WPF’s ClipToBounds property is not available on Panels in Silverlight, which can lead to some design frustration. Using the new Interactions and Blend Behavior framework, it’s easy to whip up something nearly identical!

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Windows.Interactivity;
//using Microsoft.Expression.Interactivity.Core;

namespace AutoClipperDemo
{
    public class AutoClipBehavior : Behavior<DependencyObject>
    {
        private RectangleGeometry _rectGeo;

        protected override void OnAttached()
        {
            base.OnAttached();

            if (base.AssociatedObject is FrameworkElement)
            {                 
                FrameworkElement fe = AssociatedObject as FrameworkElement;
                fe.SizeChanged += new SizeChangedEventHandler(AttachedObjectSizeChanged);
                
                _rectGeo = new RectangleGeometry();
                fe.Clip = _rectGeo;
                
                OnAdjustClip(fe, new Size(fe.ActualWidth, fe.ActualHeight));
            }            
        }

        protected virtual void OnAdjustClip(FrameworkElement fe, Size sz)
        {
            Rect rect = new Rect(0, 0, sz.Width, sz.Height);

            // it would be interesting to handle the border, but alas
            // we can't as it would clip the border as well. :)
            // best solution is to just put the border on or around
            // the panel being clipped by this
            _rectGeo.Rect = rect;
        }

        private void AttachedObjectSizeChanged(object sender, SizeChangedEventArgs e)
        {            
            OnAdjustClip(AssociatedObject as FrameworkElement, e.NewSize);
        }

        // always clean up after yourself ... remove anything that was attached
        // to prevent incorrect clipping and unnecessary event handlers
        protected override void OnDetaching()
        {
            base.OnDetaching();

            if (base.AssociatedObject is FrameworkElement)
            {
                FrameworkElement fe = AssociatedObject as FrameworkElement;
                fe.SizeChanged -= new SizeChangedEventHandler(AttachedObjectSizeChanged);
                fe.Clip = null;
                _rectGeo = null;
            }
        }
    }
}

<Border Grid.Column="4" Grid.Row="2" BorderBrush="White" BorderThickness="4" Background="#FF31C525">
    <i:Interaction.Behaviors>
        <local:AutoClipBehavior/>
    </i:Interaction.Behaviors>
    <Grid>
        <Ellipse Fill="#FF09570A" Stroke="Black" Height="250" Margin="91,138,-61,-46" VerticalAlignment="Bottom" Width="250"/>
    </Grid>
</Border>

RENÉ SCHULTE created a cool Silverlight Real-time Perlin Noise generator:

Check it out here. Full source is available as well.

Do you need a way to switch between the beta version of the tools for Visual Studio 2008 for Silverlight 3 and the released version of Silverlight 2?

Thanks to Amy for posting a solution here.

Although my Mix09 entry didn’t place/win, as promised I’m posting the source code, as-is. It’s not the final completely condensed version that I actually submitted (as that version had carriage returns/line feeds, tabs, etc. all removed).

Download Source

As a consolation prize, I did receive a limited edition T-shirt just for entering (which admittedly, didn’t make the effort worth while – but, I had fun putting it all together nonetheless).

I’ve programmed in many nasty, strict environments over the years, but it felt really dirty to do this in c#:

DateTime _t, _aL, _tS;
B[] _b, _e;
Random _r = new Random();
double TW = 12, TH = 12, SY = 50, MW, MH, SA, G = .03, CSA, SSA;
Point A;
int CW = 20, CH = 40, TB = 21, _s, GM = 0, _c, BR;
Brush _o;
IsolatedStorageSettings _a;
delegate void PAD(Canvas c);

Yeah. Seriously, those were the variable names that I used to keep the file smaller.

I shrunk the standard Application class down to it’s bare minimum and used Lamda expressions everywhere:

public partial class App : Application
{
    public App()
    {
        Startup += ((s, e) => RootVisual = new Page());
        UnhandledException += ((s, e) =>
        {
            if(!System.Diagnostics.Debugger.IsAttached)
            {
                e.Handled = true;
            }
        });
        InitializeComponent();
    }
}

and …

Loaded += ((s, e) =>
{
    _a = IsolatedStorageSettings.ApplicationSettings;
    btnP.Click += ((o, a) =>
    {
        cMs.Visibility = Visibility.Collapsed;
        RG();
        GO();
    });

Last but not least, this was probably the silliest thing I did to stop needing to use the Canvas class everywhere directly (it was still necessary in some places):

class C : Canvas
{
}

You’ve got it. I derived from Canvas so I could just refer to the Canvas class as the letter “C”! Thankfully, it wasn’t sealed.

The code does the necessary math to compute an Isometric view of the game table so that the balls on the table are properly placed.

Fully condensed down, I think I ended up with 240 bytes to spare.

 

(Are you going to Mix09? Sounds like some great stuff will be announced!)