Make reorder buttons keyboard accessible (#3372)

* [CST-15595] add keyboard drag and drop functionality

* [CST-15595] add aria live messages

* [CST-15595] fix e2e tests

* [CST-15595] fix unit tests

* [CST-15595] improve drag and drop keyboard functionality

* [CST-15595] add keydown.enter for keyboard drag and drop

---------

Co-authored-by: Andrea Barbasso <´andrea.barbasso@4science.com´>

src/app/shared/form/builder/ds-dynamic-form-ui/models/array-group/dynamic-form-array.component.html

@@ -5,9 +5,10 @@
          [ngClass]="getClass('element', 'control')">
 
       <!-- Draggable Container -->
-      <div cdkDropList cdkDropListLockAxis="y" (cdkDropListDropped)="moveSelection($event)">
+      <div role="listbox" [attr.aria-label]="'dynamic-form-array.sortable-list.label' | translate" #dropList cdkDropList cdkDropListLockAxis="y" (cdkDropListDropped)="moveSelection($event)">
         <!-- Draggable Items -->
-        <div *ngFor="let groupModel of model.groups"
+        <div #sortableElement
+             *ngFor="let groupModel of model.groups; let idx = index; let length = count"
              role="group"
              [formGroupName]="groupModel.index"
              [ngClass]="[getClass('element', 'group'), getClass('grid', 'group')]"
@@ -16,7 +17,14 @@
              [cdkDragPreviewClass]="'ds-submission-reorder-dragging'"
              [class.grey-background]="model.isInlineGroupArray">
           <!-- Item content -->
-          <div class="drag-handle" [class.drag-disable]="dragDisabled" tabindex="0" cdkDragHandle>
+          <div class="drag-handle" [class.drag-disable]="dragDisabled" tabindex="0" cdkDragHandle
+               (focus)="addInstructionMessageToLiveRegion(sortableElement)"
+               (keydown.space)="toggleKeyboardDragAndDrop($event, sortableElement, idx, length)"
+               (keydown.enter)="toggleKeyboardDragAndDrop($event, sortableElement, idx, length)"
+               (keydown.tab)="stopKeyboardDragAndDrop(sortableElement, idx, length)"
+               (keydown.escape)="cancelKeyboardDragAndDrop(sortableElement, idx, length)"
+               (keydown.arrowUp)="handleArrowPress($event, dropList, length, idx, 'up')"
+               (keydown.arrowDown)="handleArrowPress($event, dropList, length, idx, 'down')">
             <i class="drag-icon fas fa-grip-vertical fa-fw" [class.drag-disable]="dragDisabled" ></i>
           </div>
           <ng-container *ngTemplateOutlet="startTemplate?.templateRef; context: groupModel"></ng-container>

src/app/shared/form/builder/ds-dynamic-form-ui/models/array-group/dynamic-form-array.component.scss

@@ -17,7 +17,6 @@
   margin-right: calc(-0.5 * var(--bs-spacer));
   padding-right: calc(0.5 * var(--bs-spacer));
   .drag-icon {
-    visibility: hidden;
     width: calc(2 * var(--bs-spacer));
     color: var(--bs-gray-600);
     margin: var(--bs-btn-padding-y) 0;
@@ -27,9 +26,6 @@
 
   &:hover, &:focus {
     cursor: grab;
-    .drag-icon {
-      visibility: visible;
-    }
   }
 
 }
@@ -40,18 +36,12 @@
   }
 
   &:focus {
-    .drag-icon {
-      visibility: visible;
-    }
   }
 }
 
 .cdk-drop-list-dragging {
   .drag-handle {
     cursor: grabbing;
-    .drag-icon {
-      visibility: hidden;
-    }
   }
 }
 
@@ -63,3 +53,9 @@
 .cdk-drag-placeholder {
   opacity: 0;
 }
+
+::ng-deep {
+  .sorting-with-keyboard input {
+    background-color: var(--bs-gray-400);
+  }
+}

src/app/shared/form/builder/ds-dynamic-form-ui/models/array-group/dynamic-form-array.component.spec.ts

