSingleSelectionIndicator: boolean;
+
+  /** Whether checkmark indicator for multiple-selection button toggle groups is hidden. */
+  @Input({transform: booleanAttribute})
+  get hideMultipleSelectionIndicator(): boolean {
+    return this._hideMultipleSelectionIndicator;
+  }
+  set hideMultipleSelectionIndicator(value: boolean) {
+    this._hideMultipleSelectionIndicator = value;
+    this._markButtonsForCheck();
+  }
+  private _hideMultipleSelectionIndicator: boolean;
+
   constructor(
     private _changeDetector: ChangeDetectorRef,
     @Optional()
@@ -223,6 +260,8 @@ export class MatButtonToggleGroup implements ControlValueAccessor, OnInit, After
   ) {
     this.appearance =
       defaultOptions && defaultOptions.appearance ? defaultOptions.appearance : 'standard';
+    this.hideSingleSelectionIndicator = defaultOptions?.hideSingleSelectionIndicator ?? false;
+    this.hideMultipleSelectionIndicator = defaultOptions?.hideMultipleSelectionIndicator ?? false;
   }
 
   ngOnInit() {
@@ -401,7 +440,7 @@ export class MatButtonToggleGroup implements ControlValueAccessor, OnInit, After
     'role': 'presentation',
   },
   standalone: true,
-  imports: [MatRipple],
+  imports: [MatRipple, MatPseudoCheckbox],
 })
 export class MatButtonToggle implements OnInit, AfterViewInit, OnDestroy {
   private _checked = false;