chrome/browser/ui/gtk/panels/panel_drag_gtk.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 CHROME_BROWSER_UI_GTK_PANELS_PANEL_DRAG_GTK_H_
   6 #define CHROME_BROWSER_UI_GTK_PANELS_PANEL_DRAG_GTK_H_
   7
   8 #include <gtk/gtk.h>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "ui/base/gtk/gtk_signal.h"
  13
  14 class Panel;
  15 class PanelDragDelegate;
  16
  17 // Class for GTK handling of move-drag and resize-drag on a panel.
  18 // Only one type of drag may be active at any time.
  19 // Dragging only begins if the mouse is moved beyond the drag threshold.
  20 // If mouse is released without exceeding the drag threshold, the mouse
  21 // press and release is treated as a mouse click.
  22 class PanelDragGtk {
  23  public:
  24   explicit PanelDragGtk(Panel* panel);
  25   ~PanelDragGtk();
  26
  27   GtkWidget* widget() const { return drag_widget_; }
  28
  29   // Sets up mouse and keyboard events processing while the mouse
  30   // is pressed on a window edge.
  31   // |event| is the mouse press event.
  32   // |cursor| is the cursor to display during the drag.
  33   // |edge| is the window edge from which to resize the panel.
  34   void InitialWindowEdgeMousePress(GdkEventButton* event, GdkCursor* cursor,
  35                                    GdkWindowEdge& edge);
  36
  37   // Sets up mouse and keyboard events processing while the mouse is
  38   // pressed on the titlebar.
  39   // |event| is the mouse press event.
  40   // |titlebar_widget| should handle the mouse release event if the mouse
  41   // is released without exceeding the drag threshold (a mouse click).
  42   void InitialTitlebarMousePress(GdkEventButton* event,
  43                                  GtkWidget* titlebar_widget);
  44
  45  private:
  46   friend class GtkNativePanelTesting;
  47
  48   enum DragState {
  49     NOT_DRAGGING,
  50     DRAG_CAN_START,  // mouse pressed
  51     DRAG_IN_PROGRESS,  // mouse moved beyond drag threshold
  52     DRAG_ENDED_WAITING_FOR_MOUSE_RELEASE
  53   };
  54
  55   // Callbacks for GTK mouse and key events.
  56   CHROMEGTK_CALLBACK_1(PanelDragGtk, gboolean, OnMouseMoveEvent,
  57                        GdkEventMotion*);
  58   CHROMEGTK_CALLBACK_1(PanelDragGtk, gboolean, OnButtonPressEvent,
  59                        GdkEventButton*);
  60   CHROMEGTK_CALLBACK_1(PanelDragGtk, gboolean, OnButtonReleaseEvent,
  61                        GdkEventButton*);
  62   CHROMEGTK_CALLBACK_1(PanelDragGtk, gboolean, OnKeyPressEvent,
  63                        GdkEventKey*);
  64   CHROMEGTK_CALLBACK_1(PanelDragGtk, gboolean, OnKeyReleaseEvent,
  65                        GdkEventKey*);
  66   CHROMEGTK_CALLBACK_1(PanelDragGtk, gboolean, OnGrabBrokenEvent,
  67                        GdkEventGrabBroken*);
  68
  69   // Utility to dcheck a bunch of state to ensure a clean slate.
  70   // Returns only if all the dchecks pass.
  71   void AssertCleanState();
  72
  73   void GrabPointerAndKeyboard(GdkEventButton* event,
  74                               GdkCursor* cursor);
  75   void ReleasePointerAndKeyboardGrab();
  76
  77   // Ends any drag that is currently in progress (if any).
  78   // Resets all drag state except for pointer and keyboard grabs.
  79   // The grabs are released when the mouse is released to prevent a
  80   // mouse release *after* the drag has ended (e.g. via ESC key) from
  81   // being treated as a mouse click.
  82   void EndDrag(bool canceled);
  83
  84   // Weak pointer to the panel being dragged.
  85   Panel* panel_;
  86
  87   // Invisible event box to receive mouse and key events.
  88   GtkWidget* drag_widget_;
  89
  90   DragState drag_state_;
  91
  92   // A copy of the initial button press event.
  93   GdkEvent* initial_mouse_down_;
  94
  95   // Widget that should process the mouse click if mouse is released
  96   // without exceeding the drag threshold. May be NULL if no click
  97   // handling is necessary.
  98   GtkWidget* click_handler_;
  99
 100   // Delegate for processing drag depends on actual type of drag.
 101   PanelDragDelegate* drag_delegate_;
 102
 103   DISALLOW_COPY_AND_ASSIGN(PanelDragGtk);
 104 };
 105
 106 #endif  // CHROME_BROWSER_UI_GTK_PANELS_PANEL_DRAG_GTK_H_