Home | History | Annotate | Download | only in web_contents 
      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #ifndef CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_DRAG_WIN_H_
      6 #define CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_DRAG_WIN_H_
      7 
      8 #include "base/callback.h"
      9 #include "base/compiler_specific.h"
     10 #include "base/memory/ref_counted.h"
     11 #include "base/memory/scoped_ptr.h"
     12 #include "base/threading/platform_thread.h"
     13 #include "content/common/content_export.h"
     14 #include "third_party/WebKit/public/web/WebDragOperation.h"
     15 #include "ui/base/dragdrop/os_exchange_data_provider_win.h"
     16 #include "ui/gfx/native_widget_types.h"
     17 #include "ui/gfx/point.h"
     18 
     19 class SkBitmap;
     20 
     21 namespace gfx {
     22 class ImageSkia;
     23 }
     24 
     25 namespace content {
     26 class DragDropThread;
     27 class WebContents;
     28 class WebDragDest;
     29 class WebDragSource;
     30 struct DropData;
     31 
     32 // Windows-specific drag-and-drop handling in WebContentsView.
     33 // If we are dragging a virtual file out of the browser, we use a background
     34 // thread to do the drag-and-drop because we do not want to run nested
     35 // message loop in the UI thread. For all other cases, the drag-and-drop happens
     36 // in the UI thread.
     37 class CONTENT_EXPORT WebContentsDragWin
     38     : NON_EXPORTED_BASE(public ui::DataObjectImpl::Observer),
     39       public base::RefCountedThreadSafe<WebContentsDragWin> {
     40  public:
     41   WebContentsDragWin(gfx::NativeWindow source_window,
     42                      WebContents* web_contents,
     43                      WebDragDest* drag_dest,
     44                      const base::Callback<void()>& drag_end_callback);
     45   virtual ~WebContentsDragWin();
     46 
     47   // Called on UI thread.
     48   void StartDragging(const DropData& drop_data,
     49                      WebKit::WebDragOperationsMask ops,
     50                      const gfx::ImageSkia& image,
     51                      const gfx::Vector2d& image_offset);
     52   void CancelDrag();
     53 
     54   // DataObjectImpl::Observer implementation.
     55   // Called on drag-and-drop thread.
     56   virtual void OnWaitForData();
     57   virtual void OnDataObjectDisposed();
     58 
     59   // Don't invoke OLE DoDragDrop during tests.
     60   static void DisableDragDropForTesting();
     61 
     62  private:
     63   // Called on either UI thread or drag-and-drop thread.
     64   void PrepareDragForDownload(const DropData& drop_data,
     65                               ui::OSExchangeData* data,
     66                               const GURL& page_url,
     67                               const std::string& page_encoding);
     68   void PrepareDragForFileContents(const DropData& drop_data,
     69                                   ui::OSExchangeData* data);
     70   void PrepareDragForUrl(const DropData& drop_data,
     71                          ui::OSExchangeData* data);
     72   // Returns false if the source window becomes invalid when the drag ends.
     73   // This could happen when the window gets destroyed when the drag is still in
     74   // progress. No further processing should be done beyond this return point
     75   // because the instance has been destroyed.
     76   bool DoDragging(const DropData& drop_data,
     77                   WebKit::WebDragOperationsMask ops,
     78                   const GURL& page_url,
     79                   const std::string& page_encoding,
     80                   const gfx::ImageSkia& image,
     81                   const gfx::Vector2d& image_offset);
     82 
     83   // Called on drag-and-drop thread.
     84   void StartBackgroundDragging(const DropData& drop_data,
     85                                WebKit::WebDragOperationsMask ops,
     86                                const GURL& page_url,
     87                                const std::string& page_encoding,
     88                                const gfx::ImageSkia& image,
     89                                const gfx::Vector2d& image_offset);
     90   // Called on UI thread.
     91   void EndDragging();
     92   void CloseThread();
     93 
     94   // For debug check only. Access only on drag-and-drop thread.
     95   base::PlatformThreadId drag_drop_thread_id_;
     96 
     97   // All the member variables below are accessed on UI thread.
     98 
     99   gfx::NativeWindow source_window_;
    100   WebContents* web_contents_;
    101   WebDragDest* drag_dest_;
    102 
    103   // |drag_source_| is our callback interface passed to the system when we
    104   // want to initiate a drag and drop operation.  We use it to tell if a
    105   // drag operation is happening.
    106   scoped_refptr<WebDragSource> drag_source_;
    107 
    108   // The thread used by the drag-out download. This is because we want to avoid
    109   // running nested message loop in main UI thread.
    110   scoped_ptr<DragDropThread> drag_drop_thread_;
    111 
    112   // The flag to guard that EndDragging is not called twice.
    113   bool drag_ended_;
    114 
    115   base::Callback<void()> drag_end_callback_;
    116 
    117   DISALLOW_COPY_AND_ASSIGN(WebContentsDragWin);
    118 };
    119 
    120 }  // namespace content
    121 
    122 #endif  // CONTENT_BROWSER_WEB_CONTENTS_WEB_CONTENTS_DRAG_WIN_H_
    123