protected override void OnRender(DrawingContext dc)
{
base.OnRender(dc);
dc.DrawRectangle(Background, null, ContentBounds);
dc.DrawRectangle(VisualBrush, null, ContentBounds);
if (ViewportRect.IntersectsWith(new Rect(RenderSize)))
{
// draw shadow rectangles over the non-viewport regions
Rect r1 = new Rect(new Point(0, 0), new Size(RenderSize.Width, Math.Max(0, ViewportRect.Top)));
Rect r2 = new Rect(new Point(0, ViewportRect.Top),
new Size(Math.Max(0, ViewportRect.Left), ViewportRect.Height));
Rect r3 = new Rect(new Point(ViewportRect.Right, ViewportRect.Top),
new Size(Math.Max(0, RenderSize.Width - ViewportRect.Right), ViewportRect.Height));
Rect r4 = new Rect(new Point(0, ViewportRect.Bottom),
new Size(RenderSize.Width, Math.Max(0, RenderSize.Height - ViewportRect.Bottom)));
dc.DrawRectangle(ShadowBrush, null, r1);
dc.DrawRectangle(ShadowBrush, null, r2);
dc.DrawRectangle(ShadowBrush, null, r3);
dc.DrawRectangle(ShadowBrush, null, r4);
// draw the rectangle around the viewport region
dc.DrawRectangle(ViewportBrush, ViewportPen, ViewportRect);
}
else
{
// if no part of the Rect is visible, just draw a
// shadow over the entire content bounds
dc.DrawRectangle(ShadowBrush, null, new Rect(RenderSize));
}
}
public ViewportRect Clamp(ViewportRect bounds)
{
return(new ViewportRect()
{
startX = Math.Max(bounds.startX, startX),
startY = Math.Max(bounds.startY, startY),
endX = Math.Min(bounds.endX, endX),
endY = Math.Min(bounds.endY, endY)
});
}
public static bool IsInScreen(Rectangle rect)
{
return(ViewportRect.Intersects(rect));
}
