Moving webview api back to proposed for more polishing

#49022

src/vs/vscode.d.ts

@@ -5417,23 +5417,6 @@ declare module 'vscode' {
 		readonly webviewPanel: WebviewPanel;
 	}
 
-	/**
-	 * Restore webview panels that have been persisted when vscode shuts down.
-	 */
-	interface WebviewPanelSerializer {
-		/**
-		 * Restore a webview panel from its serialized `state`.
-		 *
-		 * Called when a serialized webview first becomes visible.
-		 *
-		 * @param webviewPanel Webview panel to restore. The serializer should take ownership of this panel.
-		 * @param state Persisted state. This state comes from the value set inside the webview by `acquireVsCodeApi().setState`.
-		 *
-		 * @return Thenable indicating that the webview has been fully restored.
-		 */
-		deserializeWebviewPanel(webviewPanel: WebviewPanel, state: any): Thenable<void>;
-	}
-
 	/**
 	 * Namespace describing the environment the editor runs in.
 	 */
@@ -5928,19 +5911,6 @@ declare module 'vscode' {
 		 */
 		export function createWebviewPanel(viewType: string, title: string, showOptions: ViewColumn | { viewColumn: ViewColumn, preserveFocus?: boolean }, options?: WebviewPanelOptions & WebviewOptions): WebviewPanel;
 
-		/**
-		 * Registers a [webview panel serializer](#WebviewPanelSerializer).
-		 *
-		 * Extensions that support reviving should have an `"onWebviewPanel:viewType"` activation method and
-		 * make sure that [registerWebviewPanelSerializer](#registerWebviewPanelSerializer) is called during activation.
-		 *
-		 * Only a single serializer may be registered at a time for a given `viewType`.
-		 *
-		 * @param viewType Type of the webview panel that can be serialized.
-		 * @param serializer Webview serializer.
-		 */
-		export function registerWebviewPanelSerializer(viewType: string, serializer: WebviewPanelSerializer): Disposable;
-
 		/**
 		 * Set a message to the status bar. This is a short hand for the more powerful
 		 * status bar [items](#window.createStatusBarItem).

src/vs/vscode.proposed.d.ts

@@ -467,4 +467,40 @@ declare module 'vscode' {
 
 	//#endregion
 
+
+	//#region Matt: WebView Serializer
+
+	/**
+	 * Restore webview panels that have been persisted when vscode shuts down.
+	 */
+	interface WebviewPanelSerializer {
+		/**
+		 * Restore a webview panel from its seriailzed `state`.
+		 *
+		 * Called when a serialized webview first becomes visible.
+		 *
+		 * @param webviewPanel Webview panel to restore. The serializer should take ownership of this panel.
+		 * @param state Persisted state.
+		 *
+		 * @return Thanble indicating that the webview has been fully restored.
+		 */
+		deserializeWebviewPanel(webviewPanel: WebviewPanel, state: any): Thenable<void>;
+	}
+
+	namespace window {
+		/**
+		 * Registers a webview panel serializer.
+		 *
+		 * Extensions that support reviving should have an `"onWebviewPanel:viewType"` activation method and
+		 * make sure that [registerWebviewPanelSerializer](#registerWebviewPanelSerializer) is called during activation.
+		 *
+		 * Only a single serializer may be registered at a time for a given `viewType`.
+		 *
+		 * @param viewType Type of the webview panel that can be serialized.
+		 * @param serializer Webview serializer.
+		 */
+		export function registerWebviewPanelSerializer(viewType: string, serializer: WebviewPanelSerializer): Disposable;
+	}
+
+	//#endregion
 }

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

@@ -419,9 +419,6 @@ export function createApiFactory(
 			createWebviewPanel(viewType: string, title: string, showOptions: vscode.ViewColumn | { viewColumn: vscode.ViewColumn, preserveFocus?: boolean }, options: vscode.WebviewPanelOptions & vscode.WebviewOptions): vscode.WebviewPanel {
 				return extHostWebviews.createWebview(viewType, title, showOptions, options, extension.extensionLocation);
 			},
-			registerWebviewPanelSerializer(viewType: string, serializer: vscode.WebviewPanelSerializer) {
-				return extHostWebviews.registerWebviewPanelSerializer(viewType, serializer);
-			},
 			createTerminal(nameOrOptions: vscode.TerminalOptions | string, shellPath?: string, shellArgs?: string[]): vscode.Terminal {
 				if (typeof nameOrOptions === 'object') {
 					return extHostTerminalService.createTerminalFromOptions(<vscode.TerminalOptions>nameOrOptions);
@@ -441,6 +438,9 @@ export function createApiFactory(
 			registerDecorationProvider: proposedApiFunction(extension, (provider: vscode.DecorationProvider) => {
 				return extHostDecorations.registerDecorationProvider(provider, extension.id);
 			}),
+			registerWebviewPanelSerializer: proposedApiFunction(extension, (viewType: string, serializer: vscode.WebviewPanelSerializer) => {
+				return extHostWebviews.registerWebviewPanelSerializer(viewType, serializer);
+			}),
 			registerProtocolHandler: proposedApiFunction(extension, (handler: vscode.ProtocolHandler) => {
 				return extHostUrls.registerProtocolHandler(extension.id, handler);
 			})