private static void OnValueChanged(DependencyObject d)
{
AnimatedRadialGauge radialGauge = (AnimatedRadialGauge)d;
if (!double.IsNaN(radialGauge.Value))
{
if (radialGauge.StepSize != 0)
{
radialGauge.Value = radialGauge.RoundToMultiple(radialGauge.Value, radialGauge.StepSize);
}
var middleOfScale = 100 - radialGauge.ScalePadding - (radialGauge.ScaleWidth / 2);
var valueText = radialGauge.GetTemplateChild(ValueTextPartName) as TextBlock;
radialGauge.ValueAngle = radialGauge.ValueToAngle(radialGauge.Value);
// Needle
if (radialGauge._needle != null)
{
radialGauge._needle.RotationAngleInDegrees = (float)radialGauge.ValueAngle;
}
// Trail
var trail = radialGauge.GetTemplateChild(TrailPartName) as Path;
if (trail != null)
{
if (radialGauge.ValueAngle > radialGauge.NormalizedMinAngle)
{
trail.Visibility = Visibility.Visible;
if (radialGauge.ValueAngle - radialGauge.NormalizedMinAngle == 360)
{
// Draw full circle.
var eg = new EllipseGeometry();
eg.Center = new Windows.Foundation.Point(100, 100);
eg.RadiusX = 100 - radialGauge.ScalePadding - (radialGauge.ScaleWidth / 2);
eg.RadiusY = eg.RadiusX;
trail.Data = eg;
}
else
{
// Draw arc.
var pg = new PathGeometry();
var pf = new PathFigure();
pf.IsClosed = false;
pf.StartPoint = radialGauge.ScalePoint(radialGauge.NormalizedMinAngle, middleOfScale);
var seg = new ArcSegment();
seg.SweepDirection = SweepDirection.Clockwise;
seg.IsLargeArc = radialGauge.ValueAngle > (180 + radialGauge.NormalizedMinAngle);
seg.Size = new Size(middleOfScale, middleOfScale);
seg.Point = radialGauge.ScalePoint(Math.Min(radialGauge.ValueAngle, radialGauge.NormalizedMaxAngle), middleOfScale); // On overflow, stop trail at MaxAngle.
pf.Segments.Add(seg);
pg.Figures.Add(pf);
trail.Data = pg;
}
}
else
{
trail.Visibility = Visibility.Collapsed;
}
}
// Value Text
if (valueText != null)
{
valueText.Text = radialGauge.Value.ToString(radialGauge.ValueStringFormat);
}
}
}
