// begins an animated self transition
private void _beginAnimatedSelfTransition(Transition transition, Action onComplete) {
InTransition = true;
CoerceValue(ClipToBoundsProperty);
_transitionData = new TransitionEventArgs(TransitionPanel.TransitionStartedEvent, this) {
Bounds = RenderSize,
OldContent = FrontLayer.Content,
NewContent = FrontLayer.Content,
Transition = transition
};
_transitionData.BackSnapshot = _selfTransitionSnapshot;
_transitionData.FrontSnapshot = _captureSnapshot(FrontLayer, true);
_transitionData.OnCompleteCallback = () => {
_onCompleteAnimatedTransition(_transitionData);
if (onComplete != null) onComplete();
};
RaiseEvent(_transitionData);
transition.InvokeBeginTransition(_transitionData);
}
// begins an animated transition
private void _beginAnimatedTransition(Transition transition, Action onComplete) {
// swap the front and back layers (without adding and removing them from the visual tree to avoid superfluous loaded/unloaded events)
_flipLayers = !_flipLayers;
// set the front layer's content
FrontLayer.Content = Content;
FrontLayer.ContentTemplate = ContentTemplate;
FrontLayer.ContentTemplateSelector = ContentTemplateSelector;
// start the transition from back layer to front layer
InTransition = true;
CoerceValue(ClipToBoundsProperty);
_transitionData = new TransitionEventArgs(TransitionPanel.TransitionStartedEvent, this) {
Bounds = RenderSize,
OldContent = BackLayer.Content,
NewContent = FrontLayer.Content,
Transition = transition
};
_transitionData.OnCompleteCallback = () => {
_onCompleteAnimatedTransition(_transitionData);
if (onComplete != null) onComplete();
};
Action invokeTransition = () => {
_transitionData.BackSnapshot = _captureSnapshot(BackLayer, true);
_transitionData.FrontSnapshot = _captureSnapshot(FrontLayer, true);
transition.InvokeBeginTransition(_transitionData);
};
RaiseEvent(_transitionData);
if ((Content is DependencyObject) && GetHasNestedTransitionPanel((DependencyObject)Content)) {
// if content has a nested transition panel, use a timer to allow the nested transition panel to draw its initial state before the
// enclosing transition is started to avoid seeing a blank panel during the transition
var timer = new GuiTimer(DispatcherPriority.Background);
timer.Start(t => invokeTransition());
} else {
invokeTransition();
}
}
