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using System;
using Windows.Foundation;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
#if WINDOWS_UWP
namespace Xamarin.Forms.Platform.UWP
#else
namespace Xamarin.Forms.Platform.WinRT
#endif
{
public class ViewToRendererConverter : Windows.UI.Xaml.Data.IValueConverter
{
public object Convert(object value, Type targetType, object parameter, string language)
{
var view = value as View;
if (view == null)
{
var page = value as Page;
if (page != null)
{
IVisualElementRenderer renderer = page.GetOrCreateRenderer();
return renderer.ContainerElement;
}
}
if (view == null)
return null;
return new WrapperControl(view);
}
public object ConvertBack(object value, Type targetType, object parameter, string language)
{
throw new NotSupportedException();
}
class WrapperControl : ContentControl
{
readonly View _view;
public WrapperControl(View view)
{
_view = view;
_view.MeasureInvalidated += (sender, args) => { InvalidateMeasure(); };
IVisualElementRenderer renderer = Platform.CreateRenderer(view);
Platform.SetRenderer(view, renderer);
NotifyWrapperAwareDescendants(view, renderer);
Content = renderer.ContainerElement;
// make sure we re-measure once the template is applied
FrameworkElement frameworkElement = renderer.ContainerElement;
if (frameworkElement != null)
frameworkElement.Loaded += (sender, args) => InvalidateMeasure();
}
protected override Windows.Foundation.Size ArrangeOverride(Windows.Foundation.Size finalSize)
{
_view.IsInNativeLayout = true;
Layout.LayoutChildIntoBoundingRegion(_view, new Rectangle(0, 0, finalSize.Width, finalSize.Height));
_view.IsInNativeLayout = false;
var content = Content as FrameworkElement;
content.Arrange(new Rect(0, 0, finalSize.Width, finalSize.Height));
return finalSize;
}
protected override Windows.Foundation.Size MeasureOverride(Windows.Foundation.Size availableSize)
{
var content = Content as FrameworkElement;
content?.Measure(availableSize);
Size request = _view.Measure(availableSize.Width, availableSize.Height, MeasureFlags.IncludeMargins).Request;
var result = new Windows.Foundation.Size();
if (_view.HorizontalOptions.Alignment == LayoutAlignment.Fill && !double.IsInfinity(availableSize.Width) && availableSize.Width != 0)
{
result = new Windows.Foundation.Size(availableSize.Width, request.Height);
}
else
{
result = new Windows.Foundation.Size(request.Width, request.Height);
}
_view.Layout(new Rectangle(0, 0, result.Width, result.Width));
return result;
}
void NotifyWrapperAwareDescendants(Element currentView, IVisualElementRenderer currentRenderer)
{
// If any of the child renderers need to handle anything differently because they're in
// a wrapper in a list view, let them know that they're being wrapped
var wrapperAwareRenderer = currentRenderer as IWrapperAware;
wrapperAwareRenderer?.NotifyWrapped();
foreach (Element child in currentView.LogicalChildren)
{
var childView = child as View;
if (childView == null)
{
continue;
}
NotifyWrapperAwareDescendants(childView, Platform.GetRenderer(childView));
}
}
}
}
}
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