ash/wm/gestures/edge_gesture_handler.h

   1 // Copyright (c) 2013 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 ASH_WM_GESTURES_EDGE_GESTURE_HANDLER_H_
   6 #define ASH_WM_GESTURES_EDGE_GESTURE_HANDLER_H_
   7
   8 #include "ash/shelf/shelf_types.h"
   9 #include "ash/wm/gestures/shelf_gesture_handler.h"
  10 #include "base/basictypes.h"
  11
  12 namespace aura {
  13 class Window;
  14 }
  15
  16 namespace gfx {
  17 class Point;
  18 class Rect;
  19 }
  20
  21 namespace ui {
  22 class GestureEvent;
  23 }
  24
  25 namespace ash {
  26 namespace internal {
  27
  28 enum EdgeScrollOrientation {
  29   EDGE_SCROLL_ORIENTATION_UNSET = 0,
  30   EDGE_SCROLL_ORIENTATION_HORIZONTAL,
  31   EDGE_SCROLL_ORIENTATION_VERTICAL
  32 };
  33
  34 // Handles touch gestures that occur at the edge of the screen without the aid
  35 // of a bezel sensor and might have actions associated with them.
  36 class EdgeGestureHandler {
  37  public:
  38   EdgeGestureHandler();
  39   virtual ~EdgeGestureHandler();
  40
  41   // Returns true of the gesture has been handled and it should not be processed
  42   // any farther, false otherwise.
  43   bool ProcessGestureEvent(aura::Window* target, const ui::GestureEvent& event);
  44
  45  private:
  46   // Handle events meant for showing the launcher. Returns true when no further
  47   // events from this gesture should be sent.
  48   bool HandleLauncherControl(const ui::GestureEvent& event);
  49
  50   bool HandleEdgeGestureStart(aura::Window* target,
  51                               const ui::GestureEvent& event);
  52
  53   // Determine the gesture orientation (if not yet done).
  54   // Returns true when the orientation has been successfully determined.
  55   bool DetermineGestureOrientation(const ui::GestureEvent& event);
  56
  57   // Handles a gesture update once the orientation has been found.
  58   bool HandleEdgeGestureUpdate(aura::Window* target,
  59                                const ui::GestureEvent& event);
  60
  61   bool HandleEdgeGestureEnd(aura::Window* target,
  62                             const ui::GestureEvent& event);
  63
  64   // Check that gesture starts near enough to the edge of the screen to be
  65   // handled here. If so, set |start_location_| and return true, otherwise
  66   // return false.
  67   bool GestureStartInEdgeArea(const gfx::Rect& screen,
  68                               const ui::GestureEvent& event);
  69
  70   // Test if the gesture orientation makes sense to be dragging in or out the
  71   // launcher.
  72   bool IsGestureInLauncherOrientation(const ui::GestureEvent& event);
  73
  74   // Bit flags for which edges the gesture is close to. In the case that a
  75   // gesture begins in a corner of the screen more then one flag may be set and
  76   // the orientation of the gesture will be needed to disambiguate.
  77   unsigned int start_location_;
  78
  79   // Orientation relative to the screen that the gesture is moving in
  80   EdgeScrollOrientation orientation_;
  81   ShelfGestureHandler shelf_handler_;
  82
  83   DISALLOW_COPY_AND_ASSIGN(EdgeGestureHandler);
  84 };
  85
  86 }  // namespace internal
  87 }  // namespace ash
  88
  89 #endif  // ASH_WM_GESTURES_EDGE_GESTURE_HANDLER_H_