protected virtual void OnChildAdded(VisualElement view)
{
if (_isDisposed)
{
return;
}
var reference = Guid.NewGuid().ToString();
Performance.Start(reference);
if (CompressedLayout.GetIsHeadless(view))
{
var packager = new VisualElementPackager(Renderer, view);
view.IsPlatformEnabled = true;
packager.Load();
}
else
{
var viewRenderer = Platform.CreateRenderer(view);
Platform.SetRenderer(view, viewRenderer);
var uiview = Renderer.NativeView;
uiview.AddSubview(viewRenderer.NativeView);
if (Renderer.ViewController != null && viewRenderer.ViewController != null)
{
Renderer.ViewController.AddChildViewController(viewRenderer.ViewController);
}
EnsureChildrenOrder();
}
Performance.Stop(reference);
}
void AddChild(VisualElement view, IVisualElementRenderer oldRenderer = null, RendererPool pool = null, bool sameChildren = false)
{
var reference = Guid.NewGuid().ToString();
Performance.Start(reference);
if (CompressedLayout.GetIsHeadless(view))
{
var packager = new VisualElementPackager(_renderer, view);
if (_childPackagers == null)
{
_childPackagers = new Dictionary <BindableObject, VisualElementPackager>();
}
view.IsPlatformEnabled = true;
packager.Load();
_childPackagers[view] = packager;
}
else
{
if (_childViews == null)
{
_childViews = new List <IVisualElementRenderer>();
}
IVisualElementRenderer renderer = oldRenderer;
if (pool != null)
{
renderer = pool.GetFreeRenderer(view);
}
if (renderer == null)
{
Performance.Start(reference, "New renderer");
renderer = Platform.CreateRenderer(view, _renderer.View.Context);
Performance.Stop(reference, "New renderer");
}
if (renderer == oldRenderer)
{
Platform.SetRenderer(renderer.Element, null);
renderer.SetElement(view);
}
Performance.Start(reference, "Set renderer");
Platform.SetRenderer(view, renderer);
Performance.Stop(reference, "Set renderer");
Performance.Start(reference, "Add view");
if (!sameChildren)
{
(_renderer.View as ViewGroup)?.AddView(renderer.View);
_childViews.Add(renderer);
}
Performance.Stop(reference, "Add view");
Performance.Stop(reference);
}
}
void AddChild(VisualElement view, IVisualElementRenderer oldRenderer = null, RendererPool pool = null, bool sameChildren = false)
{
Performance.Start();
if (CompressedLayout.GetIsHeadless(view))
{
var packager = new VisualElementPackager(_renderer, view);
view.IsPlatformEnabled = true;
packager.Load();
}
else
{
if (_childViews == null)
{
_childViews = new List <IVisualElementRenderer>();
}
IVisualElementRenderer renderer = oldRenderer;
if (pool != null)
{
renderer = pool.GetFreeRenderer(view);
}
if (renderer == null)
{
Performance.Start("New renderer");
renderer = Platform.CreateRenderer(view);
Performance.Stop("New renderer");
}
if (renderer == oldRenderer)
{
Platform.SetRenderer(renderer.Element, null);
renderer.SetElement(view);
}
Performance.Start("Set renderer");
Platform.SetRenderer(view, renderer);
Performance.Stop("Set renderer");
Performance.Start("Add view");
if (!sameChildren)
{
(_renderer.View as ViewGroup)?.AddView(renderer.View);
_childViews.Add(renderer);
}
Performance.Stop("Add view");
}
Performance.Stop();
}
static double ComputeAbsoluteY(VisualElement e)
{
var parentY = 0.0;
if (e.RealParent is VisualElement ve)
{
if (CompressedLayout.GetIsHeadless(e.RealParent))
{
parentY = ComputeAbsoluteY(ve);
}
else
{
parentY = Forms.ConvertToScaledDP(Platform.GetRenderer(e.RealParent).GetNativeContentGeometry().Y);
}
}
return(e.Y + parentY);
}
static void UpdateLayout(IEnumerable <Element> children)
{
foreach (Element element in children)
{
var visualElement = element as VisualElement;
if (visualElement == null)
{
continue;
}
IVisualElementRenderer renderer = AppCompat.Platform.GetRenderer(visualElement);
if (renderer == null && CompressedLayout.GetIsHeadless(visualElement))
{
UpdateLayout(visualElement.LogicalChildren);
}
renderer?.UpdateLayout();
}
}
protected virtual void AddHeadlessChild(VisualElement element, IContainable <EvasObject> parent)
{
foreach (var child in (element as IVisualTreeElement).GetVisualChildren())
{
if (child is VisualElement visualChild)
{
if (CompressedLayout.GetIsHeadless(visualChild))
{
AddHeadlessChild(visualChild, parent);
visualChild.IsPlatformEnabled = true;
}
else
{
var childRenderer = Platform.GetOrCreateRenderer(visualChild);
parent.Children.Add(childRenderer.NativeView);
}
}
}
}
/// <summary>
/// Adds a new child if it's derived from the VisualElement class. Otherwise this method does nothing.
/// </summary>
/// <param name="child">Child to be added.</param>
protected virtual void AddChild(Element child)
{
if (child is VisualElement ve)
{
if (CompressedLayout.GetIsHeadless(ve) && NativeView is IContainable <EvasObject> containerNativeView)
{
AddHeadlessChild(ve, containerNativeView);
ve.IsPlatformEnabled = true;
}
else
{
var childRenderer = Platform.GetOrCreateRenderer(ve);
// if the native view can have children, attach the new child
if (NativeView is IContainable <EvasObject> containerView)
{
containerView.Children.Add(childRenderer.NativeView);
}
}
}
}
void FillChildrenWithRenderers(VisualElement element)
{
foreach (var logicalChild in ((IElementController)element).LogicalChildren)
{
var child = logicalChild as VisualElement;
if (child != null)
{
if (CompressedLayout.GetIsHeadless(child))
{
child.IsPlatformEnabled = true;
FillChildrenWithRenderers(child);
}
else
{
var renderer = GetFreeRenderer(child) ?? Platform.CreateRenderer(child);
Platform.SetRenderer(child, renderer);
_parent.NativeView.AddSubview(renderer.NativeView);
}
}
}
}
static double ComputeAbsoluteY(VisualElement e)
{
var parentY = 0.0;
if (e.RealParent is VisualElement parent)
{
if (CompressedLayout.GetIsHeadless(e.RealParent))
{
parentY = ComputeAbsoluteY(parent);
}
else
{
if (parent.Handler is IPlatformViewHandler nativeHandler)
{
parentY = nativeHandler.GetPlatformContentGeometry().Y.ToScaledDP();
}
else
{
parentY = Forms.ConvertToScaledDP(Platform.GetRenderer(e.RealParent).GetNativeContentGeometry().Y);
}
}
}
return(e.Y + parentY);
}