Supports FontList::DeriveFontListWithSizeDeltaAndStyle, etc.

ui/gfx/font_list.cc

Index: ui/gfx/font_list.cc
diff --git a/ui/gfx/font_list.cc b/ui/gfx/font_list.cc
index cb6cc9763de556591cf561610d23db741866fa8f..e01483a7cc1e9c811171e56ccd8c448004fb5186 100644
--- a/ui/gfx/font_list.cc
+++ b/ui/gfx/font_list.cc
@@ -70,37 +70,60 @@ std::string BuildFontDescription(const std::vector<std::string>& font_names,
 
 namespace gfx {
 
-FontList::FontList() : common_height_(-1), common_baseline_(-1) {
+FontList::FontList()
+    : common_height_(-1),
+      common_baseline_(-1),
+      font_style_(-1),
+      font_size_(-1) {
   fonts_.push_back(Font());
 }
 
 FontList::FontList(const std::string& font_description_string)
     : font_description_string_(font_description_string),
       common_height_(-1),
-      common_baseline_(-1) {
+      common_baseline_(-1),
+      font_style_(-1),
+      font_size_(-1) {
   DCHECK(!font_description_string.empty());
   // DCHECK description string ends with "px" for size in pixel.
   DCHECK(EndsWith(font_description_string, "px", true));
 }
 
+FontList::FontList(const std::vector<std::string>& font_names,
+                   int font_style,
+                   int font_size)
+    : font_description_string_(BuildFontDescription(font_names, font_style,
+                                                    font_size)),
+      common_height_(-1),
+      common_baseline_(-1),
+      font_style_(font_style),
+      font_size_(font_size) {
+  DCHECK(!font_names.empty());
+  DCHECK(!font_names[0].empty());
+}
+
 FontList::FontList(const std::vector<Font>& fonts)
     : fonts_(fonts),
       common_height_(-1),
-      common_baseline_(-1) {
+      common_baseline_(-1),
+      font_style_(-1),
+      font_size_(-1) {
   DCHECK(!fonts.empty());
+  font_style_ = fonts[0].GetStyle();
+  font_size_ = fonts[0].GetFontSize();
   if (DCHECK_IS_ON()) {
-    int style = fonts[0].GetStyle();
-    int size = fonts[0].GetFontSize();
     for (size_t i = 1; i < fonts.size(); ++i) {
-      DCHECK_EQ(fonts[i].GetStyle(), style);
-      DCHECK_EQ(fonts[i].GetFontSize(), size);
+      DCHECK_EQ(fonts[i].GetStyle(), font_style_);
+      DCHECK_EQ(fonts[i].GetFontSize(), font_size_);
     }
   }
 }
 
 FontList::FontList(const Font& font)
     : common_height_(-1),
-      common_baseline_(-1) {
+      common_baseline_(-1),
+      font_style_(-1),
+      font_size_(-1) {
   fonts_.push_back(font);
 }
 
@@ -108,89 +131,74 @@ FontList::~FontList() {
 }
 
 FontList FontList::DeriveFontList(int font_style) const {
-  // If there is a font vector, derive from that.
-  if (!fonts_.empty()) {
-    std::vector<Font> fonts = fonts_;
-    for (size_t i = 0; i < fonts.size(); ++i)
-      fonts[i] = fonts[i].DeriveFont(0, font_style);
-    return FontList(fonts);
-  }
-
-  // Otherwise, parse the font description string to derive from it.
-  std::vector<std::string> font_names;
-  int old_style;
-  int font_size;
-  ParseFontDescriptionString(font_description_string_, &font_names,
-                             &old_style, &font_size);
-  return FontList(BuildFontDescription(font_names, font_style, font_size));
+  return DeriveFontListWithSizeDeltaAndStyle(0, font_style);
 }
 
 FontList FontList::DeriveFontListWithSize(int size) const {
   DCHECK_GT(size, 0);
+  return DeriveFontListWithSizeDeltaAndStyle(size - GetFontSize(),
+                                             GetFontStyle());
+}
+
+FontList FontList::DeriveFontListWithSizeDelta(int size_delta) const {
+  return DeriveFontListWithSizeDeltaAndStyle(size_delta, GetFontStyle());
+}
 
+FontList FontList::DeriveFontListWithSizeDeltaAndStyle(int size_delta,
+                                                       int style) const {
   // If there is a font vector, derive from that.
-  int old_size = 0;
   if (!fonts_.empty()) {
-    old_size = fonts_[0].GetFontSize();
-    if (old_size == size)
-      return FontList(fonts_);
-
     std::vector<Font> fonts = fonts_;
     for (size_t i = 0; i < fonts.size(); ++i)
-      fonts[i] = fonts[i].DeriveFont(size - old_size);
+      fonts[i] = fonts[i].DeriveFont(size_delta, style);
     return FontList(fonts);
   }
 
