Rework gfx::Font by moving platform-specific code into inner classes....

gfx/platform_font_mac.mm

Index: gfx/platform_font_mac.mm
===================================================================
--- gfx/platform_font_mac.mm	(revision 55264)
+++ gfx/platform_font_mac.mm	(working copy)
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "gfx/font.h"
+#include "gfx/platform_font_mac.h"
 
 #include <Cocoa/Cocoa.h>
 
@@ -10,78 +10,75 @@
 #include "base/scoped_nsobject.h"
 #include "base/sys_string_conversions.h"
 #include "gfx/canvas_skia.h"
+#include "gfx/font.h"
 
 namespace gfx {
 
-// static
-Font Font::CreateFont(const std::wstring& font_name, int font_size) {
-  return Font(font_name, font_size, NORMAL);
+////////////////////////////////////////////////////////////////////////////////
+// PlatformFontMac, public:
+
+PlatformFontMac::PlatformFontMac() {
+  font_size_ = [NSFont systemFontSize];
+  style_ = gfx::Font::NORMAL;
+  NSFont* system_font = [NSFont systemFontOfSize:font_size_];
+  font_name_ = base::SysNSStringToWide([system_font fontName]);
+  CalculateMetrics();
 }
 
-Font::Font(const std::wstring& font_name, int font_size, int style)
-    : font_name_(font_name),
-      font_size_(font_size),
-      style_(style) {
-  calculateMetrics();
+PlatformFontMac::PlatformFontMac(const Font& other) {
 }
 
-Font::Font()
-    : font_size_([NSFont systemFontSize]),
-      style_(NORMAL) {
-  NSFont* system_font = [NSFont systemFontOfSize:font_size_];
-  font_name_ = base::SysNSStringToWide([system_font fontName]);
-  calculateMetrics();
+PlatformFontMac::PlatformFontMac(NativeFont native_font) {
 }
 
-void Font::calculateMetrics() {
-  NSFont* font = nativeFont();
-  scoped_nsobject<NSLayoutManager> layout_manager(
-      [[NSLayoutManager alloc] init]);
-  height_ = [layout_manager defaultLineHeightForFont:font];
-  ascent_ = [font ascender];
-  avg_width_ = [font boundingRectForGlyph:[font glyphWithName:@"x"]].size.width;
+PlatformFontMac::PlatformFontMac(const std::wstring& font_name,
+                                 int font_size) {
+  InitWithNameSizeAndStyle(font_name, font_size, gfx::Font::NORMAL);
 }
 
-Font Font::DeriveFont(int size_delta, int style) const {
-  return Font(font_name_, font_size_ + size_delta, style);
+////////////////////////////////////////////////////////////////////////////////
+// PlatformFontMac, PlatformFont implementation:
+
+Font PlatformFontMac::DeriveFont(int size_delta, int style) const {
+  return Font(new PlatformFontMac(font_name_, font_size_ + size_delta, style));
 }
 
-int Font::height() const {
+int PlatformFontMac::GetHeight() const {
   return height_;
 }
 
-int Font::baseline() const {
+int PlatformFontMac::GetBaseline() const {
   return ascent_;
 }
 
-int Font::ave_char_width() const {
-  return avg_width_;
+int PlatformFontMac::GetAverageCharacterWidth() const {
+  return average_width_;
 }
 
-int Font::GetStringWidth(const std::wstring& text) const {
+int PlatformFontMac::GetStringWidth(const std::wstring& text) const {
   int width = 0, height = 0;
-  CanvasSkia::SizeStringInt(text, *this, &width, &height,
-                            gfx::Canvas::NO_ELLIPSIS);
+  CanvasSkia::SizeStringInt(text, Font(const_cast<PlatformFontMac*>(this)),
+                            &width, &height, gfx::Canvas::NO_ELLIPSIS);
   return width;
 }
 
-int Font::GetExpectedTextWidth(int length) const {
-  return length * avg_width_;
+int PlatformFontMac::GetExpectedTextWidth(int length) const {
+  return length * average_width_;
 }
 
-int Font::style() const {
+int PlatformFontMac::GetStyle() const {
   return style_;
 }
 
-const std::wstring& Font::FontName() const {
+const std::wstring& PlatformFontMac::GetFontName() const {
   return font_name_;
 }
 
-int Font::FontSize() {
+int PlatformFontMac::GetFontSize() const {
   return font_size_;
 }
 
-NativeFont Font::nativeFont() const {
+NativeFont PlatformFontMac::GetNativeFont() const {
   // TODO(pinkerton): apply |style_| to font. http://crbug.com/34667
   // We could cache this, but then we'd have to conditionally change the
   // dtor just for MacOS. Not sure if we want to/need to do that.
@@ -89,4 +86,57 @@
                          size:font_size_];
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// PlatformFontMac, private:
+
+PlatformFontMac::PlatformFontMac(const std::wstring& font_name,
+                                 int font_size,
+                                 int style) {
+  InitWithNameSizeAndStyle(font_name, font_size, style);
+}
+
+void PlatformFontMac::InitWithNameSizeAndStyle(const std::wstring& font_name,
+                                               int font_size,
+                                               int style) {
+  font_name_ = font_name;
+  font_size_ = font_size;
+  style_ = style;
+  CalculateMetrics();
+}
+
+void PlatformFontMac::CalculateMetrics() {
+  NSFont* font = GetNativeFont();
+  scoped_nsobject<NSLayoutManager> layout_manager(
+      [[NSLayoutManager alloc] init]);
+  height_ = [layout_manager defaultLineHeightForFont:font];
+  ascent_ = [font ascender];
+  average_width_ =
+      [font boundingRectForGlyph:[font glyphWithName:@"x"]].size.width;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// PlatformFont, public:
+
+// static
+PlatformFont* PlatformFont::CreateDefault() {
+  return new PlatformFontMac;
+}
+
+// static
+PlatformFont* PlatformFont::CreateFromFont(const Font& other) {
+  return new PlatformFontMac(other);
+}
+
+// static
+PlatformFont* PlatformFont::CreateFromNativeFont(NativeFont native_font) {
+  return new PlatformFontMac(native_font);
+}
+
+// static
+PlatformFont* PlatformFont::CreateFromNameAndSize(const std::wstring& font_name,
+                                                  int font_size) {
+  return new PlatformFontMac(font_name, font_size);
+}
+
 }  // namespace gfx
+