/// <summary>
/// Reacts to a change in a <see cref="PerspexProperty"/> value in order to animate the
/// change if a <see cref="PropertyTransition"/> is set for the property..
/// </summary>
/// <param name="e">The event args.</param>
protected override void OnPropertyChanged(PerspexPropertyChangedEventArgs e)
{
if (e.Priority != BindingPriority.Animation && _propertyTransitions != null)
{
var match = _propertyTransitions.FirstOrDefault(x => x.Property == e.Property);
if (match != null)
{
Animate.Property(this, e.Property, e.OldValue, e.NewValue, match.Easing, match.Duration);
}
}
}
/// <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>
/// <returns>
/// A <see cref="Task"/> that tracks the progress of the animation.
/// </returns>
public async Task Start(IVisual from, IVisual to)
{
var tasks = new List <Task>();
if (to != null)
{
to.Opacity = 0;
}
if (from != null)
{
tasks.Add(Animate.Property(
(IPerspexObject)from,
Visual.OpacityProperty,
from.Opacity,
0,
LinearEasing.For <double>(),
Duration).ToTask());
}
if (to != null)
{
to.Opacity = 0;
to.IsVisible = true;
tasks.Add(Animate.Property(
(IPerspexObject)to,
Visual.OpacityProperty,
0,
1,
LinearEasing.For <double>(),
Duration).ToTask());
}
await Task.WhenAll(tasks.ToArray());
if (from != null)
{
from.IsVisible = false;
from.Opacity = 1;
}
if (to != null)
{
to.Opacity = 1;
}
}
/// <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;
}
}