protected override void OnSizeAllocated(double width, double height)
{
base.OnSizeAllocated(width, height);
if (width <= 0 || height <= 0)
{
return;
}
var bounds = new Rectangle(0, 0, width, height);
var w = Math.Min(width, height);
var center = bounds.Center;
var half = w / 2;
var bRect = new Rectangle(center.X - half, center.Y - half, w, w);
BackgroundView.BorderRadius = half;
BackgroundView.Layout(bRect);
thumbRadius = w / 4;
Thumb.HeightRequest = Thumb.WidthRequest = half;
Thumb.BorderRadius = thumbRadius;
ThumbCenter = Center;
Radius = half;
UpdateThumb();
}
protected override void LayoutChildren(double x, double y, double width, double height)
{
var bounds = new Rectangle(x, y, width, height);
if (lastBounds == bounds)
{
return;
}
lastBounds = bounds;
var w = Math.Min(width, height);
var center = bounds.Center;
var half = w / 2;
var bRect = new Rectangle(center.X - half, center.Y - half, Radius * 2, Radius * 2);
BackgroundView.Layout(bRect);
thumbRadius = width / 4;
Thumb.Layout(new Rectangle(0, 0, Radius, Radius));
UpdateThumb();
}
