(Views only) Add a gradient background to the tabstrip of the view tabbed pane implementation.

BUG=138063
TEST=none


Review URL: https://chromiumcodereview.appspot.com/10823229

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@151017 0039d316-1c4b-4281-b951-d872f2087c98

ui/views/background.cc

@@ -113,6 +113,19 @@ Background* Background::CreateVerticalGradientBackground(SkColor color1,
   return background;
 }
 
+//static
+Background* Background::CreateVerticalMultiColorGradientBackground(
+    SkColor* colors,
+    SkScalar* pos,
+    size_t count) {
+  Background* background = CreateBackgroundPainter(
+      true, Painter::CreateVerticalMultiColorGradient(colors, pos, count));
+  background->SetNativeControlColor(
+      color_utils::AlphaBlend(colors[0], colors[count-1], 128));
+
+  return background;
+}
+
 //static
 Background* Background::CreateBackgroundPainter(bool owns_painter,
                                                 Painter* painter) {

ui/views/background.h

@@ -59,6 +59,15 @@ class VIEWS_EXPORT Background {
   static Background* CreateVerticalGradientBackground(SkColor color1,
                                                       SkColor color2);
 
+  // Creates a background that contains a vertical gradient. The gradient can
+  // have multiple |colors|. The |pos| array contains the relative positions of
+  // each corresponding color. |colors| and |pos| must be the same size. The
+  // first element in |pos| must be 0.0 and the last element must be 1.0.
+  // |count| contains the number of elements in |colors| and |pos|.
+  static Background* CreateVerticalMultiColorGradientBackground(SkColor* colors,
+                                                                SkScalar* pos,
+                                                                size_t count);
+
   // Creates Chrome's standard panel background
   static Background* CreateStandardPanelBackground();
 

ui/views/controls/tabbed_pane/native_tabbed_pane_views.cc

@@ -124,6 +124,20 @@ class TabStrip : public View {
   explicit TabStrip(NativeTabbedPaneViews* owner)
       : owner_(owner),
         selected_tab_(NULL) {
+    const int kCount = 4;
+    // The gradient colors are derived from the tabbed panes used for the
+    // WebUI.
+    SkColor colors[] = {
+        SkColorSetRGB(0xff, 0xff, 0xff),
+        SkColorSetRGB(0xff, 0xff, 0xff),
+        SkColorSetRGB(0xfa, 0xfa, 0xfa),
+        SkColorSetRGB(0xf2, 0xf2, 0xf2)
+    };
+    // The relative positions of the gradient colors are derived from the
+    // tabbed panes used for the WebUI.
+    SkScalar pos[4] = {0.0f, 0.6f, 0.8f, 1.0f};
+    set_background(Background::CreateVerticalMultiColorGradientBackground(
+        colors, pos, kCount));
   }
   virtual ~TabStrip() {}
 
@@ -167,6 +181,9 @@ class TabStrip : public View {
     }
   }
   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE {
+    OnPaintBackground(canvas);
+
+    // Draw the TabStrip border.
     SkPaint paint;
     paint.setColor(kTabBorderColor);
     paint.setStrokeWidth(kTabBorderThickness);

ui/views/painter.cc

@@ -20,13 +20,24 @@ namespace {
 
 class GradientPainter : public Painter {
  public:
-  GradientPainter(bool horizontal, SkColor top, SkColor bottom)
-      : horizontal_(horizontal) {
-    colors_[0] = top;
-    colors_[1] = bottom;
+  GradientPainter(bool horizontal,
+                  SkColor* colors,
+                  SkScalar* pos,
+                  size_t count)
+      : horizontal_(horizontal),
+        count_(count) {
+    pos_ = new SkScalar[count_];
+    colors_ = new SkColor[count_];
+
+    for (size_t i = 0; i < count_; ++i) {
+      pos_[i] = pos[i];
+      colors_[i] = colors[i];
+    }
   }
 
   virtual ~GradientPainter() {
+    delete[] pos_;
+    delete[] colors_;
   }
 
   // Overridden from Painter:
@@ -39,7 +50,7 @@ class GradientPainter : public Painter {
     else
       p[1].iset(0, size.height());
 
-    SkShader* s = SkGradientShader::CreateLinear(p, colors_, NULL, 2,
+    SkShader* s = SkGradientShader::CreateLinear(p, colors_, pos_, count_,
         SkShader::kClamp_TileMode, NULL);
     paint.setStyle(SkPaint::kFill_Style);
     paint.setShader(s);
@@ -52,8 +63,14 @@ class GradientPainter : public Painter {
   }
 
  private:
+  // If |horizontal_| is true then the gradiant is painted horizontally.
   bool horizontal_;
-  SkColor colors_[2];
+  // The gradient colors.
+  SkColor* colors_;
+  // The relative positions of the corresponding gradient colors.
+  SkScalar* pos_;
+  // The number of elements in |colors_| and |pos_|.
+  size_t count_;
 
   DISALLOW_COPY_AND_ASSIGN(GradientPainter);
 };
@@ -163,12 +180,27 @@ void Painter::PaintPainterAt(gfx::Canvas* canvas,
 
 // static
 Painter* Painter::CreateHorizontalGradient(SkColor c1, SkColor c2) {
-  return new GradientPainter(true, c1, c2);
+  SkColor colors[2];
+  colors[0] = c1;
+  colors[1] = c2;
+  SkScalar pos[] = {0, 1};
+  return new GradientPainter(true, colors, pos, 2);
 }
 
 // static
 Painter* Painter::CreateVerticalGradient(SkColor c1, SkColor c2) {
-  return new GradientPainter(false, c1, c2);
+  SkColor colors[2];
+  colors[0] = c1;
+  colors[1] = c2;
+  SkScalar pos[] = {0, 1};
+  return new GradientPainter(false, colors, pos, 2);
+}
+
+// static
+Painter* Painter::CreateVerticalMultiColorGradient(SkColor* colors,
+                                                   SkScalar* pos,
+                                                   size_t count) {
+  return new GradientPainter(false, colors, pos, count);
 }
 
 // static

ui/views/painter.h

@@ -35,6 +35,14 @@ class VIEWS_EXPORT Painter {
   static Painter* CreateHorizontalGradient(SkColor c1, SkColor c2);
   static Painter* CreateVerticalGradient(SkColor c1, SkColor c2);
 
+  // Creates a painter that draws a multi-color gradient. |colors| contains the
+  // gradient colors and |pos| the relative positions of the colors. The first
+  // element in |pos| must be 0.0 and the last element 1.0. |count| contains
+  // the number of elements in |colors| and |pos|.
+  static Painter* CreateVerticalMultiColorGradient(SkColor* colors,
+                                                   SkScalar* pos,
+                                                   size_t count);
+
   // Creates a painter that divides |image| into nine regions. The four corners
   // are rendered at the size specified in insets (for example, the upper
   // left corners is rendered at 0x0 with a size of