//sets the orientation of the indicator based on the scale and on the value
private void SetIndicatorAngle(RadialScale scale, double value)
{
double angle = scale.GetAngleFromValue(Value);
if (scale.SweepDirection == SweepDirection.Counterclockwise)
{
angle = -angle;
}
//rotate the needle
TransformGroup tg = RenderTransform as TransformGroup;
if (tg != null)
{
RotateTransform rt = tg.Children[1] as RotateTransform;
if (rt != null)
{
rt.Angle = angle;
// TODO : Commented to avoid a bug
// Debug.WriteLine("angle changed to " + angle);
}
}
}
//sets the indicator geometry based on the scale and the current value
private void SetIndicatorGeometry(RadialScale scale, double value)
{
if (thePath != null)
{
double min = scale.MinAngle;
double max = scale.GetAngleFromValue(Value);
if (scale.SweepDirection == SweepDirection.Counterclockwise)
{
min = -min;
max = -max;
}
double rad = scale.GetIndicatorRadius();
if (rad > BarThickness)
{
Geometry geom = RadialScaleHelper.CreateArcGeometry(min, max, rad, BarThickness, scale.SweepDirection);
//stop the recursive loop. only set a new geometry if it is different from the current one
if (thePath.Data == null || thePath.Data.Bounds != geom.Bounds)
thePath.Data = geom;
}
}
}