ui/views/widget/desktop_aura/desktop_drag_drop_client_aurax11.h

   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 UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_
   6 #define UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_
   7
   8 #include <set>
   9 #include <vector>
  10 #include <X11/Xlib.h>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/memory/weak_ptr.h"
  15 #include "base/timer/timer.h"
  16 #include "ui/aura/window_observer.h"
  17 #include "ui/base/cursor/cursor.h"
  18 #include "ui/base/dragdrop/drag_drop_types.h"
  19 #include "ui/gfx/point.h"
  20 #include "ui/gfx/x/x11_atom_cache.h"
  21 #include "ui/views/views_export.h"
  22 #include "ui/views/widget/desktop_aura/x11_move_loop_delegate.h"
  23 #include "ui/wm/public/drag_drop_client.h"
  24
  25 namespace aura {
  26 namespace client {
  27 class DragDropDelegate;
  28 }
  29 }
  30
  31 namespace gfx {
  32 class ImageSkia;
  33 class Point;
  34 }
  35
  36 namespace ui {
  37 class DragSource;
  38 class DropTargetEvent;
  39 class OSExchangeData;
  40 class OSExchangeDataProviderAuraX11;
  41 class SelectionFormatMap;
  42 }
  43
  44 namespace views {
  45 class DesktopNativeCursorManager;
  46 class Widget;
  47 class X11MoveLoop;
  48
  49 // Implements drag and drop on X11 for aura. On one side, this class takes raw
  50 // X11 events forwarded from DesktopWindowTreeHostLinux, while on the other, it
  51 // handles the views drag events.
  52 class VIEWS_EXPORT DesktopDragDropClientAuraX11
  53     : public aura::client::DragDropClient,
  54       public aura::WindowObserver,
  55       public X11MoveLoopDelegate {
  56  public:
  57   DesktopDragDropClientAuraX11(
  58       aura::Window* root_window,
  59       views::DesktopNativeCursorManager* cursor_manager,
  60       Display* xdisplay,
  61       ::Window xwindow);
  62   virtual ~DesktopDragDropClientAuraX11();
  63
  64   // We maintain a mapping of live DesktopDragDropClientAuraX11 objects to
  65   // their ::Windows. We do this so that we're able to short circuit sending
  66   // X11 messages to windows in our process.
  67   static DesktopDragDropClientAuraX11* GetForWindow(::Window window);
  68
  69   void Init();
  70
  71   // These methods handle the various X11 client messages from the platform.
  72   void OnXdndEnter(const XClientMessageEvent& event);
  73   void OnXdndLeave(const XClientMessageEvent& event);
  74   void OnXdndPosition(const XClientMessageEvent& event);
  75   void OnXdndStatus(const XClientMessageEvent& event);
  76   void OnXdndFinished(const XClientMessageEvent& event);
  77   void OnXdndDrop(const XClientMessageEvent& event);
  78
  79   // Called when XSelection data has been copied to our process.
  80   void OnSelectionNotify(const XSelectionEvent& xselection);
  81
  82   // Overridden from aura::client::DragDropClient:
  83   virtual int StartDragAndDrop(
  84       const ui::OSExchangeData& data,
  85       aura::Window* root_window,
  86       aura::Window* source_window,
  87       const gfx::Point& root_location,
  88       int operation,
  89       ui::DragDropTypes::DragEventSource source) OVERRIDE;
  90   virtual void DragUpdate(aura::Window* target,
  91                           const ui::LocatedEvent& event) OVERRIDE;
  92   virtual void Drop(aura::Window* target,
  93                     const ui::LocatedEvent& event) OVERRIDE;
  94   virtual void DragCancel() OVERRIDE;
  95   virtual bool IsDragDropInProgress() OVERRIDE;
  96
  97   // Overridden from aura::WindowObserver:
  98   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
  99
 100   // Overridden from X11WholeScreenMoveLoopDelegate:
 101   virtual void OnMouseMovement(XMotionEvent* event) OVERRIDE;
 102   virtual void OnMouseReleased() OVERRIDE;
 103   virtual void OnMoveLoopEnded() OVERRIDE;
 104
 105  protected:
 106   // The following methods are virtual for the sake of testing.
