private static void TransformerChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
PathListBoxItemTransformer transformer = (PathListBoxItemTransformer)d;
if (transformer != null && transformer.pathLayoutItem != null && transformer.pathListBox != null)
{
transformer.UpdateTransform();
}
}
private void UpdateTransform()
{
if (this.pathListBox == null)
{
this.pathListBox = PathListBoxItemTransformer.FindAncestor <PathListBox>(this);
if (this.pathListBox == null)
{
return;
}
}
if (this.pathLayoutItem == null)
{
this.pathLayoutItem = PathListBoxItemTransformer.FindAncestor <IPathLayoutItem>(this);
if (this.pathLayoutItem == null)
{
return;
}
this.pathLayoutItem.PathLayoutUpdated += this.IPathLayoutItem_PathLayoutUpdated;
}
double offset = 0;
if (this.UseGlobalOffset)
{
offset = this.pathLayoutItem.GlobalOffset;
}
else
{
offset = this.pathLayoutItem.LocalOffset;
}
offset = (offset + Math.Abs(this.Shift)) % 1;
int zIndex = 0;
int layoutPathIndex = -1;
zIndex = this.pathLayoutItem.LocalIndex;
layoutPathIndex = this.pathLayoutItem.LayoutPathIndex;
// Adjust the offset so that it is normalized over a range of -1 to 1 if falloff from center.
if (this.IsCentered)
{
offset = Math.Abs(PathListBoxItemTransformer.Lerp(-1, 1, (offset + 0.5) % 1.0));
int numItems = this.pathListBox.GetItemsArrangedCount(layoutPathIndex) / 2;
zIndex = (int)Math.Round(offset * numItems);
}
UIElement element = this.pathLayoutItem as UIElement;
if (element != null && Canvas.GetZIndex(element) != zIndex)
{
Canvas.SetZIndex(element, (int)zIndex);
}
// Adjust the offset by the user specified easing function.
if (this.Ease != null)
{
offset = this.Ease.Ease(offset);
}
// Check value before setting it to avoid layout cycle exceptions.
if (this.AdjustedOffset != offset)
{
this.AdjustedOffset = offset;
}
// Use the adjusted offset to interpolate between the user specified start and end for scale and opacity.
double scale = 1;
scale = PathListBoxItemTransformer.Lerp(this.ScaleRange.X, this.ScaleRange.Y, this.AdjustedOffset);
ScaleTransform scaleTransform = (ScaleTransform)this.transformGroup.Children[0];
scaleTransform.ScaleX = scale;
scaleTransform.ScaleY = scale;
double angle = PathListBoxItemTransformer.Lerp(this.AngleRange.X, this.AngleRange.Y, this.AdjustedOffset) + this.pathLayoutItem.OrientationAngle;
RotateTransform rotateTransform = (RotateTransform)this.transformGroup.Children[1];
rotateTransform.Angle = angle;
this.Opacity = PathListBoxItemTransformer.Lerp(this.OpacityRange.X, this.OpacityRange.Y, this.AdjustedOffset);
}
