fix selection and improve active text editor behaviour

packages/plugin-ext/src/main/browser/main-context.ts

@@ -109,7 +109,7 @@ export function setUpPluginApi(rpc: RPCProtocol, container: interfaces.Container
     rpc.set(PLUGIN_RPC_CONTEXT.NOTEBOOK_RENDERERS_MAIN, new NotebookRenderersMainImpl(rpc, container));
     const notebookEditorsMain = new NotebookEditorsMainImpl(rpc, container);
     rpc.set(PLUGIN_RPC_CONTEXT.NOTEBOOK_EDITORS_MAIN, notebookEditorsMain);
-    rpc.set(PLUGIN_RPC_CONTEXT.NOTEBOOK_DOCUMENTS_AND_EDITORS_MAIN, new NotebooksAndEditorsMain(rpc, container, notebookDocumentsMain, notebookEditorsMain));
+    rpc.set(PLUGIN_RPC_CONTEXT.NOTEBOOK_DOCUMENTS_AND_EDITORS_MAIN, new NotebooksAndEditorsMain(rpc, container, tabsMain, notebookDocumentsMain, notebookEditorsMain));
     rpc.set(PLUGIN_RPC_CONTEXT.NOTEBOOK_KERNELS_MAIN, new NotebookKernelsMainImpl(rpc, container));
 
     const editorsMain = new TextEditorsMainImpl(editorsAndDocuments, documentsMain, rpc, container);

packages/plugin-ext/src/main/browser/notebooks/notebook-documents-and-editors-main.ts

@@ -31,6 +31,7 @@ import { NotebookEditorsMainImpl } from './notebook-editors-main';
 import { NotebookDocumentsMainImpl } from './notebook-documents-main';
 import { diffMaps, diffSets } from '../../../common/collections';
 import { Mutex } from 'async-mutex';
+import { TabsMainImpl } from '../tabs/tabs-main';
 
 interface NotebookAndEditorDelta {
     removedDocuments: UriComponents[];
@@ -96,6 +97,7 @@ export class NotebooksAndEditorsMain implements NotebookDocumentsAndEditorsMain
     constructor(
         rpc: RPCProtocol,
         container: interfaces.Container,
+        tabsMain: TabsMainImpl,
         protected readonly notebookDocumentsMain: NotebookDocumentsMainImpl,
         protected readonly notebookEditorsMain: NotebookEditorsMainImpl
     ) {
@@ -113,7 +115,12 @@ export class NotebooksAndEditorsMain implements NotebookDocumentsAndEditorsMain
         // this.WidgetManager.onActiveEditorChanged(() => this.updateState(), this, this.disposables);
         this.notebookEditorService.onDidAddNotebookEditor(async editor => this.handleEditorAdd(editor), this, this.disposables);
         this.notebookEditorService.onDidRemoveNotebookEditor(async editor => this.handleEditorRemove(editor), this, this.disposables);
-        this.notebookEditorService.onDidChangeCurrentEditor(async editor => this.updateState(editor), this, this.disposables);
+        this.notebookEditorService.onDidChangeCurrentEditor(async editor => {
+            if (editor) {
+                await tabsMain.waitForWidget(editor);
+            }
+            this.updateState(editor);
+        }, this, this.disposables);
     }
 
     dispose(): void {

packages/plugin-ext/src/main/browser/text-editor-main.ts

@@ -388,11 +388,16 @@ export class TextEditorPropertiesMain {
         if (editor && editor instanceof MonacoEditor) {
             result = editor.getControl().getSelections() || undefined;
         } else if (editor && editor instanceof SimpleMonacoEditor) {
-            result = editor.getControl().getSelections()?.map(selection => new monaco.Selection(
-                selection.startLineNumber,
-                selection.startColumn,
-                selection.positionLineNumber,
-                selection.positionColumn));
+            result = editor.getControl().getSelections()?.map(selection => {
+                const monacoSelection = new monaco.Selection(
+                    selection.selectionStartLineNumber,
+                    selection.selectionStartColumn,
+                    selection.positionLineNumber,
+                    selection.positionColumn);
+                monacoSelection.setStartPosition(selection.startLineNumber, selection.startColumn);
+                monacoSelection.setEndPosition(selection.endLineNumber, selection.endColumn);
+                return monacoSelection;
+            });
         }
 
         if (!result && prevProperties) {

packages/plugin-ext/src/plugin/notebook/notebooks.ts

@@ -20,7 +20,7 @@
 
 import { CancellationToken, Disposable, DisposableCollection, Emitter, Event, URI } from '@theia/core';
 import { URI as TheiaURI } from '../types-impl';
-import * as theia from '@theia/plugin';
+import type * as theia from '@theia/plugin';
 import {
     NotebookCellStatusBarListDto, NotebookDataDto,
     NotebookDocumentsAndEditorsDelta, NotebookDocumentShowOptions, NotebookDocumentsMain, NotebookEditorAddData, NotebookEditorsMain, NotebooksExt, NotebooksMain, Plugin,
@@ -337,12 +337,14 @@ export class NotebooksExtImpl implements NotebooksExt {
                 console.error(`FAILED to find active notebook editor ${delta.newActiveEditor}`);
             }
             this.activeNotebookEditor = this.editors.get(delta.newActiveEditor);
-            if (this.textDocumentsAndEditors.activeEditor()?.document.uri.path !== this.activeNotebookEditor?.notebookData.uri.path) {
-                this.textDocumentsAndEditors.acceptEditorsAndDocumentsDelta({
-                    newActiveEditor: null
-                });
-            }
             this.onDidChangeActiveNotebookEditorEmitter.fire(this.activeNotebookEditor?.apiEditor);
+
+            const newActiveCell = this.activeApiNotebookEditor?.notebook.cellAt(this.activeApiNotebookEditor.selection.start);
+            this.textDocumentsAndEditors.acceptEditorsAndDocumentsDelta({
+                newActiveEditor: newActiveCell?.kind === 2 /* code cell */ ?
+                    this.textDocumentsAndEditors.allEditors().find(editor => editor.document.uri.toString() === newActiveCell.document.uri.toString())?.id ?? null :
+                    null
+            });
         }
     }