Merge from vscode 2cfc8172e533e50c90e6a3152f6bfb1f82f963f3 (#6516)

* Merge from vscode 2cfc8172e533e50c90e6a3152f6bfb1f82f963f3

* fix tests

src/vs/base/browser/ui/tree/compressedObjectTree.ts

@@ -0,0 +1,56 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the Source EULA. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { Iterator, ISequence } from 'vs/base/common/iterator';
+import { AbstractTree, IAbstractTreeOptions } from 'vs/base/browser/ui/tree/abstractTree';
+import { ISpliceable } from 'vs/base/common/sequence';
+import { ITreeNode, ITreeModel, ITreeElement, ITreeRenderer, ITreeSorter, ICollapseStateChangeEvent } from 'vs/base/browser/ui/tree/tree';
+import { IListVirtualDelegate } from 'vs/base/browser/ui/list/list';
+import { Event } from 'vs/base/common/event';
+import { CompressedTreeModel, ICompressedTreeNode } from 'vs/base/browser/ui/tree/compressedObjectTreeModel';
+
+export interface IObjectTreeOptions<T, TFilterData = void> extends IAbstractTreeOptions<T, TFilterData> {
+	sorter?: ITreeSorter<T>;
+}
+
+export class CompressedObjectTree<T extends NonNullable<any>, TFilterData = void> extends AbstractTree<ICompressedTreeNode<T> | null, TFilterData, T | null> {
+
+	protected model: CompressedTreeModel<T, TFilterData>;
+
+	get onDidChangeCollapseState(): Event<ICollapseStateChangeEvent<ICompressedTreeNode<T> | null, TFilterData>> { return this.model.onDidChangeCollapseState; }
+
+	constructor(
+		container: HTMLElement,
+		delegate: IListVirtualDelegate<ICompressedTreeNode<T>>,
+		renderers: ITreeRenderer<ICompressedTreeNode<T>, TFilterData, any>[],
+		options: IObjectTreeOptions<ICompressedTreeNode<T>, TFilterData> = {}
+	) {
+		super(container, delegate, renderers, options);
+	}
+
+	setChildren(
+		element: T | null,
+		children?: ISequence<ITreeElement<T>>
+	): Iterator<ITreeElement<T | null>> {
+		return this.model.setChildren(element, children);
+	}
+
+	rerender(element?: T): void {
+		if (element === undefined) {
+			this.view.rerender();
+			return;
+		}
+
+		this.model.rerender(element);
+	}
+
+	resort(element: T, recursive = true): void {
+		this.model.resort(element, recursive);
+	}
+
+	protected createModel(view: ISpliceable<ITreeNode<ICompressedTreeNode<T>, TFilterData>>, options: IObjectTreeOptions<ICompressedTreeNode<T>, TFilterData>): ITreeModel<ICompressedTreeNode<T> | null, TFilterData, T | null> {
+		return new CompressedTreeModel(view, options);
+	}
+}