Ash Utility

Arc Curve Corner

Here is an example arc curve corner:

An arc curve corner is a corner shape consisting of arcs and lines. It can be specified with the following parameters:

• width: The width of the arc curve corner. In this example, the width is 10+12+16+20*2=78.
• height: The height of the arc curve corner. In this example, the height is 8+20+10=38.
• convex radius: The radius of the convex rounded corner. In this example, this value is 10.
• concave radius: The radius of the concave rounded corner. In this example, this value is 12.

NOTE: A valid arc curve corner must satisfy

• width >= 2*convex_radius+concave_radius
• height >= 2*convex_radius+concave_radius

Draw an arc curve corner in code

GetArcCurveRectPath() accepts three parameters:

• size: The size of the bounding rectangle with an arc curve corner.
• arc_curve_corner: An arc curve corner specified by the aforementioned parameters.
• corner_radius: If given, specifies the corner radius of the corners that are not shaped with an arc curve.

Typically, we clip a view with the path returned by GetArcCurveRectPath() in the overridden OnBoundsChanged() function. For example:

class ViewWithArcCurveCorner : public views::View {
  // ...

  // views::View:
  void OnBoundsChanged(const gfx::Rect& previous_bounds) override {
    SetClipPath(GetArcCurveRectPath(
                            GetContentsBounds().size(),
                            ArcCurveCorner(/*parameters...*/),
                            kCornerRadius));
  }
};