ui/gfx/display.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_GFX_DISPLAY_H_
   6 #define UI_GFX_DISPLAY_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "ui/gfx/geometry/rect.h"
  11 #include "ui/gfx/gfx_export.h"
  12
  13 namespace gfx {
  14
  15 // This class typically, but does not always, correspond to a physical display
  16 // connected to the system. A fake Display may exist on a headless system, or a
  17 // Display may correspond to a remote, virtual display.
  18 //
  19 // Note: The screen and display currently uses pixel coordinate
  20 // system. For platforms that support DIP (density independent pixel),
  21 // |bounds()| and |work_area| will return values in DIP coordinate
  22 // system, not in backing pixels.
  23 class GFX_EXPORT Display {
  24  public:
  25   // Screen Rotation in clock-wise degrees.
  26   enum Rotation {
  27     ROTATE_0 = 0,
  28     ROTATE_90,
  29     ROTATE_180,
  30     ROTATE_270,
  31   };
  32
  33   // The display rotation can have multiple causes for change. A user can set a
  34   // preference. On devices with accelerometers, they can change the rotation.
  35   // RotationSource allows for the tracking of a Rotation per source of the
  36   // change. ROTATION_SOURCE_ACTIVE is the current rotation of the display.
  37   // Rotation changes not due to an accelerometer, nor the user, are to use this
  38   // source directly.
  39   enum RotationSource {
  40     ROTATION_SOURCE_ACCELEROMETER = 0,
  41     ROTATION_SOURCE_ACTIVE,
  42     ROTATION_SOURCE_USER,
  43   };
  44
  45   // Touch support for the display.
  46   enum TouchSupport {
  47     TOUCH_SUPPORT_UNKNOWN,
  48     TOUCH_SUPPORT_AVAILABLE,
  49     TOUCH_SUPPORT_UNAVAILABLE,
  50   };
  51
  52   // Creates a display with kInvalidDisplayID as default.
  53   Display();
  54   explicit Display(int64 id);
  55   Display(int64 id, const Rect& bounds);
  56   ~Display();
  57
  58   // Returns the forced device scale factor, which is given by
  59   // "--force-device-scale-factor".
  60   static float GetForcedDeviceScaleFactor();
  61
  62   // Indicates if a device scale factor is being explicitly enforced from the
  63   // command line via "--force-device-scale-factor".
  64   static bool HasForceDeviceScaleFactor();
  65
  66   // Resets the caches used to determine if a device scale factor is being
  67   // forced from the command line via "--force-device-scale-factor", and thus
  68   // ensures that the command line is reevaluated.
  69   static void ResetForceDeviceScaleFactorForTesting();
  70
  71   // Sets/Gets unique identifier associated with the display.
  72   // -1 means invalid display and it doesn't not exit.
  73   int64 id() const { return id_; }
  74   void set_id(int64 id) { id_ = id; }
  75
  76   // Gets/Sets the display's bounds in gfx::Screen's coordinates.
  77   const Rect& bounds() const { return bounds_; }
  78   void set_bounds(const Rect& bounds) { bounds_ = bounds; }
  79
  80   // Gets/Sets the display's work area in gfx::Screen's coordinates.
  81   const Rect& work_area() const { return work_area_; }
  82   void set_work_area(const Rect& work_area) { work_area_ = work_area; }
  83
  84   // Output device's pixel scale factor. This specifies how much the
  85   // UI should be scaled when the actual output has more pixels than
  86   // standard displays (which is around 100~120dpi.) The potential return
  87   // values depend on each platforms.
  88   float device_scale_factor() const { return device_scale_factor_; }
  89   void set_device_scale_factor(float scale) { device_scale_factor_ = scale; }
  90
  91   Rotation rotation() const { return rotation_; }
  92   void set_rotation(Rotation rotation) { rotation_ = rotation; }
  93   int RotationAsDegree() const;
  94   void SetRotationAsDegree(int rotation);
  95
  96   TouchSupport touch_support() const { return touch_support_; }
  97   void set_touch_support(TouchSupport support) { touch_support_ = support; }
  98
  99   // Utility functions that just return the size of display and
 100   // work area.
 101   const Size& size() const { return bounds_.size(); }
 102   const Size& work_area_size() const { return work_area_.size(); }
 103
 104   // Returns the work area insets.
 105   Insets GetWorkAreaInsets() const;
 106
 107   // Sets the device scale factor and display bounds in pixel. This
 108   // updates the work are using the same insets between old bounds and
 109   // work area.
 110   void SetScaleAndBounds(float device_scale_factor,
 111                          const gfx::Rect& bounds_in_pixel);
 112
 113   // Sets the display's size. This updates the work area using the same insets
 114   // between old bounds and work area.
 115   void SetSize(const gfx::Size& size_in_pixel);
 116
 117   // Computes and updates the display's work are using
 118   // |work_area_insets| and the bounds.
 119   void UpdateWorkAreaFromInsets(const gfx::Insets& work_area_insets);
 120
 121   // Returns the display's size in pixel coordinates.
 122   gfx::Size GetSizeInPixel() const;
 123
 124   // Returns a string representation of the display;
 125   std::string ToString() const;
 126
 127   // True if the display contains valid display id.
 128   bool is_valid() const { return id_ != kInvalidDisplayID; }
 129
 130   // True if the display corresponds to internal panel.
 131   bool IsInternal() const;
 132
 133   // Gets/Sets an id of display corresponding to internal panel.
 134   static int64 InternalDisplayId();
 135   static void SetInternalDisplayId(int64 internal_display_id);
 136
 137   // True if there is an internal display.
 138   static bool HasInternalDisplay();
 139
 140   static const int64 kInvalidDisplayID;
 141
 142  private:
 143   int64 id_;
 144   Rect bounds_;
 145   Rect work_area_;
 146   float device_scale_factor_;
 147   Rotation rotation_;
 148   TouchSupport touch_support_;
 149 };
 150
 151 }  // namespace gfx
 152
 153 #endif  // UI_GFX_DISPLAY_H_