   // Otherwise, parse the font description string to derive from it.
   std::vector<std::string> font_names;
-  int font_style = 0;
+  int old_size;
+  int old_style;
   ParseFontDescriptionString(font_description_string_, &font_names,
-                             &font_style, &old_size);
-
-  if (old_size == size)
-    return FontList(font_description_string_);
-
-  return FontList(BuildFontDescription(font_names, font_style, size));
+                             &old_style, &old_size);
+  int size = old_size + size_delta;
+  DCHECK_GT(size, 0);
+  return FontList(font_names, style, size);
 }
 
 int FontList::GetHeight() const {
-  if (common_height_ < 0) {
-    int ascent = 0;
-    int descent = 0;
-    const std::vector<Font>& fonts = GetFonts();
-    for (std::vector<Font>::const_iterator i = fonts.begin();
-         i != fonts.end(); ++i) {
-      ascent = std::max(ascent, i->GetBaseline());
-      descent = std::max(descent, i->GetHeight() - i->GetBaseline());
-    }
-    common_height_ = ascent + descent;
-  }
+  if (common_height_ == -1)
+    CacheCommonFontHeightAndBaseline();
   return common_height_;
 }
 
 int FontList::GetBaseline() const {
-  if (common_baseline_ < 0) {
-    int baseline = 0;
-    const std::vector<Font>& fonts = GetFonts();
-    for (std::vector<Font>::const_iterator i = fonts.begin();
-         i != fonts.end(); ++i) {
-      baseline = std::max(baseline, i->GetBaseline());
-    }
-    common_baseline_ = baseline;
-  }
+  if (common_baseline_ == -1)
+    CacheCommonFontHeightAndBaseline();
   return common_baseline_;
 }
 
-int FontList::GetFontStyle() const {
-  if (!fonts_.empty())
-    return fonts_[0].GetStyle();
+int FontList::GetStringWidth(const base::string16& text) const {
+  // Rely on the primary font metrics for the time being.
+  // TODO(yukishiino): Not only the first font, all the fonts in the list should
+  // be taken into account to compute the pixels needed to display |text|.
+  // Also this method, including one in Font class, should be deprecated and
+  // client code should call Canvas::GetStringWidth(text, font_list) directly.
+  // Our plan is as follows:
+  //   1. Introduce the FontList version of Canvas::GetStringWidth().
+  //   2. Make client code call Canvas::GetStringWidth().
+  //   3. Retire {Font,FontList}::GetStringWidth().
+  return GetPrimaryFont().GetStringWidth(text);
+}
 
-  std::vector<std::string> font_names;
-  int font_style;
-  int font_size;
-  ParseFontDescriptionString(font_description_string_, &font_names,
-                             &font_style, &font_size);
-  return font_style;
+int FontList::GetExpectedTextWidth(int length) const {
+  // Rely on the primary font metrics for the time being.
+  return GetPrimaryFont().GetExpectedTextWidth(length);
+}
+
+int FontList::GetFontStyle() const {
+  if (font_style_ == -1)
+    CacheFontStyleAndSize();
+  return font_style_;
 }
 
 const std::string& FontList::GetFontDescriptionString() const {
@@ -209,15 +217,9 @@ const std::string& FontList::GetFontDescriptionString() const {
 }
 
 int FontList::GetFontSize() const {
-  if (!fonts_.empty())
-    return fonts_[0].GetFontSize();
-
-  std::vector<std::string> font_names;
-  int font_style;
-  int font_size;
-  ParseFontDescriptionString(font_description_string_, &font_names,
-                             &font_style, &font_size);
-  return font_size;
+  if (font_size_ == -1)
+    CacheFontStyleAndSize();
+  return font_size_;
 }
 
 const std::vector<Font>& FontList::GetFonts() const {
@@ -225,18 +227,16 @@ const std::vector<Font>& FontList::GetFonts() const {
     DCHECK(!font_description_string_.empty());
 
     std::vector<std::string> font_names;
-    int font_style;
-    int font_size;
     ParseFontDescriptionString(font_description_string_, &font_names,
-                               &font_style, &font_size);
+                               &font_style_, &font_size_);
     for (size_t i = 0; i < font_names.size(); ++i) {
       DCHECK(!font_names[i].empty());
 
-      Font font(font_names[i], font_size);
-      if (font_style == Font::NORMAL)
+      Font font(font_names[i], font_size_);
+      if (font_style_ == Font::NORMAL)
         fonts_.push_back(font);
       else
-        fonts_.push_back(font.DeriveFont(0, font_style));
+        fonts_.push_back(font.DeriveFont(0, font_style_));
     }
   }
   return fonts_;
@@ -246,4 +246,28 @@ const Font& FontList::GetPrimaryFont() const {
   return GetFonts()[0];
 }
 
+void FontList::CacheCommonFontHeightAndBaseline() const {
+  int ascent = 0;
+  int descent = 0;
+  const std::vector<Font>& fonts = GetFonts();
+  for (std::vector<Font>::const_iterator i = fonts.begin();
+       i != fonts.end(); ++i) {
+    ascent = std::max(ascent, i->GetBaseline());
+    descent = std::max(descent, i->GetHeight() - i->GetBaseline());
+  }
+  common_height_ = ascent + descent;
+  common_baseline_ = ascent;
+}
+
+void FontList::CacheFontStyleAndSize() const {
+  if (!fonts_.empty()) {
+    font_style_ = fonts_[0].GetStyle();
+    font_size_ = fonts_[0].GetFontSize();
+  } else {
+    std::vector<std::string> font_names;
+    ParseFontDescriptionString(font_description_string_, &font_names,
+                               &font_style_, &font_size_);
+  }
+}
+
 }  // namespace gfx