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_BASE_LAYOUT_H_ 6 #define UI_BASE_LAYOUT_H_ 7 8 #include <vector> 9 10 #include "build/build_config.h" 11 #include "ui/base/ui_base_export.h" 12 #include "ui/gfx/native_widget_types.h" 13 14 namespace ui { 15 16 // Supported UI scale factors for the platform. This is used as an index 17 // into the array |kScaleFactorScales| which maps the enum value to a float. 18 // SCALE_FACTOR_NONE is used for density independent resources such as 19 // string, html/js files or an image that can be used for any scale factors 20 // (such as wallpapers). 21 enum ScaleFactor { 22 SCALE_FACTOR_NONE = 0, 23 SCALE_FACTOR_100P, 24 SCALE_FACTOR_125P, 25 SCALE_FACTOR_133P, 26 SCALE_FACTOR_140P, 27 SCALE_FACTOR_150P, 28 SCALE_FACTOR_180P, 29 SCALE_FACTOR_200P, 30 SCALE_FACTOR_250P, 31 SCALE_FACTOR_300P, 32 33 NUM_SCALE_FACTORS // This always appears last. 34 }; 35 36 // Changes the value of GetSupportedScaleFactors() to |scale_factors|. 37 // Use ScopedSetSupportedScaleFactors for unit tests as not to affect the 38 // state of other tests. 39 UI_BASE_EXPORT void SetSupportedScaleFactors( 40 const std::vector<ScaleFactor>& scale_factors); 41 42 // Returns a vector with the scale factors which are supported by this 43 // platform, in ascending order. 44 UI_BASE_EXPORT const std::vector<ScaleFactor>& GetSupportedScaleFactors(); 45 46 // Returns the supported ScaleFactor which most closely matches |scale|. 47 // Converting from float to ScaleFactor is inefficient and should be done as 48 // little as possible. 49 UI_BASE_EXPORT ScaleFactor GetSupportedScaleFactor(float image_scale); 50 51 // Returns the ScaleFactor used by |view|. 52 UI_BASE_EXPORT float GetScaleFactorForNativeView(gfx::NativeView view); 53 54 // Returns the image scale for the scale factor passed in. 55 UI_BASE_EXPORT float GetScaleForScaleFactor(ScaleFactor scale_factor); 56 57 namespace test { 58 // Class which changes the value of GetSupportedScaleFactors() to 59 // |new_scale_factors| for the duration of its lifetime. 60 class UI_BASE_EXPORT ScopedSetSupportedScaleFactors { 61 public: 62 explicit ScopedSetSupportedScaleFactors( 63 const std::vector<ui::ScaleFactor>& new_scale_factors); 64 ~ScopedSetSupportedScaleFactors(); 65 66 private: 67 std::vector<ui::ScaleFactor>* original_scale_factors_; 68 69 DISALLOW_COPY_AND_ASSIGN(ScopedSetSupportedScaleFactors); 70 }; 71 72 } // namespace test 73 74 } // namespace ui 75 76 #endif // UI_BASE_LAYOUT_H_ 77