Set active instance in tab when instance focus changes

src/vs/workbench/parts/terminal/common/terminal.ts

@@ -221,6 +221,8 @@ export interface ITerminalInstance {
 	 */
 	onDisposed: Event<ITerminalInstance>;
 
+	onFocused: Event<ITerminalInstance>;
+
 	onProcessIdReady: Event<ITerminalInstance>;
 
 	/**

src/vs/workbench/parts/terminal/electron-browser/terminalInstance.ts

@@ -78,6 +78,7 @@ export class TerminalInstance implements ITerminalInstance {
 	private _processReady: TPromise<void>;
 	private _isDisposed: boolean;
 	private _onDisposed: Emitter<ITerminalInstance>;
+	private _onFocused: Emitter<ITerminalInstance>;
 	private _onProcessIdReady: Emitter<ITerminalInstance>;
 	private _onTitleChanged: Emitter<string>;
 	private _process: cp.ChildProcess;
@@ -105,6 +106,7 @@ export class TerminalInstance implements ITerminalInstance {
 	public get id(): number { return this._id; }
 	public get processId(): number { return this._processId; }
 	public get onDisposed(): Event<ITerminalInstance> { return this._onDisposed.event; }
+	public get onFocused(): Event<ITerminalInstance> { return this._onFocused.event; }
 	public get onProcessIdReady(): Event<ITerminalInstance> { return this._onProcessIdReady.event; }
 	public get onTitleChanged(): Event<string> { return this._onTitleChanged.event; }
 	public get title(): string { return this._title; }
@@ -142,6 +144,7 @@ export class TerminalInstance implements ITerminalInstance {
 		this._preLaunchInputQueue = '';
 
 		this._onDisposed = new Emitter<TerminalInstance>();
+		this._onFocused = new Emitter<TerminalInstance>();
 		this._onProcessIdReady = new Emitter<TerminalInstance>();
 		this._onTitleChanged = new Emitter<string>();
 
@@ -407,6 +410,7 @@ export class TerminalInstance implements ITerminalInstance {
 
 			this._instanceDisposables.push(dom.addDisposableListener(this._xterm.textarea, 'focus', (event: KeyboardEvent) => {
 				this._terminalFocusContextKey.set(true);
+				this._onFocused.fire(this);
 			}));
 			this._instanceDisposables.push(dom.addDisposableListener(this._xterm.textarea, 'blur', (event: KeyboardEvent) => {
 				this._terminalFocusContextKey.reset();

src/vs/workbench/parts/terminal/electron-browser/terminalTab.ts

@@ -208,6 +208,7 @@ export class TerminalTab extends Disposable implements ITerminalTab {
 		this._terminalInstances.push(instance);
 		this._activeInstanceIndex = 0;
 		instance.addDisposable(instance.onDisposed(instance => this._onInstanceDisposed(instance)));
+		instance.addDisposable(instance.onFocused(instance => this._setActiveInstance(instance)));
 
 		this._rootSplitPane = new RootSplitPane();
 		this._rootSplitPane.instance = instance;
@@ -218,8 +219,6 @@ export class TerminalTab extends Disposable implements ITerminalTab {
 		if (this._container) {
 			this.attachToElement(this._container);
 		}
-
-		// TODO: Listen to instance focus and update activeInstanceIndex accordingly
 	}
 
 	public dispose(): void {
@@ -275,6 +274,24 @@ export class TerminalTab extends Disposable implements ITerminalTab {
 		return null;
 	}
 
+	private _setActiveInstance(instance: ITerminalInstance): void {
+		this.setActiveInstanceByIndex(this._getIndexFromId(instance.id));
+	}
+
+	// TODO: This is duplicated in ITerminalService
+	private _getIndexFromId(terminalId: number): number {
+		let terminalIndex = -1;
+		this.terminalInstances.forEach((terminalInstance, i) => {
+			if (terminalInstance.id === terminalId) {
+				terminalIndex = i;
+			}
+		});
+		if (terminalIndex === -1) {
+			throw new Error(`Terminal with ID ${terminalId} does not exist (has it already been disposed?)`);
+		}
+		return terminalIndex;
+	}
+
 	public setActiveInstanceByIndex(index: number): boolean {
 		// Check for invalid value
 		if (index >= this._terminalInstances.length) {