Remove top and bottom margins from TrayBubbleView

ui/views/bubble/tray_bubble_view.cc

Index: ui/views/bubble/tray_bubble_view.cc
diff --git a/ui/views/bubble/tray_bubble_view.cc b/ui/views/bubble/tray_bubble_view.cc
index d83055bef30b98d451d61c0b314741ad9c1c7575..adacb81ea22768359dda811bd1eb04016ad1d026 100644
--- a/ui/views/bubble/tray_bubble_view.cc
+++ b/ui/views/bubble/tray_bubble_view.cc
@@ -117,59 +117,34 @@ class TrayBubbleBorder : public views::BubbleBorder {
   DISALLOW_COPY_AND_ASSIGN(TrayBubbleBorder);
 };
 
-// Custom background for TrayBubbleView. Fills in the top and bottom margins
-// with appropriate background colors without overwriting the rounded corners.
-class TrayBubbleBackground : public views::Background {
+class TrayBubbleContentMask : public ui::Layer, public ui::LayerDelegate {

[sky, 2012/11/07 00:37:05]

This code won't work on windows non-aura.

[bartfab (slow), 2012/11/07 12:12:16]

I modified the CL to preserve the previous implementation when defined(OS_WIN)
&& !defined(USE_AURA)

  public:
-  explicit TrayBubbleBackground(views::BubbleBorder* border,
-                                SkColor top_color,
-                                SkColor bottom_color)
-      : border_(border),
-        top_color_(top_color),
-        bottom_color_(bottom_color),
-        radius_(SkIntToScalar(border->GetBorderCornerRadius() - 1)) {
+  TrayBubbleContentMask(views::BubbleBorder* border)
+     : Layer(ui::LAYER_TEXTURED),
+       radius_(SkIntToScalar(border->GetBorderCornerRadius() - 1)) {
+    set_delegate(this);
   }
 
-  SkScalar radius() const { return radius_; }
-
-  // Overridden from Background:
-  virtual void Paint(gfx::Canvas* canvas, views::View* view) const OVERRIDE {
-    canvas->Save();
-
-    // Set a clip mask for the bubble's rounded corners.
-    gfx::Rect bounds(view->GetContentsBounds());
-    const int border_thickness(border_->GetBorderThickness());
-    bounds.Inset(-border_thickness, -border_thickness);
+  // Overridden from LayerDelegate:
+  virtual void OnPaintLayer(gfx::Canvas* canvas) OVERRIDE {
     SkPath path;
-    path.addRoundRect(gfx::RectToSkRect(bounds), radius_, radius_);
-    canvas->ClipPath(path);
-
-    // Paint the header and footer (assumes the bubble contents fill in their
-    // own backgrounds).
+    path.addRoundRect(gfx::RectToSkRect(bounds()), radius_, radius_);

[sky, 2012/11/07 00:37:05]

Bounds() is in the coordinate system of the parent. Don't you want
gfx::Rect(bounds().size()) ?

[bartfab (slow), 2012/11/07 12:12:16]

Done.

bounds() actually worked here because the bounds happen to be set by
TrayBubbleView::UpdateBubble() to a rect whose top-left corner is (0,0). But
yes, it is safer to use bounds().size() just in case this ever changes.

     SkPaint paint;
     paint.setStyle(SkPaint::kFill_Style);

[stevenjb, 2012/11/06 21:43:26]

What are we drawing here? I'm unfamiliar with what a default SkPaint will draw.

[bartfab (slow), 2012/11/06 23:09:14]

Since this is a mask layer, only alpha matters. A default SkPaint will draw in a
fully opaque color, exactly as needed here.

[stevenjb, 2012/11/06 23:17:45]

I see. Might be worth commenting to that effect (or setting the color explicitly
anyway).

[bartfab (slow), 2012/11/07 12:12:16]

I added an explicit setAlpha() call.

+    canvas->DrawPath(path, paint);
+  }
 
-    gfx::Rect top_rect(bounds);
-    top_rect.set_height(radius_);
-    paint.setColor(top_color_);
-    canvas->DrawRect(top_rect, paint);
-
-    gfx::Rect bottom_rect(bounds);
-    bottom_rect.set_y(bounds.y() + (bounds.height() - radius_));
-    bottom_rect.set_height(radius_);
-    paint.setColor(bottom_color_);
-    canvas->DrawRect(bottom_rect, paint);
+  virtual void OnDeviceScaleFactorChanged(float device_scale_factor) OVERRIDE {
+  }
 
-    canvas->Restore();
+  virtual base::Closure PrepareForLayerBoundsChange() OVERRIDE {
+    return base::Closure();
   }
 
  private:
-  views::BubbleBorder* border_;
-  SkColor top_color_;
-  SkColor bottom_color_;
   SkScalar radius_;
 
-  DISALLOW_COPY_AND_ASSIGN(TrayBubbleBackground);
+  DISALLOW_COPY_AND_ASSIGN(TrayBubbleContentMask);
 };
 
 // Custom layout for the bubble-view. Does the default box-layout if there is
@@ -212,7 +187,7 @@ class BottomAlignedBoxLayout : public views::BoxLayout {
 }  // namespace internal
 
 using internal::TrayBubbleBorder;
-using internal::TrayBubbleBackground;
+using internal::TrayBubbleContentMask;
 using internal::BottomAlignedBoxLayout;
 
 // static
@@ -227,7 +202,6 @@ TrayBubbleView::InitParams::InitParams(AnchorType anchor_type,
       max_height(0),
       can_activate(false),
       close_on_deactivate(true),
-      top_color(SK_ColorBLACK),
       arrow_color(SK_ColorBLACK),
       arrow_location(views::BubbleBorder::NONE),
       arrow_offset(kArrowDefaultOffset),
@@ -265,23 +239,17 @@ TrayBubbleView::TrayBubbleView(gfx::NativeView parent_window,
       params_(init_params),
       delegate_(delegate),
       bubble_border_(NULL),
-      bubble_background_(NULL),
       is_gesture_dragging_(false) {
   set_parent_window(parent_window);
   set_notify_enter_exit_on_child(true);
   set_close_on_deactivate(init_params.close_on_deactivate);
+  set_margins(gfx::Insets());
   SetPaintToLayer(true);
   SetFillsBoundsOpaquely(true);
 
   bubble_border_ = new TrayBubbleBorder(this, anchor_view(), params_);
 
-  bubble_background_ = new TrayBubbleBackground(
-      bubble_border_, init_params.top_color, init_params.arrow_color);
-
-  // Inset the view on the top and bottom by the corner radius to avoid drawing
-  // over the the bubble corners.
-  const int radius = bubble_background_->radius();
-  set_margins(gfx::Insets(radius, 0, radius, 0));
+  bubble_content_mask_.reset(new TrayBubbleContentMask(bubble_border_));
 }
 
 TrayBubbleView::~TrayBubbleView() {
@@ -295,12 +263,15 @@ void TrayBubbleView::InitializeAndShowBubble() {
   SetAlignment(views::BubbleBorder::ALIGN_EDGE_TO_ANCHOR_EDGE);
   bubble_border_->UpdateArrowOffset();
 
+  layer()->parent()->SetMaskLayer(bubble_content_mask_.get());
+
   Show();
   UpdateBubble();
 }
 
 void TrayBubbleView::UpdateBubble() {
   SizeToContents();
+  bubble_content_mask_->SetBounds(GetContentsBounds());
   GetWidget()->GetRootView()->SchedulePaint();
 }
 
@@ -336,12 +307,11 @@ bool TrayBubbleView::CanActivate() const {
   return params_.can_activate;
 }
 
-// Overridden to create BubbleFrameView and set a custom border and background.
+// Overridden to create BubbleFrameView and set a custom border.
 views::NonClientFrameView* TrayBubbleView::CreateNonClientFrameView(
     views::Widget* widget) {
   views::BubbleFrameView* bubble_frame_view =
       new views::BubbleFrameView(margins(), bubble_border_);
-  bubble_frame_view->set_background(bubble_background_);
   return bubble_frame_view;
 }