Make Notebook preferences registration substitutable

Implement the commonly employed pattern for preference contribution
registration to enable substitution of the Notebook preference schema.

Fixes #13913

Signed-off-by: Christian W. Damus <cdamus.ext@eclipsesource.com>

packages/notebook/src/browser/contributions/notebook-preferences.ts

@@ -19,7 +19,8 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { nls } from '@theia/core';
-import { PreferenceSchema } from '@theia/core/lib/browser';
+import { interfaces } from '@theia/core/shared/inversify';
+import { PreferenceContribution, PreferenceSchema } from '@theia/core/lib/browser';
 
 export namespace NotebookPreferences {
     export const NOTEBOOK_LINE_NUMBERS = 'notebook.lineNumbers';
@@ -81,3 +82,11 @@ export const notebookPreferenceSchema: PreferenceSchema = {
 
     }
 };
+
+export const NotebookPreferenceContribution = Symbol('NotebookPreferenceContribution');
+
+export function bindNotebookPreferences(bind: interfaces.Bind): void {
+    // We don't need a NotePreferenceConfiguration class, so there's no preference proxy to bind
+    bind(NotebookPreferenceContribution).toConstantValue({ schema: notebookPreferenceSchema });
+    bind(PreferenceContribution).toService(NotebookPreferenceContribution);
+}

packages/notebook/src/browser/notebook-frontend-module.ts

@@ -16,7 +16,7 @@
 import '../../src/browser/style/index.css';
 
 import { ContainerModule } from '@theia/core/shared/inversify';
-import { FrontendApplicationContribution, KeybindingContribution, LabelProviderContribution, OpenHandler, PreferenceContribution, WidgetFactory } from '@theia/core/lib/browser';
+import { FrontendApplicationContribution, KeybindingContribution, LabelProviderContribution, OpenHandler, WidgetFactory } from '@theia/core/lib/browser';
 import { ColorContribution } from '@theia/core/lib/browser/color-application-contribution';
 import { NotebookOpenHandler } from './notebook-open-handler';
 import { CommandContribution, MenuContribution, ResourceResolver, } from '@theia/core';
@@ -44,7 +44,7 @@ import { NotebookOutlineContribution } from './contributions/notebook-outline-co
 import { NotebookLabelProviderContribution } from './contributions/notebook-label-provider-contribution';
 import { NotebookOutputActionContribution } from './contributions/notebook-output-action-contribution';
 import { NotebookClipboardService } from './service/notebook-clipboard-service';
-import { notebookPreferenceSchema } from './contributions/notebook-preferences';
+import { bindNotebookPreferences } from './contributions/notebook-preferences';
 import { NotebookOptionsService } from './service/notebook-options';
 
 export default new ContainerModule((bind, unbind, isBound, rebind) => {
@@ -106,6 +106,6 @@ export default new ContainerModule((bind, unbind, isBound, rebind) => {
     bind(NotebookLabelProviderContribution).toSelf().inSingletonScope();
     bind(LabelProviderContribution).toService(NotebookLabelProviderContribution);
 
-    bind(PreferenceContribution).toConstantValue({ schema: notebookPreferenceSchema });
+    bindNotebookPreferences(bind);
     bind(NotebookOptionsService).toSelf().inSingletonScope();
 });