diff options
Diffstat (limited to 'gfx/font.h')
| -rw-r--r-- | gfx/font.h | 268 |
1 files changed, 47 insertions, 221 deletions
@@ -6,63 +6,50 @@ #define GFX_FONT_H_ #pragma once -#include "build/build_config.h" - #include <string> -#if defined(OS_WIN) -typedef struct HFONT__* HFONT; -#elif !defined(OS_MACOSX) -#include "third_party/skia/include/core/SkRefCnt.h" -class SkPaint; -class SkTypeface; -#endif - -#if defined(OS_WIN) -typedef struct HFONT__* NativeFont; -#elif defined(OS_MACOSX) -#ifdef __OBJC__ -@class NSFont; -#else -class NSFont; -#endif -typedef NSFont* NativeFont; -#else -typedef struct _PangoFontDescription PangoFontDescription; -class SkTypeface; -typedef SkTypeface* NativeFont; -#endif - -#include "base/basictypes.h" #include "base/ref_counted.h" -#include "base/scoped_ptr.h" +#include "gfx/native_widget_types.h" namespace gfx { +class PlatformFont; + // Font provides a wrapper around an underlying font. Copy and assignment // operators are explicitly allowed, and cheap. class Font { public: // The following constants indicate the font style. - enum { + enum FontStyle { NORMAL = 0, BOLD = 1, ITALIC = 2, UNDERLINED = 4, }; - // Creates a Font given font name (e.g. arial), font size (e.g. 12). - // Skia actually expects a family name and not a font name. - static Font CreateFont(const std::wstring& font_name, int font_size); + // Creates a font with the default name and style. + Font(); + + // Creates a font that is a clone of another font object. + Font(const Font& other); + gfx::Font& operator=(const Font& other); + + // Creates a font from the specified native font. + explicit Font(NativeFont native_font); - ~Font() { } + // Construct a Font object with the specified PlatformFont object. The Font + // object takes ownership of the PlatformFont object. + explicit Font(PlatformFont* platform_font); + + // Creates a font with the specified name and size. + Font(const std::wstring& font_name, int font_size); + + ~Font(); // Returns a new Font derived from the existing font. // size_deta is the size to add to the current font. For example, a value // of 5 results in a font 5 units bigger than this font. - Font DeriveFont(int size_delta) const { - return DeriveFont(size_delta, style()); - } + Font DeriveFont(int size_delta) const; // Returns a new Font derived from the existing font. // size_delta is the size to add to the current font. See the single @@ -76,212 +63,51 @@ class Font { // greater than just ascent + descent. Specifically, the Windows and Mac // implementations include leading and the Linux one does not. This may // need to be revisited in the future. - int height() const; + int GetHeight() const; // Returns the baseline, or ascent, of the font. - int baseline() const; + int GetBaseline() const; // Returns the average character width for the font. - int ave_char_width() const; + int GetAverageCharacterWidth() const; // Returns the number of horizontal pixels needed to display the specified // string. int GetStringWidth(const std::wstring& text) const; - // Returns the expected number of horizontal pixels needed to display - // the specified length of characters. - // Call GetStringWidth() to retrieve the actual number. + // Returns the expected number of horizontal pixels needed to display the + // specified length of characters. Call GetStringWidth() to retrieve the + // actual number. int GetExpectedTextWidth(int length) const; // Returns the style of the font. - int style() const; - - // Font Name. - // It is actually a font family name, because Skia expects a family name - // and not a font name. - const std::wstring& FontName() const; + int GetStyle() const; - // Font Size. - int FontSize(); + // Returns the font name. + const std::wstring& GetFontName() const; - NativeFont nativeFont() const; + // Returns the font size in pixels. + int GetFontSize() const; - // Creates a font with the default name and style. - Font(); - -#if defined(OS_WIN) - // Creates a Font from the specified HFONT. The supplied HFONT is effectively - // copied. - static Font CreateFont(HFONT hfont); - - // Returns the handle to the underlying HFONT. This is used by gfx::Canvas to - // draw text. - HFONT hfont() const { return font_ref_->hfont(); } - - // Dialog units to pixels conversion. - // See http://support.microsoft.com/kb/145994 for details. - int horizontal_dlus_to_pixels(int dlus) { - return dlus * font_ref_->dlu_base_x() / 4; - } - int vertical_dlus_to_pixels(int dlus) { - return dlus * font_ref_->height() / 8; - } - - // Callback that returns the minimum height that should be used for - // gfx::Fonts. Optional. If not specified, the minimum font size is 0. - typedef int (*GetMinimumFontSizeCallback)(); - static GetMinimumFontSizeCallback get_minimum_font_size_callback; + // Returns the native font handle. + // Lifetime lore: + // Windows: This handle is owned by the Font object, and should not be + // destroyed by the caller. + // Mac: Caller must release this object. + // Gtk: This handle is created on demand, and must be freed by calling + // pango_font_description_free() when the caller is done using it. + NativeFont GetNativeFont() const; - // Callback that adjusts a LOGFONT to meet suitability requirements of the - // embedding