 107
 108   // Creates a move loop.
 109   virtual scoped_ptr<X11MoveLoop> CreateMoveLoop(
 110       X11MoveLoopDelegate* delegate);
 111
 112   // Finds the topmost X11 window at |screen_point| and returns it if it is
 113   // Xdnd aware. Returns NULL otherwise.
 114   virtual ::Window FindWindowFor(const gfx::Point& screen_point);
 115
 116   // Sends |xev| to |xid|, optionally short circuiting the round trip to the X
 117   // server.
 118   virtual void SendXClientEvent(::Window xid, XEvent* xev);
 119
 120  private:
 121   enum SourceState {
 122     // |source_current_window_| will receive a drop once we receive an
 123     // XdndStatus from it.
 124     SOURCE_STATE_PENDING_DROP,
 125
 126     // The move looped will be ended once we receive XdndFinished from
 127     // |source_current_window_|. We should not send XdndPosition to
 128     // |source_current_window_| while in this state.
 129     SOURCE_STATE_DROPPED,
 130
 131     // There is no drag in progress or there is a drag in progress and the
 132     // user has not yet released the mouse.
 133     SOURCE_STATE_OTHER,
 134   };
 135
 136   // Processes a mouse move at |screen_point|.
 137   void ProcessMouseMove(const gfx::Point& screen_point,
 138                         unsigned long event_time);
 139
 140   // Start timer to end the move loop if the target is too slow to respond after
 141   // the mouse is released.
 142   void StartEndMoveLoopTimer();
 143
 144   // Ends the move loop.
 145   void EndMoveLoop();
 146
 147   // When we receive an position x11 message, we need to translate that into
 148   // the underlying aura::Window representation, as moves internal to the X11
 149   // window can cause internal drag leave and enter messages.
 150   void DragTranslate(const gfx::Point& root_window_location,
 151                      scoped_ptr<ui::OSExchangeData>* data,
 152                      scoped_ptr<ui::DropTargetEvent>* event,
 153                      aura::client::DragDropDelegate** delegate);
 154
 155   // Called when we need to notify the current aura::Window that we're no
 156   // longer dragging over it.
 157   void NotifyDragLeave();
 158
 159   // Converts our bitfield of actions into an Atom that represents what action
 160   // we're most likely to take on drop.
 161   ::Atom DragOperationToAtom(int drag_operation);
 162
 163   // Converts a single action atom to a drag operation.
 164   ui::DragDropTypes::DragOperation AtomToDragOperation(::Atom atom);
 165
 166   // During the blocking StartDragAndDrop() call, this converts the views-style
 167   // |drag_operation_| bitfield into a vector of Atoms to offer to other
 168   // processes.
 169   std::vector< ::Atom> GetOfferedDragOperations();
 170
 171   // This returns a representation of the data we're offering in this
 172   // drag. This is done to bypass an asynchronous roundtrip with the X11
 173   // server.
 174   ui::SelectionFormatMap GetFormatMap() const;
 175
 176   // Handling XdndPosition can be paused while waiting for more data; this is
 177   // called either synchronously from OnXdndPosition, or asynchronously after
 178   // we've received data requested from the other window.
 179   void CompleteXdndPosition(::Window source_window,
 180                             const gfx::Point& screen_point);
 181
 182   void SendXdndEnter(::Window dest_window);
 183   void SendXdndLeave(::Window dest_window);
 184   void SendXdndPosition(::Window dest_window,
 185                         const gfx::Point& screen_point,
 186                         unsigned long event_time);
 187   void SendXdndDrop(::Window dest_window);
 188
 189   // Creates a widget for the user to drag around.
 190   void CreateDragWidget(const gfx::ImageSkia& image);
 191
 192   // Returns true if |image| has any visible regions (defined as having a pixel
 193   // with alpha > 32).
