support updating messages in progress dialogs

src/vs/base/browser/ui/dialog/dialog.css

@@ -64,8 +64,8 @@
 }
 
 .monaco-workbench .dialog-box .dialog-message-row .dialog-icon {
-	height: 30px;
 	flex: 0 0 30px;
+	height: 30px;
 	padding-right: 4px;
 	padding-left: 4px;
 	background-position: center;

src/vs/base/browser/ui/dialog/dialog.ts

@@ -33,6 +33,7 @@ export class Dialog extends Disposable {
 	private element: HTMLElement | undefined;
 	private modal: HTMLElement | undefined;
 	private buttonsContainer: HTMLElement | undefined;
+	private messageDetailElement: HTMLElement | undefined;
 	private iconElement: HTMLElement | undefined;
 	private toolbarContainer: HTMLElement | undefined;
 	private buttonGroup: ButtonGroup | undefined;
@@ -56,13 +57,19 @@ export class Dialog extends Disposable {
 			messageElement.innerText = this.message;
 		}
 
-		const messageDetailElement = messageContainer.appendChild($('.dialog-message-detail'));
-		messageDetailElement.innerText = this.options.detail ? this.options.detail : message;
+		this.messageDetailElement = messageContainer.appendChild($('.dialog-message-detail'));
+		this.messageDetailElement.innerText = this.options.detail ? this.options.detail : message;
 
 		const toolbarRowElement = this.element.appendChild($('.dialog-toolbar-row'));
 		this.toolbarContainer = toolbarRowElement.appendChild($('.dialog-toolbar'));
 	}
 
+	updateMessage(message: string): void {
+		if (this.messageDetailElement) {
+			this.messageDetailElement.innerText = message;
+		}
+	}
+
 	async show(): Promise<number> {
 		return new Promise<number>((resolve) => {
 			if (!this.element || !this.buttonsContainer || !this.iconElement || !this.toolbarContainer) {

src/vs/workbench/services/progress/browser/progressService2.ts

@@ -304,6 +304,8 @@ export class ProgressService2 implements IProgressService2 {
 		const updateDialog = (message?: string) => {
 			if (message && !dialog) {
 				dialog = createDialog(message);
+			} else if (message) {
+				dialog.updateMessage(message);
 			}
 		};