Add RenderText DirectionalityMode enum and support; etc.

ui/gfx/canvas_skia.cc

Index: ui/gfx/canvas_skia.cc
diff --git a/ui/gfx/canvas_skia.cc b/ui/gfx/canvas_skia.cc
index 4a6ef61adb98b2db12e67eff04cc4f68e54a63f7..440ae64dc521ba85c7feb675e94f02a515db49fe 100644
--- a/ui/gfx/canvas_skia.cc
+++ b/ui/gfx/canvas_skia.cc
@@ -19,37 +19,22 @@
 
 namespace {
 
-// If necessary, wraps |text| with RTL/LTR directionality characters based on
-// |flags| and |text| content.
-// Returns true if the text will be rendered right-to-left.
-// TODO(msw): Nix this, now that RenderTextWin supports directionality directly.
-bool AdjustStringDirection(int flags, string16* text) {
-  // TODO(msw): FORCE_LTR_DIRECTIONALITY does not work for RTL text now.
-
-  // If the string is empty or LTR was forced, simply return false since the
-  // default RenderText directionality is already LTR.
-  if (text->empty() || (flags & gfx::Canvas::FORCE_LTR_DIRECTIONALITY))
-    return false;
-
-  // If RTL is forced, apply it to the string.
-  if (flags & gfx::Canvas::FORCE_RTL_DIRECTIONALITY) {
-    base::i18n::WrapStringWithRTLFormatting(text);
-    return true;
-  }
+// If necessary, force RTL/LTR base directionality.
+// Returns true if the text will be rendered with an RTL base direction.
+bool AdjustStringDirection(int flags,
+                           const string16& text,
+                           gfx::RenderText* render_text) {
+  if (flags & gfx::Canvas::FORCE_LTR_DIRECTIONALITY)
+    render_text->SetDirectionalityMode(gfx::FORCE_LTR);
+  else if (flags & gfx::Canvas::FORCE_RTL_DIRECTIONALITY)
+    render_text->SetDirectionalityMode(gfx::FORCE_RTL);
 
   // If a direction wasn't forced but the UI language is RTL and there were
   // strong RTL characters, ensure RTL is applied.
-  if (base::i18n::IsRTL() && base::i18n::StringContainsStrongRTLChars(*text)) {
-    base::i18n::WrapStringWithRTLFormatting(text);
-    return true;
-  }
+  if (base::i18n::IsRTL() && base::i18n::StringContainsStrongRTLChars(text))
+    render_text->SetDirectionalityMode(gfx::FORCE_RTL);
 
-  // In the default case, the string should be rendered as LTR. RenderText's
-  // default directionality is LTR, so the text doesn't need to be wrapped.
-  // Note that individual runs within the string may still be rendered RTL
-  // (which will be the case for RTL text under non-RTL locales, since under RTL
-  // locales it will be handled by the if statement above).
-  return false;
+  return render_text->GetTextDirection() == base::i18n::RIGHT_TO_LEFT;
 }
 
 // Checks each pixel immediately adjacent to the given pixel in the bitmap. If
@@ -208,8 +193,10 @@ void Canvas::SizeStringInt(const string16& text,
   flags = AdjustPlatformSpecificFlags(text, flags);
 
   string16 adjusted_text = text;
+  scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
+
 #if defined(OS_WIN)
-  AdjustStringDirection(flags, &adjusted_text);
+  AdjustStringDirection(flags, adjusted_text, render_text.get());
 #endif
 
   if ((flags & MULTI_LINE) && *width != 0) {
@@ -223,7 +210,6 @@ void Canvas::SizeStringInt(const string16& text,
     std::vector<string16> strings;
     ui::ElideRectangleText(adjusted_text, font, rect.width(), rect.height(),
                            wrap_behavior, &strings);
-    scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
     UpdateRenderText(rect, string16(), font, flags, 0, render_text.get());
 
     int h = 0;
@@ -245,7 +231,6 @@ void Canvas::SizeStringInt(const string16& text,
       *width = adjusted_text.length() * font.GetAverageCharacterWidth();
       *height = font.GetHeight();
     } else {
-      scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
       gfx::Rect rect(*width, *height);
       StripAcceleratorChars(flags, &adjusted_text);
       UpdateRenderText(rect, adjusted_text, font, flags, 0, render_text.get());
@@ -285,13 +270,13 @@ void Canvas::DrawStringWithShadows(const string16& text,
   gfx::Rect rect(text_bounds);
   string16 adjusted_text = text;
 
-#if defined(OS_WIN)
-  AdjustStringDirection(flags, &adjusted_text);
-#endif
-
   scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
   render_text->SetTextShadows(shadows);
 
+#if defined(OS_WIN)
+  AdjustStringDirection(flags, adjusted_text, render_text.get());
+#endif
+
   if (flags & MULTI_LINE) {
     ui::WordWrapBehavior wrap_behavior = ui::IGNORE_LONG_WORDS;
     if (flags & CHARACTER_BREAK)
@@ -428,7 +413,8 @@ void Canvas::DrawFadeTruncatingString(
 
   scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
   string16 clipped_text = text;
-  const bool is_rtl = AdjustStringDirection(flags, &clipped_text);
+  const bool is_rtl =
+      AdjustStringDirection(flags, clipped_text, render_text.get());
 
   switch (truncate_mode) {
     case TruncateFadeTail: