/// <summary>
/// Transitions the new <see cref="T:System.Windows.UIElement"/>.
/// </summary>
/// <param name="newTransition">The <see cref="T:Microsoft.Phone.Controls.ITransition"/>
/// for the new <see cref="T:System.Windows.UIElement"/>.</param>
/// <param name="navigationInTransition">The <see cref="T:Microsoft.Phone.Controls.NavigationInTransition"/>
/// for the new <see cref="T:System.Windows.UIElement"/>.</param>
private void TransitionNewContent(ITransition newTransition, TelegramNavigationInTransition navigationInTransition)
{
if (_oldContentPresenter != null)
{
_oldContentPresenter.Visibility = Visibility.Collapsed;
_oldContentPresenter.Content = null;
}
if (null == newTransition)
{
RestoreContentPresenterInteractivity(_newContentPresenter);
return;
}
EnsureStoppedTransition(newTransition);
newTransition.Completed += delegate
{
CompleteTransition(navigationInTransition, _newContentPresenter, newTransition);
};
_readyToTransitionToNewContent = false;
_storedNavigationInTransition = null;
_storedNewTransition = null;
PerformTransition(navigationInTransition, _newContentPresenter, newTransition);
}
/// <summary>
/// Stops the last navigation transition if it's active and a new navigation occurs.
/// </summary>
private void EnsureLastTransitionIsComplete()
{
_readyToTransitionToNewContent = false;
_contentReady = false;
if (_performingExitTransition)
{
Debug.Assert(_storedOldTransition != null && _storedNavigationOutTransition != null);
// If the app calls GoBack on NavigatedTo, we want the old content to be null
// because you can't have the same content in two spots on the visual tree.
if (_oldContentPresenter != null)
{
_oldContentPresenter.Content = null;
}
if (_storedOldTransition != null)
{
_storedOldTransition.Stop();
}
_storedNavigationOutTransition = null;
_storedOldTransition = null;
if (_storedNewTransition != null)
{
_storedNewTransition.Stop();
_storedNewTransition = null;
_storedNavigationInTransition = null;
}
_performingExitTransition = false;
}
}
/// <summary>
/// Handles the completion of the exit transition, automatically
/// continuing to bring in the new element's transition as well if it is
/// ready.
/// </summary>
/// <param name="sender">The source object.</param>
/// <param name="e">The event arguments.</param>
private void OnExitTransitionCompleted(object sender, System.EventArgs e)
{
_readyToTransitionToNewContent = true;
_performingExitTransition = false;
if (_navigationStopped)
{
// Restore the old content presenter's interactivity if the navigation is cancelled.
CompleteTransition(_storedNavigationOutTransition, _oldContentPresenter, _storedOldTransition);
_navigationStopped = false;
}
else
{
CompleteTransition(_storedNavigationOutTransition, /*_oldContentPresenter*/ null, _storedOldTransition);
}
_storedNavigationOutTransition = null;
_storedOldTransition = null;
if (_contentReady)
{
ITransition newTransition = _storedNewTransition;
TelegramNavigationInTransition navigationInTransition = _storedNavigationInTransition;
_storedNewTransition = null;
_storedNavigationInTransition = null;
TransitionNewContent(newTransition, navigationInTransition);
}
}
/// <summary>
/// Sets a
/// <see cref="T:Microsoft.Phone.Controls.NavigationTransition"/>
/// to
/// <see cref="M:Microsoft.Phone.Controls.TransitionService.NavigationInTransitionProperty"/>
/// for a
/// <see cref="T:System.Windows.UIElement"/>.
/// </summary>
/// <param name="element">The <see cref="T:System.Windows.UIElement"/>.</param>
/// <param name="value">The <see cref="T:Microsoft.Phone.Controls.NavigationTransition"/>.</param>
/// <returns>The </returns>
public static void SetNavigationInTransition(UIElement element, TelegramNavigationInTransition value)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
element.SetValue(NavigationInTransitionProperty, value);
}
/// <summary>
/// Called when the value of the
/// <see cref="P:System.Windows.Controls.ContentControl.Content"/>
/// property changes.
/// </summary>
/// <param name="oldContent">The old <see cref="T:System.Object"/>.</param>
/// <param name="newContent">The new <see cref="T:System.Object"/>.</param>
protected override void OnContentChanged(object oldContent, object newContent)
{
base.OnContentChanged(oldContent, newContent);
_contentReady = true;
UIElement oldElement = oldContent as UIElement;
UIElement newElement = newContent as UIElement;
// Require the appropriate template parts plus a new element to
// transition to.
if (_firstContentPresenter == null || _secondContentPresenter == null || newElement == null)
{
return;
}
TelegramNavigationInTransition navigationInTransition = null;
ITransition newTransition = null;
if (newElement != null)
{
navigationInTransition = TelegramTransitionService.GetNavigationInTransition(newElement);
TransitionElement newTransitionElement = null;
if (navigationInTransition != null)
{
newTransitionElement = _isForwardNavigation ? navigationInTransition.Forward : navigationInTransition.Backward;
}
if (newTransitionElement != null)
{
newElement.UpdateLayout();
newTransition = newTransitionElement.GetTransition(newElement);
PrepareContentPresenterForCompositor(_newContentPresenter);
}
}
_newContentPresenter.Opacity = 0;
_newContentPresenter.Visibility = Visibility.Visible;
_newContentPresenter.Content = newElement;
_oldContentPresenter.Opacity = 1;
_oldContentPresenter.Visibility = Visibility.Visible;
_oldContentPresenter.Content = oldElement;
if (_readyToTransitionToNewContent)
{
TransitionNewContent(newTransition, navigationInTransition);
}
else
{
_storedNewTransition = newTransition;
_storedNavigationInTransition = navigationInTransition;
}
}
