Drag-and-drop: Target drag messages to specific RenderWidgets.

content/browser/web_contents/web_contents_view_aura.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_AURA_H_
 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_AURA_H_
 
 #include <memory>
 #include <vector>
 
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "content/browser/renderer_host/overscroll_controller_delegate.h"
 #include "content/browser/renderer_host/render_view_host_delegate_view.h"
 #include "content/browser/web_contents/web_contents_view.h"
 #include "content/common/content_export.h"
 #include "ui/aura/client/drag_drop_delegate.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/aura/window_observer.h"
 
 namespace aura {
 class Window;
 }
 
 namespace ui {
 class DropTargetEvent;
 class TouchSelectionController;
 }
 
 namespace content {
 class GestureNavSimple;
 class OverscrollNavigationOverlay;
+class RenderWidgetHostImpl;
 class RenderWidgetHostViewAura;
 class TouchSelectionControllerClientAura;
 class WebContentsViewDelegate;
 class WebContentsImpl;
 class WebDragDestDelegate;
 
 class CONTENT_EXPORT WebContentsViewAura
     : NON_EXPORTED_BASE(public WebContentsView),
       public RenderViewHostDelegateView,
       public OverscrollControllerDelegate,
@@ skipping 66 matching lines @@
   void RenderViewSwappedIn(RenderViewHost* host) override;
   void SetOverscrollControllerEnabled(bool enabled) override;
 
   // Overridden from RenderViewHostDelegateView:
   void ShowContextMenu(RenderFrameHost* render_frame_host,
                        const ContextMenuParams& params) override;
   void StartDragging(const DropData& drop_data,
                      blink::WebDragOperationsMask operations,
                      const gfx::ImageSkia& image,
                      const gfx::Vector2d& image_offset,
-                     const DragEventSourceInfo& event_info) override;
+                     const DragEventSourceInfo& event_info,
+                     RenderWidgetHostImpl* source_rwh) override;
   void UpdateDragCursor(blink::WebDragOperation operation) override;
   void GotFocus() override;
   void TakeFocus(bool reverse) override;
 #if defined(USE_EXTERNAL_POPUP_MENU)
   void ShowPopupMenu(RenderFrameHost* render_frame_host,
                      const gfx::Rect& bounds,
                      int item_height,
                      double item_font_size,
                      int selected_item,
                      const std::vector<MenuItem>& items,
@@ skipping 53 matching lines @@
   WebContentsImpl* web_contents_;
 
   std::unique_ptr<WebContentsViewDelegate> delegate_;
 
   blink::WebDragOperationsMask current_drag_op_;
 
   std::unique_ptr<DropData> current_drop_data_;
 
   WebDragDestDelegate* drag_dest_delegate_;
 
-  // We keep track of the render view host we're dragging over.  If it changes
-  // during a drag, we need to re-send the DragEnter message.  WARNING:
-  // this pointer should never be dereferenced.  We only use it for comparing
-  // pointers.
+  // We keep track of the RenderWidgetHost we're dragging over. If it changes
+  // during a drag, we need to re-send the DragEnter message.
+  base::WeakPtr<RenderWidgetHostImpl> current_rwh_for_drag_;
+
+  // We also keep track of the RenderViewHost we're dragging over to avoid
+  // sending the drag exited message after leaving the current
+  // view. |current_rvh_for_drag_| should not be dereferenced.
   void* current_rvh_for_drag_;
 
+  // We keep track of the RenderWidgetHost from which the current drag started,
+  // in order to properly route the drag end message to it.
+  base::WeakPtr<RenderWidgetHostImpl> drag_start_rwh_;
+
   // The overscroll gesture currently in progress.
   OverscrollMode current_overscroll_gesture_;
 
   // This is the completed overscroll gesture. This is used for the animation
   // callback that happens in response to a completed overscroll gesture.
   OverscrollMode completed_overscroll_gesture_;
 
   // This manages the overlay window that shows the screenshot during a history
   // navigation triggered by the overscroll gesture.
   std::unique_ptr<OverscrollNavigationOverlay> navigation_overlay_;
 
   std::unique_ptr<GestureNavSimple> gesture_nav_simple_;
 
   bool init_rwhv_with_null_parent_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsViewAura);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_VIEW_AURA_H_