Add registerCustomEditorProvider2

Create a temporary overload for testing `CustomEditor`. In finalization, we'd update `registerCustomEditorProvider` to take both types of custom editor instead

extensions/image-preview/src/extension.ts

@@ -23,7 +23,7 @@ export function activate(context: vscode.ExtensionContext) {
 
 	const previewManager = new PreviewManager(extensionRoot, sizeStatusBarEntry, binarySizeStatusBarEntry, zoomStatusBarEntry);
 
-	context.subscriptions.push(vscode.window.registerCustomEditorProvider(PreviewManager.viewType, previewManager));
+	context.subscriptions.push(vscode.window.registerCustomEditorProvider2(PreviewManager.viewType, previewManager));
 
 	context.subscriptions.push(vscode.commands.registerCommand('imagePreview.zoomIn', () => {
 		previewManager.activePreview?.zoomIn();

src/vs/vscode.proposed.d.ts

@@ -1491,6 +1491,19 @@ declare module 'vscode' {
 		readonly editingDelegate?: CustomEditorEditingDelegate<EditType>;
 	}
 
+	namespace window {
+		/**
+		 * Temporary overload for `registerCustomEditorProvider` that takes a `CustomEditorProvider`.
+		 */
+		export function registerCustomEditorProvider2(
+			viewType: string,
+			provider: CustomEditorProvider,
+			options?: {
+				readonly webviewOptions?: WebviewPanelOptions;
+			}
+		): Disposable;
+	}
+
 	// #endregion
 
 	//#region Custom editor move https://github.com/microsoft/vscode/issues/86146

src/vs/workbench/api/common/extHost.api.impl.ts

@@ -582,7 +582,11 @@ export function createApiFactoryAndRegisterActors(accessor: ServicesAccessor): I
 			registerWebviewPanelSerializer: (viewType: string, serializer: vscode.WebviewPanelSerializer) => {
 				return extHostWebviews.registerWebviewPanelSerializer(extension, viewType, serializer);
 			},
-			registerCustomEditorProvider: (viewType: string, provider: vscode.CustomEditorProvider | vscode.CustomTextEditorProvider, options?: { webviewOptions?: vscode.WebviewPanelOptions }) => {
+			registerCustomEditorProvider: (viewType: string, provider: vscode.CustomTextEditorProvider, options?: { webviewOptions?: vscode.WebviewPanelOptions }) => {
+				return extHostWebviews.registerCustomEditorProvider(extension, viewType, provider, options?.webviewOptions);
+			},
+			registerCustomEditorProvider2: (viewType: string, provider: vscode.CustomEditorProvider, options?: { webviewOptions?: vscode.WebviewPanelOptions }) => {
+				checkProposedApiEnabled(extension);
 				return extHostWebviews.registerCustomEditorProvider(extension, viewType, provider, options?.webviewOptions);
 			},
 			registerDecorationProvider(provider: vscode.DecorationProvider) {