| // Copyright (c) 2012 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef UI_GFX_PLATFORM_FONT_WIN_H_ |
| #define UI_GFX_PLATFORM_FONT_WIN_H_ |
| |
| #include <string> |
| |
| #include "base/compiler_specific.h" |
| #include "base/gtest_prod_util.h" |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "ui/gfx/gfx_export.h" |
| #include "ui/gfx/platform_font.h" |
| |
| #include <windows.h> |
| |
| struct IDWriteFactory; |
| struct IDWriteFont; |
| |
| namespace gfx { |
| |
| class GFX_EXPORT PlatformFontWin : public PlatformFont { |
| public: |
| PlatformFontWin(); |
| explicit PlatformFontWin(NativeFont native_font); |
| PlatformFontWin(const std::string& font_name, int font_size); |
| |
| // Dialog units to pixels conversion. |
| // See http://support.microsoft.com/kb/145994 for details. |
| int horizontal_dlus_to_pixels(int dlus) const { |
| return dlus * font_ref_->GetDluBaseX() / 4; |
| } |
| int vertical_dlus_to_pixels(int dlus) const { |
| 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; |
| |
| // 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; |
| |
| // Returns the font name for the system locale. Some fonts, particularly |
| // East Asian fonts, have different names per locale. If the localized font |
| // name could not be retrieved, returns GetFontName(). |
| std::string GetLocalizedFontName() const; |
| |
| // Overridden from PlatformFont: |
| Font DeriveFont(int size_delta, |
| int style, |
| Font::Weight weight) const override; |
| int GetHeight() override; |
| Font::Weight GetWeight() const override; |
| int GetBaseline() override; |
| int GetCapHeight() override; |
| int GetExpectedTextWidth(int length) override; |
| int GetStyle() const override; |
| const std::string& GetFontName() const override; |
| std::string GetActualFontNameForTesting() const override; |
| int GetFontSize() const override; |
| const FontRenderParams& GetFontRenderParams() override; |
| NativeFont GetNativeFont() const override; |
| |
| // Called once during initialization if we should be retrieving font metrics |
| // from skia and DirectWrite. |
| static void SetDirectWriteFactory(IDWriteFactory* factory); |
| |
| static bool IsDirectWriteEnabled(); |
| |
| // Returns the GDI metrics for the font passed in. |
| static void GetTextMetricsForFont(HDC hdc, |
| HFONT font, |
| TEXTMETRIC* text_metrics); |
| |
| // Returns the size of the font based on the font information passed in. |
| static int GetFontSize(const LOGFONT& font_info); |
| |
| private: |
| FRIEND_TEST_ALL_PREFIXES(RenderTextHarfBuzzTest, HarfBuzz_UniscribeFallback); |
| FRIEND_TEST_ALL_PREFIXES(PlatformFontWinTest, Metrics_SkiaVersusGDI); |
| FRIEND_TEST_ALL_PREFIXES(PlatformFontWinTest, DirectWriteFontSubstitution); |
| |
| ~PlatformFontWin() override; |
| |
| // 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 GFX_EXPORT 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 font_size, |
| int height, |
| int baseline, |
| int cap_height, |
| int ave_char_width, |
| Font::Weight weight, |
| int style); |
| |
| // Accessors |
| HFONT hfont() const { return hfont_; } |
| int height() const { return height_; } |
| int baseline() const { return baseline_; } |
| int cap_height() const { return cap_height_; } |
| int ave_char_width() const { return ave_char_width_; } |
| Font::Weight weight() const { return weight_; } |
| int style() const { return style_; } |
| const std::string& font_name() const { return font_name_; } |
| int font_size() const { return font_size_; } |
| int requested_font_size() const { return requested_font_size_; } |
| |
| // Returns the average character width in dialog units. |
| int GetDluBaseX(); |
| |
| // Helper to return the average character width using the text extent |
| // technique mentioned here. http://support.microsoft.com/kb/125681. |
| static int GetAverageCharWidthInDialogUnits(HFONT gdi_font); |
| |
| private: |
| friend class base::RefCounted<HFontRef>; |
| FRIEND_TEST_ALL_PREFIXES(RenderTextHarfBuzzTest, |
| HarfBuzz_UniscribeFallback); |
| FRIEND_TEST_ALL_PREFIXES(PlatformFontWinTest, Metrics_SkiaVersusGDI); |
| FRIEND_TEST_ALL_PREFIXES(PlatformFontWinTest, DirectWriteFontSubstitution); |
| |
| ~HFontRef(); |
| |
| const HFONT hfont_; |
| const int font_size_; |
| const int height_; |
| const int baseline_; |
| const int cap_height_; |
| const int ave_char_width_; |
| const Font::Weight weight_; |
| const int style_; |
| // Average character width in dialog units. This is queried lazily from the |
| // system, with an initial value of -1 meaning it hasn't yet been queried. |
| int dlu_base_x_; |
| std::string font_name_; |
| |
| // If the requested font size is not possible for the font, |font_size_| |
| // will be different than |requested_font_size_|. This is stored separately |
| // so that code that increases the font size in a loop will not cause the |
| // loop to get stuck on the same size. |
| int requested_font_size_; |
| |
| DISALLOW_COPY_AND_ASSIGN(HFontRef); |
| }; |
| |
| // Initializes this object with a copy of the specified HFONT. |
| void InitWithCopyOfHFONT(HFONT hfont); |
| |
| // Initializes this object with the specified font name and size. |
| void InitWithFontNameAndSize(const std::string& font_name, |
| int font_size); |
| |
| // 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); |
| |
| // Creates and returns a new HFontRef from the specified HFONT. Uses provided |
| // |font_metrics| instead of calculating new one. |
| static HFontRef* CreateHFontRefFromGDI(HFONT font, |
| const TEXTMETRIC& font_metrics); |
| |
| // Creates and returns a new HFontRef from the specified HFONT using metrics |
| // from skia. Currently this is only used if we use DirectWrite for font |
| // metrics. |
| // |gdi_font| : Handle to the GDI font created via CreateFontIndirect. |
| // |font_metrics| : The GDI font metrics retrieved via the GetTextMetrics |
| // API. This is currently used to calculate the correct height of the font |
| // in case we get a font created with a positive height. |
| // A positive height represents the cell height (ascent + descent). |
| // A negative height represents the character Em height which is cell |
| // height minus the internal leading value. |
| static PlatformFontWin::HFontRef* CreateHFontRefFromSkia( |
| HFONT gdi_font, |
| const TEXTMETRIC& font_metrics); |
| |
| // Creates a new PlatformFontWin with the specified HFontRef. Used when |
| // constructing a Font from a HFONT we don't want to copy. |
| explicit PlatformFontWin(HFontRef* hfont_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_; |
| |
| // Pointer to the global IDWriteFactory interface. |
| static IDWriteFactory* direct_write_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PlatformFontWin); |
| }; |
| |
| // Returns the family name for the |IDWriteFont| interface passed in. |
| // The family name is returned in the |family_name| parameter. |
| // Returns S_OK on success. |
| HRESULT GetFamilyNameFromDirectWriteFont(IDWriteFont* dwrite_font, |
| base::string16* family_name); |
| |
| } // namespace gfx |
| |
| #endif // UI_GFX_PLATFORM_FONT_WIN_H_ |