From f0ed5580947a4a52cf12ba3ff4d7ef8b39f24d28 Mon Sep 17 00:00:00 2001
From: Ivan Donchev <idonchev@vmware.com>
Date: Thu, 30 Jun 2022 20:44:25 +0300
Subject: [PATCH] feat(datagrid): range selection with shift key

Signed-off-by: Ivan Donchev <idonchev@vmware.com>
---
 projects/angular/clarity.api.md               |   5 +-
 .../src/data/datagrid/datagrid-row.html       |   4 +-
 .../angular/src/data/datagrid/datagrid-row.ts |  58 ++++++++-
 .../src/data/datagrid/datagrid.spec.ts        | 117 +++++++++++++++++-
 .../angular/src/data/datagrid/datagrid.ts     |  25 +++-
 .../src/data/datagrid/providers/selection.ts  |   9 ++
 6 files changed, 210 insertions(+), 8 deletions(-)

diff --git a/projects/angular/clarity.api.md b/projects/angular/clarity.api.md
index 4bd3cf256c..acf500c036 100644
--- a/projects/angular/clarity.api.md
+++ b/projects/angular/clarity.api.md
@@ -1124,7 +1124,7 @@ export class ClrDatagrid<T = any> implements AfterContentInit, AfterViewInit, On
     // Warning: (ae-forgotten-export) The symbol "Page" needs to be exported by the entry point index.d.ts
     // Warning: (ae-forgotten-export) The symbol "ColumnsService" needs to be exported by the entry point index.d.ts
     // Warning: (ae-forgotten-export) The symbol "KeyNavigationGridController" needs to be exported by the entry point index.d.ts
-    constructor(organizer: DatagridRenderOrganizer, items: Items<T>, expandableRows: ExpandableRowsCount, selection: Selection_2<T>, rowActionService: RowActionService, stateProvider: StateProvider<T>, displayMode: DisplayModeService, renderer: Renderer2, detailService: DetailService, datagridId: string, el: ElementRef, page: Page, commonStrings: ClrCommonStringsService, columnsService: ColumnsService, keyNavigation: KeyNavigationGridController);
+    constructor(organizer: DatagridRenderOrganizer, items: Items<T>, expandableRows: ExpandableRowsCount, selection: Selection_2<T>, rowActionService: RowActionService, stateProvider: StateProvider<T>, displayMode: DisplayModeService, renderer: Renderer2, detailService: DetailService, datagridId: string, document: any, el: ElementRef, page: Page, commonStrings: ClrCommonStringsService, columnsService: ColumnsService, keyNavigation: KeyNavigationGridController, zone: NgZone);
     get allSelected(): boolean;
     set allSelected(_value: boolean);
     // (undocumented)
@@ -1704,11 +1704,12 @@ export class ClrDatagridPlaceholder<T = any> {
 
