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 29f6f773063167ce12b6431ea46899a9ba45345b..d33567e88370a7061c9da082bd6f1c9256f70b50 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.

[Alexei Svitkine (slow), 2012/07/31 23:33:29]

Remove the return value here and use GetTextDirection() in callers.

That will also do the right thing in the default case (notice that at this
point, we haven't yet set the text on the render_text).

[msw, 2012/08/01 17:30:10]

Good point! Done.

+bool AdjustStringDirection(int flags,
+                           const string16& text,
+                           gfx::RenderText* render_text) {
+  if (flags & gfx::Canvas::FORCE_LTR_DIRECTIONALITY)
+    render_text->SetDirectionalityMode(gfx::DIRECTIONALITY_FORCE_LTR);
+  else if (flags & gfx::Canvas::FORCE_RTL_DIRECTIONALITY)
+    render_text->SetDirectionalityMode(gfx::DIRECTIONALITY_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::DIRECTIONALITY_FROM_UI);
 
-  // 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
@@ -203,8 +188,10 @@ 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) {
@@ -218,7 +205,6 @@ 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;
@@ -240,7 +226,6 @@ 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());
@@ -280,13 +265,13 @@ 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)
@@ -423,7 +408,8 @@ 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: