internal override int IndexFromContainerInner(DependencyObject container)
{
if (_isProcessingReorder)
{
// When we process a re-ordering, the "attached" indexes (IndexForItemContainerProperty) are known to be valid,
// but the native (NativePanel) is not (moved item is still at it's original location / index).
return(base.IndexFromContainerInner(container));
}
if (NativePanel != null)
{
var selectorItem = container as SelectorItem;
if (selectorItem == null)
{
return(-1);
}
if (selectorItem.LayoutParameters is RecyclerView.LayoutParams)
{
var displayPosition = NativePanel.GetChildLayoutPosition(selectorItem);
var index = ConvertDisplayPositionToIndex(displayPosition);
return(index);
}
}
return(base.IndexFromContainerInner(container));
}
public void ScrollIntoView(object item, ScrollIntoViewAlignment alignment)
{
var index = IndexFromItem(item);
var displayPosition = ConvertIndexToDisplayPosition(index);
NativePanel?.ScrollIntoView(displayPosition, alignment);
}
private void ReplaceGroup(int groupIndexInView)
{
NativePanel?.ReloadSections(NSIndexSet.FromIndex(groupIndexInView));
if (ManagedVirtualizingPanel != null)
{
Refresh();
}
}
/// <summary>
/// Add a group using the native in-place modifier.
/// </summary>
/// <param name="groupIndexInView">The index of the group from the native collection view's perspective, ie ignoring empty groups
/// if HidesIfEmpty=true.</param>
private void AddGroup(int groupIndexInView)
{
NativePanel?.InsertSections(NSIndexSet.FromIndex(groupIndexInView));
if (ManagedVirtualizingPanel != null)
{
Refresh();
}
}
public void ScrollIntoView(object item, ScrollIntoViewAlignment alignment)
{
// Dispatching ScrollIntoView on Android prevents issues where layout/render changes
// occuring during scrolling are not always properly picked up by the layouting/rendering engine.
Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () =>
{
var index = IndexFromItem(item);
var displayPosition = ConvertIndexToDisplayPosition(index);
NativePanel?.ScrollIntoView(displayPosition, alignment);
});
}
protected internal override IEnumerable <DependencyObject> GetItemsPanelChildren()
{
if (NativePanel != null)
{
return(NativePanel.GetChildren().OfType <DependencyObject>());
}
else
{
return(base.GetItemsPanelChildren());
}
}
private void Refresh()
{
NativePanel?.Refresh();
if (ManagedVirtualizingPanel != null)
{
ManagedVirtualizingPanel.GetLayouter().Refresh();
InvalidateMeasure();
}
}
public void ScrollIntoView(object item)
{
if (NativePanel != null)
{
NativePanel.ScrollIntoView(item);
}
else if (this.Log().IsEnabled(LogLevel.Warning))
{
this.Log().LogWarning($"{nameof(ScrollIntoView)} not supported when using non-virtualizing panels.");
}
}
private protected override void Refresh()
{
base.Refresh();
NativePanel?.Refresh();
if (ManagedVirtualizingPanel != null)
{
ManagedVirtualizingPanel.GetLayouter().Refresh();
InvalidateMeasure();
}
}
internal override DependencyObject ContainerFromIndexInner(int index)
{
if (NativePanel != null)
{
var indexPath = GetIndexPathFromIndex(index)?.ToNSIndexPath();
if (indexPath != null)
{
return(NativePanel.ContainerFromIndex(indexPath));
}
}
return(base.ContainerFromIndexInner(index));
}
internal override int IndexFromContainerInner(DependencyObject container)
{
if (NativePanel != null)
{
var nativeContainer = (container as SelectorItem)?.FindFirstParent <ListViewBaseInternalContainer>();
if (nativeContainer == null)
{
return(-1);
}
var indexPath = NativePanel.IndexPathForCell(nativeContainer);
if (indexPath != null)
{
return(GetIndexFromIndexPath(indexPath.ToIndexPath()));
}
}
return(base.IndexFromContainerInner(container));
}
internal override int IndexFromContainerInner(DependencyObject container)
{
if (NativePanel != null)
{
var selectorItem = container as SelectorItem;
if (selectorItem == null)
{
return(-1);
}
if (selectorItem.LayoutParameters is RecyclerView.LayoutParams)
{
var displayPosition = NativePanel.GetChildLayoutPosition(selectorItem);
var index = ConvertDisplayPositionToIndex(displayPosition);
