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_PLATFORM_FONT_PANGO_H_ 6 #define UI_GFX_PLATFORM_FONT_PANGO_H_ 7 8 #include <string> 9 10 #include "base/compiler_specific.h" 11 #include "base/memory/scoped_ptr.h" 12 #include "skia/ext/refptr.h" 13 #include "third_party/skia/include/core/SkRefCnt.h" 14 #include "ui/gfx/platform_font.h" 15 16 class SkTypeface; 17 class SkPaint; 18 19 namespace gfx { 20 21 class GFX_EXPORT PlatformFontPango : public PlatformFont { 22 public: 23 PlatformFontPango(); 24 explicit PlatformFontPango(NativeFont native_font); 25 PlatformFontPango(const std::string& font_name, int font_size); 26 27 // Converts |gfx_font| to a new pango font. Free the returned font with 28 // pango_font_description_free(). 29 static PangoFontDescription* PangoFontFromGfxFont(const gfx::Font& gfx_font); 30 31 // Resets and reloads the cached system font used by the default constructor. 32 // This function is useful when the system font has changed, for example, when 33 // the locale has changed. 34 static void ReloadDefaultFont(); 35 36 #if defined(OS_CHROMEOS) 37 // Sets the default font. 38 static void SetDefaultFontDescription(const std::string& font_description); 39 #endif 40 41 // Position as an offset from the height of the drawn text, used to draw 42 // an underline. This is a negative number, so the underline would be 43 // drawn at y + height + underline_position. 44 double underline_position() const; 45 // The thickness to draw the underline. 46 double underline_thickness() const; 47 48 // Overridden from PlatformFont: 49 virtual Font DeriveFont(int size_delta, int style) const OVERRIDE; 50 virtual int GetHeight() const OVERRIDE; 51 virtual int GetBaseline() const OVERRIDE; 52 virtual int GetCapHeight() const OVERRIDE; 53 virtual int GetAverageCharacterWidth() const OVERRIDE; 54 virtual int GetStringWidth(const base::string16& text) const OVERRIDE; 55 virtual int GetExpectedTextWidth(int length) const OVERRIDE; 56 virtual int GetStyle() const OVERRIDE; 57 virtual std::string GetFontName() const OVERRIDE; 58 virtual std::string GetActualFontNameForTesting() const OVERRIDE; 59 virtual int GetFontSize() const OVERRIDE; 60 virtual NativeFont GetNativeFont() const OVERRIDE; 61 62 private: 63 // Create a new instance of this object with the specified properties. Called 64 // from DeriveFont. 65 PlatformFontPango(const skia::RefPtr<SkTypeface>& typeface, 66 const std::string& name, 67 int size, 68 int style); 69 virtual ~PlatformFontPango(); 70 71 // Returns a Pango font description (suitable for parsing by 72 // pango_font_description_from_string()) for the default UI font. 73 static std::string GetDefaultFont(); 74 75 // Initialize this object. 76 void InitWithNameAndSize(const std::string& font_name, int font_size); 77 void InitWithTypefaceNameSizeAndStyle( 78 const skia::RefPtr<SkTypeface>& typeface, 79 const std::string& font_family, 80 int font_size, 81 int style); 82 void InitFromPlatformFont(const PlatformFontPango* other); 83 84 // Potentially slow call to get pango metrics (average width, underline info). 85 void InitPangoMetrics(); 86 87 // Setup a Skia context to use the current typeface. 88 void PaintSetup(SkPaint* paint) const; 89 90 // Make |this| a copy of |other|. 91 void CopyFont(const Font& other); 92 93 // The average width of a character, initialized and cached if needed. 94 double GetAverageWidth() const; 95 96 skia::RefPtr<SkTypeface> typeface_; 97 98 // Additional information about the face 99 // Skia actually expects a family name and not a font name. 100 std::string font_family_; 101 int font_size_pixels_; 102 int style_; 103 104 // Cached metrics, generated at construction. 105 int height_pixels_; 106 int ascent_pixels_; 107 108 // The pango metrics are much more expensive so we wait until we need them 109 // to compute them. 110 bool pango_metrics_inited_; 111 double average_width_pixels_; 112 double underline_position_pixels_; 113 double underline_thickness_pixels_; 114 115 // The default font, used for the default constructor. 116 static Font* default_font_; 117 118 #if defined(OS_CHROMEOS) 119 static std::string* default_font_description_; 120 #endif 121 122 DISALLOW_COPY_AND_ASSIGN(PlatformFontPango); 123 }; 124 125 } // namespace gfx 126 127 #endif // UI_GFX_PLATFORM_FONT_PANGO_H_ 128
