protected override void OnPaint(PaintEventArgs pevent) {
// We don't do double-buffering on purpose:
// 1) we'd have to meddle with is_visible, it destroys the buffers if !visible
// 2) We don't draw much, no need to double buffer
base.OnPaint(pevent);
OnDraw (new DrawToolTipEventArgs (pevent.Graphics, associated_control, associated_control, ClientRectangle, this.Text, this.BackColor, this.ForeColor, this.Font));
}