void StartAnimation(DependencyProperty property, TimeSpan beginTime, bool isLast = false)
{
DoubleAnimationUsingKeyFrames d = new DoubleAnimationUsingKeyFrames();
d.KeyFrames.Add(new LinearDoubleKeyFrame(.25d, KeyTime.FromPercent(.10d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(.3d, KeyTime.FromPercent(.15d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(.7d, KeyTime.FromPercent(.85d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(.75d, KeyTime.FromPercent(.90d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(1d, KeyTime.FromPercent(1d)));
d.Duration = TimeSpan.FromSeconds(3);
d.BeginTime = beginTime;
d.FillBehavior = FillBehavior.Stop;
if (isLast)
{
if (this.observedAnimation != null)
{
this.observedAnimation.StopObserving();
}
this.observedAnimation = new AnimationObserver(this, d);
}
this.BeginAnimation(property, null);
this.BeginAnimation(property, d);
}
void StartAnimation(DependencyProperty property, TimeSpan beginTime, bool isLast = false)
{
DoubleAnimationUsingKeyFrames d = new DoubleAnimationUsingKeyFrames();
d.KeyFrames.Add(new LinearDoubleKeyFrame(.25d, KeyTime.FromPercent(.10d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(.3d, KeyTime.FromPercent(.15d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(.7d, KeyTime.FromPercent(.85d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(.75d, KeyTime.FromPercent(.90d)));
d.KeyFrames.Add(new LinearDoubleKeyFrame(1d, KeyTime.FromPercent(1d)));
d.Duration = TimeSpan.FromSeconds(3);
d.BeginTime = beginTime;
d.FillBehavior = FillBehavior.Stop;
if (isLast)
{
if (this.observedAnimation != null)
{
this.observedAnimation.StopObserving();
}
this.observedAnimation = new AnimationObserver(this, d);
}
this.BeginAnimation(property, null);
this.BeginAnimation(property, d);
}
void OnLastAnimationCompleted(AnimationObserver observer)
{
if (observer == this.observedAnimation)
{
this.observedAnimation = null;
StartOrStopAnimations();
}
}
void OnLastAnimationCompleted(AnimationObserver observer)
{
if (observer == this.observedAnimation)
{
this.observedAnimation = null;
StartOrStopAnimations();
}
}
/// <summary>
/// Handles changes to the 'AnimationType' attached property.
/// </summary>
private static void OnAnimationTypePropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
var frameworkElement = sender as FrameworkElement;
if (frameworkElement != null)
{
// If AnimationType is set to True on this framework element,
if (GetAnimationType(frameworkElement) != AnimationType.None)
{
// Add this framework element to hooked list ...
AnimationObserver.MonitorElement(frameworkElement);
}
else
{
// ... otherwise, remove it from the hooked list
AnimationObserver.ReleaseElement(frameworkElement);
}
}
}
/// <summary>
/// Coerce visibility.
/// </summary>
private static object CoerceVisibility(DependencyObject dependencyObject, object baseValue)
{
// Make sure the DependencyObject is a FrameworkElement
var frameworkElement = dependencyObject as FrameworkElement;
if (frameworkElement == null)
{
return(baseValue);
}
// Cast to type safe value
var visibility = (Visibility)baseValue;
// If Visibility value hasn't change, do nothing. This can happen if the Visibility property is set
// using data binding and the binding source has changed but the new visibility value hasn't changed.
if (visibility == frameworkElement.Visibility)
{
return(baseValue);
}
// If element is not hooked by our attached property, stop here
if (AnimationObserver.IsMonitoredElement(frameworkElement) == false)
{
return(baseValue);
}
// If element has IgnoreFirstTime flag set, then ignore the first time the property is coerced.
if (GetIgnoreFirstTime(frameworkElement) == true)
{
SetIgnoreFirstTime(frameworkElement, false);
return(baseValue);
}
// Update animation flag. If animation already started - don't restart it (otherwise, infinite loop)
if (AnimationObserver.ReverseAnimationRunningFlag(frameworkElement) == true)
{
return(baseValue);
}
// If we get here, it means we have to start fade in or fade out animation. In any case return value
// of this method will be Visibility.Visible, to allow the animation.
var doubleAnimation = new DoubleAnimation
{
Duration = new Duration(TimeSpan.FromMilliseconds(GetAnimationDuration(frameworkElement)))
};
// When animation completes, set the visibility value to the requested value (baseValue)
doubleAnimation.Completed += (sender, eventArgs) =>
{
if (visibility == Visibility.Visible)
{
// In case we change into Visibility.Visible, the correct value is already set.
// So just update the animation started flag
AnimationObserver.ReverseAnimationRunningFlag(frameworkElement);
}
else
{
// This will trigger value coercion again but ReverseAnimationRunningFlag() function will
// return true this time, thus animation will not be triggered.
if (BindingOperations.IsDataBound(frameworkElement, UIElement.VisibilityProperty))
{
// Set visiblity using bounded value
var bindingValue = BindingOperations.GetBinding(frameworkElement, UIElement.VisibilityProperty);
if (bindingValue == null)
{
return;
}
BindingOperations.SetBinding(frameworkElement, UIElement.VisibilityProperty, bindingValue);
}
else
{
// No binding, just assign the value
frameworkElement.Visibility = visibility;
}
}
};
doubleAnimation.To = visibility == Visibility.Visible ? 1.0 : 0.0;
// Start animation
frameworkElement.BeginAnimation(UIElement.OpacityProperty, doubleAnimation);
// Make sure the element remains visible during the animation. The original requested value will be
// set in the completed event of the animation
return(Visibility.Visible);
}
