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