Use pango underline metrics in RenderTextLinux.

ui/gfx/render_text.cc

Index: ui/gfx/render_text.cc
===================================================================
--- ui/gfx/render_text.cc	(revision 140345)
+++ ui/gfx/render_text.cc	(working copy)
@@ -179,9 +179,14 @@
 
 namespace internal {
 
+// Indicates that an underline metric has not been set explicitly.
+const SkScalar kUnderlineMetricNotSet = SK_ScalarNaN;

[msw, 2012/06/06 18:35:25]

optional nit: just using SK_ScalarNaN directly it would be sufficient.

[Alexei Svitkine (slow), 2012/06/06 18:46:23]

Done.

+
 SkiaTextRenderer::SkiaTextRenderer(Canvas* canvas)
     : canvas_skia_(canvas->sk_canvas()),
-      started_drawing_(false) {
+      started_drawing_(false),
+      underline_thickness_(kUnderlineMetricNotSet),
+      underline_position_(kUnderlineMetricNotSet) {
   DCHECK(canvas_skia_);
   paint_.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
   paint_.setStyle(SkPaint::kFill_Style);
@@ -221,7 +226,7 @@
   paint_.setTypeface(typeface);
 }
 
-void SkiaTextRenderer::SetTextSize(int size) {
+void SkiaTextRenderer::SetTextSize(SkScalar size) {
   paint_.setTextSize(size);
 }
 
@@ -252,6 +257,13 @@
   paint_.setShader(shader);
 }
 
+void SkiaTextRenderer::SetUnderlineMetrics(SkScalar thickness,
+                                           SkScalar position) {
+  underline_thickness_ = thickness;
+  underline_position_ = position;
+  printf("Set to %f %f\n", underline_thickness_, underline_position_);

[msw, 2012/06/06 18:35:25]

oops :) please remove

[Alexei Svitkine (slow), 2012/06/06 18:46:23]

Done.

+}
+
 void SkiaTextRenderer::DrawPosText(const SkPoint* pos,
                                    const uint16* glyphs,
                                    size_t glyph_count) {
@@ -304,9 +316,14 @@
   r.fRight = x + width;
 
   if (style.underline) {
-    SkScalar offset = SkScalarMulAdd(text_size, kUnderlineOffset, y);
-    r.fTop = offset;
-    r.fBottom = offset + height;
+    if (underline_position_ == kUnderlineMetricNotSet)
+      r.fTop = SkScalarMulAdd(text_size, kUnderlineOffset, y);
+    else
+      r.fTop = y + underline_position_;
+    if (underline_thickness_ == kUnderlineMetricNotSet)
+      r.fBottom = r.fTop + height;
+    else
+      r.fBottom = r.fTop + underline_thickness_;
     canvas_skia_->drawRect(r, paint_);
   }
   if (style.strike) {