return(index);
}
}
return(base.IndexFromContainerInner(container));
}
public Rect MakeVisible(UIElement visual, Rect rectangle)
{
if (visual is FrameworkElement fe)
{
var scrollRect = new Rect(
_occludedRectPadding.Left,
_occludedRectPadding.Top,
ActualWidth - _occludedRectPadding.Right,
ActualHeight - _occludedRectPadding.Bottom
);
var visualPoint = UIElement.TransformToVisual(visual, null).TransformPoint(new Point());
var visualRect = new Rect(visualPoint, new Size(fe.ActualWidth, fe.ActualHeight));
var deltaX = Math.Min(visualRect.Left - scrollRect.Left, Math.Max(0, visualRect.Right - scrollRect.Right));
var deltaY = Math.Min(visualRect.Top - scrollRect.Top, Math.Max(0, visualRect.Bottom - scrollRect.Bottom));
NativePanel.SmoothScrollBy(ViewHelper.LogicalToPhysicalPixels(deltaX), ViewHelper.LogicalToPhysicalPixels(deltaY));
}
return(rectangle);
}
partial void OnApplyTemplatePartial()
{
var source = new ListViewBaseSource(NativePanel);
NativePanel.Source = source;
NativePanel.NativeLayout.Source = new WeakReference <ListViewBaseSource>(NativePanel.Source);
BindToPanel(nameof(ItemsSource));
NativePanel.AnimateScrollIntoView = AnimateScrollIntoView;
var disposables = new CompositeDisposable();
Action headerFooterCallback = () => NativePanel?.UpdateHeaderAndFooter();
RegisterCallback(HeaderProperty, headerFooterCallback).DisposeWith(disposables);
RegisterCallback(HeaderTemplateProperty, headerFooterCallback).DisposeWith(disposables);
RegisterCallback(FooterProperty, headerFooterCallback).DisposeWith(disposables);
RegisterCallback(FooterTemplateProperty, headerFooterCallback).DisposeWith(disposables);
_callbackSubscriptions.Disposable = disposables;
}
private protected override void Refresh()
{
base.Refresh();
NativePanel?.Refresh();
}
/// <summary>
/// Add a group using the native in-place modifier.
/// </summary>
/// <param name="groupIndexInView">The index of the group from the native collection view's perspective, ie ignoring empty groups
/// if HidesIfEmpty=true.</param>
private void AddGroup(int groupIndexInView)
{
NativePanel?.InsertSections(NSIndexSet.FromIndex(groupIndexInView));
}
public override void ScrollTo(int x, int y)
{
NativePanel?.ScrollTo(x, y);
}
private void Refresh()
{
NativePanel?.Refresh();
}
void IScrollContentPresenter.SmoothScrollTo(int physicalDeltaX, int physicalDeltaY) => NativePanel?.SmoothScrollTo(physicalDeltaX, physicalDeltaY);
/// <summary>
/// Bind a property on the native collection panel to its equivalent on ListViewBase
/// </summary>
private void BindToPanel(string propertyName, BindingMode bindingMode = BindingMode.OneWay)
{
NativePanel.Binding(propertyName, propertyName, this, bindingMode);
}
private void ReplaceGroup(int groupIndexInView)
{
NativePanel?.ReloadSections(NSIndexSet.FromIndex(groupIndexInView));
}
private void RemoveGroup(int groupIndexInView)
{
NativePanel?.DeleteSections(NSIndexSet.FromIndex(groupIndexInView));
}
public void SmoothScrollTo(int x, int y)
{
NativePanel?.SmoothScrollTo(x, y);
}
public override bool DispatchTouchEvent(MotionEvent e)
{
NativePanel?.TrackMotionDirections(e);
return(base.DispatchTouchEvent(e));
}
private void RemoveItems(int firstItem, int count, int section)
{
NativePanel?.DeleteItems(GetIndexPathsFromStartAndCount(firstItem, count, section));
ManagedVirtualizingPanel?.GetLayouter().RemoveItems(firstItem, count, section);
}
partial void NativeReplaceItems(int firstItem, int count, int section)
{
NativePanel?.ReloadItems(GetIndexPathsFromStartAndCount(firstItem, count, section));
}
private void AddItems(int firstItem, int count, int section)
{
NativePanel?.InsertItems(GetIndexPathsFromStartAndCount(firstItem, count, section));
}
private ContentControl ContainerFromGroupIndex(int groupIndex)
{
return(NativePanel?.ContainerFromGroupIndex(NSIndexPath.FromRowSection(0, groupIndex)));
}
private void RemoveItems(int firstItem, int count, int section)
{
NativePanel?.DeleteItems(GetIndexPathsFromStartAndCount(firstItem, count, section));
}