 // @public (undocumented)
 export class ClrDatagridRow<T = any> implements AfterContentInit, AfterViewInit {
-    constructor(selection: Selection_2<T>, rowActionService: RowActionService, globalExpandable: ExpandableRowsCount, expand: DatagridIfExpandService, detailService: DetailService, displayMode: DisplayModeService, vcr: ViewContainerRef, renderer: Renderer2, el: ElementRef, commonStrings: ClrCommonStringsService);
+    constructor(selection: Selection_2<T>, rowActionService: RowActionService, globalExpandable: ExpandableRowsCount, expand: DatagridIfExpandService, detailService: DetailService, displayMode: DisplayModeService, vcr: ViewContainerRef, renderer: Renderer2, el: ElementRef, commonStrings: ClrCommonStringsService, items: Items, document: any);
     // (undocumented)
     _calculatedCells: ViewContainerRef;
     // (undocumented)
     checkboxId: string;
+    clearRanges(event: MouseEvent): void;
     set clrDgDetailCloseLabel(label: string);
     // (undocumented)
     get clrDgDetailCloseLabel(): string;
diff --git a/projects/angular/src/data/datagrid/datagrid-row.html b/projects/angular/src/data/datagrid/datagrid-row.html
index ac4bb8810b..6e0a562c77 100644
--- a/projects/angular/src/data/datagrid/datagrid-row.html
+++ b/projects/angular/src/data/datagrid/datagrid-row.html
@@ -2,7 +2,7 @@
   We need to wrap the #rowContent in label element if we are in rowSelectionMode.
   Clicking of that wrapper label will equate to clicking on the whole row, which triggers the checkbox to toggle.
 -->
-<label class="datagrid-row-clickable" *ngIf="selection.rowSelectionMode">
+<label class="datagrid-row-clickable" *ngIf="selection.rowSelectionMode" (mousedown)="clearRanges($event)">
   <clr-expandable-animation [clrExpandTrigger]="expandAnimationTrigger" *ngIf="expand.expandable">
     <ng-template [ngTemplateOutlet]="rowContent"></ng-template>
   </clr-expandable-animation>
@@ -53,7 +53,7 @@
               [attr.aria-label]="clrDgRowAriaLabel"
             />
             <!-- Usage of class clr-col-null here prevents clr-col-* classes from being added when a datagrid is wrapped inside clrForm -->
-            <label [for]="checkboxId" class="clr-control-label clr-col-null">
+            <label [for]="checkboxId" class="clr-control-label clr-col-null" (click)="clearRanges($event)">
               <span class="clr-sr-only">{{commonStrings.keys.select}}</span>
             </label>
           </div>
diff --git a/projects/angular/src/data/datagrid/datagrid-row.ts b/projects/angular/src/data/datagrid/datagrid-row.ts
index b127a5947b..cdb8d27f4f 100644
--- a/projects/angular/src/data/datagrid/datagrid-row.ts
+++ b/projects/angular/src/data/datagrid/datagrid-row.ts
@@ -4,6 +4,7 @@
  * The full license information can be found in LICENSE in the root directory of this project.
  */
 
+import { DOCUMENT } from '@angular/common';
 import {
   AfterContentInit,
   AfterViewInit,
@@ -11,6 +12,7 @@ import {
   ContentChildren,
   ElementRef,
   EventEmitter,
+  Inject,
   Injector,
   Input,
   Output,
@@ -33,6 +35,7 @@ import { SelectionType } from './enums/selection-type';
 import { DetailService } from './providers/detail.service';
 import { DisplayModeService } from './providers/display-mode.service';
 import { ExpandableRowsCount } from './providers/global-expandable-rows';
+import { Items } from './providers/items';
 import { RowActionService } from './providers/row-action-service';
 import { Selection } from './providers/selection';
 import { WrappedRow } from './wrapped-row';
@@ -74,6 +77,25 @@ export class ClrDatagridRow<T = any> implements AfterContentInit, AfterViewInit
 
   public expandAnimationTrigger = false;
 
