GTK: implement extension bookmark manager drag api....

chrome/browser/gtk/custom_drag.h

 // Copyright (c) 2010 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 CHROME_BROWSER_GTK_DOWNLOAD_ITEM_DRAG_H_
-#define CHROME_BROWSER_GTK_DOWNLOAD_ITEM_DRAG_H_
+#ifndef CHROME_BROWSER_GTK_CUSTOM_DRAG_H_
+#define CHROME_BROWSER_GTK_CUSTOM_DRAG_H_
 
 #include <gtk/gtk.h>
+#include <vector>
 
+#include "app/gtk_signal.h"
 #include "base/basictypes.h"
 
+class BookmarkNode;
 class DownloadItem;
+class Profile;
 class SkBitmap;
 
-class DownloadItemDrag {
+// Base class for programatically generated drags.
+class CustomDrag {
+ protected:
+  explicit CustomDrag(SkBitmap* icon, int code_mask, GdkDragAction action);
+  virtual ~CustomDrag();
+
+  virtual void OnDragDataGet(GtkWidget* widget, GdkDragContext* context,
+                             GtkSelectionData* selection_data,
+                             guint target_type, guint time) = 0;
+
+ private:
+  CHROMEGTK_CALLBACK_1(CustomDrag, void, OnDragBegin, GdkDragContext*);
+  CHROMEGTK_CALLBACK_1(CustomDrag, void, OnDragEnd, GdkDragContext*);
+
+  // Since this uses a virtual function, we can't use a macro.
+  static void OnDragDataGetThunk(GtkWidget* widget, GdkDragContext* context,
+                                 GtkSelectionData* selection_data,
+                                 guint target_type, guint time,
+                                 CustomDrag* custom_drag) {
+    return custom_drag->OnDragDataGet(widget, context, selection_data,
+                                      target_type, time);
+  }
+
+  GtkWidget* drag_widget_;
+  GdkPixbuf* pixbuf_;
+
+  DISALLOW_COPY_AND_ASSIGN(CustomDrag);
+};
+
+// Encapsulates functionality for drags of download items.
+class DownloadItemDrag : public CustomDrag {
  public:
   // Sets |widget| as a source for drags pertaining to |item|. No
   // DownloadItemDrag object is created.
   static void SetSource(GtkWidget* widget, DownloadItem* item);
 
   // Creates a new DownloadItemDrag, the lifetime of which is tied to the
   // system drag.
   static void BeginDrag(const DownloadItem* item, SkBitmap* icon);
 
  private:
-  explicit DownloadItemDrag(const DownloadItem* item, SkBitmap* icon);
-  ~DownloadItemDrag();
+  DownloadItemDrag(const DownloadItem* item, SkBitmap* icon);
+  virtual ~DownloadItemDrag();
 
-  static void OnDragBegin(GtkWidget* widget,
-                          GdkDragContext* drag_context,
-                          DownloadItemDrag* drag);
+  virtual void OnDragDataGet(GtkWidget* widget, GdkDragContext* context,
+                             GtkSelectionData* selection_data,
+                             guint target_type, guint time);
 
-  static void OnDragEnd(GtkWidget* widget,
-                        GdkDragContext* drag_context,
-                        DownloadItemDrag* drag);
-
-  GtkWidget* drag_widget_;
-  GdkPixbuf* pixbuf_;
+  const DownloadItem* download_item_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadItemDrag);
 };
 
-#endif  // CHROME_BROWSER_GTK_DOWNLOAD_ITEM_DRAG_H_
+// Encapsulates functionality for drags of one or more bookmarks.
+class BookmarkDrag : public CustomDrag {
+ public:
+  // Creates a new BookmarkDrag, the lifetime of which is tied to the
+  // system drag.
+  static void BeginDrag(Profile* profile,
+                        const std::vector<const BookmarkNode*>& nodes);
+
+ private:
+  BookmarkDrag(Profile* profile,
+               const std::vector<const BookmarkNode*>& nodes);
+  virtual ~BookmarkDrag();
+
+  virtual void OnDragDataGet(GtkWidget* widget, GdkDragContext* context,
+                             GtkSelectionData* selection_data,
+                             guint target_type, guint time);
+
+  Profile* profile_;
+  std::vector<const BookmarkNode*> nodes_;
+
+  DISALLOW_COPY_AND_ASSIGN(BookmarkDrag);
+};
+
+#endif  // CHROME_BROWSER_GTK_CUSTOM_DRAG_H_