support in-app DND to editor area

src/vs/workbench/browser/parts/editor/sideBySideEditorControl.ts

@@ -762,20 +762,32 @@ export class SideBySideEditorControl implements ISideBySideEditorControl, IVerti
 		node.addEventListener(DOM.EventType.DROP, (e: DragEvent) => {
 			DOM.EventHelper.stop(e);
 
-			// Check for native file transfer
-			if (e.dataTransfer && e.dataTransfer.files) {
-				let thepaths: string[] = [];
-				for (let i = 0; i < e.dataTransfer.files.length; i++) {
-					if (e.dataTransfer.files[i] && e.dataTransfer.files[i].path) {
-						thepaths.push(e.dataTransfer.files[i].path);
+			const droppedResources: URI[] = [];
+			if (e.dataTransfer.types.length > 0) {
+
+				// Check for in-app DND
+				const rawData = e.dataTransfer.getData(e.dataTransfer.types[0]);
+				if (rawData) {
+					const resource = URI.parse(rawData);
+					if (resource.scheme === 'file' || resource.scheme === 'untitled') {
+						droppedResources.push(resource);
 					}
 				}
 
-				if (thepaths.length) {
-					window.focus(); // make sure this window has focus so that the open call reaches the right window!
-					this.openFromDrop(thepaths.map(p => URI.file(p)), <HTMLElement>e.toElement).done(null, errors.onUnexpectedError);
+				// Check for native file transfer
+				if (e.dataTransfer && e.dataTransfer.files) {
+					for (let i = 0; i < e.dataTransfer.files.length; i++) {
+						if (e.dataTransfer.files[i] && e.dataTransfer.files[i].path) {
+							droppedResources.push(URI.file(e.dataTransfer.files[i].path));
+						}
+					}
 				}
 			}
+
+			if (droppedResources.length) {
+				window.focus(); // make sure this window has focus so that the open call reaches the right window!
+				this.openFromDrop(droppedResources, <HTMLElement>e.toElement).done(null, errors.onUnexpectedError);
+			}
 		});
 	}