#34685 Collapse search results one level at a time

src/vs/base/parts/tree/browser/tree.ts

@@ -96,10 +96,10 @@ export interface ITree extends Events.IEventEmitter {
 
 	/**
 	 * Collapses several elements.
-	 * Provide no arguments and it will recursively collapse all elements in the tree
+	 * Collapses all elements at the greatest tree depth that has expanded elements.
 	 * The returned promise returns a boolean for whether the elements were collapsed or not.
 	 */
-	collapseAll(elements?: any[], recursive?: boolean): WinJS.Promise;
+	collapseDeepestExpandedLevel(): WinJS.Promise;
 
 	/**
 	 * Toggles an element's expansion state.

src/vs/base/parts/tree/browser/treeDefaults.ts

@@ -427,7 +427,7 @@ export class CollapseAllAction extends Action {
 			return TPromise.as(null); // Global action disabled if user is in edit mode from another action
 		}
 
-		this.viewer.collapseAll();
+		this.viewer.collapseDeepestExpandedLevel();
 		this.viewer.clearSelection();
 		this.viewer.clearFocus();
 		this.viewer.DOMFocus();

src/vs/base/parts/tree/browser/treeImpl.ts

@@ -182,8 +182,8 @@ export class Tree extends Events.EventEmitter implements _.ITree {
 		return this.model.collapse(element, recursive);
 	}
 
-	public collapseAll(elements: any[] = null, recursive: boolean = false): WinJS.Promise {
-		return this.model.collapseAll(elements, recursive);
+	public collapseDeepestExpandedLevel(): WinJS.Promise {
+		return this.model.collapseDeepestExpandedLevel();
 	}
 
 	public toggleExpansion(element: any, recursive: boolean = false): WinJS.Promise {

src/vs/base/parts/tree/browser/treeModel.ts

@@ -486,6 +486,17 @@ export class Item extends Events.EventEmitter {
 		return result;
 	}
 
+	public getChildren(): Item[] {
+		var child = this.firstChild;
+		var results = [];
+		while (child) {
+			results.push(child);
+			child = child.next;
+		}
+
+		return results;
+	}
+
 	private isAncestorOf(item: Item): boolean {
 		while (item) {
 			if (item.id === this.id) {
@@ -882,18 +893,29 @@ export class TreeModel extends Events.EventEmitter {
 		return item.collapse(recursive);
 	}
 
-	public collapseAll(elements: any[] = null, recursive: boolean = false): WinJS.Promise {
-		if (!elements) {
-			elements = [this.input];
-			recursive = true;
-		}
-		var promises = [];
-		for (var i = 0, len = elements.length; i < len; i++) {
-			promises.push(this.collapse(elements[i], recursive));
+	public collapseDeepestExpandedLevel(): WinJS.Promise {
+		var levelToCollapse = this.findDeepestExpandedLevel(this.input, 0);
+
+		var items = [this.input];
+		for (var i = 0; i < levelToCollapse; i++) {
+			items = items
+				.map(node => node.getChildren())
+				.reduce((prev, current) => prev.concat(current), []);
 		}
+
+		var promises = items.map(child => this.collapse(child, false));
 		return WinJS.Promise.join(promises);
 	}
 
+	private findDeepestExpandedLevel(item: Item, currentLevel: number): number {
+		var expandedChildren = item.getChildren().filter(child => child.isExpanded());
+		if (!expandedChildren.length) {
+			return currentLevel;
+		}
+
+		return Math.max(...expandedChildren.map(child => this.findDeepestExpandedLevel(child, currentLevel + 1)));
+	}
+
 	public toggleExpansion(element: any, recursive: boolean = false): WinJS.Promise {
 		return this.isExpanded(element) ? this.collapse(element, recursive) : this.expand(element);
 	}

src/vs/base/parts/tree/test/browser/treeModel.test.ts

@@ -614,7 +614,7 @@ suite('TreeModel - Expansion', () => {
 		});
 	});
 
-	test('collapseAll', (done) => {
+	test('collapseDeepestExpandedLevel', (done) => {
 		model.setInput(SAMPLE.DEEP2).done(() => {
 			model.expand(SAMPLE.DEEP2.children[0]).done(() => {
 				model.expand(SAMPLE.DEEP2.children[0].children[0]).done(() => {
@@ -622,13 +622,10 @@ suite('TreeModel - Expansion', () => {
 					assert(model.isExpanded(SAMPLE.DEEP2.children[0]));
 					assert(model.isExpanded(SAMPLE.DEEP2.children[0].children[0]));
 
-					model.collapseAll().done(() => {
-						assert(!model.isExpanded(SAMPLE.DEEP2.children[0]));
-
-						model.expand(SAMPLE.DEEP2.children[0]).done(() => {
-							assert(!model.isExpanded(SAMPLE.DEEP2.children[0].children[0]));
-							done();
-						});
+					model.collapseDeepestExpandedLevel().done(() => {
+						assert(model.isExpanded(SAMPLE.DEEP2.children[0]));
+						assert(!model.isExpanded(SAMPLE.DEEP2.children[0].children[0]));
+						done();
 					});
 				});
 			});
@@ -684,22 +681,6 @@ suite('TreeModel - Expansion', () => {
 		});
 	});
 
-	test('top level collapsed', (done) => {
-		model.setInput(SAMPLE.AB).done(() => {
-
-			model.collapseAll([{ id: 'a' }, { id: 'b' }, { id: 'c' }]);
-
-			var nav = model.getNavigator();
-			assert.equal(nav.next().id, 'a');
-			assert.equal(nav.next().id, 'b');
-			assert.equal(nav.next().id, 'c');
-			assert.equal(nav.previous().id, 'b');
-			assert.equal(nav.previous().id, 'a');
-			assert.equal(nav.previous() && false, null);
-			done();
-		});
-	});
-
 	test('shouldAutoexpand', (done) => {
 		// setup
 		const model = new TreeModel({

src/vs/workbench/browser/viewlet.ts

@@ -259,12 +259,12 @@ export class ToggleViewletAction extends Action {
 export class CollapseAction extends Action {
 
 	constructor(viewer: ITree, enabled: boolean, clazz: string) {
-		super('workbench.action.collapse', nls.localize('collapse', "Collapse All"), clazz, enabled, (context: any) => {
+		super('workbench.action.collapse', nls.localize('collapse', "Collapse"), clazz, enabled, (context: any) => {
 			if (viewer.getHighlight()) {
 				return TPromise.as(null); // Global action disabled if user is in edit mode from another action
 			}
 
-			viewer.collapseAll();
+			viewer.collapseDeepestExpandedLevel();
 			viewer.clearSelection();
 			viewer.clearFocus();
 			viewer.DOMFocus();