Views: Small refactoring of rounded corners logic

This CL introduces a GetCornerRadius() helper to the DialogDelegate
and a GetClientCornerRadii() helper to the BubbleFrameView. This will
help when implementing the rounded corners fast path for MD rounded
corners in a follow-up CL.

Bug: 822075
Change-Id: Ia90c56b0ba6d58d682bc9c14bae688c247d612d8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2359022
Commit-Queue: Thomas Lukaszewicz <tluk@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#798665}

ui/views/bubble/bubble_dialog_delegate_view.cc

@@ -378,12 +378,8 @@ BubbleDialogDelegate::CreateNonClientFrameView(Widget* widget) {
 
   std::unique_ptr<BubbleBorder> border =
       std::make_unique<BubbleBorder>(arrow(), GetShadow(), color());
-  if (CustomShadowsSupported() && GetParams().round_corners) {
-    border->SetCornerRadius(
-        base::FeatureList::IsEnabled(features::kEnableMDRoundedCornersOnDialogs)
-            ? provider->GetCornerRadiusMetric(views::EMPHASIS_MEDIUM)
-            : 2);
-  }
+  if (CustomShadowsSupported() && GetParams().round_corners)
+    border->SetCornerRadius(GetCornerRadius());
 
   frame->SetBubbleBorder(std::move(border));
   return frame;

ui/views/bubble/bubble_frame_view.cc

@@ -19,6 +19,7 @@
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/color_palette.h"
+#include "ui/gfx/geometry/rounded_corners_f.h"
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/gfx/skia_util.h"
 #include "ui/native_theme/native_theme.h"
@@ -184,29 +185,19 @@ bool BubbleFrameView::GetClientMask(const gfx::Size& size, SkPath* path) const {
   DCHECK_EQ(GetBoundsForClientView().size(), size);
   DCHECK_EQ(GetWidget()->client_view()->size(), size);
 
-  const int radius = bubble_border_->corner_radius();
-  const gfx::Insets insets =
-      GetClientInsetsForFrameWidth(GetContentsBounds().width());
+  const gfx::RoundedCornersF corner_radii = GetClientCornerRadii();
 
-  // A mask is not needed if the content does not overlap the rounded corners.
-  if ((insets.top() > radius && insets.bottom() > radius) ||
-      (insets.left() > radius && insets.right() > radius)) {
+  // If corner radii are all zero we do not need to apply a mask.
+  if (corner_radii.IsEmpty())
     return false;
-  }
 
-  // We want to clip the client view to a rounded rect that's consistent with
-  // the bubble's rounded border. However, if there is a header, the top of the
-  // client view should be straight and flush with that. Likewise, if there is
-  // a footer, the client view should be straight and flush with that. Therefore
-  // we set the corner radii separately for top and bottom.
-  const SkRect rect = SkRect::MakeIWH(size.width(), size.height());
-  const SkScalar top_radius = header_view_ ? 0.0f : radius;
-  const SkScalar bottom_radius = footnote_container_ ? 0.0f : radius;
   // Format is upper-left x, upper-left y, upper-right x, and so forth,
   // clockwise around the boundary.
-  SkScalar radii[]{top_radius,    top_radius,    top_radius,    top_radius,
-                   bottom_radius, bottom_radius, bottom_radius, bottom_radius};
-  path->addRoundRect(rect, radii);
+  SkScalar radii[]{corner_radii.upper_left(),  corner_radii.upper_left(),
+                   corner_radii.upper_right(), corner_radii.upper_right(),
+                   corner_radii.lower_right(), corner_radii.lower_right(),
+                   corner_radii.lower_left(),  corner_radii.lower_left()};
+  path->addRoundRect(SkRect::MakeIWH(size.width(), size.height()), radii);
   return true;
 }
 
@@ -664,6 +655,34 @@ gfx::Rect BubbleFrameView::GetCloseButtonMirroredBounds() const {
   return close_->GetMirroredBounds();
 }
 
