/// <summary>
/// Places the control in search mode.
/// </summary>
private void EnterSearchMode()
{
_inSearchMode = true;
BeginUpdate();
_normalSelectedNode = SelectedNode;
// copy normal nodes
_normalNodes.Clear();
_normalNodes.AddRange(Nodes);
// clear and make way for search results
Nodes.Clear();
SelectedNode = null;
EndUpdate();
DropDownControl.ProcessKeys = false;
Cursor = Cursors.IBeam;
}
void _services_TextChanged(object sender, EventArgs e)
{
// cancel any existing search operation
if (_cts != null)
{
_cts.Cancel();
_cts.Dispose();
_cts = null;
}
if (_services.Length > 0)
{
if (!_inSearchMode)
{
EnterSearchMode();
}
if (_services.Length >= MinSearchTermLength)
{
// start async search operation
BeginUpdate();
Nodes.Clear();
Nodes.Add(new ComboTreeNode("Searching...")
{
Selectable = false, FontStyle = FontStyle.Italic
});
EndUpdate();
_cts = new CancellationTokenSource();
ComboTreeNodeCollection results = new ComboTreeNodeCollection(null);
var task = Task.Factory.StartNew(() => OnPerformSearch(new PerformSearchEventArgs(_services.Text, _cts.Token, results)), _cts.Token);
task.ContinueWith(t => {
if (t.IsFaulted)
{
results.Clear();
string errorText = t.Exception.InnerExceptions.Select(x => x.Message).FirstOrDefault() ?? "an error occured";
results.Add(new ComboTreeNode(String.Format("({0})", errorText))
{
Selectable = false, FontStyle = FontStyle.Italic
});
}
if (!t.IsCanceled)
{
ApplySearchResults(results);
}
});
}
else
{
// wait until the search term is long enough
BeginUpdate();
Nodes.Clear();
string msg = String.Format("(type at least {0} characters)", MinSearchTermLength);
Nodes.Add(new ComboTreeNode(msg)
{
Selectable = false, FontStyle = FontStyle.Italic
});
EndUpdate();
}
}
else
{
if (_inSearchMode)
{
LeaveSearchMode(false);
}
}
}