@@ -0,0 +1,159 @@
+import { HttpClient } from '@angular/common/http';
+import { EventEmitter } from '@angular/core';
+import {
+  ComponentFixture,
+  inject,
+  TestBed,
+} from '@angular/core/testing';
+import { ReactiveFormsModule } from '@angular/forms';
+import { By } from '@angular/platform-browser';
+import {
+  DYNAMIC_FORM_CONTROL_MAP_FN,
+  DynamicFormLayoutService,
+  DynamicFormService,
+  DynamicFormValidationService,
+  DynamicInputModel,
+} from '@ng-dynamic-forms/core';
+import { provideMockStore } from '@ngrx/store/testing';
+import {
+  TranslateModule,
+  TranslateService,
+} from '@ngx-translate/core';
+import { NgxMaskModule } from 'ngx-mask';
+import { of } from 'rxjs';
+
+import {
+  APP_CONFIG,
+  APP_DATA_SERVICES_MAP,
+} from '../../../../../../../config/app-config.interface';
+import { environment } from '../../../../../../../environments/environment.test';
+import { SubmissionService } from '../../../../../../submission/submission.service';
+import { DsDynamicFormControlContainerComponent } from '../../ds-dynamic-form-control-container.component';
+import { dsDynamicFormControlMapFn } from '../../ds-dynamic-form-control-map-fn';
+import { DynamicRowArrayModel } from '../ds-dynamic-row-array-model';
+import { DsDynamicFormArrayComponent } from './dynamic-form-array.component';
+
+describe('DsDynamicFormArrayComponent', () => {
+  const translateServiceStub = {
+    get: () => of('translated-text'),
+    instant: () => 'translated-text',
+    onLangChange: new EventEmitter(),
+    onTranslationChange: new EventEmitter(),
+    onDefaultLangChange: new EventEmitter(),
+  };
+
+  let component: DsDynamicFormArrayComponent;
+  let fixture: ComponentFixture<DsDynamicFormArrayComponent>;
+
+  beforeEach(async () => {
+    await TestBed.configureTestingModule({
+      imports: [
+        ReactiveFormsModule,
+        DsDynamicFormArrayComponent,
+        NgxMaskModule.forRoot(),
+        TranslateModule.forRoot(),
+      ],
+      providers: [
+        DynamicFormLayoutService,
+        DynamicFormValidationService,
+        provideMockStore(),
+        { provide: APP_DATA_SERVICES_MAP, useValue: {} },
+        { provide: TranslateService, useValue: translateServiceStub },
+        { provide: HttpClient, useValue: {} },
+        { provide: SubmissionService, useValue: {} },
+        { provide: APP_CONFIG, useValue: environment },
+        { provide: DYNAMIC_FORM_CONTROL_MAP_FN, useValue: dsDynamicFormControlMapFn },
+      ],
+    }).overrideComponent(DsDynamicFormArrayComponent, {
+      remove: {
+        imports: [DsDynamicFormControlContainerComponent],
+      },
+    })
+      .compileComponents();
+  });
+
+  beforeEach(inject([DynamicFormService], (service: DynamicFormService) => {
+    const formModel = [
+      new DynamicRowArrayModel({
+        id: 'testFormRowArray',
+        initialCount: 5,
+        notRepeatable: false,
+        relationshipConfig: undefined,
+        submissionId: '1234',
+        isDraggable: true,
+        groupFactory: () => {
+          return [
+            new DynamicInputModel({ id: 'testFormRowArrayGroupInput' }),
+          ];
+        },
+        required: false,
+        metadataKey: 'dc.contributor.author',
+        metadataFields: ['dc.contributor.author'],
+        hasSelectableMetadata: true,