+  /**
+   * The default behavior in Chrome and Firefox for shift-clicking on a label is to perform text-selection.
+   * This prevents our intended range-selection, because this text-selection overrides our shift-click event.
+   * We need to clear the stored selection range when shift-clicking. This will override the mostly unused shift-click
+   * selection browser functionality, which is inconsistently implemented in browsers anyway.
+   */
+  clearRanges(event: MouseEvent) {
+    if (event.shiftKey) {
+      this.document.getSelection().removeAllRanges();
+      // Firefox is too persistent about its text-selection behaviour. So we need to add a preventDefault();
+      // We should not try to enforce this on the other browsers, though, because their toggle cycle does not get canceled by
+      // the preventDefault() and they toggle the checkbox second time, effectively retrurning it to not-selected.
+      if (window.navigator.userAgent.indexOf('Firefox') !== -1) {
+        event.preventDefault();
+        this.toggle(true);
+      }
+    }
+  }
+
   constructor(
     public selection: Selection<T>,
     public rowActionService: RowActionService,
@@ -84,7 +106,9 @@ export class ClrDatagridRow<T = any> implements AfterContentInit, AfterViewInit
     private vcr: ViewContainerRef,
     private renderer: Renderer2,
     private el: ElementRef,
-    public commonStrings: ClrCommonStringsService
+    public commonStrings: ClrCommonStringsService,
+    private items: Items,
+    @Inject(DOCUMENT) private document: any
   ) {
     nbRow++;
     this.id = 'clr-dg-row' + nbRow;
@@ -127,6 +151,11 @@ export class ClrDatagridRow<T = any> implements AfterContentInit, AfterViewInit
     if (this.selection.selectionType === SelectionType.None) {
       this._selected = value as boolean;
     } else {
+      if (value && this.selection.selectionType === SelectionType.Multi) {
+        this.rangeSelect();
+      } else {
+        this.selection.rangeStart = null;
+      }
       this.selection.setSelected(this.item, value as boolean);
     }
   }
@@ -250,6 +279,33 @@ export class ClrDatagridRow<T = any> implements AfterContentInit, AfterViewInit
     );
   }
 
+  private rangeSelect() {
+    const items = this.items.displayed;
+    if (!items) {
+      return;
+    }
+    const startIx = items.indexOf(this.selection.rangeStart);
+    if (
+      this.selection.rangeStart &&
+      this.selection.current.includes(this.selection.rangeStart) &&
+      this.selection.shiftPressed &&
+      startIx !== -1
+    ) {
+      const endIx = items.indexOf(this.item);
+      // Using Set to remove duplicates
+      const newSelection = new Set(
+        this.selection.current.concat(items.slice(Math.min(startIx, endIx), Math.max(startIx, endIx) + 1))
+      );
+      this.selection.clearSelection();
+      this.selection.current.push(...newSelection);
+    } else {
+      // page number has changed or
+      // no Shift was pressed or
+      // rangeStart not yet set
+      this.selection.rangeStart = this.item;
+    }
+  }
+
   private subscriptions: Subscription[] = [];
 
   ngOnDestroy() {
diff --git a/projects/angular/src/data/datagrid/datagrid.spec.ts b/projects/angular/src/data/datagrid/datagrid.spec.ts
index 18fd099e6a..bda7666ba5 100644
--- a/projects/angular/src/data/datagrid/datagrid.spec.ts
+++ b/projects/angular/src/data/datagrid/datagrid.spec.ts
@@ -131,6 +131,24 @@ class MultiSelectionTest {
   @Input() selected: any[] = [];
 }
 
+@Component({
+  template: `
+    <clr-datagrid [(clrDgSelected)]="selected">
+      <clr-dg-column>First</clr-dg-column>
+      <clr-dg-column>Second</clr-dg-column>
+
+      <clr-dg-row *clrDgItems="let item of items" [clrDgItem]="item">
+        <clr-dg-cell>{{ item }}</clr-dg-cell>
+        <clr-dg-cell>{{ item * item }}</clr-dg-cell>
+      </clr-dg-row>
+    </clr-datagrid>
+  `,
+})
+class MultiSelectionSimpleTest {
+  items: any[] = [1, 2, 3, 4, 5, 6, 7];
+  selected: any[] = [];
+}
+
 @Component({
   template: `
     <clr-datagrid [(clrDgSingleSelected)]="selected" clrDgSingleSelectionAriaLabel="Select row from Datagrid">
@@ -988,7 +1006,7 @@ export default function (): void {
       });
     });
 
-    describe('Multi selection', function () {
+    describe('Multi selection (OnPush)', function () {
       let context: TestContext<ClrDatagrid<number>, OnPushTest>;
       let selection: Selection<number>;
 
@@ -1011,6 +1029,103 @@ export default function (): void {
       });
     });
 
