Tree data transfer dnd (#128666)

src/vs/workbench/api/common/shared/treeDataTransfer.ts

@@ -0,0 +1,44 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { ITreeDataTransfer, ITreeDataTransferItem } from 'vs/workbench/common/views';
+
+interface TreeDataTransferItemDTO {
+	asString: string;
+}
+
+export interface TreeDataTransferDTO {
+	types: string[];
+	items: TreeDataTransferItemDTO[];
+}
+
+export namespace TreeDataTransferConverter {
+	export function toITreeDataTransfer(value: TreeDataTransferDTO): ITreeDataTransfer {
+		const newDataTransfer: ITreeDataTransfer = {
+			items: new Map<string, ITreeDataTransferItem>()
+		};
+		value.types.forEach((type, index) => {
+			newDataTransfer.items.set(type, {
+				asString: async () => value.items[index].asString
+			});
+		});
+		return newDataTransfer;
+	}
+
+	export async function toTreeDataTransferDTO(value: ITreeDataTransfer): Promise<TreeDataTransferDTO> {
+		const newDTO: TreeDataTransferDTO = {
+			types: [],
+			items: []
+		};
+		const entries = Array.from(value.items.entries());
+		for (const entry of entries) {
+			newDTO.types.push(entry[0]);
+			newDTO.items.push({
+				asString: await entry[1].asString()
+			});
+		}
+		return newDTO;
+	}
+}