+        showButtons: true,
+        typeBindRelations: [{ match: 'VISIBLE', operator: 'OR', when: [{ id: 'dc.type', value: 'Book' }] }],
+      }),
+    ];
+
+    fixture = TestBed.createComponent(DsDynamicFormArrayComponent);
+    component = fixture.componentInstance;
+    component.model = formModel[0] as DynamicRowArrayModel;
+
+    component.group = service.createFormGroup(formModel);
+
+    fixture.detectChanges();
+  }));
+
+  it('should move element up and maintain focus', () => {
+    const dropList = fixture.debugElement.query(By.css('.cdk-drop-list')).nativeElement;
+    component.handleArrowPress(new KeyboardEvent('keydown', { key: 'ArrowUp' }), dropList, 3, 1, 'up');
+    fixture.detectChanges();
+    expect(component.model.groups[0]).toBeDefined();
+    expect(document.activeElement).toBe(dropList.querySelectorAll('[cdkDragHandle]')[0]);
+  });
+
+  it('should move element down and maintain focus', () => {
+    const dropList = fixture.debugElement.query(By.css('.cdk-drop-list')).nativeElement;
+    component.handleArrowPress(new KeyboardEvent('keydown', { key: 'ArrowDown' }), dropList, 3, 1, 'down');
+    fixture.detectChanges();
+    expect(component.model.groups[2]).toBeDefined();
+    expect(document.activeElement).toBe(dropList.querySelectorAll('[cdkDragHandle]')[2]);
+  });
+
+  it('should wrap around when moving up from the first element', () => {
+    const dropList = fixture.debugElement.query(By.css('.cdk-drop-list')).nativeElement;
+    component.handleArrowPress(new KeyboardEvent('keydown', { key: 'ArrowUp' }), dropList, 3, 0, 'up');
+    fixture.detectChanges();
+    expect(component.model.groups[2]).toBeDefined();
+    expect(document.activeElement).toBe(dropList.querySelectorAll('[cdkDragHandle]')[2]);
+  });
+
+  it('should wrap around when moving down from the last element', () => {
+    const dropList = fixture.debugElement.query(By.css('.cdk-drop-list')).nativeElement;
+    component.handleArrowPress(new KeyboardEvent('keydown', { key: 'ArrowDown' }), dropList, 3, 2, 'down');
+    fixture.detectChanges();
+    expect(component.model.groups[0]).toBeDefined();
+    expect(document.activeElement).toBe(dropList.querySelectorAll('[cdkDragHandle]')[0]);
+  });
+
+  it('should not move element if keyboard drag is not active', () => {
+    const dropList = fixture.debugElement.query(By.css('.cdk-drop-list')).nativeElement;
+    component.elementBeingSorted = null;
+    component.handleArrowPress(new KeyboardEvent('keydown', { key: 'ArrowDown' }), dropList, 3, 1, 'down');
+    fixture.detectChanges();
+    expect(component.model.groups[1]).toBeDefined();
+    expect(document.activeElement).toBe(dropList.querySelectorAll('[cdkDragHandle]')[2]);
+  });
+
+  it('should cancel keyboard drag and drop', () => {
+    const dropList = fixture.debugElement.query(By.css('.cdk-drop-list')).nativeElement;
+    component.elementBeingSortedStartingIndex = 2;
+    component.elementBeingSorted = dropList.querySelectorAll('[cdkDragHandle]')[2];
+    component.model.moveGroup(2, 1);
+    fixture.detectChanges();
+    component.cancelKeyboardDragAndDrop(dropList, 1, 3);
+    fixture.detectChanges();
+    expect(component.elementBeingSorted).toBeNull();
+    expect(component.elementBeingSortedStartingIndex).toBeNull();
+  });
+});

