protected override void OnApplyTemplate()
{
base.OnApplyTemplate();
ScrollViewer = this.GetTemplateChild("ScrollViewer") as ScrollViewer;
// NativePanel may not exist if we're using a non-virtualizing ItemsPanel.
if (NativePanel != null)
{
NativePanel.XamlParent = this;
// Propagate the DataContext manually, since ItemsPanelRoot isn't really part of the visual tree
ItemsPanelRoot.SetValue(DataContextProperty, DataContext, DependencyPropertyValuePrecedences.Inheritance);
OnApplyTemplatePartial();
if (ScrollViewer?.Style?.Precedence == DependencyPropertyValuePrecedences.ImplicitStyle)
{
throw new InvalidOperationException($"Performance hit: {this} is using a ScrollViewer in its template with a default style, which would break virtualization. A Style containing {nameof(ListViewBaseScrollContentPresenter)} must be used.");
}
if (ScrollViewer != null)
{
NativePanel.HorizontalScrollBarVisibility = ScrollViewer.HorizontalScrollBarVisibility;
NativePanel.VerticalScrollBarVisibility = ScrollViewer.VerticalScrollBarVisibility;
}
}
else
{
if (ScrollViewer?.Style == Uno.UI.GlobalStaticResources.ListViewBaseScrollViewerStyle)
{
// We're not using NativeListViewBase so we need a 'real' ScrollViewer
ScrollViewer.Style = Uno.UI.GlobalStaticResources.DefaultScrollViewerStyle;
}
}
}
partial void OnApplyTemplatePartial()
{
// NativePanel may not exist if we're using a non-virtualizing ItemsPanel.
if (NativePanel != null)
{
// Propagate the DataContext manually, since ItemsPanelRoot isn't really part of the visual tree
ItemsPanelRoot.SetValue(DataContextProperty, DataContext, DependencyPropertyValuePrecedences.Inheritance);
if (ScrollViewer?.Style == null)
{
throw new InvalidOperationException($"Performance hit: {this} is using a ScrollViewer in its template with a default style, which would break virtualization. A Style containing {nameof(ListViewBaseScrollContentPresenter)} must be used.");
}
if (ScrollViewer != null)
{
NativePanel.HorizontalScrollBarVisibility = ScrollViewer.HorizontalScrollBarVisibility;
NativePanel.VerticalScrollBarVisibility = ScrollViewer.VerticalScrollBarVisibility;
}
}
else
{
if (ScrollViewer?.Style != null && ScrollViewer.Style == ResourceResolver.GetSystemResource <Style>("ListViewBaseScrollViewerStyle")) //TODO: this, too, properly
{
// We're not using NativeListViewBase so we need a 'real' ScrollViewer, remove the internal custom style
ScrollViewer.Style = null;
}
}
}
internal protected override void OnDataContextChanged(DependencyPropertyChangedEventArgs e)
{
base.OnDataContextChanged(e);
// Propagate the DataContext manually, since ItemsPanelRoot isn't really part of the visual tree
ItemsPanelRoot?.SetValue(DataContextProperty, DataContext, DependencyPropertyValuePrecedences.Inheritance);
OnDataContextChangedPartial();
}
/// <summary>
/// Re-size the ListView's Panel when the SplitView is compact so the items
/// will fit within the visible space and correctly display a keyboard focus rect.
/// </summary>
private void OnPaneToggled()
{
if (splitView.IsPaneOpen)
{
ItemsPanelRoot.ClearValue(WidthProperty);
ItemsPanelRoot.ClearValue(HorizontalAlignmentProperty);
}
else if (splitView.DisplayMode == SplitViewDisplayMode.CompactInline || splitView.DisplayMode == SplitViewDisplayMode.CompactOverlay)
{
ItemsPanelRoot.SetValue(WidthProperty, splitView.CompactPaneLength);
ItemsPanelRoot.SetValue(HorizontalAlignmentProperty, HorizontalAlignment.Left);
}
}
/// <summary>
/// Re-size the ListView's Panel when the SplitView is compact so the items
/// will fit within the visible space and correctly display a keyboard focus rect.
/// </summary>
private void OnPaneToggled()
{
if (_splitViewHost.IsPaneOpen)
{
ItemsPanelRoot.ClearValue(FrameworkElement.WidthProperty);
ItemsPanelRoot.ClearValue(FrameworkElement.HorizontalAlignmentProperty);
}
else if (this._splitViewHost.DisplayMode == SplitViewDisplayMode.CompactInline ||
this._splitViewHost.DisplayMode == SplitViewDisplayMode.CompactOverlay)
{
ItemsPanelRoot.SetValue(FrameworkElement.WidthProperty, this._splitViewHost.CompactPaneLength);
ItemsPanelRoot.SetValue(FrameworkElement.HorizontalAlignmentProperty, HorizontalAlignment.Left);
}
}