GLSP-211: Revise TypeHints and server side feedback for creation actions

- Refactor EdgeTypeHint definition
  -  Add a new 'dynamic' property, indicating that new edges need and additional check with the server before allowing creation
  -  Make source/target element type ids properties optional
  If not defined, all potential element types are considered to be valid sources/targets
- Add `RequestEdgeCheckAction` and `EdgeCheckResultAction` response to implement
 the dynamic check
- Update the EdgeCreationTool to check with the server when trying to
create a new edge configured as Dynamic

-Refactor `TypeHintsProvider` and `ApplyTypeHintsCommand
 - Simplify type-hints aware can connect implementation. Just validate against the source/target types
    of the edge hint that is applicable for the given routable 
  - Ensure that the default (i.e. class-level implementation) of  `canConnect` is called if no typehint is applicable to the given routable
 - Remove `getValidEdgeElementTypes` function from `TypeHintsProvider`.  Was only used
    for the old type-hints aware `canConnect` implementation. Is no longer needed and incomplete anyways (does not consider nested subtypes)
- Add tests for type-hints feature
  Fixes eclipse-glsp/glsp#45
- Remove `hasCompatibleType` utility function from `smodel-util` as it is no longer used
  and the implementation was incomplete anyways (did not consider nested subtypes)

- Also: Don't use stroked lines for edges until eclipse-glsp/glsp/issues/1083 is fixed

Part of eclipse-glsp/glsp/issues/211

Co-authored-by: Camille Letavernier <[email protected] >

packages/client/css/glsp-sprotty.css

@@ -98,9 +98,6 @@
 .sprotty-edge.selected {
     stroke: #1d80d1;
     stroke-width: 1.5px;
-    stroke-dashoffset: 5;
-    stroke-dasharray: 5, 5;
-    stroke-linecap: round;
 }
 
