linux_aura: Implement dropping in chrome.

ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.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 UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_
+#define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_
+
+#include <X11/Xlib.h>
+
+// Get rid of a macro from Xlib.h that conflicts with Aura's RootWindow class.
+#undef RootWindow
+
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "ui/aura/client/drag_drop_client.h"
+#include "ui/aura/window_observer.h"
+#include "ui/base/x/x11_atom_cache.h"
+#include "ui/gfx/point.h"
+#include "ui/views/views_export.h"
+
+namespace aura {
+class RootWindow;
+namespace client {
+class DragDropDelegate;
+}
+}
+
+namespace gfx {
+class Point;
+}
+
+namespace ui {
+class DragSource;
+class DropTargetEvent;
+class OSExchangeData;
+class RootWindow;
+}
+
+namespace views {
+class DesktopRootWindowHostX11;
+
+// Implements drag and drop on X11 for aura. On one side, this class takes raw
+// X11 events forwarded from DesktopRootWindowHostLinux, while on the other, it
+// handles the views drag events.
+class VIEWS_EXPORT DesktopDragDropClientAuraX11
+    : public aura::client::DragDropClient,
+      public aura::WindowObserver {
+ public:
+  DesktopDragDropClientAuraX11(
+      views::DesktopRootWindowHostX11* root_window_host,
+      aura::RootWindow* root_window,
+      Display* xdisplay,
+      ::Window xwindow);
+  virtual ~DesktopDragDropClientAuraX11();
+
+  // These methods handle the various X11 client messages from the platform.
+  void OnXdndEnter(const XClientMessageEvent& event);
+  void OnXdndLeave(const XClientMessageEvent& event);
+  void OnXdndPosition(const XClientMessageEvent& event);
+  void OnXdndStatus(const XClientMessageEvent& event);
+  void OnXdndFinished(const XClientMessageEvent& event);
+  void OnXdndDrop(const XClientMessageEvent& event);
+
+  // Overridden from aura::client::DragDropClient:
+  virtual int StartDragAndDrop(
+      const ui::OSExchangeData& data,
+      aura::RootWindow* root_window,
+      aura::Window* source_window,
+      const gfx::Point& root_location,
+      int operation,
+      ui::DragDropTypes::DragEventSource source) OVERRIDE;
+  virtual void DragUpdate(aura::Window* target,
+                          const ui::LocatedEvent& event) OVERRIDE;
+  virtual void Drop(aura::Window* target,
+                    const ui::LocatedEvent& event) OVERRIDE;
+  virtual void DragCancel() OVERRIDE;
+  virtual bool IsDragDropInProgress() OVERRIDE;
+
+  // aura::WindowObserver implementation:
+  virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
+
+ private:
+  // When we receive an position x11 message, we need to translate that into
+  // the underlying aura::Window representation, as moves internal to the X11
+  // window can cause internal drag leave and enter messages.
+  void DragTranslate(const gfx::Point& root_window_location,
+                     scoped_ptr<ui::OSExchangeData>* data,
+                     scoped_ptr<ui::DropTargetEvent>* event,
+                     aura::client::DragDropDelegate** delegate);
+
+  // Called when we need to notify the current aura::Window that we're no
+  // longer dragging over it.
+  void NotifyDragLeave();
+
+  // Converts our bitfield of actions into an Atom that represents what action
+  // we're most likely to take on drop.
+  unsigned long DragOperationToAtom(int drag_operation);
+
+  // Sends |xev| to |xid|, optionally short circuiting the round trip to the X
+  // server.
+  void SendXClientEvent(unsigned long xid, XEvent* xev);
+
+  views::DesktopRootWindowHostX11* root_window_host_;
+  aura::RootWindow* root_window_;
+
+  Display* xdisplay_;
+  ::Window xwindow_;
+
+  ui::X11AtomCache atom_cache_;
+
+  // Target side information.
+
+  class X11DragContext;
+  scoped_ptr<X11DragContext> current_context_;
+
+  // The Aura window that is currently under the cursor. We need to manually
+  // keep track of this because Windows will only call our drag enter method
+  // once when the user enters the associated X Window. But inside that X
+  // Window there could be multiple aura windows, so we need to generate drag
+  // enter events for them.
+  aura::Window* target_window_;
+
+  // Because Xdnd messages don't contain the position in messages other than
+  // the XdndPosition message, we must manually keep track of the last position
+  // change.
+  gfx::Point target_window_location_;
+  gfx::Point target_window_root_location_;
+
+  bool drag_drop_in_progress_;
+
+  int drag_operation_;
+
+  DISALLOW_COPY_AND_ASSIGN(DesktopDragDropClientAuraX11);
+};
+
+}  // namespace views
+
+#endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_