+gfx::RoundedCornersF BubbleFrameView::GetClientCornerRadii() const {
+  DCHECK(bubble_border_);
+  const int radius = bubble_border_->corner_radius();
+  const gfx::Insets insets =
+      GetClientInsetsForFrameWidth(GetContentsBounds().width());
+
+  // Rounded corners do not need to be applied to the client view if the client
+  // view is sufficiently inset such that its unclipped bounds will not
+  // intersect with the corners of the containing bubble frame view.
+  if ((insets.top() > radius && insets.bottom() > radius) ||
+      (insets.left() > radius && insets.right() > radius)) {
+    return gfx::RoundedCornersF();
+  }
+
+  // We want to clip the client view to a rounded rect that's consistent with
+  // the bubble's rounded border. However, if there is a header, the top of the
+  // client view should be straight and flush with that. Likewise, if there is
+  // a footer, the client view should be straight and flush with that. Therefore
+  // we set the corner radii separately for top and bottom.
+  gfx::RoundedCornersF corner_radii;
+  corner_radii.set_upper_left(header_view_ ? 0 : radius);
+  corner_radii.set_upper_right(header_view_ ? 0 : radius);
+  corner_radii.set_lower_left(footnote_container_ ? 0 : radius);
+  corner_radii.set_lower_right(footnote_container_ ? 0 : radius);
+
+  return corner_radii;
+}
+
 void BubbleFrameView::MirrorArrowIfOutOfBounds(
     bool vertical,
     const gfx::Rect& anchor_rect,

ui/views/bubble/bubble_frame_view.h

@@ -20,6 +20,10 @@
 #include "ui/views/input_event_activation_protector.h"
 #include "ui/views/window/non_client_view.h"
 
+namespace gfx {
+class RoundedCornersF;
+}
+
 namespace views {
 
 class FootnoteContainerView;
@@ -179,6 +183,12 @@ class VIEWS_EXPORT BubbleFrameView : public NonClientFrameView,
   bool IsCloseButtonVisible() const;
   gfx::Rect GetCloseButtonMirroredBounds() const;
 
+  // Helper function that gives the corner radius values that should be applied
+  // to the BubbleFrameView's client view. These values depend on the amount of
+  // inset present on the client view and the presence of header and footer
+  // views.
+  gfx::RoundedCornersF GetClientCornerRadii() const;
+
   BubbleBorder* bubble_border_for_testing() const { return bubble_border_; }
 
  private:

ui/views/window/dialog_delegate.cc

@@ -233,13 +233,8 @@ std::unique_ptr<NonClientFrameView> DialogDelegate::CreateDialogFrameView(
   border->set_use_theme_background_color(true);
   DialogDelegate* delegate = widget->widget_delegate()->AsDialogDelegate();
   if (delegate) {
-    if (delegate->GetParams().round_corners) {
-      border->SetCornerRadius(
-          base::FeatureList::IsEnabled(
-              features::kEnableMDRoundedCornersOnDialogs)
-              ? provider->GetCornerRadiusMetric(views::EMPHASIS_MEDIUM)
-              : 2);
-    }
+    if (delegate->GetParams().round_corners)
+      border->SetCornerRadius(delegate->GetCornerRadius());
     frame->SetFootnoteView(delegate->DisownFootnoteView());
   }
   frame->SetBubbleBorder(std::move(border));
@@ -411,6 +406,14 @@ ax::mojom::Role DialogDelegate::GetAccessibleWindowRole() {
   return ax::mojom::Role::kDialog;
 }
 
+int DialogDelegate::GetCornerRadius() const {
+  return base::FeatureList::IsEnabled(
+             features::kEnableMDRoundedCornersOnDialogs)
+             ? LayoutProvider::Get()->GetCornerRadiusMetric(
+                   views::EMPHASIS_MEDIUM)
+             : 2;
+}
+
 std::unique_ptr<View> DialogDelegate::DisownFootnoteView() {
   return std::move(footnote_view_);
 }

ui/views/window/dialog_delegate.h

@@ -285,6 +285,8 @@ class VIEWS_EXPORT DialogDelegate : public WidgetDelegate {
 
   const Params& GetParams() const { return params_; }
 
+  int GetCornerRadius() const;
+
   // Return ownership of the footnote view for this dialog. Only use this in
   // subclass overrides of CreateNonClientFrameView.
   std::unique_ptr<View> DisownFootnoteView();