 .sprotty-edge.mouseover:not(.selected) .arrow,

packages/client/src/features/hints/type-hint-provider.ts

@@ -0,0 +1,248 @@
+/********************************************************************************
+ * Copyright (c) 2019-2023 EclipseSource 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 { inject, injectable } from 'inversify';
+import {
+    Action,
+    CommandExecutionContext,
+    Connectable,
+    EdgeTypeHint,
+    IActionHandler,
+    RequestTypeHintsAction,
+    SEdge,
+    SModelElement,
+    SModelElementSchema,
+    SModelRoot,
+    SRoutableElement,
+    SShapeElement,
+    SetTypeHintsAction,
+    ShapeTypeHint,
+    TYPES,
+    TypeHint,
+    connectableFeature,
+    deletableFeature,
+    editFeature,
+    isConnectable,
+    moveFeature
+} from '~glsp-sprotty';
+import { GLSPActionDispatcher } from '../../base/action-dispatcher';
+import { IFeedbackActionDispatcher } from '../../base/feedback/feedback-action-dispatcher';
+import { FeedbackCommand } from '../../base/feedback/feedback-command';
+import { IDiagramStartup } from '../../base/model/diagram-loader';
+import { getElementTypeId } from '../../utils/smodel-util';
+import { resizeFeature } from '../change-bounds/model';
+import { reconnectFeature } from '../reconnect/model';
+import { containerFeature, isContainable, reparentFeature } from './model';
+
+/**
+ * Is dispatched by the {@link TypeHintProvider} to apply the type hints received from the server
+ * onto the graphical model. The action is dispatched as persistent feedback to ensure the applied type hints
+ * don't get lost after a server-side model update.
+ */
+export interface ApplyTypeHintsAction extends Action {
+    kind: typeof ApplyTypeHintsAction.KIND;
+}
+
+export namespace ApplyTypeHintsAction {
+    export const KIND = 'applyTypeHints';
+
+    export function is(object: any): object is ApplyTypeHintsAction {
+        return Action.hasKind(object, KIND);
+    }
+
+    export function create(): ApplyTypeHintsAction {
+        return { kind: KIND };
+    }
+}
+
+type CanConnectFn = Connectable['canConnect'];
+
+/**
+ * Command that processes the entire model and for each model element applies its
+ * type hints i.e. translates the type hint information into corresponding model features
+ * and adds/removes them from the model element.
+ */
+@injectable()
+export class ApplyTypeHintsCommand extends FeedbackCommand {
+    public static KIND = ApplyTypeHintsAction.KIND;
+    public override readonly priority = 10;
+
+    @inject(TYPES.ITypeHintProvider)
+    protected typeHintProvider: ITypeHintProvider;
+
+    constructor(@inject(TYPES.Action) protected action: ApplyTypeHintsAction) {
+        super();
+    }
+
+    execute(context: CommandExecutionContext): SModelRoot {
+        context.root.index.all().forEach(element => {
+            if (element instanceof SShapeElement || element instanceof SModelRoot) {
+                return this.applyShapeTypeHint(element);
+            }
+            if (element instanceof SEdge) {
+                this.applyEdgeTypeHint(element);
+            }
+        });
+        return context.root;
+    }
+
+    protected applyEdgeTypeHint(element: SModelElement): void {
+        const hint = this.typeHintProvider.getEdgeTypeHint(element);
+
+        if (hint && element.features instanceof Set) {
+            addOrRemove(element.features, deletableFeature, hint.deletable);
+            addOrRemove(element.features, editFeature, hint.routable);
+            addOrRemove(element.features, reconnectFeature, hint.repositionable);
+        }
+    }
+
+    protected applyShapeTypeHint(element: SModelElement): void {
+        const hint = this.typeHintProvider.getShapeTypeHint(element);
+        if (hint && element.features instanceof Set) {
+            addOrRemove(element.features, deletableFeature, hint.deletable);
+            addOrRemove(element.features, moveFeature, hint.repositionable);
+            addOrRemove(element.features, resizeFeature, hint.resizable);
+            addOrRemove(element.features, reparentFeature, hint.reparentable);
+
+            addOrRemove(element.features, containerFeature, true);
+            if (isContainable(element)) {
+                element.isContainableElement = input => this.isContainableElement(input, hint);
+            }
+
+            const fallbackCanConnect = isConnectable(element) ? element.canConnect.bind(element) : undefined;
+            addOrRemove(element.features, connectableFeature, true);
+            if (isConnectable(element)) {
+                element.canConnect = (routable, role) => this.canConnect(routable, role, element, fallbackCanConnect);
+            }
+        }
+    }
+
+    /**
+     * Type hints aware wrapper function for  `Connectable.canConnect`. After type hints have been applied
+     * the `canConnect` implementation of `connectable` model elements  (with a matching hint) will forward to this method.
+     */
+    protected canConnect(
+        routable: SRoutableElement,
+        role: 'source' | 'target',
+        element: SModelElement,
+        fallbackCanConnect?: CanConnectFn
+    ): boolean {
+        const edgeHint = this.typeHintProvider.getEdgeTypeHint(routable.type);
+        if (!edgeHint) {
+            return fallbackCanConnect?.(routable, role) ?? false;
+        }
