ui/events/ozone/chromeos/cursor_controller.h

   1 // Copyright 2014 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_EVENTS_OZONE_CHROMEOS_CURSOR_CONTROLLER_H_
   6 #define UI_EVENTS_OZONE_CHROMEOS_CURSOR_CONTROLLER_H_
   7
   8 #include <map>
   9
  10 #include "base/event_types.h"
  11 #include "base/memory/singleton.h"
  12 #include "base/synchronization/lock.h"
  13 #include "ui/events/ozone/events_ozone_export.h"
  14 #include "ui/gfx/display.h"
  15 #include "ui/gfx/geometry/vector2d_f.h"
  16 #include "ui/gfx/native_widget_types.h"
  17
  18 namespace ui {
  19
  20 // Manager for per-window cursor settings.
  21 //
  22 // This is used to apply a rotation & acceleration to each vector added to the
  23 // cursor position on ChromeOS.
  24 //
  25 // This has 3 uses:
  26 //
  27 //  (1) Fixing cursor movement direction for rotated displays.
  28 //  (2) Fixing cursor movement speed based on scale factor.
  29 //  (3) Tweaking cursor movement speed on external displays.
  30 //
  31 // This HACK is necessary because ash handles rotation and handles scaling but
  32 // does NOT handle the cursor movement (except that it sends a message to x11 or
  33 // ozone to activate this hack).
  34 //
  35 // TODO(spang): Don't worry, we have a plan to remove this.
  36 class EVENTS_OZONE_EXPORT CursorController {
  37  public:
  38   static CursorController* GetInstance();
  39
  40   // Changes the rotation & scale applied for a window.
  41   void SetCursorConfigForWindow(gfx::AcceleratedWidget widget,
  42                                 gfx::Display::Rotation rotation,
  43                                 float scale);
  44
  45   // Cleans up all state associated with a window.
  46   void ClearCursorConfigForWindow(gfx::AcceleratedWidget widget);
  47
  48   // Applies the current settings for a window to a cursor movement vector.
  49   //
  50   // The rotation applies counter-clockwise (to negate clockwise display
  51   // rotation) and the result is multiplied by scale.
  52   //
  53   // e.g. if (dx, dy) = (2, 3) and (scale, rotation) = (2.f, 90deg)
  54   //      then we set (dx, dy) = (-6, 4)
  55   //
  56   // Since scale generally includes DSF, you can think of the input
  57   // vector unit as DIP and the output vector unit as pixels.
  58   void ApplyCursorConfigForWindow(gfx::AcceleratedWidget widget,
  59                                   gfx::Vector2dF* delta) const;
  60
  61  private:
  62   CursorController();
  63   ~CursorController();
  64   friend struct base::DefaultSingletonTraits<CursorController>;
  65
  66   struct PerWindowCursorConfiguration {
  67     gfx::Display::Rotation rotation;
  68     float scale;
  69   };
  70
  71   typedef std::map<gfx::AcceleratedWidget, PerWindowCursorConfiguration>
  72       WindowToCursorConfigurationMap;
  73
  74   WindowToCursorConfigurationMap window_to_cursor_configuration_map_;
  75   mutable base::Lock window_to_cursor_configuration_map_lock_;
  76
  77   DISALLOW_COPY_AND_ASSIGN(CursorController);
  78 };
  79
  80 }  // namespace ui
  81
  82 #endif  // UI_EVENTS_OZONE_CHROMEOS_CURSOR_CONTROLLER_H_