Simple SL control for an URL shortener service that copies text to clipboard

UrlShortenerTextBox.xaml

<!-- Author: Peter Nelson / @_peterdn - A simple SL control that copies text 
    to the user's clipboard.  Currently used in my URL (not-so) shortener
    at http://u.peterdn.com, on supported clients. -->
    
<UserControl x:Class="UrlShortenerTextBox.UrlShortenerTextBox"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    d:DesignHeight="49" d:DesignWidth="500" Loaded="UserControl_Loaded" xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk">

    <Grid x:Name="LayoutRoot" Background="White" Height="32" Width="390">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="103*" />
            <ColumnDefinition Width="397*" />
        </Grid.ColumnDefinitions>
        <sdk:Label Height="32" Background="#E3FDC1" 
                   BorderBrush="#BBB" HorizontalAlignment="Left" 
                   Name="textBoxUrl" VerticalAlignment="Center" 
                   Width="390" FontFamily="Georgia" FontSize="20" 
                   Foreground="#555" Grid.ColumnSpan="2" 
                   Cursor="Hand" Canvas.ZIndex="1"
                   MouseLeftButtonDown="textBoxUrl_MouseLeftButtonDown" 
                   Padding="9,0,0,0" BorderThickness="1" 
                   MouseEnter="textBoxUrl_MouseEnter" MouseLeave="textBoxUrl_MouseLeave">
            <TextBlock>http://u.peterdn.com</TextBlock>
        </sdk:Label>
        <sdk:Label Grid.Column="1" Height="32" 
                   HorizontalAlignment="Center" Margin="174,0,0,0" 
                   Name="statusLabel" VerticalAlignment="Center" 
                   Width="0" Background="#FFF" FontFamily="Georgia"
                   FontSize="20" Foreground="#F0B000" BorderBrush="#BBB"
                   BorderThickness="1" MouseLeftButtonDown="statusLabel_MouseLeftButtonDown"
                   MouseEnter="textBoxUrl_MouseEnter" MouseLeave="textBoxUrl_MouseLeave"
                   Canvas.ZIndex="2" Cursor="Hand" />
    </Grid>
</UserControl>

UrlShortenerTextBox.xaml.cs

/* 
    Author: Peter Nelson / @_peterdn - A simple SL control that copies text 
    to the user's clipboard.  Currently used in my URL (not-so) shortener
    at http://u.peterdn.com, on supported clients. 
*/

using System;
using System.Security;
using System.Windows;
using System.Windows.Browser;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Threading;

namespace UrlShortenerTextBox
{
    public partial class UrlShortenerTextBox : UserControl
    {
        // config-ish constants
        private const int ANIMATE_INTERVAL_MS   = 10;
        private const int ANIMATE_DELAY         = 80;
        private const int ANIMATE_DX            = 10;
        private const int MAX_STATUS_WIDTH      = 135;
        private const string COPY_TEXT          = "Click to Copy";
        private const string COPIED_TEXT        = "Copied!";
        private const string NOTCOPIED_TEXT     = "Not Copied";

        public UrlShortenerTextBox()
        {
            InitializeComponent();
        }

        private void UserControl_Loaded(object sender, RoutedEventArgs e)
        {
            // Assumes that the shortened url key is in the last segment of
            // the url, e.g. as in scheme://my.url/view/details/KEY.
            // Constructs a shortened url of the form http://my.url/KEY.

            var uri = HtmlPage.Document.DocumentUri;
            var segments = uri.ToString().Split('/');
            textBoxUrl.Content = "http://" + uri.Host + /* ":" + port + */ 
              "/" + segments[segments.Length - 1];

            _animateTimer.Tick += new EventHandler(timer_Tick);
            _animateTimer.Interval = new TimeSpan(0, 0, 0, 0, ANIMATE_INTERVAL_MS);
        }

        private void statusLabel_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            copyToClipboard();
        }

        private void textBoxUrl_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            copyToClipboard();
        }

        private void copyToClipboard()
        {
            try
            {
                Clipboard.SetText(textBoxUrl.Content.ToString());
                statusLabel.Content = COPIED_TEXT;
            }
            catch (SecurityException)
            {
                // User denied the operation.  Ideally we would
                // redirect them to a non-SL page at this point.
                statusLabel.Content = NOTCOPIED_TEXT;
            }

            _delay = ANIMATE_DELAY;
        }

        private void textBoxUrl_MouseEnter(object sender, MouseEventArgs e)
        {
            statusLabel.Content = COPY_TEXT;
            _delay = ANIMATE_DELAY;
            this.animate(true);
        }

        private void textBoxUrl_MouseLeave(object sender, MouseEventArgs e)
        {
            this.animate(false);
        }

        private void animate(bool Show)
        {
            _showing = Show;
            if (!_animateTimer.IsEnabled)
                _animateTimer.Start();
        }

        // Animation state vars
        DispatcherTimer _animateTimer = new DispatcherTimer();
        private bool _showing = false;
        private int _delay = 0;

        private void timer_Tick(object sender, EventArgs e)
        {
            // Do a simple bit of animation by adjusting widths and margins.
            // There's probably a more SL way of doing this with storyboards 
            // and what not, but I'm going to stick with this method for the
            // moment.  Saying that, it needs tweaking to work nicely for
            // the case when MAX_STATUS_WIDTH != 135...

            if (_showing || _delay > 0)
            {
                // Display the status label.
                statusLabel.Width = statusLabel.Width <= (MAX_STATUS_WIDTH - ANIMATE_DX) ?
                  statusLabel.Width + ANIMATE_DX : MAX_STATUS_WIDTH;
                var margin = statusLabel.Margin;
                margin.Right = statusLabel.Width - MAX_STATUS_WIDTH;
                statusLabel.Margin = margin;
                if (statusLabel.Width == MAX_STATUS_WIDTH && _delay == 0)
                    ((DispatcherTimer)sender).Stop();
            }
            else
            {
                // Hide the status label.
                statusLabel.Width = statusLabel.Width >= ANIMATE_DX ? 
                    statusLabel.Width - ANIMATE_DX : 0;
                var margin = statusLabel.Margin;
                margin.Right = statusLabel.Width - MAX_STATUS_WIDTH;
                statusLabel.Margin = margin;
                if (statusLabel.Width == 0 && _delay == 0)
                    ((DispatcherTimer)sender).Stop();
            }

            if (_delay > 0)
                _delay--;
        }
    }
}