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