Merged in DSC-106 (pull request DSpace#643)

[DSC-106] Date input usable via keyboard using tab

Approved-by: Vincenzo Mecca

Author: alisaismailati

src/app/shared/form/builder/ds-dynamic-form-ui/models/date-picker/date-picker.component.spec.ts

@@ -1,7 +1,7 @@
 // Load the implementations that should be tested
-import { ChangeDetectorRef, Component, CUSTOM_ELEMENTS_SCHEMA } from '@angular/core';
-import { ComponentFixture, inject, TestBed, waitForAsync, } from '@angular/core/testing';
 import { UntypedFormControl, UntypedFormGroup } from '@angular/forms';
+import { ChangeDetectorRef, Component, CUSTOM_ELEMENTS_SCHEMA, Renderer2 } from '@angular/core';
+import { ComponentFixture, fakeAsync, inject, TestBed, tick, waitForAsync, } from '@angular/core/testing';
 
 import { NgbModule } from '@ng-bootstrap/ng-bootstrap';
 import { DynamicFormLayoutService, DynamicFormValidationService } from '@ng-dynamic-forms/core';
@@ -13,6 +13,7 @@ import {
   mockDynamicFormLayoutService,
   mockDynamicFormValidationService
 } from '../../../../../testing/dynamic-form-mock-services';
+import { By } from '@angular/platform-browser';
 
 
 export const DATE_TEST_GROUP = new UntypedFormGroup({
@@ -39,6 +40,11 @@ describe('DsDatePickerComponent test suite', () => {
   let dateFixture: ComponentFixture<DsDatePickerComponent>;
   let html;
 
+  const renderer2: Renderer2 = {
+    selectRootElement: jasmine.createSpy('selectRootElement'),
+    querySelector: jasmine.createSpy('querySelector'),
+  } as unknown as Renderer2;
+
   // waitForAsync beforeEach
   beforeEach(waitForAsync(() => {
 
@@ -54,7 +60,8 @@ describe('DsDatePickerComponent test suite', () => {
         ChangeDetectorRef,
         DsDatePickerComponent,
         { provide: DynamicFormLayoutService, useValue: mockDynamicFormLayoutService },
-        { provide: DynamicFormValidationService, useValue: mockDynamicFormValidationService }
+        { provide: DynamicFormValidationService, useValue: mockDynamicFormValidationService },
+        { provide: Renderer2, useValue: renderer2 },
       ],
       schemas: [CUSTOM_ELEMENTS_SCHEMA]
     });
@@ -233,6 +240,102 @@ describe('DsDatePickerComponent test suite', () => {
         expect(dateComp.disabledMonth).toBeFalsy();
         expect(dateComp.disabledDay).toBeFalsy();
       });
+
+      it('should move focus on month field when on year field and tab pressed', fakeAsync(() => {
+        const event = {
+          field: 'day',
+          value: null
+        };
+        const event1 = {
+          field: 'month',
+          value: null
+        };
+        dateComp.onChange(event);
+        dateComp.onChange(event1);
+
+        const yearElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_year`));
+        const monthElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_month`));
+
+        yearElement.nativeElement.focus();
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(yearElement.nativeElement);
+
+        dateFixture.nativeElement.dispatchEvent(new KeyboardEvent('keydown', { key: 'tab' }));
+        dateFixture.detectChanges();
+
+        tick(200);
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(monthElement.nativeElement);
+      }));
+
+      it('should move focus on day field when on month field and tab pressed', fakeAsync(() => {
+        const event = {
+          field: 'day',
+          value: null
+        };
+        dateComp.onChange(event);
+
+        const monthElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_month`));
+        const dayElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_day`));
+
+        monthElement.nativeElement.focus();
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(monthElement.nativeElement);
+
+        dateFixture.nativeElement.dispatchEvent(new KeyboardEvent('keydown', { key: 'tab' }));
+        dateFixture.detectChanges();
+
+        tick(200);
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(dayElement.nativeElement);
+      }));
+
+      it('should move focus on month field when on day field and shift tab pressed', fakeAsync(() => {
+        const event = {
+          field: 'day',
+          value: null
+        };
+        dateComp.onChange(event);
+
+        const monthElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_month`));
+        const dayElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_day`));
+
+        dayElement.nativeElement.focus();
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(dayElement.nativeElement);
+
+        dateFixture.nativeElement.dispatchEvent(new KeyboardEvent('keydown', { key: 'shift.tab' }));
+        dateFixture.detectChanges();
+
+        tick(200);
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(monthElement.nativeElement);
+      }));
+
+      it('should move focus on year field when on month field and shift tab pressed', fakeAsync(() => {
+        const yearElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_year`));
+        const monthElement = dateFixture.debugElement.query(By.css(`#${dateComp.model.id}_month`));
+
+        monthElement.nativeElement.focus();
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(monthElement.nativeElement);
+
+        dateFixture.nativeElement.dispatchEvent(new KeyboardEvent('keydown', { key: 'shift.tab' }));
+        dateFixture.detectChanges();
+
+        tick(200);
+        dateFixture.detectChanges();
+
+        expect(document.activeElement).toBe(yearElement.nativeElement);
+      }));
+
     });
   });
 

