private View GetOrCreateConent(ITabItem tab)
{
if (!(Tabs?.Any() == true && ContentTemplate != null))
{
return(null);
}
View element = null;
if (!(_tabViews.TryGetValue(tab, out element)))
{
var selector = ContentTemplate as DataTemplateSelector;
if (selector != null)
{
var template = selector.SelectTemplate(tab, this);
element = template?.CreateContent() as View;
}
else
{
element = (View)ContentTemplate.CreateContent();
}
if (element == null)
{
throw new InvalidOperationException(
"Could not instantiate content. Please make sure that your ContentTemplate is configured correctly.");
}
_tabViews[tab] = element;
element.BindingContext = tab;
}
return(element);
}
/// <summary>
/// Page is appeared to screen and animation is finished
/// </summary>
public virtual void OnAppeared(AppearEventArgs args)
{
if (IsDebugEnabled)
{
Debug.WriteLine(NavigationBar.GetTitle(this) + ": OnAppeared");
}
LifecycleState = LifecycleStates.Appeared;
if (ContentCreateEvent == ContentCreateEvents.Appeared && ContentTemplate != null && Content is View == false && _contentElement == null)
{
if (_contentElement != null && Children.Contains(_contentElement))
{
Children.Remove(_contentElement);
}
_contentElement = ContentTemplate.CreateContent() as View;
Children.Insert(0, _contentElement);
if (Content != null)
{
_contentElement.BindingContext = Content;
}
}
}
/// <summary>
/// Called when TabItem is appeared on TabView's viewport
/// </summary>
public void OnAppeared(CarouselAppearingArgs args)
{
if (ContentTemplate != null &&
Content is View == false &&
_actualContentElement == null &&
(ContentCreateEvent == ContentCreateEvents.Appeared || (ContentCreateEvent == ContentCreateEvents.ScrollEnded && args.IsScrolling == false)))
{
_actualContentElement = ContentTemplate.CreateContent() as View;
if (Content != null)
{
_actualContentElement.BindingContext = Content;
}
if (ContentCreateEvent == ContentCreateEvents.ScrollEnded && ContentAnimation != null)
{
Animation animation = ContentAnimation.Create(_actualContentElement);
EventHandler eventHandler = null;
eventHandler = (s, e) =>
{
_actualContentElement.SizeChanged -= eventHandler;
Device.BeginInvokeOnMainThread(() =>
{
animation.Commit(this, "ContentCreateAnimationName", 64, (uint)ContentAnimation.Duration);
});
};
_actualContentElement.SizeChanged += eventHandler;
}
Children.Add(_actualContentElement);
ContentCreated?.Invoke(this, new EventArgs());
}
}
/// <summary>
/// Called when properties changes
/// </summary>
protected override void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
if (propertyName == ContentProperty.PropertyName)
{
if (Content is View content)
{
if (_contentElement != null && Children.Contains(_contentElement))
{
Children.Remove(_contentElement);
}
_contentElement = content;
Children.Insert(0, _contentElement);
}
else if (_contentElement != null)
{
_contentElement.BindingContext = Content;
}
}
else if (propertyName == ContentTemplateProperty.PropertyName && ContentCreateEvent == ContentCreateEvents.Appearing)
{
if (ContentTemplate != null && Content is View == false)
{
if (_contentElement != null && Children.Contains(_contentElement))
{
Children.Remove(_contentElement);
}
_contentElement = ContentTemplate.CreateContent() as View;
Children.Insert(0, _contentElement);
if (Content != null)
{
_contentElement.BindingContext = Content;
}
}
}
else if (propertyName == FooterProperty.PropertyName)
{
if (Footer is View footer)
{
if (_footerElement != null && Children.Contains(_footerElement))
{
Children.Remove(_footerElement);
}
_footerElement = footer;
Children.Insert(0, _footerElement);
}
else if (_footerElement != null)
{
_footerElement.BindingContext = Footer;
}
}
else if (propertyName == FooterTemplateProperty.PropertyName)
{
if (FooterTemplate != null && Footer is View == false)
{
if (_footerElement != null && Children.Contains(_footerElement))
{
Children.Remove(_footerElement);
}
_footerElement = ContentTemplate.CreateContent() as View;
Children.Insert(0, _footerElement);
if (Footer != null)
{
_footerElement.BindingContext = Footer;
}
}
}
else
{
base.OnPropertyChanged(propertyName);
}
}
/// <summary>
/// Called when popup IsOpened changes
/// </summary>
private void OnIsOpenChanged(bool oldValue, bool newValue)
{
if (PlacementTarget == null || Content == null)
{
throw new Exception("PlacementTarget is null");
}
if (PopupLayout == null)
{
throw new Exception("PopupLayout is null. Set app popup layout when app start.");
}
this.AbortAnimation(_openingAnimationName);
this.AbortAnimation(_closingAnimationName);
if (newValue)
{
// If actual content is not created
if (_actualContent == null)
{
if (Content is View content)
{
_actualContent = content;
}
else if (ContentTemplate != null)
{
_actualContent = ContentTemplate.CreateContent() as View;
if (Content != null)
{
Binding bind = new Binding("Content");
bind.Source = this;
bind.Mode = BindingMode.OneWay;
_actualContent.SetBinding(View.BindingContextProperty, bind);
}
}
}
if (_popupRootLayout.Content != _actualContent)
{
_popupRootLayout.Content = _actualContent;
}
_openPopups.Add(this);
InitializeForOpeningAnimation();
SetContentLayoutOptions(Placement);
// Create opening animation
_openingAnimationGroup = CreateOpeningAnimation();
if (PopupLayout.Children.Contains(_popupRootLayout) == false)
{
// Add popup to layout
PopupLayout.Children.Add(_popupRootLayout);
}
if (_openingAnimationGroup != null)
{
_openingAnimationGroup.Commit(this, _openingAnimationName, 64, (uint)OpeningAnimation.Duration, Easing.Linear, (double p, bool isAborted) =>
{
AnimationFinished?.Invoke(this, IsOpen);
});
}
else
{
AnimationFinished?.Invoke(this, IsOpen);
}
IsOpenChanged?.Invoke(this, IsOpen);
OnOpened();
}
else
{
_openPopups.Remove(this);
// Create closing animation
_closingAnimationGroup = CreateClosingAnimation();
if (_closingAnimationGroup != null)
{
_closingAnimationGroup.Commit(this, _closingAnimationName, 64, (uint)ClosingAnimation.Duration, Easing.Linear, (arg1, arg2) =>
{
if (arg2 == false)
{
PopupLayout.Children.Remove(_popupRootLayout);
}
AnimationFinished?.Invoke(this, IsOpen);
});
}
else
{
PopupLayout.Children.Remove(_popupRootLayout);
AnimationFinished?.Invoke(this, IsOpen);
}
IsOpenChanged?.Invoke(this, IsOpen);
OnClosed();
}
}