#1029 Introduce moving and zooming of the viewport and elements via t…

…he keyboard (eclipse-glsp#241)

- Introduce tool and handler for moving viewport and elements via keyboard shortcut
- Introduce tool and handler for zooming viewport and elements via keyboard shortcut
- Provide tool for an improved implementation for deselecting elements

Part of eclipse-glsp/glsp#1029

packages/client/src/features/accessibility/di.config.ts

@@ -15,12 +15,16 @@
  ********************************************************************************/
 
 import { ContainerModule } from 'inversify';
+import { configureMoveZoom } from './move-zoom/di.config';
 import { configureSearchPaletteModule } from './search/di.config';
+import { configureViewKeyTools } from './view-key-tools/di.config';
 
 /**
  * Enables the accessibility tools for a keyboard-only-usage
  */
-export const glspAccessibilityModule = new ContainerModule((bind, _unbind, isBound, rebind) => {
-    const context = { bind, isBound, rebind };
+export const glspAccessibilityModule = new ContainerModule((bind, unbind, isBound, rebind) => {
+    const context = { bind, unbind, isBound, rebind };
+    configureViewKeyTools(context);
+    configureMoveZoom(context);
     configureSearchPaletteModule(context);
 });

packages/client/src/features/accessibility/move-zoom/di.config.ts

@@ -0,0 +1,43 @@
+/********************************************************************************
+ * Copyright (c) 2023 Business Informatics Group (TU Wien) and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { BindingContext } from '@eclipse-glsp/protocol';
+import { ContainerModule } from 'inversify';
+import { configureActionHandler } from 'sprotty';
+import { MoveElementAction, MoveElementHandler, MoveViewportAction, MoveViewportHandler } from './move-handler';
+import { ZoomElementAction, ZoomElementHandler, ZoomViewportAction, ZoomViewportHandler } from './zoom-handler';
+
+/**
+ * Handles move and zoom actions.
+ */
+export const glspMoveZoomModule = new ContainerModule((bind, unbind, isBound, rebind) => {
+    const context = { bind, unbind, isBound, rebind };
+    configureMoveZoom(context);
+});
+
+export function configureMoveZoom(context: BindingContext): void {
+    context.bind(MoveViewportHandler).toSelf().inSingletonScope();
+    context.bind(MoveElementHandler).toSelf().inSingletonScope();
+
+    context.bind(ZoomViewportHandler).toSelf().inSingletonScope();
+    context.bind(ZoomElementHandler).toSelf().inSingletonScope();
+
+    configureActionHandler(context, MoveViewportAction.KIND, MoveViewportHandler);
+    configureActionHandler(context, MoveElementAction.KIND, MoveElementHandler);
+
+    configureActionHandler(context, ZoomViewportAction.KIND, ZoomViewportHandler);
+    configureActionHandler(context, ZoomElementAction.KIND, ZoomElementHandler);
+}

