private void AnimationItemIn(ContentPresenter contentPresenter, bool reverse = false, EventHandler onCompleted = null)
{
if (contentPresenter == null || VisualTreeHelper.GetChildrenCount(contentPresenter) != 1)
{
onCompleted?.Invoke(this, EventArgs.Empty);
}
else
{
var controls = contentPresenter.VisualDepthFirstTraversal().OfType <ButtonBase>().Reverse();
var last = controls.Count() - 1;
var sineEase = new SineEase {
EasingMode = EasingMode.EaseOut
};
int translateFrom = 80;
var i = 0;
var zeroKeyTime = KeyTime.FromPercent(0.0);
foreach (var uiElement in controls)
{
if (uiElement != null)
{
var deferredStart = i++ *20;
var deferredEnd = deferredStart + 200.0;
var deferredStartKeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(deferredStart));
var deferredEndKeyTime = KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(deferredEnd));
var elementTranslateFrom = translateFrom * i;
ScaleTransform scaleTransform = null;
TranslateTransform translateTransform = null;
var transformGroup = uiElement.RenderTransform as TransformGroup;
if (transformGroup != null && transformGroup.Children.Count == 2)
{
scaleTransform = transformGroup.Children[0] as ScaleTransform;
translateTransform = transformGroup.Children[1] as TranslateTransform;
}
//Ensure transform created
if (translateTransform == null || scaleTransform == null)
{
scaleTransform = new ScaleTransform(0, 0);
translateTransform = new TranslateTransform {
Y = elementTranslateFrom
};
uiElement.RenderTransform = transformGroup = new TransformGroup()
{
Children = new TransformCollection(new Transform[] { scaleTransform, translateTransform })
};
uiElement.SetCurrentValue(RenderTransformOriginProperty, new Point(.5, .5));
}
//Opacity
var opacityAnimation = new DoubleAnimationUsingKeyFrames();
opacityAnimation.KeyFrames.Add(new EasingDoubleKeyFrame(0, zeroKeyTime, sineEase));
opacityAnimation.KeyFrames.Add(new EasingDoubleKeyFrame(0, deferredStartKeyTime, sineEase));
opacityAnimation.KeyFrames.Add(new EasingDoubleKeyFrame((double)uiElement.GetAnimationBaseValue(OpacityProperty), deferredEndKeyTime, sineEase));
//ScaleX
var scalex = new DoubleAnimationUsingKeyFrames();
scalex.KeyFrames.Add(new EasingDoubleKeyFrame(0, zeroKeyTime, sineEase));
scalex.KeyFrames.Add(new EasingDoubleKeyFrame(0, deferredStartKeyTime, sineEase));
scalex.KeyFrames.Add(new EasingDoubleKeyFrame(1, deferredEndKeyTime, sineEase));
//ScaleY
var scaley = new DoubleAnimationUsingKeyFrames();
scaley.KeyFrames.Add(new EasingDoubleKeyFrame(0, zeroKeyTime, sineEase));
scaley.KeyFrames.Add(new EasingDoubleKeyFrame(0, deferredStartKeyTime, sineEase));
scaley.KeyFrames.Add(new EasingDoubleKeyFrame(1, deferredEndKeyTime, sineEase));
//TranslateY
var translatey = new DoubleAnimationUsingKeyFrames();
translatey.KeyFrames.Add(new EasingDoubleKeyFrame(elementTranslateFrom, zeroKeyTime, sineEase));
translatey.KeyFrames.Add(new EasingDoubleKeyFrame(elementTranslateFrom, deferredStartKeyTime, sineEase));
translatey.KeyFrames.Add(new EasingDoubleKeyFrame(0, deferredEndKeyTime, sineEase));
//Begin animation
Storyboard.SetTargetProperty(opacityAnimation, new PropertyPath("Opacity"));
Storyboard.SetTargetProperty(scalex, new PropertyPath("(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleX)"));
Storyboard.SetTargetProperty(scaley, new PropertyPath("(UIElement.RenderTransform).(TransformGroup.Children)[0].(ScaleTransform.ScaleY)"));
Storyboard.SetTargetProperty(translatey, new PropertyPath("(UIElement.RenderTransform).(TransformGroup.Children)[1].(TranslateTransform.Y)"));
Storyboard.SetTarget(opacityAnimation, uiElement);
Storyboard.SetTarget(scalex, uiElement);
Storyboard.SetTarget(scaley, uiElement);
Storyboard.SetTarget(translatey, uiElement);
//Init storyboard
var storyboard = new Storyboard();
storyboard.Children.Add(opacityAnimation);
storyboard.Children.Add(scalex);
storyboard.Children.Add(scaley);
storyboard.Children.Add(translatey);
//Add handler
if (i == last && onCompleted != null)
{
EventHandler unsubscribe = null;
unsubscribe = (sender, e) =>
{
storyboard.Completed -= unsubscribe;
storyboard.Completed -= onCompleted;
};
storyboard.Completed += onCompleted;
storyboard.Completed += unsubscribe;
}
if (reverse)
{
storyboard.AutoReverse = true;
storyboard.Begin();
storyboard.Seek(TimeSpan.FromMilliseconds(deferredEnd));
storyboard.Resume();
}
else
{
storyboard.Begin();
}
}
}
}
}
