App.xaml.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace Imperial_Commander_Editor
{
	/// <summary>
	/// Interaction logic for App.xaml
	/// </summary>
	public partial class App : Application
	{
		protected override void OnStartup( StartupEventArgs e )
		{
			// Select the text in a TextBox when it receives focus
			EventManager.RegisterClassHandler( typeof( TextBox ), TextBox.PreviewMouseLeftButtonDownEvent,
					new MouseButtonEventHandler( SelectivelyIgnoreMouseButton ) );
			EventManager.RegisterClassHandler( typeof( TextBox ), TextBox.GotKeyboardFocusEvent,
					new RoutedEventHandler( SelectAllText ) );
			EventManager.RegisterClassHandler( typeof( TextBox ), TextBox.MouseDoubleClickEvent,
					new RoutedEventHandler( SelectAllText ) );
			base.OnStartup( e );
		}

		void SelectivelyIgnoreMouseButton( object sender, MouseButtonEventArgs e )
		{
			// Find the TextBox
			DependencyObject parent = e.OriginalSource as UIElement;
			while ( parent != null && !(parent is TextBox) )
				parent = VisualTreeHelper.GetParent( parent );

			if ( parent != null )
			{
				var textBox = (TextBox)parent;
				if ( !textBox.IsKeyboardFocusWithin )
				{
					// If the text box is not yet focused, give it the focus and
					// stop further processing of this click event
					textBox.Focus();
					e.Handled = true;
				}
			}
		}

		void SelectAllText( object sender, RoutedEventArgs e )
		{
			var textBox = e.OriginalSource as TextBox;
			if ( textBox != null )
				textBox.SelectAll();
		}
	}
}