ChromeCanvas->gfx::Canvas

app/gfx/chrome_font.h

-// Copyright (c) 2006-2008 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 APP_GFX_FONT_H_
-#define APP_GFX_FONT_H_
-
-#include "build/build_config.h"
-
-#include <string>
-
-#if defined(OS_WIN)
-typedef struct HFONT__* HFONT;
-#elif defined(OS_LINUX)
-#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;
-#elif defined(OS_LINUX)
-class SkTypeface;
-typedef SkTypeface* NativeFont;
-#else  // null port.
-#error No known OS defined
-#endif
-
-#include "base/basictypes.h"
-#include "base/ref_counted.h"
-#include "base/scoped_ptr.h"
-
-namespace gfx {
-
-// 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 {
-    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);
-
-  ~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());
-  }
-
-  // Returns a new Font derived from the existing font.
-  // size_deta is the size to add to the current font. See the single
-  // argument version of this method for an example.
-  // The style parameter specifies the new style for the font, and is a
-  // bitmask of the values: BOLD, ITALIC and UNDERLINED.
-  Font DeriveFont(int size_delta, int style) const;
-
-  // Returns the number of vertical pixels needed to display characters from
-  // the specified font.
-  int height() const;
-
-  // Returns the baseline, or ascent, of the font.
-  int baseline() const;
-
-  // Returns the average character width for the font.
-  int ave_char_width() 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.
-  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.
-  std::wstring FontName();
-
-  // Font Size.
-  int FontSize();
-
-  NativeFont nativeFont() 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 ChromeCanvas 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;
-  }
-#elif defined(OS_LINUX)
-  // 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;
-#endif
-
- 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);
-    ~HFontRef();
-
-    // 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_; }
-
-   private:
-    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_;
-
-    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_LINUX)
-  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_;
-
-  // 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_;
-  int avg_width_;
-#elif defined(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
-
-};
-
-}  // namespace gfx
-
-#endif  // APP_GFX_FONT_H_