refactor: remove deprecated drag-and-drop code (#34615)

shell/browser/ui/drag_util_mac.mm

@@ -10,53 +10,78 @@
 #include "base/strings/sys_string_conversions.h"
 #include "shell/browser/ui/drag_util.h"
 
-namespace electron {
+// Contents largely copied from
+// chrome/browser/download/drag_download_item_mac.mm.
+
+@interface DragDownloadItemSource : NSObject <NSDraggingSource>
+@end
+
+@implementation DragDownloadItemSource
+
+- (NSDragOperation)draggingSession:(NSDraggingSession*)session
+    sourceOperationMaskForDraggingContext:(NSDraggingContext)context {
+  return NSDragOperationEvery;
+}
+
+@end
 
 namespace {
 
-// Write information about the file being dragged to the pasteboard.
+id<NSDraggingSource> GetDraggingSource() {
-void AddFilesToPasteboard(NSPasteboard* pasteboard,
+  static id<NSDraggingSource> source = [[DragDownloadItemSource alloc] init];
-                          const std::vector<base::FilePath>& files) {
+  return source;
-  NSMutableArray* fileList = [NSMutableArray array];
-  for (const base::FilePath& file : files)
-    [fileList addObject:base::SysUTF8ToNSString(file.value())];
-  [pasteboard declareTypes:[NSArray arrayWithObject:NSFilenamesPboardType]
-                     owner:nil];
-  [pasteboard setPropertyList:fileList forType:NSFilenamesPboardType];
 }
 
 }  // namespace
 
+namespace electron {
+
 void DragFileItems(const std::vector<base::FilePath>& files,
                    const gfx::Image& icon,
                    gfx::NativeView view) {
-  NSPasteboard* pasteboard =
+  auto* native_view = view.GetNativeNSView();
-      [NSPasteboard pasteboardWithName:NSPasteboardNameDrag];
+  NSPoint current_position =
-  AddFilesToPasteboard(pasteboard, files);
+      [[native_view window] mouseLocationOutsideOfEventStream];
+  current_position =
+      [native_view backingAlignedRect:NSMakeRect(current_position.x,
+                                                 current_position.y, 0, 0)
+                              options:NSAlignAllEdgesOutward]
+          .origin;
+
+  NSMutableArray* file_items = [NSMutableArray array];
+  for (auto const& file : files) {
+    NSURL* file_url =
+        [NSURL fileURLWithPath:base::SysUTF8ToNSString(file.value())];
+    NSDraggingItem* file_item = [[[NSDraggingItem alloc]
+        initWithPasteboardWriter:file_url] autorelease];
+    NSImage* file_image = icon.ToNSImage();
+    NSSize image_size = file_image.size;
+    NSRect image_rect = NSMakeRect(current_position.x - image_size.width / 2,
+                                   current_position.y - image_size.height / 2,
+                                   image_size.width, image_size.height);
+    [file_item setDraggingFrame:image_rect contents:file_image];
+    [file_items addObject:file_item];
+  }
 
   // Synthesize a drag event, since we don't have access to the actual event
   // that initiated a drag (possibly consumed by the Web UI, for example).
-  NSWindow* window = [view.GetNativeNSView() window];
+  NSPoint position = [[native_view window] mouseLocationOutsideOfEventStream];
-  NSPoint position = [window mouseLocationOutsideOfEventStream];
   NSTimeInterval eventTime = [[NSApp currentEvent] timestamp];
-  NSEvent* dragEvent = [NSEvent mouseEventWithType:NSEventTypeLeftMouseDragged
+  NSEvent* dragEvent =
+      [NSEvent mouseEventWithType:NSEventTypeLeftMouseDragged
                          location:position
                     modifierFlags:NSEventMaskLeftMouseDragged
                         timestamp:eventTime
-                                      windowNumber:[window windowNumber]
+                     windowNumber:[[native_view window] windowNumber]
                           context:nil
                       eventNumber:0
                        clickCount:1
                          pressure:1.0];
 
   // Run the drag operation.
-  [window dragImage:icon.ToNSImage()
+  [native_view beginDraggingSessionWithItems:file_items
-                 at:position
-             offset:NSZeroSize
                                        event:dragEvent
-         pasteboard:pasteboard
+                                      source:GetDraggingSource()];
-             source:view.GetNativeNSView()
-          slideBack:YES];
 }
 
 }  // namespace electron