protected override void OnControlAdded (ControlEventArgs e)
{
if (this.Dock == DockStyle.Left || this.Dock == DockStyle.Right)
(e.Control as ToolStrip).LayoutStyle = ToolStripLayoutStyle.VerticalStackWithOverflow;
else
(e.Control as ToolStrip).LayoutStyle = ToolStripLayoutStyle.HorizontalStackWithOverflow;
if (done_first_layout && e.Control is ToolStrip)
this.AddControlToRows (e.Control);
base.OnControlAdded (e);
}