application. Optional. If not specified, no adjustments are - // performed other than clamping to a minimum font height if - // |get_minimum_font_size_callback| is specified. - typedef void (*AdjustFontCallback)(LOGFONT* lf); - static AdjustFontCallback adjust_font_callback; - -#elif !defined(OS_MACOSX) - static Font CreateFont(PangoFontDescription* desc); - // We need a copy constructor and assignment operator to deal with - // the Skia reference counting. - Font(const Font& other); - Font& operator=(const Font& other); - // Setup a Skia context to use the current typeface - void PaintSetup(SkPaint* paint) const; - - // Converts |gfx_font| to a new pango font. Free the returned font with - // pango_font_description_free(). - static PangoFontDescription* PangoFontFromGfxFont(const gfx::Font& gfx_font); - - // Position as an offset from the height of the drawn text, used to draw - // an underline. This is a negative number, so the underline would be - // drawn at y + height + underline_position; - double underline_position() const; - // The thickness to draw the underline. - double underline_thickness() const; -#endif + // Raw access to the underlying platform font implementation. Can be + // static_cast to a known implementation type if needed. + PlatformFont* platform_font() const { return platform_font_.get(); } private: - -#if defined(OS_WIN) - // Chrome text drawing bottoms out in the Windows GDI functions that take an - // HFONT (an opaque handle into Windows). To avoid lots of GDI object - // allocation and destruction, Font indirectly refers to the HFONT by way of - // an HFontRef. That is, every Font has an HFontRef, which has an HFONT. - // - // HFontRef is reference counted. Upon deletion, it deletes the HFONT. - // By making HFontRef maintain the reference to the HFONT, multiple - // HFontRefs can share the same HFONT, and Font can provide value semantics. - class HFontRef : public base::RefCounted<HFontRef> { - public: - // This constructor takes control of the HFONT, and will delete it when - // the HFontRef is deleted. - HFontRef(HFONT hfont, - int height, - int baseline, - int ave_char_width, - int style, - int dlu_base_x); - - // Accessors - HFONT hfont() const { return hfont_; } - int height() const { return height_; } - int baseline() const { return baseline_; } - int ave_char_width() const { return ave_char_width_; } - int style() const { return style_; } - int dlu_base_x() const { return dlu_base_x_; } - const std::wstring& font_name() const { return font_name_; } - - private: - friend class base::RefCounted<HFontRef>; - - ~HFontRef(); - - const HFONT hfont_; - const int height_; - const int baseline_; - const int ave_char_width_; - const int style_; - // Constants used in converting dialog units to pixels. - const int dlu_base_x_; - std::wstring font_name_; - - DISALLOW_COPY_AND_ASSIGN(HFontRef); - }; - - // Returns the base font ref. This should ONLY be invoked on the - // UI thread. - static HFontRef* GetBaseFontRef(); - - // Creates and returns a new HFONTRef from the specified HFONT. - static HFontRef* CreateHFontRef(HFONT font); - - explicit Font(HFontRef* font_ref) : font_ref_(font_ref) { } - - // Reference to the base font all fonts are derived from. - static HFontRef* base_font_ref_; - - // Indirect reference to the HFontRef, which references the underlying HFONT. - scoped_refptr<HFontRef> font_ref_; -#elif !defined(OS_MACOSX) - explicit Font(SkTypeface* typeface, const std::wstring& name, - int size, int style); - // Calculate and cache the font metrics. - void calculateMetrics(); - // Make |this| a copy of |other|. - void CopyFont(const Font& other); - - // The default font, used for the default constructor. - static Font* default_font_; - - // Return the scale factor for fonts that account for DPI. - static float GetPangoScaleFactor(); - - // The average width of a character, initialized and cached if needed. - double avg_width() const; - - // Potentially slow call to get pango metrics (avg width, underline info). - void InitPangoMetrics(); - - // These two both point to the same SkTypeface. We use the SkAutoUnref to - // handle the reference counting, but without @typeface_ we would have to - // cast the SkRefCnt from @typeface_helper_ every time. - scoped_ptr<SkAutoUnref> typeface_helper_; - SkTypeface *typeface_; - - // Additional information about the face - // Skia actually expects a family name and not a font name. - std::wstring font_family_; - int font_size_; - int style_; - - // Cached metrics, generated at construction - int height_; - int ascent_; - - // The pango metrics are much more expensive so we wait until we need them - // to compute them. - bool pango_metrics_inited_; - double avg_width_; - double underline_position_; - double underline_thickness_; -#else // OS_MACOSX - explicit Font(const std::wstring& font_name, int font_size, int style); - - // Calculate and cache the font metrics. - void calculateMetrics(); - - std::wstring font_name_; - int font_size_; - int style_; - - // Cached metrics, generated at construction - int height_; - int ascent_; - int avg_width_; -#endif - + // Wrapped platform font implementation. + scoped_refptr<PlatformFont> platform_font_; }; } // namespace gfx #endif // GFX_FONT_H_ + |