list: unpack drag and drop data

related to #66291

src/vs/base/browser/ui/list/listView.ts

@@ -76,55 +76,51 @@ const DefaultOptions = {
 
 export class ElementsDragAndDropData<T> implements IDragAndDropData {
 
-	private elements: T[];
+	readonly elements: T[];
 
 	constructor(elements: T[]) {
 		this.elements = elements;
 	}
 
-	public update(dataTransfer: DataTransfer): void {
-		// no-op
-	}
+	update(): void { }
 
-	public getData(): any {
+	getData(): any {
 		return this.elements;
 	}
 }
 
 export class ExternalElementsDragAndDropData<T> implements IDragAndDropData {
 
-	private elements: T[];
+	readonly elements: T[];
 
 	constructor(elements: T[]) {
 		this.elements = elements;
 	}
 
-	public update(dataTransfer: DataTransfer): void {
-		// no-op
-	}
+	update(): void { }
 
-	public getData(): any {
+	getData(): any {
 		return this.elements;
 	}
 }
 
 export class DesktopDragAndDropData implements IDragAndDropData {
 
-	private types: any[];
-	private files: any[];
+	readonly types: any[];
+	readonly files: any[];
 
 	constructor() {
 		this.types = [];
 		this.files = [];
 	}
 
-	public update(dataTransfer: DataTransfer): void {
+	update(dataTransfer: DataTransfer): void {
 		if (dataTransfer.types) {
-			this.types = [...dataTransfer.types];
+			this.types.splice(0, this.types.length, ...dataTransfer.types);
 		}
 
 		if (dataTransfer.files) {
-			this.files = [];
+			this.files.splice(0, this.files.length);
 
 			for (let i = 0; i < dataTransfer.files.length; i++) {
 				const file = dataTransfer.files.item(i);
@@ -136,7 +132,7 @@ export class DesktopDragAndDropData implements IDragAndDropData {
 		}
 	}
 
-	public getData(): any {
+	getData(): any {
 		return {
 			types: this.types,
 			files: this.files

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

@@ -15,6 +15,7 @@ import { ITreeModel, ITreeNode, ITreeRenderer, ITreeEvent, ITreeMouseEvent, ITre
 import { ISpliceable } from 'vs/base/common/sequence';
 import { IDragAndDropData } from 'vs/base/browser/dnd';
 import { range } from 'vs/base/common/arrays';
+import { ElementsDragAndDropData } from 'vs/base/browser/ui/list/listView';
 
 class TreeNodeListDragAndDrop<T, TFilterData, TRef> implements IListDragAndDrop<ITreeNode<T, TFilterData>> {
 
@@ -42,7 +43,14 @@ class TreeNodeListDragAndDrop<T, TFilterData, TRef> implements IListDragAndDrop<
 	}
 
 	onDragOver(data: IDragAndDropData, targetNode: ITreeNode<T, TFilterData> | undefined, targetIndex: number | undefined, originalEvent: DragEvent, raw = true): boolean | IListDragOverReaction {
-		const result = this.dnd.onDragOver(data, targetNode && targetNode.element, targetIndex, originalEvent);
+		let treeData: IDragAndDropData = data;
+
+		if (data instanceof ElementsDragAndDropData) {
+			const nodes = (data as ElementsDragAndDropData<ITreeNode<T, TFilterData>>).elements;
+			treeData = new ElementsDragAndDropData(nodes.map(node => node.element));
+		}
+
+		const result = this.dnd.onDragOver(treeData, targetNode && targetNode.element, targetIndex, originalEvent);
 		const didChangeAutoExpandNode = this.autoExpandNode !== targetNode;
 
 		if (didChangeAutoExpandNode) {

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

@@ -13,6 +13,8 @@ import { timeout, always } from 'vs/base/common/async';
 import { IListStyles } from 'vs/base/browser/ui/list/listWidget';
 import { toggleClass } from 'vs/base/browser/dom';
 import { Iterator } from 'vs/base/common/iterator';
+import { IDragAndDropData } from 'vs/base/browser/dnd';
+import { ElementsDragAndDropData } from 'vs/base/browser/ui/list/listView';
 
 enum AsyncDataTreeNodeState {
 	Uninitialized,
@@ -147,7 +149,14 @@ function asObjectTreeOptions<TInput, T, TFilterData>(options?: IAsyncDataTreeOpt
 				}
 			},
 			onDragOver(data, targetNode, targetIndex, originalEvent) {
-				return options.dnd!.onDragOver(data, targetNode && targetNode.element as T, targetIndex, originalEvent);
+				let treeData: IDragAndDropData = data;
+
+				if (data instanceof ElementsDragAndDropData) {
+					const nodes = (data as ElementsDragAndDropData<IAsyncDataTreeNode<TInput, T>>).elements;
+					treeData = new ElementsDragAndDropData(nodes.map(node => node.element));
+				}
+
+				return options.dnd!.onDragOver(treeData, targetNode && targetNode.element as T, targetIndex, originalEvent);
 			},
 			drop(data, targetNode, targetIndex, originalEvent) {
 				options.dnd!.drop(data, targetNode && targetNode.element as T, targetIndex, originalEvent);

src/vs/workbench/parts/debug/electron-browser/watchExpressionsView.ts

@@ -29,6 +29,7 @@ import { IThemeService } from 'vs/platform/theme/common/themeService';
 import { IAsyncDataSource, ITreeMouseEvent, ITreeContextMenuEvent, ITreeDragAndDrop, ITreeDragOverReaction } from 'vs/base/browser/ui/tree/tree';
 import { IDragAndDropData } from 'vs/base/browser/dnd';
 import { onUnexpectedError } from 'vs/base/common/errors';
+import { ElementsDragAndDropData } from 'vs/base/browser/ui/list/listView';
 
 const MAX_VALUE_RENDER_LENGTH_IN_VIEWLET = 1024;
 
@@ -264,9 +265,12 @@ class WatchExpressionsDragAndDrop implements ITreeDragAndDrop<IExpression> {
 	constructor(private debugService: IDebugService) { }
 
 	onDragOver(data: IDragAndDropData): boolean | ITreeDragOverReaction {
-		const draggedData = data.getData();
+		if (!(data instanceof ElementsDragAndDropData)) {
+			return false;
+		}
 
-		return Array.isArray(draggedData) && draggedData[0] && draggedData[0].element.element instanceof Expression;
+		const expressions = (data as ElementsDragAndDropData<IExpression>).elements;
+		return expressions.length > 0 && expressions[0] instanceof Expression;
 	}
 
 	getDragURI(element: IExpression): string | null {