| // 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/memory/ref_counted.h" |
| #include "ui/gfx/gfx_export.h" |
| #include "ui/gfx/platform_font.h" |
| |
| 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; |
| |
| // Returns a derived Font with the specified |style| and with height at most |
| // |height|. If the height and style of the receiver already match, it is |
| // returned. Otherwise, the returned Font will have the largest size such that |
| // its height is less than or equal to |height| (since there may not exist a |
| // size that matches the exact |height| specified). |
| Font DeriveFontWithHeight(int height, int style); |
| |
| // Overridden from PlatformFont: |
| virtual Font DeriveFont(int size_delta, int style) const OVERRIDE; |
| virtual int GetHeight() const OVERRIDE; |
| virtual int GetBaseline() const OVERRIDE; |
| virtual int GetCapHeight() const OVERRIDE; |
| virtual int GetExpectedTextWidth(int length) const OVERRIDE; |
| virtual int GetStyle() const OVERRIDE; |
| virtual std::string GetFontName() const OVERRIDE; |
| virtual std::string GetActualFontNameForTesting() const OVERRIDE; |
| virtual int GetFontSize() const OVERRIDE; |
| virtual NativeFont GetNativeFont() const OVERRIDE; |
| |
| private: |
| virtual ~PlatformFontWin() {} |
| |
| // 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 font_size, |
| int height, |
| int baseline, |
| int cap_height, |
| int ave_char_width, |
| 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_; } |
| 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(); |
| |
| private: |
| friend class base::RefCounted<HFontRef>; |
| |
| ~HFontRef(); |
| |
| const HFONT hfont_; |
| const int font_size_; |
| const int height_; |
| const int baseline_; |
| const int cap_height_; |
| const int ave_char_width_; |
| 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 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_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PlatformFontWin); |
| }; |
| |
| } // namespace gfx |
| |
| #endif // UI_GFX_PLATFORM_FONT_WIN_H_ |