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using System.Collections.Specialized;
using System.ComponentModel;
using Android.Content;
using Android.Support.V4.View;
using Android.Views;
namespace Xamarin.Forms.Platform.Android.AppCompat
{
public class CarouselPageRenderer : VisualElementRenderer<CarouselPage>, ViewPager.IOnPageChangeListener
{
bool _disposed;
FormsViewPager _viewPager;
public CarouselPageRenderer()
{
AutoPackage = false;
}
void ViewPager.IOnPageChangeListener.OnPageScrolled(int position, float positionOffset, int positionOffsetPixels)
{
}
void ViewPager.IOnPageChangeListener.OnPageScrollStateChanged(int state)
{
}
IPageController PageController => Element as IPageController;
void ViewPager.IOnPageChangeListener.OnPageSelected(int position)
{
Element.CurrentPage = Element.Children[position];
}
protected override void Dispose(bool disposing)
{
if (disposing && !_disposed)
{
_disposed = true;
RemoveAllViews();
foreach (ContentPage pageToRemove in Element.Children)
{
IVisualElementRenderer pageRenderer = Android.Platform.GetRenderer(pageToRemove);
if (pageRenderer != null)
{
pageRenderer.ViewGroup.RemoveFromParent();
pageRenderer.Dispose();
}
pageToRemove.ClearValue(Android.Platform.RendererProperty);
}
if (_viewPager != null)
{
_viewPager.Adapter.Dispose();
_viewPager.Dispose();
_viewPager = null;
}
if (Element != null)
PageController.InternalChildren.CollectionChanged -= OnChildrenCollectionChanged;
}
base.Dispose(disposing);
}
protected override void OnAttachedToWindow()
{
base.OnAttachedToWindow();
PageController.SendAppearing();
}
protected override void OnDetachedFromWindow()
{
base.OnDetachedFromWindow();
PageController.SendDisappearing();
}
protected override void OnElementChanged(ElementChangedEventArgs<CarouselPage> e)
{
base.OnElementChanged(e);
var activity = (FormsAppCompatActivity)Context;
if (e.OldElement != null)
((IPageController)e.OldElement).InternalChildren.CollectionChanged -= OnChildrenCollectionChanged;
if (e.NewElement != null)
{
FormsViewPager pager =
_viewPager =
new FormsViewPager(activity)
{
OverScrollMode = OverScrollMode.Never,
EnableGesture = true,
LayoutParameters = new LayoutParams(LayoutParams.MatchParent, LayoutParams.MatchParent),
Adapter = new FormsFragmentPagerAdapter<ContentPage>(e.NewElement, activity.SupportFragmentManager) { CountOverride = e.NewElement.Children.Count }
};
pager.Id = FormsAppCompatActivity.GetUniqueId();
pager.AddOnPageChangeListener(this);
AddView(pager);
CarouselPage carouselPage = e.NewElement;
if (carouselPage.CurrentPage != null)
ScrollToCurrentPage();
((IPageController)carouselPage).InternalChildren.CollectionChanged += OnChildrenCollectionChanged;
}
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == "CurrentPage")
ScrollToCurrentPage();
}
protected override void OnLayout(bool changed, int l, int t, int r, int b)
{
FormsViewPager pager = _viewPager;
Context context = Context;
int width = r - l;
int height = b - t;
pager.Measure(MeasureSpecFactory.MakeMeasureSpec(width, MeasureSpecMode.AtMost), MeasureSpecFactory.MakeMeasureSpec(height, MeasureSpecMode.AtMost));
if (width > 0 && height > 0)
{
PageController.ContainerArea = new Rectangle(0, 0, context.FromPixels(width), context.FromPixels(height));
pager.Layout(0, 0, width, b);
}
base.OnLayout(changed, l, t, r, b);
}
void OnChildrenCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
FormsViewPager pager = _viewPager;
((FormsFragmentPagerAdapter<ContentPage>)pager.Adapter).CountOverride = Element.Children.Count;
pager.Adapter.NotifyDataSetChanged();
}
void ScrollToCurrentPage()
{
_viewPager.SetCurrentItem(Element.Children.IndexOf(Element.CurrentPage), true);
}
}
}
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