feat(material/input): add the ability to interact with disabled inputs

Adds the `disabledInteractive` input to `MatInput` which allows users to opt into having disabled input receive focus and dispatch events. Changing the value is prevented through the `readonly` attribute while disabled state is conveyed via `aria-disabled`.

Author: crisbeto

src/dev-app/input/input-demo.html

@@ -711,6 +711,73 @@ <h3>&lt;textarea&gt; with bindable autosize </h3>
   </mat-card-content>
 </mat-card>
 
+<mat-card class="demo-card demo-basic">
+  <mat-toolbar color="primary">Disabled interactive inputs</mat-toolbar>
+  <mat-card-content>
+    <div>
+      <mat-form-field>
+        <mat-label>Label</mat-label>
+        <input
+          matNativeControl
+          disabled
+          disabledInteractive
+          value="Value"
+          matTooltip="I can trigger a tooltip!">
+      </mat-form-field>
+
+      <mat-form-field>
+        <mat-label>Label</mat-label>
+        <input
+          matNativeControl
+          disabled
+          disabledInteractive
+          matTooltip="I can trigger a tooltip!">
+      </mat-form-field>
+
+      <mat-form-field>
+        <mat-label>Label</mat-label>
+        <input
+          matNativeControl
+          disabled
+          disabledInteractive
+          placeholder="Placeholder"
+          matTooltip="I can trigger a tooltip!">
+      </mat-form-field>
+    </div>
+
+    <div>
+      <mat-form-field appearance="outline">
+        <mat-label>Label</mat-label>
+        <input
+          matNativeControl
+          disabled
+          disabledInteractive
+          value="Value"
+          matTooltip="I can trigger a tooltip!">
+      </mat-form-field>
+
+      <mat-form-field appearance="outline">
+        <mat-label>Label</mat-label>
+        <input
+          matNativeControl
+          disabled
+          disabledInteractive
+          matTooltip="I can trigger a tooltip!">
+      </mat-form-field>
+
+      <mat-form-field appearance="outline">
+        <mat-label>Label</mat-label>
+        <input
+          matNativeControl
+          disabled
+          disabledInteractive
+          placeholder="Placeholder"
+          matTooltip="I can trigger a tooltip!">
+      </mat-form-field>
+    </div>
+  </mat-card-content>
+</mat-card>
+
 <mat-card class="demo-card demo-basic">
   <mat-toolbar color="primary">Textarea form-fields</mat-toolbar>
   <mat-card-content>

src/material/form-field/_mdc-text-field-structure.scss

@@ -65,8 +65,8 @@
       opacity: 0;
     }
 
-    .mdc-text-field--no-label &,
-    .mdc-text-field--focused & {
+    .mdc-text-field--no-label:not(.mdc-text-field--disabled) &,
+    .mdc-text-field--focused:not(.mdc-text-field--disabled) & {
       @include vendor-prefixes.input-placeholder {
         opacity: 1;
       }

src/material/input/input.spec.ts

@@ -403,6 +403,63 @@ describe('MatMdcInput without forms', () => {
     expect(inputEl.disabled).toBe(true);
   }));
 
+  it('should be able to set an input as being disabled and interactive', fakeAsync(() => {
+    const fixture = createComponent(MatInputWithDisabled);
+    fixture.componentInstance.disabled = true;
+    fixture.detectChanges();
+
+    const input = fixture.nativeElement.querySelector('input') as HTMLInputElement;
+    expect(input.disabled).toBe(true);
+    expect(input.readOnly).toBe(false);
+    expect(input.hasAttribute('aria-disabled')).toBe(false);
+
+    fixture.componentInstance.disabledInteractive = true;
+    fixture.changeDetectorRef.markForCheck();
+    fixture.detectChanges();
+
+    expect(input.disabled).toBe(false);
+    expect(input.readOnly).toBe(true);
+    expect(input.getAttribute('aria-disabled')).toBe('true');
+  }));
+
+  it('should not float the label when disabled and disabledInteractive are set', fakeAsync(() => {
+    const fixture = createComponent(MatInputTextTestController);
+    fixture.componentInstance.disabled = fixture.componentInstance.disabledInteractive = true;
+    fixture.detectChanges();
+
+    const label = fixture.nativeElement.querySelector('label');
+    const input = fixture.debugElement
+      .query(By.directive(MatInput))!
+      .injector.get<MatInput>(MatInput);
+
+    expect(label.classList).not.toContain('mdc-floating-label--float-above');
+
+    // Call the focus handler directly to avoid flakyness where
+    // browsers don't focus elements if the window is minimized.
+    input._focusChanged(true);
+    fixture.detectChanges();
+
+    expect(label.classList).not.toContain('mdc-floating-label--float-above');
+  }));
+
+  it('should float the label when disabledInteractive is set and the input has a value', fakeAsync(() => {
+    const fixture = createComponent(MatInputWithDynamicLabel);
+    fixture.componentInstance.shouldFloat = 'auto';
+    fixture.componentInstance.disabled = fixture.componentInstance.disabledInteractive = true;
+    fixture.detectChanges();
+
+    const input = fixture.nativeElement.querySelector('input');
+    const label = fixture.nativeElement.querySelector('label');
+
+    expect(label.classList).not.toContain('mdc-floating-label--float-above');
+
+    input.value = 'Text';
+    dispatchFakeEvent(input, 'input');
+    fixture.detectChanges();
+
+    expect(label.classList).toContain('mdc-floating-label--float-above');
+  }));
+
   it('supports the disabled attribute as binding for select', fakeAsync(() => {
     const fixture = createComponent(MatInputSelect);
     fixture.detectChanges();
@@ -719,16 +776,13 @@ describe('MatMdcInput without forms', () => {
     expect(labelEl.classList).not.toContain('mdc-floating-label--float-above');
   }));
 
