using System.Windows;
using System.Windows.Input;
using System.Windows.Interactivity;

namespace ExtraBehaviors
{
  /// <summary>
  /// The BubbleScrollEvent behavior can be used to prevent the mousewheel scrolling on a scrollable control.
  /// The event will be bubble up to the parent control.
  /// This behavior can be prevent with the left Shift key.
  /// </summary>
  public class BubbleScrollEvent : Behavior<UIElement>
  {
    protected override void OnAttached() {
      base.OnAttached();
      this.AssociatedObject.PreviewMouseWheel -= this.AssociatedObject_PreviewMouseWheel;
      this.AssociatedObject.PreviewMouseWheel += this.AssociatedObject_PreviewMouseWheel;
    }

    protected override void OnDetaching() {
      this.AssociatedObject.PreviewMouseWheel -= this.AssociatedObject_PreviewMouseWheel;
      base.OnDetaching();
    }

    void AssociatedObject_PreviewMouseWheel(object sender, MouseWheelEventArgs e) {
      if (!Keyboard.IsKeyDown(Key.LeftShift)) {
        e.Handled = true;
        var e2 = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta) {RoutedEvent = UIElement.MouseWheelEvent};
        this.AssociatedObject.RaiseEvent(e2);
      }
    }
  }
}