using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.Threading;
using System.Windows.Forms;
namespace Aga.Controls.Tree.NodeControls{
/// <summary>
/// Displays an animated icon for those nodes, who are in expanding state.
/// Parent TreeView must have AsyncExpanding property set to true.
/// </summary>
public class ExpandingIcon: NodeControl
{
private static GifDecoder _gif = ResourceHelper.LoadingIcon;
private static int _index = 0;
private static volatile Thread _animatingThread;
private static object _lock = new object();
public override Size MeasureSize(TreeNodeAdv node, DrawContext context)
{
return ResourceHelper.LoadingIcon.FrameSize;
}
protected override void OnIsVisibleValueNeeded(NodeControlValueEventArgs args)
{
args.Value = args.Node.IsExpandingNow;
base.OnIsVisibleValueNeeded(args);
}
public override void Draw(TreeNodeAdv node, DrawContext context)
{
Rectangle rect = GetBounds(node, context);
Image img = _gif.GetFrame(_index).Image;
context.Graphics.DrawImage(img, rect.Location);
}
public static void Start()
{
lock (_lock)
{
if (_animatingThread == null)
{
_index = 0;
_animatingThread = new Thread(new ThreadStart(IterateIcons));
_animatingThread.IsBackground = true;
_animatingThread.Priority = ThreadPriority.Lowest;
_animatingThread.Start();
}
}
}
public static void Stop()
{
lock (_lock)
{
_index = 0;
_animatingThread = null;
}
}
private static void IterateIcons()
{
while (_animatingThread != null)
{
if (_index < _gif.FrameCount - 1)
_index++;
else
_index = 0;
if (IconChanged != null)
IconChanged(null, EventArgs.Empty);
int delay = _gif.GetFrame(_index).Delay;
Thread.Sleep(delay);
}
System.Diagnostics.Debug.WriteLine("IterateIcons Stopped");
}
public static event EventHandler IconChanged;
}
}
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