MacViews: Implemented Drag & Drop

ui/views/cocoa/bridged_content_view.mm

Index: ui/views/cocoa/bridged_content_view.mm
diff --git a/ui/views/cocoa/bridged_content_view.mm b/ui/views/cocoa/bridged_content_view.mm
index c269729cc2e73633e333f5df86dbb614518c3f0a..44709c7c4b612b1c2ee7d1be1198dc703837f387 100644
--- a/ui/views/cocoa/bridged_content_view.mm
+++ b/ui/views/cocoa/bridged_content_view.mm
@@ -10,6 +10,7 @@
 #include "base/strings/sys_string_conversions.h"
 #include "skia/ext/skia_utils_mac.h"
 #include "ui/base/cocoa/cocoa_base_utils.h"
+#include "ui/base/dragdrop/os_exchange_data_provider_mac.h"
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/compositor/canvas_painter.h"
@@ -23,9 +24,12 @@
 #import "ui/gfx/path_mac.h"
 #include "ui/gfx/scoped_ns_graphics_context_save_gstate_mac.h"
 #include "ui/strings/grit/ui_strings.h"
+#import "ui/views/cocoa/bridged_native_widget.h"
+#include "ui/views/cocoa/drag_drop_client_mac.h"
 #include "ui/views/controls/menu/menu_config.h"
 #include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/view.h"
+#include "ui/views/widget/native_widget_mac.h"
 #include "ui/views/widget/widget.h"
 
 using views::MenuController;
@@ -191,6 +195,8 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
 // Notification handler invoked when the Full Keyboard Access mode is changed.
 - (void)onFullKeyboardAccessModeChanged:(NSNotification*)notification;
 
+- (views::DragDropClientMac*)dragDropClient;
+
 // Menu action handlers.
 - (void)undo:(id)sender;
 - (void)redo:(id)sender;
@@ -239,6 +245,10 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
     // setting.
     [self updateFullKeyboardAccess];
   }
+
+  [self registerForDraggedTypes:ui::OSExchangeDataProviderMac::
+                                    SupportedPasteboardTypes()];
+
   return self;
 }
 
@@ -270,6 +280,22 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
   hostedView_->GetWidget()->OnMouseEvent(&event);
 }
 
+- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
+  return [self dragDropClient]->DragUpdate(sender);

[tapted, 2016/05/24 08:06:01]

[self dragDropClient] needs to return null under some weird lifetime scenarios
(see below) -- we will have to check on all of these methods

[spqchan, 2016/05/26 01:56:53]

Done.

+}
+
+- (NSDragOperation)draggingUpdated:(id)sender {
+  return [self dragDropClient]->DragUpdate(sender);
+}
+
+- (void)draggingEnded:(id)sender {
+  [self dragDropClient]->EndDrag();
+}
+
+- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
+  return [self dragDropClient]->Drop(sender) != NSDragOperationNone;
+}
+
 - (void)updateTooltipIfRequiredAt:(const gfx::Point&)locationInContent {
   DCHECK(hostedView_);
   base::string16 newTooltipText;
@@ -362,6 +388,11 @@ gfx::Rect GetFirstRectForRangeHelper(const ui::TextInputClient* client,
   [self updateFullKeyboardAccess];
 }
 
+- (views::DragDropClientMac*)dragDropClient {
+  return views::NativeWidgetMac::GetBridgeForNativeWindow([self window])

[tapted, 2016/05/24 08:06:00]

GetBridgeForNativeWindow can return null. Annoying things like when AppKit has
an NSEvent sitting in the event queue, which might also have a retained NSWindow
or NSView referenced from it. So that needs to propagate through.

[spqchan, 2016/05/26 01:56:53]

Done.

+      ->drag_drop_client();
+}
+
 - (void)undo:(id)sender {
   // This DCHECK is more strict than a similar check in handleAction:. It can be
   // done here because the actors sending these actions should be calling