+    describe('Multi selection', function () {
+      let context: TestContext<ClrDatagrid<number>, MultiSelectionSimpleTest>;
+      let selection: Selection<number>;
+
+      beforeEach(function () {
+        context = this.create(ClrDatagrid, MultiSelectionSimpleTest, [Selection]);
+        selection = context.getClarityProvider(Selection) as Selection<number>;
+      });
+
+      describe('Range selection', function () {
+        let checkboxes: HTMLElement[];
+
+        beforeEach(function () {
+          checkboxes = Array.from(context.clarityElement.querySelectorAll('input[type=checkbox]')) as HTMLElement[];
+        });
+
+        it('updates selection independently without Shift key', function () {
+          // We use .clr-control-label because the datagrid implementation hides the
+          // real checkbox and only leaves visible the label area.
+          expect(checkboxes.length).toEqual(8); // "select all" option in header included
+          checkboxes[1].click();
+          expect(selection.current).toEqual([1]);
+          checkboxes[3].click();
+          expect(selection.current).toEqual([1, 3]);
+        });
+
+        it('updates selection range when Shift key pressed', function () {
+          checkboxes[1].click();
+          expect(selection.current).toEqual([1]);
+          expect(selection.shiftPressed).toBeFalse();
+          document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Shift' }));
+          expect(selection.shiftPressed).toBeTrue();
+          checkboxes[3].click();
+          document.body.dispatchEvent(new KeyboardEvent('keyup', { key: 'Shift' }));
+          expect(selection.shiftPressed).toBeFalse();
+          expect(selection.current).toEqual([1, 2, 3]);
+        });
+
+        it('updates selection range in reverse order', function () {
+          checkboxes[3].click();
+          expect(selection.current).toEqual([3]);
+          document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Shift' }));
+          checkboxes[1].click();
+          document.body.dispatchEvent(new KeyboardEvent('keyup', { key: 'Shift' }));
+          // We don't really care about the order, do we?
+          expect(selection.current.every(x => [1, 2, 3].includes(x))).toBeTrue();
+        });
+
+        it('can update ranges in a sequence, without releasing Shift', function () {
+          // first range
+          checkboxes[1].click();
+          expect(selection.current).toEqual([1]);
+          document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Shift' }));
+          checkboxes[3].click();
+          expect(selection.current).toEqual([1, 2, 3]);
+          // second range
+          checkboxes[5].click();
+          expect(selection.current).toEqual([1, 2, 3, 4, 5]);
+          checkboxes[7].click();
+          document.body.dispatchEvent(new KeyboardEvent('keyup', { key: 'Shift' }));
+          // final state
+          expect(selection.current.every(x => [1, 2, 3, 4, 5, 6, 7].includes(x))).toBeTrue();
+        });
+        it('can update ranges in a sequence, releasing Shift', function () {
+          // first range
+          checkboxes[1].click();
+          expect(selection.current).toEqual([1]);
+          document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Shift' }));
+          checkboxes[3].click();
+          document.body.dispatchEvent(new KeyboardEvent('keyup', { key: 'Shift' }));
+          expect(selection.current).toEqual([1, 2, 3]);
+          // second range
+          checkboxes[5].click();
+          expect(selection.current).toEqual([1, 2, 3, 5]);
+          document.body.dispatchEvent(new KeyboardEvent('keydown', { key: 'Shift' }));
+          checkboxes[7].click();
+          document.body.dispatchEvent(new KeyboardEvent('keyup', { key: 'Shift' }));
+          expect(selection.current.includes(4)).toBeFalse();
+          // final state
+          expect(selection.current.every(x => [1, 2, 3, 5, 6, 7].includes(x))).toBeTrue();
+        });
+        it('can deselect items inside a range', fakeAsync(function () {
+          // define range
+          selection.current.push(1, 2, 3, 4, 5, 6, 7);
+          context.detectChanges();
+          tick();
+          // // deselect inside range
+          checkboxes[2].click();
+          checkboxes[4].click();
+          checkboxes[6].click();
+          context.detectChanges();
+          tick();
+          expect(selection.current).toEqual([1, 3, 5, 7]);
+        }));
+      });
+    });
+
     describe('Chocolate', function () {
       describe('clrDgItems', function () {
         it("doesn't taunt with chocolate on actionable rows", function () {
diff --git a/projects/angular/src/data/datagrid/datagrid.ts b/projects/angular/src/data/datagrid/datagrid.ts
index 37afe42585..36ce68cf8e 100644
--- a/projects/angular/src/data/datagrid/datagrid.ts
+++ b/projects/angular/src/data/datagrid/datagrid.ts
@@ -4,6 +4,7 @@
  * The full license information can be found in LICENSE in the root directory of this project.
  */
 
