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_H_ 6 #define UI_GFX_PLATFORM_FONT_H_ 7 8 #include <string> 9 10 #include "base/memory/ref_counted.h" 11 #include "base/strings/string16.h" 12 #include "ui/base/ui_export.h" 13 #include "ui/gfx/native_widget_types.h" 14 15 namespace gfx { 16 17 class Font; 18 19 class UI_EXPORT PlatformFont : public base::RefCounted<PlatformFont> { 20 public: 21 // Creates an appropriate PlatformFont implementation. 22 static PlatformFont* CreateDefault(); 23 static PlatformFont* CreateFromNativeFont(NativeFont native_font); 24 // Creates a PlatformFont implementation with the specified |font_name| 25 // (encoded in UTF-8) and |font_size| in pixels. 26 static PlatformFont* CreateFromNameAndSize(const std::string& font_name, 27 int font_size); 28 29 // Returns a new Font derived from the existing font. 30 // |size_delta| is the size in pixels to add to the current font. 31 // The style parameter specifies the new style for the font, and is a 32 // bitmask of the values: BOLD, ITALIC and UNDERLINE. 33 virtual Font DeriveFont(int size_delta, int style) const = 0; 34 35 // Returns the number of vertical pixels needed to display characters from 36 // the specified font. This may include some leading, i.e. height may be 37 // greater than just ascent + descent. Specifically, the Windows and Mac 38 // implementations include leading and the Linux one does not. This may 39 // need to be revisited in the future. 40 virtual int GetHeight() const = 0; 41 42 // Returns the baseline, or ascent, of the font. 43 virtual int GetBaseline() const = 0; 44 45 // Returns the average character width for the font. 46 virtual int GetAverageCharacterWidth() const = 0; 47 48 // Returns the number of horizontal pixels needed to display the specified 49 // string. 50 virtual int GetStringWidth(const base::string16& text) const = 0; 51 52 // Returns the expected number of horizontal pixels needed to display the 53 // specified length of characters. Call GetStringWidth() to retrieve the 54 // actual number. 55 virtual int GetExpectedTextWidth(int length) const = 0; 56 57 // Returns the style of the font. 58 virtual int GetStyle() const = 0; 59 60 // Returns the font name in UTF-8. 61 virtual std::string GetFontName() const = 0; 62 63 // Returns the font size in pixels. 64 virtual int GetFontSize() const = 0; 65 66 // Returns the native font handle. 67 virtual NativeFont GetNativeFont() const = 0; 68 69 protected: 70 virtual ~PlatformFont() {} 71 72 private: 73 friend class base::RefCounted<PlatformFont>; 74 }; 75 76 } // namespace gfx 77 78 #endif // UI_GFX_PLATFORM_FONT_H_ 79 80
