void CircularGaugeControl_MouseLeftButtonDown(object sender, MouseButtonEventArgs e) {
CircularGaugeControl gauge = sender as CircularGaugeControl;
if(gauge != null) {
CircularGaugeHitInfo hitInfo = gauge.CalcHitInfo(e.GetPosition(gauge));
if(hitInfo.InNeedle)
selectedNeedle = hitInfo.Needle;
}
}
void CircularGaugeControl_MouseMove(object sender, MouseEventArgs e) {
CircularGaugeControl gauge = (CircularGaugeControl)sender;
ArcScaleNeedle currentSelectedNeedle = selectedNeedle != null ? selectedNeedle : gauge.CalcHitInfo(e.GetPosition(gauge)).Needle;
if(currentSelectedNeedle != null)
ShowTooltip(currentSelectedNeedle, this, e.GetPosition(this));
else
HideTooltip();
}