+        const validElementIds = role === 'source' ? edgeHint.sourceElementTypeIds : edgeHint.targetElementTypeIds;
+        // If no source/target element ids are defined in the hint all elements are considered valid
+        if (!validElementIds) {
+            return true;
+        }
+        const elementType = element.type + ':';
+        return validElementIds.some(type => elementType.startsWith(type));
+    }
+
+    /**
+     * Type hints aware wrapper function for  `Containable.isContainableElement`. After type hints have been applied
+     * the `isContainableElement` implementation of `containable` model elements (with a matching hint) will forward to this method.
+     */
+    protected isContainableElement(input: SModelElement | SModelElementSchema | string, hint: ShapeTypeHint): boolean {
+        const elemenType = getElementTypeId(input) + ':';
+        return hint.containableElementTypeIds?.some(type => elemenType.startsWith(type)) ?? false;
+    }
+}
+
+function addOrRemove(features: Set<symbol>, feature: symbol, add: boolean): void {
+    if (add && !features.has(feature)) {
+        features.add(feature);
+    } else if (!add && features.has(feature)) {
+        features.delete(feature);
+    }
+}
+
+/**
+ * Provides query methods for retrieving the type hint that is applicable for a given model element.
+ * If there is no type hint registered for the given element type the hint of the most concrete subtype (if any)
+ * is returned instead. Subtypes are declared with a `:` delimiter.
+ * For example consider the type `node:task:manual`. Then the provider fist checks wether there is
+ * a type hint registered for `node:task:manual`. If not it checks wether there is one registered
+ * for `node:task` and finally it checks wether there is a type hint for `node`.
+ */
+export interface ITypeHintProvider {
+    /**
+     * Retrieve the most applicable {@link ShapeTypeHint} for the given model element.
+     *
+     * @param input The model element whose type hint should be retrieved
+     * @returns The most applicable hint of the given element or `undefined` if no matching hint is registered.
+     */
+    getShapeTypeHint(input: SModelElement | SModelElementSchema | string): ShapeTypeHint | undefined;
+    /**
+     * Retrieve the most applicable {@link EdgeTypeHint} for the given model element.
+     *
+     * @param input The model element whose type hint should be retrieved
+     * @returns The most applicable hint of the given element or `undefined` if no matching hint is registered.
+     */
+    getEdgeTypeHint(input: SModelElement | SModelElementSchema | string): EdgeTypeHint | undefined;
+}
+
+@injectable()
+export class TypeHintProvider implements IActionHandler, ITypeHintProvider, IDiagramStartup {
+    @inject(TYPES.IFeedbackActionDispatcher)
+    protected feedbackActionDispatcher: IFeedbackActionDispatcher;
+
+    @inject(GLSPActionDispatcher)
+    protected actionDispatcher: GLSPActionDispatcher;
+
+    protected shapeHints: Map<string, ShapeTypeHint> = new Map();
+    protected edgeHints: Map<string, EdgeTypeHint> = new Map();
+
+    handle(action: SetTypeHintsAction): void {
+        this.shapeHints.clear();
+        this.edgeHints.clear();
+        action.shapeHints.forEach(hint => this.shapeHints.set(hint.elementTypeId, hint));
+        action.edgeHints.forEach(hint => this.edgeHints.set(hint.elementTypeId, hint));
+        this.feedbackActionDispatcher.registerFeedback(this, [ApplyTypeHintsAction.create()]);
+    }
+
+    getShapeTypeHint(input: SModelElement | SModelElementSchema | string): ShapeTypeHint | undefined {
+        return this.getTypeHint(input, this.shapeHints);
+    }
+
+    getEdgeTypeHint(input: SModelElement | SModelElementSchema | string): EdgeTypeHint | undefined {
+        return this.getTypeHint(input, this.edgeHints);
+    }
+
+    protected getTypeHint<T extends TypeHint>(input: SModelElement | SModelElementSchema | string, hints: Map<string, T>): T | undefined {
+        const type = getElementTypeId(input);
+        let hint = hints.get(type);
+        // Check subtypes
+        if (hint === undefined) {
+            const subtypes = type.split(':');
+            while (hint === undefined && subtypes.length > 0) {
+                subtypes.pop();
+                hint = hints.get(subtypes.join(':'));
+                if (hint) {
+                    // add received subtype hint to map to avoid future recomputation
+                    hints.set(type, hint);
+                    break;
+                }
+            }
+        }
+        return hint;
+    }
+
+    async postRequestModel(): Promise<void> {
+        const setTypeHintsAction = await this.actionDispatcher.request(RequestTypeHintsAction.create());
+        this.handle(setTypeHintsAction);
+    }
+}

packages/client/src/features/hints/type-hints-module.ts

@@ -14,7 +14,7 @@
  * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
  ********************************************************************************/
 import { FeatureModule, SetTypeHintsAction, TYPES, bindAsService, configureActionHandler, configureCommand } from '~glsp-sprotty';
-import { ApplyTypeHintsCommand, TypeHintProvider } from './type-hints';
+import { ApplyTypeHintsCommand, TypeHintProvider } from './type-hint-provider';
 
 export const typeHintsModule = new FeatureModule((bind, unbind, isBound) => {
     const context = { bind, unbind, isBound };