I am happy for you to make commercial use of this class, as long as you link to this blog in some way.

Glad you liked the subtle reference

Colin E.

I am wondering what the policy is regarding using your Clip class within a commercial project? It was exactly what I needed to get my project working as I wanted.

Currently I have the class included in my project and I added the URL to your blog (this page) in the comments section.

Thanks,

Ian

PS: I would also like to acknowledge the awesomeness of including Tribe lyrics. Very nice.

Since I got the basic code from you, I figure it’s only fair to share my modification back with you and the rest of the community.

///
/// This class provides a way for controls to set a rectangular clip region that scales with them. This class
/// gives an easy way to specify relative clip geometry so you can have a control that renders outside of its
/// bounds still be clipped down to those bounds without having to specify a fixed width and height.
///
///
/// To use this class, set the RelativeRectangleClip.ToRect property on a FrameworkElement. The rectangle
/// should use relative positions and relative height/width.
/// A value of “0,0,1,1″ will set a clip rectangle of the full actual bounds of the FrameworkElement.
/// Setting this property overrides any assignment of the element’s own Clip property.
///
public class RelativeRectangleClip
{
///
/// Gets the rectangle that will be used to create the clip geometry for the given object.
///
/// The object
/// The current relative clip rectangle
public static Rect GetToRect(DependencyObject depObj)
{
return (Rect)depObj.GetValue(ToRectProperty);
}

///
/// Sets the rectangle that will be used to create the clip geometry for the given object. Positions
/// and sizes should be relative values. Actual values will be calculated when the object is measured
/// and arranged.
///
/// The object
/// The desired relative clip rectangle
public static void SetToRect(DependencyObject depObj, Rect clipToRect)
{
depObj.SetValue(ToRectProperty, clipToRect);
}

///
/// Identifies the ToRect Dependency Property.
///
public static readonly DependencyProperty ToRectProperty =
DependencyProperty.RegisterAttached(“ToRect”, typeof(Rect),
typeof(RelativeRectangleClip), new PropertyMetadata(OnToRectPropertyChanged));

private static void OnToRectPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
FrameworkElement fe = d as FrameworkElement;
if (fe != null)
{
ClipToRect(fe);

// whenever the element which this property is attached to is loaded
// or re-sizes, we need to update its clipping geometry
fe.Loaded += new RoutedEventHandler(fe_Loaded);
fe.SizeChanged += new SizeChangedEventHandler(fe_SizeChanged);

}
}

///
/// Creates a rectangular clipping geometry which matches the geometry of the
/// passed element, using relative positioning of the rect based on the ToRect property.
///
private static void ClipToRect(FrameworkElement fe)
{
Rect clip = GetToRect(fe);
if ((clip.Height != 0) || (clip.Width != 0))
{
fe.Clip = new RectangleGeometry()
{
Rect = new Rect(fe.ActualWidth * clip.Left, fe.ActualHeight * clip.Top, fe.ActualWidth * clip.Width, fe.ActualHeight * clip.Height)
};
}
else
{
fe.Clip = null;
}
}

static void fe_SizeChanged(object sender, SizeChangedEventArgs e)
{
ClipToRect(sender as FrameworkElement);
}

static void fe_Loaded(object sender, RoutedEventArgs e)
{
ClipToRect(sender as FrameworkElement);
}
}

Regards, Colin E.