-  it(
-    'should not float labels when select has no value, no option label, ' + 'no option innerHtml',
-    fakeAsync(() => {
-      const fixture = createComponent(MatInputSelectWithNoLabelNoValue);
-      fixture.detectChanges();
+  it('should not float labels when select has no value, no option label, no option innerHtml', fakeAsync(() => {
+    const fixture = createComponent(MatInputSelectWithNoLabelNoValue);
+    fixture.detectChanges();
 
-      const labelEl = fixture.debugElement.query(By.css('label'))!.nativeElement;
-      expect(labelEl.classList).not.toContain('mdc-floating-label--float-above');
-    }),
-  );
+    const labelEl = fixture.debugElement.query(By.css('label'))!.nativeElement;
+    expect(labelEl.classList).not.toContain('mdc-floating-label--float-above');
+  }));
 
   it('should floating labels when select has no value but has option label', fakeAsync(() => {
     const fixture = createComponent(MatInputSelectWithLabel);
@@ -1532,6 +1586,7 @@ describe('MatFormField default options', () => {
     ).toBe(true);
   });
 });
+
 describe('MatFormField without label', () => {
   it('should not float the label when no label is defined.', () => {
     let fixture = createComponent(MatInputWithoutDefinedLabel);
@@ -1650,10 +1705,15 @@ class MatInputWithId {
 }
 
 @Component({
-  template: `<mat-form-field><input matInput [disabled]="disabled"></mat-form-field>`,
+  template: `
+    <mat-form-field>
+      <input matInput [disabled]="disabled" [disabledInteractive]="disabledInteractive">
+    </mat-form-field>
+  `,
 })
 class MatInputWithDisabled {
-  disabled: boolean;
+  disabled = false;
+  disabledInteractive = false;
 }
 
 @Component({
@@ -1783,10 +1843,18 @@ class MatInputDateTestController {}
   template: `
     <mat-form-field>
       <mat-label>Label</mat-label>
-      <input matInput type="text" placeholder="Placeholder">
+      <input
+        matInput
+        type="text"
+        placeholder="Placeholder"
+        [disabled]="disabled"
+        [disabledInteractive]="disabledInteractive">
     </mat-form-field>`,
 })
-class MatInputTextTestController {}
+class MatInputTextTestController {
+  disabled = false;
+  disabledInteractive = false;
+}
 
 @Component({
   template: `
@@ -1837,11 +1905,17 @@ class MatInputWithStaticLabel {}
   template: `
     <mat-form-field [floatLabel]="shouldFloat">
       <mat-label>Label</mat-label>
-      <input matInput placeholder="Placeholder">
+      <input
+        matInput
+        placeholder="Placeholder"
+        [disabled]="disabled"
+        [disabledInteractive]="disabledInteractive">
     </mat-form-field>`,
 })
 class MatInputWithDynamicLabel {
   shouldFloat: 'always' | 'auto' = 'always';
+  disabled = false;
+  disabledInteractive = false;
 }
 
 @Component({

src/material/input/input.ts

@@ -11,10 +11,13 @@ import {getSupportedInputTypes, Platform} from '@angular/cdk/platform';
 import {AutofillMonitor} from '@angular/cdk/text-field';
 import {
   AfterViewInit,
+  booleanAttribute,
   Directive,
   DoCheck,
   ElementRef,
+  inject,
   Inject,
+  InjectionToken,
   Input,
   NgZone,
   OnChanges,
@@ -44,6 +47,15 @@ const MAT_INPUT_INVALID_TYPES = [
 
 let nextUniqueId = 0;
 