src/app/shared/form/builder/ds-dynamic-form-ui/models/date-picker/date-picker.component.ts

@@ -1,12 +1,17 @@
-import { Component, EventEmitter, Input, OnInit, Output } from '@angular/core';
 import { UntypedFormGroup } from '@angular/forms';
+import { Component, EventEmitter, HostListener, Inject, Input, OnInit, Output, Renderer2 } from '@angular/core';
 import { DynamicDsDatePickerModel } from './date-picker.model';
 import { hasValue } from '../../../../../empty.util';
 import {
   DynamicFormControlComponent,
   DynamicFormLayoutService,
   DynamicFormValidationService
 } from '@ng-dynamic-forms/core';
+import { DOCUMENT } from '@angular/common';
+import isEqual from 'lodash/isEqual';
+
+
+export type DatePickerFieldType = '_year' | '_month' | '_day';
 
 export const DS_DATE_PICKER_SEPARATOR = '-';
 
@@ -50,8 +55,12 @@ export class DsDatePickerComponent extends DynamicFormControlComponent implement
   disabledMonth = true;
   disabledDay = true;
 
+  private readonly fields: DatePickerFieldType[] = ['_year', '_month', '_day'];
+
   constructor(protected layoutService: DynamicFormLayoutService,
-              protected validationService: DynamicFormValidationService
+              protected validationService: DynamicFormValidationService,
+              private renderer: Renderer2,
+              @Inject(DOCUMENT) private _document: Document
   ) {
     super(layoutService, validationService);
   }
@@ -166,6 +175,67 @@ export class DsDatePickerComponent extends DynamicFormControlComponent implement
     this.change.emit(value);
   }
 
+  /**
+   * Listen to keydown Tab event.
+   * Get the active element and blur it, in order to focus the next input field.
+   */
+  @HostListener('keydown.tab', ['$event'])
+  onTabKeydown(event: KeyboardEvent) {
+    event.preventDefault();
+    const activeElement: Element = this._document.activeElement;
+    (activeElement as any).blur();
+    const index = this.selectedFieldIndex(activeElement);
+    if (index < 0) {
+      return;
+    }
+    let fieldToFocusOn = index + 1;
+    if (fieldToFocusOn < this.fields.length) {
+      this.focusInput(this.fields[fieldToFocusOn]);
+    }
+  }
+
+  @HostListener('keydown.shift.tab', ['$event'])
+  onShiftTabKeyDown(event: KeyboardEvent) {
+    event.preventDefault();
+    const activeElement: Element = this._document.activeElement;
+    (activeElement as any).blur();
+    const index = this.selectedFieldIndex(activeElement);
+    let fieldToFocusOn = index - 1;
+    if (fieldToFocusOn >= 0) {
+      this.focusInput(this.fields[fieldToFocusOn]);
+    }
+  }
+
+  private selectedFieldIndex(activeElement: Element): number {
+    return this.fields.findIndex(field => isEqual(activeElement.id, this.model.id.concat(field)));
+  }
+
+  /**
+   * Focus the input field for the given type
+   * based on the model id.
+   * Used to focus the next input field
+   * in case of a disabled field.
+   * @param type DatePickerFieldType
+   */
+  focusInput(type: DatePickerFieldType) {
+    const field = this._document.getElementById(this.model.id.concat(type));
+    if (field) {
+
+      if (hasValue(this.year) && isEqual(type, '_year')) {
+        this.disabledMonth = true;
+        this.disabledDay = true;
+      }
+      if (hasValue(this.year) && isEqual(type, '_month')) {
+        this.disabledMonth = false;
+      } else if (hasValue(this.month) && isEqual(type, '_day')) {
+        this.disabledDay = false;
+      }
+      setTimeout(() => {
+        this.renderer.selectRootElement(field).focus();
+      }, 100);
+    }
+  }
+
   onFocus(event) {
     this.focus.emit(event);
   }