private void PrepareToSwitch(IXPage page, IPageAnimation animation, bool isPop)
{
Context.HideKeyboard(this);
CancelCurrentAnimation();
((isPop ? _currentPage.XamarinPage : page.XamarinPage) as IAnimationPage)?.OnAnimationStarted(isPop);
SetNavAnimationInProgress(true);
page.SetUIParams(animation.GetStartUIForAppearingPage(isPop));
_currentPage.SetUIParams(animation.GetStartUIForDisappearingPage(isPop));
}
private Task <bool> SwitchPageAsync(IXPage xPage, bool isPop)
{
Context.HideKeyboard(this);
CancelCurrentAnimation();
ProcessPageAppearing(xPage, isPop);
ProcessPageDisappearing(isPop);
_currentPage = xPage;
return(Task.FromResult(true));
}
protected override Task <bool> OnPushAsync(Page view, bool animated)
{
if (_currentPage == null) // process root page in NavigationStack
{
_currentPage = view.GetXPage();
ProcessPageAppearing(_currentPage, false);
return(Task.FromResult(true));
}
return(SwitchContentAsync(view, AnimationNavigationPage.GetAnimation(view, animated), false));
}
private Task <bool> SwitchAnimationPageAsync(IXPage xPage, IPageAnimation animation, bool isPop)
{
PrepareToSwitch(xPage, animation, isPop);
_tcs = new TaskCompletionSource <bool>();
if (animation.Type == AnimationType.Flip)
{
_currentAnimations.Add(_currentPage.GetDroidAnimation(animation, animation.GetEndUIForDisappearingPage(isPop), () => OnNewPageIsAppearing(xPage, animation, isPop), isPop));
}
else
{
OnNewPageIsAppearing(xPage, animation, isPop);
}
return(_tcs.Task);
}
private void ProcessPageAppearing(IXPage page, bool isPop)
{
if (page.GetParent() != this)
{
page.AddToNavigationRenderer(this);
}
else
{
page.SendAppearing();
}
if (!isPop && page.IsNeedToForceLayout)
{
Element.ForceLayout();
}
page.SetVisibility(ViewStates.Visible);
}
private void OnNewPageIsAppearing(IXPage xPage, IPageAnimation animation, bool isPop)
{
ProcessPageAppearing(xPage, isPop);
var pageForAnimation = animation.Type != AnimationType.Flip && isPop ? _currentPage : xPage;
var paramsForAnimation = animation.GetEndUIParamsWhenNewPageIsAppearing(isPop);
_currentAnimations.Add(pageForAnimation.GetDroidAnimation(animation, paramsForAnimation, () =>
{
((isPop ? _currentPage.XamarinPage : xPage.XamarinPage) as IAnimationPage)?.OnAnimationFinished(isPop);
ProcessPageDisappearing(isPop);
_currentPage = xPage;
_tcs.TrySetResult(true);
}, isPop));
if (animation.Type == AnimationType.Push)
{
var animPage = isPop ? xPage : _currentPage;
var animParams = isPop ? animation.GetEndUIForAppearingPage(isPop) : animation.GetEndUIForDisappearingPage(isPop);
_currentAnimations.Add(animPage.GetDroidAnimation(animation, animParams, null, isPop));
}
}