6636-custom-editor: Adds a prototype of custom editors contributed by extensions with this functionality:

- Adds a new contribution point for custom editors.
- Adds API for registering a custom editor providers.
- Implements CustomEditor extension API - based on VSCode (excluding backup functionality not implemented in this PR).
- Adds CustomEditorWidget extending WebviewWidget containing a model reference to CustomEditorModel.
- Supports two CustomEditorModel implementations: CustomTextEditorModel for text documents and MainCustomEditorModel for binary documents.
- Registers openHandlers for CustomEditors.
- Adds `openWith` command for selecting which editor to use when openning a resource.
- Adds Undo/Redo functionality for CustomEditors.

Signed-off-by: Dan Arad <dan.arad@sap.com>

Author: danarad05

packages/callhierarchy/src/common/glob.ts

@@ -25,7 +25,6 @@ import * as paths from './paths';
 import { CharCode } from '@theia/core/lib/common/char-code';
 
 /* eslint-disable @typescript-eslint/no-shadow, no-null/no-null */
-
 export interface IExpression {
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     [pattern: string]: boolean | SiblingClause | any;

packages/core/src/browser/opener-service.ts

@@ -76,7 +76,7 @@ export interface OpenerService {
      */
     getOpener(uri: URI, options?: OpenerOptions): Promise<OpenHandler>;
     /**
-     * Event that fires when a new opener is added or removed
+     * Event that fires when a new opener is added or removed.
      */
     onOpenersStateChanged?: Event<void>;
 }
@@ -88,8 +88,8 @@ export async function open(openerService: OpenerService, uri: URI, options?: Ope
 
 @injectable()
 export class DefaultOpenerService implements OpenerService {
-    // Containing OpenHandlers created for CustomEditor contributions
-    protected readonly additionalHandlers: OpenHandler[] = [];
+    // Collection of open-handlers for custom-editor contributions.
+    protected readonly customEditorOpenHandlers: OpenHandler[] = [];
 
     protected readonly onOpenersStateChangedEmitter = new Emitter<void>();
     readonly onOpenersStateChanged = this.onOpenersStateChangedEmitter.event;
@@ -100,11 +100,11 @@ export class DefaultOpenerService implements OpenerService {
     ) { }
 
     public addHandler(openHandler: OpenHandler): Disposable {
-        this.additionalHandlers.push(openHandler);
+        this.customEditorOpenHandlers.push(openHandler);
         this.onOpenersStateChangedEmitter.fire();
 
         return Disposable.create(() => {
-            this.additionalHandlers.splice(this.additionalHandlers.indexOf(openHandler), 1);
+            this.customEditorOpenHandlers.splice(this.customEditorOpenHandlers.indexOf(openHandler), 1);
             this.onOpenersStateChangedEmitter.fire();
         });
     }
@@ -135,7 +135,7 @@ export class DefaultOpenerService implements OpenerService {
     protected getHandlers(): OpenHandler[] {
         return [
             ...this.handlersProvider.getContributions(),
-            ...this.additionalHandlers
+            ...this.customEditorOpenHandlers
         ];
     }
 

packages/monaco/src/browser/monaco-editor-service.ts

@@ -20,11 +20,11 @@ import { OpenerService, open, WidgetOpenMode, ApplicationShell, PreferenceServic
 import { EditorWidget, EditorOpenerOptions, EditorManager, CustomEditorWidget } from '@theia/editor/lib/browser';
 import { MonacoEditor } from './monaco-editor';
 import { MonacoToProtocolConverter } from './monaco-to-protocol-converter';
+import { MonacoEditorModel } from './monaco-editor-model';
 
 import ICodeEditor = monaco.editor.ICodeEditor;
 import CommonCodeEditor = monaco.editor.CommonCodeEditor;
 import IResourceInput = monaco.editor.IResourceInput;
-import { MonacoEditorModel } from './monaco-editor-model';
 
 decorate(injectable(), monaco.services.CodeEditorServiceImpl);
 

packages/plugin-ext/src/main/browser/custom-editors/custom-editor-contribution.ts

@@ -15,27 +15,16 @@
  ********************************************************************************/
 
 import { injectable, inject } from 'inversify';
-import { CommandRegistry, CommandContribution, SelectionService } from '@theia/core/lib/common';
+import { CommandRegistry, CommandContribution } from '@theia/core/lib/common';
 import { ApplicationShell, CommonCommands } from '@theia/core/lib/browser';
 import { CustomEditorWidget } from './custom-editor-widget';
-import { FileService } from '@theia/filesystem/lib/browser/file-service';
-import { FileDialogService } from '@theia/filesystem/lib/browser';
 
 @injectable()
 export class CustomEditorContribution implements CommandContribution {
 
     @inject(ApplicationShell)
     protected readonly shell: ApplicationShell;
 
-    @inject(FileService)
-    protected readonly fileService: FileService;
-
-    @inject(FileDialogService)
-    protected readonly fileDialogService: FileDialogService;
-
-    @inject(SelectionService)
-    protected readonly selectionService: SelectionService;
-
     registerCommands(commands: CommandRegistry): void {
         commands.registerHandler(CommonCommands.UNDO.id, {
             isEnabled: () => this.shell.activeWidget instanceof CustomEditorWidget,

packages/workspace/src/browser/workspace-commands.ts

@@ -346,7 +346,7 @@ export class WorkspaceCommandContribution implements CommandContribution {
             registry.registerCommand(openWithCommand, this.newUriAwareCommandHandler({
                 execute: uri => opener.open(uri),
                 isEnabled: uri => opener.canHandle(uri) > 0,
-                isVisible: uri => opener.canHandle(uri) > 0 && this.areMultipleOpenHandlersPresent(uri)
+                isVisible: uri => opener.canHandle(uri) > 0 && this.areMultipleOpenHandlersPresent(this.openers, uri)
             }));
         }
     }
@@ -485,9 +485,9 @@ export class WorkspaceCommandContribution implements CommandContribution {
         }
     }
 
-    protected areMultipleOpenHandlersPresent(uri: URI): boolean {
+    protected areMultipleOpenHandlersPresent(openers: OpenHandler[], uri: URI): boolean {
         let count = 0;
-        for (const opener of this.openers) {
+        for (const opener of openers) {
             if (opener.canHandle(uri) > 0) {
                 count++;
             }