Click on menus on explorer title bar collapses the explorer (fixes #27648)

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

@@ -8,7 +8,7 @@
 import 'vs/css!./dropdown';
 import { Builder, $ } from 'vs/base/browser/builder';
 import { TPromise } from 'vs/base/common/winjs.base';
-import { Gesture, EventType } from 'vs/base/browser/touch';
+import { Gesture, EventType as GestureEventType } from 'vs/base/browser/touch';
 import { ActionRunner, IAction } from 'vs/base/common/actions';
 import { IActionItem } from 'vs/base/browser/ui/actionbar/actionbar';
 import { EventEmitter } from 'vs/base/common/eventEmitter';
@@ -16,6 +16,7 @@ import { IDisposable, dispose } from 'vs/base/common/lifecycle';
 import { IContextViewProvider } from 'vs/base/browser/ui/contextview/contextview';
 import { IMenuOptions } from 'vs/base/browser/ui/menu/menu';
 import { ResolvedKeybinding } from 'vs/base/common/keyCodes';
+import { EventHelper, EventType } from "vs/base/browser/dom";
 
 export interface ILabelRenderer {
 	(container: HTMLElement): IDisposable;
@@ -50,11 +51,15 @@ export class BaseDropdown extends ActionRunner {
 			};
 		}
 
-		this.$label.on(['mousedown', EventType.Tap], (e: Event) => {
-			e.preventDefault();
-			e.stopPropagation();
-
-			this.show();
+		this.$label.on([EventType.CLICK, EventType.MOUSE_DOWN, GestureEventType.Tap], (e: Event) => {
+			EventHelper.stop(e, true); // prevent default click behaviour to trigger
+		}).on([EventType.MOUSE_DOWN, GestureEventType.Tap], (e: Event) => {
+			// We want to show the context menu on dropdown so that as a user you can press and hold the
+			// mouse button, make a choice of action in the menu and release the mouse to trigger that
+			// action.
+			// Due to some weird bugs though, we delay showing the menu to unwind event stack
+			// (see https://github.com/Microsoft/vscode/issues/27648)
+			setTimeout(() => this.show(), 100);
 		}).appendTo(this.$el);
 
 		let cleanupFn = labelRenderer(this.$label.getHTMLElement());

src/vs/workbench/parts/files/browser/explorerViewlet.ts

@@ -99,6 +99,15 @@ export class ExplorerViewlet extends Viewlet {
 		if (this.views.length === 1) {
 			return this.views[0].getActions();
 		}
+
+		return [];
+	}
+
+	public getSecondaryActions(): IAction[] {
+		if (this.views.length === 1) {
+			return this.views[0].getSecondaryActions();
+		}
+
 		return [];
 	}
 

src/vs/workbench/parts/files/browser/views/explorerView.ts

@@ -131,7 +131,7 @@ export class ExplorerView extends CollapsibleViewletView {
 		this.tree = this.createViewer($(this.treeContainer));
 
 		if (this.toolBar) {
-			this.toolBar.setActions(prepareActions(this.getActions()), [])();
+			this.toolBar.setActions(prepareActions(this.getActions()), this.getSecondaryActions())();
 		}
 
 		const onFileIconThemeChange = (fileIconTheme: IFileIconTheme) => {