Enable bold and italic text styles in RenderText*.

To do this, the following changes were made:

Added functions GetStyle() and DeriveFontList(style) to FontList. Changed font list to use strings "Bold" and "Italic" instead of PANGO_STYLE_ITALIC and PANGO_WEIGHT_BOLD - where were actually compile constants for setting attributes and weren't recognized by Pango in a font string. (Whereas "Bold" and "Italic" are recognized).

Add RenderText test that checks that the width of a bold string > the width of a non-bold string.
Add FontList tests for the new functions.

BUG=107893
TEST=Run views_examples_exe "Text Styles" examples and try bold and italic styles (this depends on an unreleased CL). Also, new tests in FontListTest and RenderTextTest.

Review URL: http://codereview.chromium.org/8963027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@116945 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 32 insertions, 0 deletions

diff --git a/ui/gfx/render_text_linux.cc b/ui/gfx/render_text_linux.cc
index 4ebac11..a51bbef 100644
--- a/ui/gfx/render_text_linux.cc
+++ b/ui/gfx/render_text_linux.cc
@@ -258,6 +258,7 @@ void RenderTextLinux::EnsureLayout() {
     // TODO(xji): If RenderText will be used for displaying purpose, such as
     // label, we will need to remove the single-line-mode setting.
     pango_layout_set_single_paragraph_mode(layout_, true);
+    SetupPangoAttributes(layout_);
 
     current_line_ = pango_layout_get_line_readonly(layout_, 0);
     pango_layout_line_ref(current_line_);
@@ -269,6 +270,35 @@ void RenderTextLinux::EnsureLayout() {
   }
 }
 
+void RenderTextLinux::SetupPangoAttributes(PangoLayout* layout) {
+  PangoAttrList* attrs = pango_attr_list_new();
+
+  int default_font_style = font_list().GetStyle();
+  for (StyleRanges::const_iterator i = style_ranges().begin();
+       i < style_ranges().end(); ++i) {
+    // In Pango, different fonts means different runs, and it breaks Arabic
+    // shaping across run boundaries. So, set font only when it is different
+    // from the default font.
+    // TODO(xji): We'll eventually need to split up StyleRange into components
+    // (ColorRange, FontRange, etc.) so that we can combine adjacent ranges
+    // with the same Fonts (to avoid unnecessarily splitting up runs).
+    if (i->font_style != default_font_style) {
+      FontList derived_font_list = font_list().DeriveFontList(i->font_style);
+      PangoFontDescription* desc = pango_font_description_from_string(
+          derived_font_list.GetFontDescriptionString().c_str());
+
+      PangoAttribute* pango_attr = pango_attr_font_desc_new(desc);
+      pango_attr->start_index = Utf16IndexToUtf8Index(i->range.start());
+      pango_attr->end_index = Utf16IndexToUtf8Index(i->range.end());
+      pango_attr_list_insert(attrs, pango_attr);
+      pango_font_description_free(desc);
+    }
+  }
+
+  pango_layout_set_attributes(layout, attrs);
+  pango_attr_list_unref(attrs);
+}
+
 void RenderTextLinux::DrawVisualText(Canvas* canvas) {
   TRACE_EVENT0("gfx", "RenderTextLinux::DrawVisualText");
   DCHECK(layout_);
@@ -353,6 +383,7 @@ void RenderTextLinux::DrawVisualText(Canvas* canvas) {
         //                  styles evenly over the glyph. We can do this too by
         //                  clipping and drawing the glyph several times.
         renderer.SetForegroundColor(styles[style].foreground);
+        renderer.SetFontStyle(styles[style].font_style);
         renderer.DrawPosText(&pos[start], &glyphs[start], i - start);
         if (styles[style].underline || styles[style].strike) {
           renderer.DrawDecorations(start_x, y, glyph_x - start_x,
@@ -372,6 +403,7 @@ void RenderTextLinux::DrawVisualText(Canvas* canvas) {
 
     // Draw the remaining glyphs.
     renderer.SetForegroundColor(styles[style].foreground);
+    renderer.SetFontStyle(styles[style].font_style);
     renderer.DrawPosText(&pos[start], &glyphs[start], glyph_count - start);
     if (styles[style].underline || styles[style].strike) {
        renderer.DrawDecorations(start_x, y, glyph_x - start_x,