src/app/shared/form/builder/ds-dynamic-form-ui/models/array-group/dynamic-form-array.component.ts

@@ -32,9 +32,14 @@ import {
   DynamicFormValidationService,
   DynamicTemplateDirective,
 } from '@ng-dynamic-forms/core';
+import {
+  TranslateModule,
+  TranslateService,
+} from '@ngx-translate/core';
 
 import { Relationship } from '../../../../../../core/shared/item-relationships/relationship.model';
 import { hasValue } from '../../../../../empty.util';
+import { LiveRegionService } from '../../../../../live-region/live-region.service';
 import { DsDynamicFormControlContainerComponent } from '../../ds-dynamic-form-control-container.component';
 import { DynamicRowArrayModel } from '../ds-dynamic-row-array-model';
 
@@ -51,6 +56,7 @@ import { DynamicRowArrayModel } from '../ds-dynamic-row-array-model';
     CdkDragHandle,
     forwardRef(() => DsDynamicFormControlContainerComponent),
     NgTemplateOutlet,
+    TranslateModule,
   ],
   standalone: true,
 })
@@ -64,6 +70,9 @@ export class DsDynamicFormArrayComponent extends DynamicFormArrayComponent {
   @Input() model: DynamicRowArrayModel;// DynamicRow?
   @Input() templates: QueryList<DynamicTemplateDirective> | undefined;
 
+  elementBeingSorted: HTMLElement;
+  elementBeingSortedStartingIndex: number;
+
   /* eslint-disable @angular-eslint/no-output-rename */
   @Output('dfBlur') blur: EventEmitter<DynamicFormControlEvent> = new EventEmitter<DynamicFormControlEvent>();
   @Output('dfChange') change: EventEmitter<DynamicFormControlEvent> = new EventEmitter<DynamicFormControlEvent>();
@@ -74,6 +83,8 @@ export class DsDynamicFormArrayComponent extends DynamicFormArrayComponent {
 
   constructor(protected layoutService: DynamicFormLayoutService,
               protected validationService: DynamicFormValidationService,
+              protected liveRegionService: LiveRegionService,
+              protected translateService: TranslateService,
   ) {
     super(layoutService, validationService);
   }
@@ -127,4 +138,149 @@ export class DsDynamicFormArrayComponent extends DynamicFormArrayComponent {
     }
     return this.control.get([groupModel.startingIndex]);
   }
+
+  /**
+   * Toggles the keyboard drag and drop feature for the given sortable element.
+   * @param event
+   * @param sortableElement
+   * @param index
+   * @param length
+   */
+  toggleKeyboardDragAndDrop(event: KeyboardEvent, sortableElement: HTMLDivElement, index: number, length: number) {
+    event.preventDefault();
+    if (this.elementBeingSorted) {
+      this.stopKeyboardDragAndDrop(sortableElement, index, length);
+    } else {
+      sortableElement.classList.add('sorting-with-keyboard');
+      this.elementBeingSorted = sortableElement;
+      this.elementBeingSortedStartingIndex = index;
+      this.liveRegionService.clear();
+      this.liveRegionService.addMessage(this.translateService.instant('live-region.ordering.status', {
+        itemName: sortableElement.querySelector('input')?.value,
+        index: index + 1,
+        length,
+      }));
+    }
+  }
+
+  /**
+   * Stops the keyboard drag and drop feature.
+   * @param sortableElement
+   * @param index
+   * @param length
+   */
+  stopKeyboardDragAndDrop(sortableElement: HTMLDivElement, index: number, length: number) {
+    this.elementBeingSorted?.classList.remove('sorting-with-keyboard');
+    this.liveRegionService.clear();
+    if (this.elementBeingSorted) {
+      this.elementBeingSorted = null;
+      this.elementBeingSortedStartingIndex = null;
+      this.liveRegionService.addMessage(this.translateService.instant('live-region.ordering.dropped', {
+        itemName: sortableElement.querySelector('input')?.value,
+        index: index + 1,
+        length,
+      }));
+    }
+  }
+
+  /**
+   * Handles the keyboard arrow press event to move the element up or down.
+   * @param event
+   * @param dropList
+   * @param length
+   * @param idx
+   * @param direction
+   */
+  handleArrowPress(event: KeyboardEvent, dropList: HTMLDivElement, length: number, idx: number, direction: 'up' | 'down') {
+    let newIndex = direction === 'up' ? idx - 1 : idx + 1;
+    if (newIndex < 0) {
+      newIndex = length - 1;
+    } else if (newIndex >= length) {
+      newIndex = 0;
+    }
+
+    if (this.elementBeingSorted) {
+      this.model.moveGroup(idx, newIndex - idx);
+      if (hasValue(this.model.groups[newIndex]) && hasValue((this.control as any).controls[newIndex])) {
+        this.onCustomEvent({
+          previousIndex: idx,
+          newIndex,
+          arrayModel: this.model,
+          model: this.model.groups[newIndex].group[0],
+          control: (this.control as any).controls[newIndex],
+        }, 'move');
+        this.liveRegionService.clear();
+        this.liveRegionService.addMessage(this.translateService.instant('live-region.ordering.moved', {
+          itemName: this.elementBeingSorted.querySelector('input')?.value,
+          index: newIndex + 1,
+          length,
+        }));
+      }
+      event.preventDefault();
+      // Set focus back to the moved element
+      setTimeout(() => {
+        this.setFocusToDropListElementOfIndex(dropList, newIndex, direction);
+      });
+    } else {
+      event.preventDefault();
+      this.setFocusToDropListElementOfIndex(dropList, newIndex, direction);
+    }
+  }
+
+  cancelKeyboardDragAndDrop(sortableElement: HTMLDivElement, index: number, length: number) {
+    this.model.moveGroup(index, this.elementBeingSortedStartingIndex - index);
+    if (hasValue(this.model.groups[this.elementBeingSortedStartingIndex]) && hasValue((this.control as any).controls[this.elementBeingSortedStartingIndex])) {
+      this.onCustomEvent({
+        previousIndex: index,
+        newIndex: this.elementBeingSortedStartingIndex,
+        arrayModel: this.model,
+        model: this.model.groups[this.elementBeingSortedStartingIndex].group[0],
+        control: (this.control as any).controls[this.elementBeingSortedStartingIndex],
+      }, 'move');
+      this.stopKeyboardDragAndDrop(sortableElement, this.elementBeingSortedStartingIndex, length);
+    }
+  }
+
+  /**
+   * Sets focus to the drag handle of the drop list element of the given index.
+   * @param dropList
+   * @param index
+   * @param direction
+   */
+  setFocusToDropListElementOfIndex(dropList: HTMLDivElement, index: number, direction: 'up' | 'down') {
+    const newDragHandle = dropList.querySelectorAll(`[cdkDragHandle]`)[index] as HTMLElement;
+    if (newDragHandle) {
+      newDragHandle.focus();
+      if (!this.isElementInViewport(newDragHandle)) {
+        newDragHandle.scrollIntoView(direction === 'up');
+      }
+    }
+  }
+
+  /**
+   * checks if an element is in the viewport
+   * @param el
+   */
+  isElementInViewport(el: HTMLElement) {
+    const rect = el.getBoundingClientRect();
+    return (
+      rect.top >= 0 &&
+      rect.left >= 0 &&
+      rect.bottom <= (window.innerHeight || document.documentElement.clientHeight) &&
+      rect.right <= (window.innerWidth || document.documentElement.clientWidth)
+    );
+  }
+
+  /**
+   * Adds an instruction message to the live region when the user might want to sort an element.
+   * @param sortableElement
+   */
+  addInstructionMessageToLiveRegion(sortableElement: HTMLDivElement) {
+    if (!this.elementBeingSorted) {
+      this.liveRegionService.clear();
+      this.liveRegionService.addMessage(this.translateService.instant('live-region.ordering.instructions', {
+        itemName: sortableElement.querySelector('input')?.value,
+      }));
+    }
+  }
 }

src/assets/i18n/en.json5

@@ -6771,4 +6771,14 @@
   "forgot-email.form.aria.label": "Enter your e-mail address",
 
   "search-facet-option.update.announcement": "The page will be reloaded. Filter {{ filter }} is selected.",
+
+  "live-region.ordering.instructions": "Press spacebar to reorder {{ itemName }}.",
+
+  "live-region.ordering.status": "{{ itemName }}, grabbed. Current position in list: {{ index }} of  {{ length }}. Press up and down arrow keys to change position, SpaceBar to drop, Escape to cancel.",
+
+  "live-region.ordering.moved": "{{ itemName }}, moved to position {{ index }} of {{ length }}. Press up and down arrow keys to change position, SpaceBar to drop, Escape to cancel.",
+
+  "live-region.ordering.dropped": "{{ itemName }}, dropped at position {{ index }} of {{ length }}.",
+
+  "dynamic-form-array.sortable-list.label": "Sortable list",
 }