Add support for painting halos on Views Labels.

Needed for converting some TextButtons to LabelButtons.
(eg. new avatar button, bookmark buttons on drag)

BUG=155363
TEST=Label example shows a halo'ed label.
R=sky@chromium.org

Review URL: https://codereview.chromium.org/308083011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274848 0039d316-1c4b-4281-b951-d872f2087c98

ui/views/controls/label.cc

@@ -323,12 +323,18 @@ void Label::PaintText(gfx::Canvas* canvas,
                       const gfx::Rect& text_bounds,
                       int flags) {
   gfx::ShadowValues shadows;
-  if (has_shadow_)
+  if (has_shadow_) {
     shadows.push_back(gfx::ShadowValue(shadow_offset_, shadow_blur_,
         enabled() ? enabled_shadow_color_ : disabled_shadow_color_));
-  canvas->DrawStringRectWithShadows(text, font_list_,
-      enabled() ? actual_enabled_color_ : actual_disabled_color_,
-      text_bounds, line_height_, flags, shadows);
+  }
+  SkColor color = enabled() ? actual_enabled_color_ : actual_disabled_color_;
+  canvas->DrawStringRectWithShadows(text, font_list_, color, text_bounds,
+                                    line_height_, flags, shadows);
+
+  if (SkColorGetA(halo_color_) != SK_AlphaTRANSPARENT) {
+    canvas->DrawStringRectWithHalo(text, font_list_, color, halo_color_,
+                                   text_bounds, flags);
+  }
 
   if (HasFocus()) {
     gfx::Rect focus_bounds = text_bounds;
@@ -400,6 +406,7 @@ void Label::Init(const base::string16& text, const gfx::FontList& font_list) {
   shadow_offset_.SetPoint(1, 1);
   has_shadow_ = false;
   shadow_blur_ = 0;
+  halo_color_ = SK_ColorTRANSPARENT;
   cached_heights_.resize(kCachedSizeLimit);
   ResetCachedSize();
 

ui/views/controls/label.h

@@ -100,6 +100,9 @@ class VIEWS_EXPORT Label : public View {
   // Disables shadows.
   void ClearEmbellishing();
 
+  // Set the color of a halo on the painted text (use transparent for none).
+  void set_halo_color(SkColor halo_color) { halo_color_ = halo_color; }
+
   // Sets horizontal alignment. If the locale is RTL, and the directionality
   // mode is USE_UI_DIRECTIONALITY, the alignment is flipped around.
   //
@@ -270,8 +273,6 @@ class VIEWS_EXPORT Label : public View {
   bool auto_color_readability_;
   mutable gfx::Size text_size_;
   mutable bool text_size_valid_;
-  // Indicates the level of shadow blurring. Default is zero.
-  double shadow_blur_;
   int line_height_;
   bool is_multi_line_;
   bool is_obscured_;
@@ -296,6 +297,12 @@ class VIEWS_EXPORT Label : public View {
   // Should a shadow be drawn behind the text?
   bool has_shadow_;
 
+  // Indicates the level of shadow blurring. Default is zero.
+  double shadow_blur_;
+
+  // The halo color drawn around the text if it is not transparent.
+  SkColor halo_color_;
+
   // The cached heights to avoid recalculation in GetHeightForWidth().
   mutable std::vector<gfx::Size> cached_heights_;
   mutable int cached_heights_cursor_;

ui/views/examples/label_example.cc

@@ -68,10 +68,11 @@ void LabelExample::CreateExampleView(View* container) {
   label->SetEnabledColor(SK_ColorBLUE);
   container->AddChildView(label);
 
-  label = new Label(ASCIIToUTF16("A Courier-18 label with a shadow."));
+  label = new Label(ASCIIToUTF16("A Courier-18 label with a halo and shadow."));
   label->SetFontList(gfx::FontList("Courier, 18px"));
   label->SetShadowColors(SK_ColorGRAY, SK_ColorLTGRAY);
-  label->SetShadowOffset(1, 1);
+  label->SetShadowOffset(2, 2);
+  label->set_halo_color(SK_ColorGREEN);
   container->AddChildView(label);
 
   label = new PreferredSizeLabel();