+/** Object that can be used to configure the default options for the input. */
+export interface MatInputConfig {
+  /** Whether disabled inputs should be interactive. */
+  disabledInteractive?: boolean;
+}
+
+/** Injection token that can be used to provide the default options for the input. */
+export const MAT_INPUT_CONFIG = new InjectionToken<MatInputConfig>('MAT_INPUT_CONFIG');
+
 @Directive({
   selector: `input[matInput], textarea[matInput], select[matNativeControl],
       input[matNativeControl], textarea[matNativeControl]`,
@@ -61,10 +73,11 @@ let nextUniqueId = 0;
     // Native input properties that are overwritten by Angular inputs need to be synced with
     // the native input element. Otherwise property bindings for those don't work.
     '[id]': 'id',
-    '[disabled]': 'disabled',
+    '[disabled]': 'disabled && !disabledInteractive',
     '[required]': 'required',
     '[attr.name]': 'name || null',
-    '[attr.readonly]': 'readonly && !_isNativeSelect || null',
+    '[attr.readonly]': '_getReadonlyAttribute()',
+    '[attr.aria-disabled]': 'disabled && disabledInteractive ? "true" : null',
     // Only mark the input as invalid for assistive technology if it has a value since the
     // state usually overlaps with `aria-required` when the input is empty and can be redundant.
     '[attr.aria-invalid]': '(empty && required) ? null : errorState',
@@ -88,6 +101,7 @@ export class MatInput
   private _previousPlaceholder: string | null;
   private _errorStateTracker: _ErrorStateTracker;
   private _webkitBlinkWheelListenerAttached = false;
+  private _config = inject(MAT_INPUT_CONFIG, {optional: true});
 
   /** Whether the component is being rendered on the server. */
   readonly _isServer: boolean;
@@ -243,6 +257,10 @@ export class MatInput
   }
   private _readonly = false;
 
+  /** Whether the input should remain interactive when it is disabled. */
+  @Input({transform: booleanAttribute})
+  disabledInteractive: boolean;
+
   /** Whether the input is in an error state. */
   get errorState() {
     return this._errorStateTracker.errorState;
@@ -306,6 +324,7 @@ export class MatInput
     this._isNativeSelect = nodeName === 'select';
     this._isTextarea = nodeName === 'textarea';
     this._isInFormField = !!_formField;
+    this.disabledInteractive = this._config?.disabledInteractive || false;
 
     if (this._isNativeSelect) {
       this.controlType = (element as HTMLSelectElement).multiple
@@ -382,10 +401,27 @@ export class MatInput
 
   /** Callback for the cases where the focused state of the input changes. */
   _focusChanged(isFocused: boolean) {
-    if (isFocused !== this.focused) {
-      this.focused = isFocused;
-      this.stateChanges.next();
+    if (isFocused === this.focused) {
+      return;
     }
+
+    if (!this._isNativeSelect && isFocused && this.disabled && this.disabledInteractive) {
+      const element = this._elementRef.nativeElement as HTMLInputElement;
+
+      // Focusing an input that has text will cause all the text to be selected. Clear it since
+      // the user won't be able to change it. This is based on the internal implementation.
+      if (element.type === 'number') {
+        // setSelectionRange doesn't work on number inputs so it needs to be set briefly to text.
+        element.type = 'text';
+        element.setSelectionRange(0, 0);
+        element.type = 'number';
+      } else {
+        element.setSelectionRange(0, 0);
+      }
+    }
+
+    this.focused = isFocused;
+    this.stateChanges.next();
   }
 
   _onInput() {
@@ -481,7 +517,7 @@ export class MatInput
         !!(selectElement.selectedIndex > -1 && firstOption && firstOption.label)
       );
     } else {
-      return this.focused || !this.empty;
+      return (this.focused && !this.disabled) || !this.empty;
     }
   }
 
@@ -566,4 +602,17 @@ export class MatInput
       this._webkitBlinkWheelListenerAttached = true;
     }
   }
+
+  /** Gets the value to set on the `readonly` attribute. */
+  protected _getReadonlyAttribute(): string | null {
+    if (this._isNativeSelect) {
+      return null;
+    }
+
+    if (this.readonly || (this.disabled && this.disabledInteractive)) {
+      return 'true';
+    }
+
+    return null;
+  }
 }

src/material/input/public-api.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-export {MatInput} from './input';
+export {MatInput, MatInputConfig, MAT_INPUT_CONFIG} from './input';
 export {MatInputModule} from './module';
 export * from './input-value-accessor';
 export * from './input-errors';