 194   bool IsValidDragImage(const gfx::ImageSkia& image);
 195
 196   // A nested message loop that notifies this object of events through the
 197   // X11MoveLoopDelegate interface.
 198   scoped_ptr<X11MoveLoop> move_loop_;
 199
 200   aura::Window* root_window_;
 201
 202   Display* xdisplay_;
 203   ::Window xwindow_;
 204
 205   ui::X11AtomCache atom_cache_;
 206
 207   // Target side information.
 208   class X11DragContext;
 209   scoped_ptr<X11DragContext> target_current_context_;
 210
 211   // The Aura window that is currently under the cursor. We need to manually
 212   // keep track of this because Windows will only call our drag enter method
 213   // once when the user enters the associated X Window. But inside that X
 214   // Window there could be multiple aura windows, so we need to generate drag
 215   // enter events for them.
 216   aura::Window* target_window_;
 217
 218   // Because Xdnd messages don't contain the position in messages other than
 219   // the XdndPosition message, we must manually keep track of the last position
 220   // change.
 221   gfx::Point target_window_location_;
 222   gfx::Point target_window_root_location_;
 223
 224   // In the Xdnd protocol, we aren't supposed to send another XdndPosition
 225   // message until we have received a confirming XdndStatus message.
 226   bool waiting_on_status_;
 227
 228   // If we would send an XdndPosition message while we're waiting for an
 229   // XdndStatus response, we need to cache the latest details we'd send.
 230   scoped_ptr<std::pair<gfx::Point, unsigned long> > next_position_message_;
 231
 232   // Reprocesses the most recent mouse move event if the mouse has not moved
 233   // in a while in case the window stacking order has changed and
 234   // |source_current_window_| needs to be updated.
 235   base::OneShotTimer<DesktopDragDropClientAuraX11> repeat_mouse_move_timer_;
 236
 237   // When the mouse is released, we need to wait for the last XdndStatus message
 238   // only if we have previously received a status message from
 239   // |source_current_window_|.
 240   bool status_received_since_enter_;
 241
 242   // Source side information.
 243   ui::OSExchangeDataProviderAuraX11 const* source_provider_;
 244   ::Window source_current_window_;
 245   SourceState source_state_;
 246
 247   // The current drag-drop client that has an active operation. Since we have
 248   // multiple root windows and multiple DesktopDragDropClientAuraX11 instances
 249   // it is important to maintain only one drag and drop operation at any time.
 250   static DesktopDragDropClientAuraX11* g_current_drag_drop_client;
 251
 252   // The operation bitfield as requested by StartDragAndDrop.
 253   int drag_operation_;
 254
 255   // We offer the other window a list of possible operations,
 256   // XdndActionsList. This is the requested action from the other window. This
 257   // is DRAG_NONE if we haven't sent out an XdndPosition message yet, haven't
 258   // yet received an XdndStatus or if the other window has told us that there's
 259   // no action that we can agree on.
 260   ui::DragDropTypes::DragOperation negotiated_operation_;
 261
 262   // Ends the move loop if the target is too slow to respond after the mouse is
 263   // released.
 264   base::OneShotTimer<DesktopDragDropClientAuraX11> end_move_loop_timer_;
 265
 266   // Widget that the user drags around. May be NULL.
 267   scoped_ptr<Widget> drag_widget_;
 268
 269   // The offset of |drag_widget_| relative to the mouse position.
 270   gfx::Vector2d drag_widget_offset_;
 271
 272   // We use these cursors while dragging.
 273   gfx::NativeCursor grab_cursor_;
 274   gfx::NativeCursor copy_grab_cursor_;
 275   gfx::NativeCursor move_grab_cursor_;
 276
 277   base::WeakPtrFactory<DesktopDragDropClientAuraX11> weak_ptr_factory_;
 278
 279   DISALLOW_COPY_AND_ASSIGN(DesktopDragDropClientAuraX11);
 280 };
 281
 282 }  // namespace views
 283
 284 #endif  // UI_VIEWS_WIDGET_DESKTOP_AURA_DESKTOP_DRAG_DROP_CLIENT_AURAX11_H_