packages/client/src/features/accessibility/move-zoom/move-handler.ts

@@ -0,0 +1,198 @@
+/********************************************************************************
+ * Copyright (c) 2023 Business Informatics Group (TU Wien) and others.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the Eclipse
+ * Public License v. 2.0 are satisfied: GNU General Public License, version 2
+ * with the GNU Classpath Exception which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ ********************************************************************************/
+
+import { Action, ChangeBoundsOperation, Point, SetViewportAction, Viewport } from '@eclipse-glsp/protocol';
+import { inject, injectable } from 'inversify';
+import { throttle } from 'lodash';
+import { findParentByFeature, IActionDispatcher, IActionHandler, ICommand, isViewport, SModelRoot } from 'sprotty';
+import { EditorContextService } from '../../../base/editor-context-service';
+import { TYPES } from '../../../base/types';
+import { getElements, isSelectableAndBoundsAware, SelectableBoundsAware } from '../../../utils/smodel-util';
+
+/**
+ * Action for triggering moving of the viewport.
+ */
+export interface MoveViewportAction extends Action {
+    kind: typeof MoveViewportAction.KIND;
+    /**
+     * used to specify the amount to be moved in the x-axis
+     */
+    moveX: number;
+    /**
+     * used to specify the amount to be moved in the y-axis
+     */
+    moveY: number;
+}
+
+export namespace MoveViewportAction {
+    export const KIND = 'moveViewportAction';
+
+    export function is(object: any): object is MoveViewportAction {
+        return Action.hasKind(object, KIND);
+    }
+
+    export function create(moveX: number, moveY: number): MoveViewportAction {
+        return { kind: KIND, moveX, moveY };
+    }
+}
+
+/**
+ * Action for triggering moving of elements.
+ */
+export interface MoveElementAction extends Action {
+    kind: typeof MoveElementAction.KIND;
+    /**
+     * used to specify the elements to be zoomed in/out
+     */
+    elementIds: string[];
+    /**
+     * used to specify the amount to be moved in the x-axis
+     */
+    moveX: number;
+    /**
+     * used to specify the amount to be moved in the y-axis
+     */
+    moveY: number;
+}
+
+export namespace MoveElementAction {
+    export const KIND = 'moveElementAction';
+
+    export function is(object: any): object is MoveElementAction {
+        return Action.hasKind(object, KIND);
+    }
+
+    export function create(elementIds: string[], moveX: number, moveY: number): MoveElementAction {
+        return { kind: KIND, elementIds, moveX, moveY };
+    }
+}
+
+/* The MoveViewportHandler class is an implementation of the IActionHandler interface that handles
+moving of the viewport. */
+@injectable()
+export class MoveViewportHandler implements IActionHandler {
+    @inject(EditorContextService)
+    protected editorContextService: EditorContextService;
+
+    @inject(TYPES.IActionDispatcher) protected dispatcher: IActionDispatcher;
+    protected readonly throttledHandleViewportMove = throttle((action: MoveViewportAction) => this.handleMoveViewport(action), 150);
+
+    handle(action: Action): void | Action | ICommand {
+        if (MoveViewportAction.is(action)) {
+            this.throttledHandleViewportMove(action);
+        }
+    }
+
+    handleMoveViewport(action: MoveViewportAction): void {
+        const viewport = findParentByFeature(this.editorContextService.modelRoot, isViewport);
+        if (!viewport) {
+            return;
+        }
+        this.dispatcher.dispatch(this.moveViewport(viewport, action.moveX, action.moveY));
+    }
+
+    protected moveViewport(viewport: SModelRoot & Viewport, offsetX: number, offSetY: number): SetViewportAction {
+        const newViewport: Viewport = {
+            scroll: {
+                x: viewport.scroll.x + offsetX,
+                y: viewport.scroll.y + offSetY
+            },
+            zoom: viewport.zoom
+        };
+
+        return SetViewportAction.create(viewport.id, newViewport, { animate: true });
+    }
+}
+
+/* The MoveElementHandler class is an implementation of the IActionHandler interface that handles
+moving elements. */
+@injectable()
+export class MoveElementHandler implements IActionHandler {
+    @inject(EditorContextService)
+    protected editorContextService: EditorContextService;
+    @inject(TYPES.IActionDispatcher) protected dispatcher: IActionDispatcher;
+    protected readonly throttledHandleElementMove = throttle((action: MoveElementAction) => this.handleMoveElement(action), 150);
+
+    handle(action: Action): void | Action | ICommand {
+        if (MoveElementAction.is(action)) {
+            this.throttledHandleElementMove(action);
+        }
+    }
+
+    handleMoveElement(action: MoveElementAction): void {
+        const viewport = findParentByFeature(this.editorContextService.modelRoot, isViewport);
+        if (!viewport) {
+            return;
+        }
+
+        const elements = getElements(this.editorContextService.modelRoot.index, action.elementIds, isSelectableAndBoundsAware);
+
+        this.dispatcher.dispatchAll(this.move(viewport, elements, action.moveX, action.moveY));
+    }
+
+    protected getBounds(element: SelectableBoundsAware, offSetX: number, offSetY: number): Point {
+        return { x: element.bounds.x + offSetX, y: element.bounds.y + offSetY };
+    }
+
+    protected adaptViewport(
+        viewport: SModelRoot & Viewport,
+        newPoint: Point,
+        moveX: number,
+        moveY: number
+    ): MoveViewportAction | undefined {
+        if (
+            newPoint.x < viewport.scroll.x ||
+            newPoint.x > viewport.scroll.x + viewport.canvasBounds.width ||
+            newPoint.y < viewport.scroll.y ||
+            newPoint.y > viewport.scroll.y + viewport.canvasBounds.height
+        ) {
+            return MoveViewportAction.create(moveX, moveY);
+        }
+        return;
+    }
+
+    protected moveElement(element: SelectableBoundsAware, offSetX: number, offSetY: number): ChangeBoundsOperation {
+        return ChangeBoundsOperation.create([
+            {
+                elementId: element.id,
+                newSize: {
+                    width: element.bounds.width,
+                    height: element.bounds.height
+                },
+                newPosition: {
+                    x: element.bounds.x + offSetX,
+                    y: element.bounds.y + offSetY
+                }
+            }
+        ]);
+    }
+
+    protected move(viewport: SModelRoot & Viewport, selectedElements: SelectableBoundsAware[], deltaX: number, deltaY: number): Action[] {
+        const results: Action[] = [];
+
+        if (selectedElements.length !== 0) {
+            selectedElements.forEach(currentElement => {
+                results.push(this.moveElement(currentElement, deltaX, deltaY));
+                const newPosition = this.getBounds(currentElement, deltaX, deltaY);
+                const viewportAction = this.adaptViewport(viewport, newPosition, deltaX, deltaY);
+                if (viewportAction) {
+                    results.push(viewportAction);
+                }
+            });
+        }
+        return results;
+    }
+}