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      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_DPI_WIN_H_
      6 #define UI_GFX_DPI_WIN_H_
      7 
      8 #include "ui/gfx/gfx_export.h"
      9 #include "ui/gfx/point.h"
     10 #include "ui/gfx/rect.h"
     11 #include "ui/gfx/size.h"
     12 
     13 namespace gfx {
     14 
     15 // Initialization of the scale factor that should be applied for rendering
     16 // in this process. Must be called before attempts to call any of the getter
     17 // methods below in this file, e.g. in the early toolkit/resource bundle setup.
     18 // This can be called multiple times during various tests, but subsequent calls
     19 // have no effect.
     20 GFX_EXPORT void InitDeviceScaleFactor(float scale);
     21 
     22 GFX_EXPORT Size GetDPI();
     23 
     24 // Gets the scale factor of the display. For example, if the display DPI is
     25 // 96 then the scale factor is 1.0.
     26 GFX_EXPORT float GetDPIScale();
     27 
     28 // Tests to see if the command line flag "--high-dpi-support" is set.
     29 GFX_EXPORT bool IsHighDPIEnabled();
     30 
     31 GFX_EXPORT bool IsInHighDPIMode();
     32 
     33 GFX_EXPORT void EnableHighDPISupport();
     34 
     35 GFX_EXPORT void ForceHighDPISupportForTesting(float scale);
     36 
     37 // TODO(kevers|girard):  Move above methods into win namespace.
     38 
     39 namespace win {
     40 
     41 GFX_EXPORT float GetDeviceScaleFactor();
     42 
     43 GFX_EXPORT Point ScreenToDIPPoint(const Point& pixel_point);
     44 
     45 GFX_EXPORT Point DIPToScreenPoint(const Point& dip_point);
     46 
     47 // WARNING: there is no right way to scale sizes and rects. The implementation
     48 // of these strives to maintain a constant size by scaling the size independent
     49 // of the origin. An alternative is to get the enclosing rect, which is the
     50 // right way for some situations. Understand which you need before blindly
     51 // assuming this is the right way.
     52 GFX_EXPORT Rect ScreenToDIPRect(const Rect& pixel_bounds);
     53 GFX_EXPORT Rect DIPToScreenRect(const Rect& dip_bounds);
     54 GFX_EXPORT Size ScreenToDIPSize(const Size& size_in_pixels);
     55 GFX_EXPORT Size DIPToScreenSize(const Size& dip_size);
     56 
     57 // Win32's GetSystemMetrics uses pixel measures. This function calls
     58 // GetSystemMetrics for the given |metric|, then converts the result to DIP.
     59 GFX_EXPORT int GetSystemMetricsInDIP(int metric);
     60 
     61 // Returns true if the global device scale factor has been explicitly set for
     62 // the process.
     63 GFX_EXPORT bool IsDeviceScaleFactorSet();
     64 
     65 GFX_EXPORT extern const wchar_t kRegistryProfilePath[];
     66 GFX_EXPORT extern const wchar_t kHighDPISupportW[];
     67 
     68 }  // namespace win
     69 }  // namespace gfx
     70 
     71 #endif  // UI_GFX_DPI_WIN_H_
     72