public void Render(DrawingContext drawingContext, DependencyObject o)
{
Visual visual = o as Visual;
UIElement uiElement = o as UIElement;
int popCount = 0;
if (uiElement != null)
{
TranslateTransform translate = new TranslateTransform(uiElement.VisualOffset);
drawingContext.PushTransform(translate);
++popCount;
if (uiElement.Opacity != 1)
{
drawingContext.PushOpacity(uiElement.Opacity);
++popCount;
}
uiElement.OnRender(drawingContext);
}
if (visual != null)
{
for (int i = 0; i < visual.VisualChildrenCount; ++i)
{
this.Render(drawingContext, visual.GetVisualChild(i));
}
}
for (int i = 0; i < popCount; ++i)
{
drawingContext.Pop();
}
}
/// <summary>
/// Starts the animation.
/// </summary>
/// <param name="from">
/// The control that is being transitioned away from. May be null.
/// </param>
/// <param name="to">
/// The control that is being transitioned to. May be null.
/// </param>
/// <param name="forward">
/// If true, the new page is slid in from the right, or if false from the left.
/// </param>
/// <returns>
/// A <see cref="Task"/> that tracks the progress of the animation.
/// </returns>
public async Task Start(IVisual from, IVisual to, bool forward)
{
var tasks = new List<Task>();
var parent = GetVisualParent(from, to);
var distance = parent.Bounds.Width;
if (from != null)
{
var transform = new TranslateTransform();
from.RenderTransform = transform;
tasks.Add(Animate.Property(
transform,
TranslateTransform.XProperty,
0.0,
forward ? -distance : distance,
LinearEasing.For<double>(),
Duration).ToTask());
}
if (to != null)
{
var transform = new TranslateTransform();
to.RenderTransform = transform;
to.IsVisible = true;
tasks.Add(Animate.Property(
transform,
TranslateTransform.XProperty,
forward ? distance : -distance,
0.0,
LinearEasing.For<double>(),
Duration).ToTask());
}
await Task.WhenAll(tasks.ToArray());
if (from != null)
{
from.IsVisible = false;
}
}