+import { DOCUMENT } from '@angular/common';
 import {
   AfterContentInit,
   AfterViewInit,
@@ -14,6 +15,7 @@ import {
   EventEmitter,
   Inject,
   Input,
+  NgZone,
   OnDestroy,
   Output,
   QueryList,
@@ -21,7 +23,7 @@ import {
   ViewChild,
   ViewContainerRef,
 } from '@angular/core';
-import { combineLatest, Subscription } from 'rxjs';
+import { combineLatest, fromEvent, Subscription } from 'rxjs';
 
 import { ClrCommonStringsService } from '../../utils/i18n/common-strings.service';
 import { UNIQUE_ID, UNIQUE_ID_PROVIDER } from '../../utils/id-generator/id-generator.service';
@@ -87,11 +89,13 @@ export class ClrDatagrid<T = any> implements AfterContentInit, AfterViewInit, On
     private renderer: Renderer2,
     public detailService: DetailService,
     @Inject(UNIQUE_ID) datagridId: string,
+    @Inject(DOCUMENT) private document: any,
     private el: ElementRef,
     private page: Page,
     public commonStrings: ClrCommonStringsService,
     private columnsService: ColumnsService,
-    private keyNavigation: KeyNavigationGridController
+    private keyNavigation: KeyNavigationGridController,
+    private zone: NgZone
   ) {
     this.selectAllId = 'clr-dg-select-all-' + datagridId;
     this.detailService.id = datagridId;
@@ -326,6 +330,23 @@ export class ClrDatagrid<T = any> implements AfterContentInit, AfterViewInit, On
         }
       })
     );
+
+    // We need to preserve shift state, so it can be used on selection change, regardless of the input event
+    // that triggered the change. This helps us to easily resolve the k/b only case together with the mouse selection case.
+    this.zone.runOutsideAngular(() => {
+      this._subscriptions.push(
+        fromEvent(this.document.body, 'keydown').subscribe((event: KeyboardEvent) => {
+          if (event.key === 'Shift') {
+            this.selection.shiftPressed = true;
+          }
+        }),
+        fromEvent(this.document.body, 'keyup').subscribe((event: KeyboardEvent) => {
+          if (event.key === 'Shift') {
+            this.selection.shiftPressed = false;
+          }
+        })
+      );
+    });
   }
 
   /**
diff --git a/projects/angular/src/data/datagrid/providers/selection.ts b/projects/angular/src/data/datagrid/providers/selection.ts
index ebd0934d25..c4ea3d4976 100644
--- a/projects/angular/src/data/datagrid/providers/selection.ts
+++ b/projects/angular/src/data/datagrid/providers/selection.ts
@@ -239,6 +239,15 @@ export class Selection<T = any> {
     this.updateCurrent(value, true);
   }
 
+  /**
+   * Last selection, for use in range selection.
+   */
+  public rangeStart: T;
+  /**
+   * Shift key state, for use in range selection.
+   */
+  public shiftPressed = false;
+
   private valueCollector: Subject<T[]> = new Subject<T[]>();
   public updateCurrent(value: T[], emit: boolean) {
     this._current = value;