static IYogaLayout YogaLayoutNative(UIView view)
{
var yoga = ObjCRuntime.Runtime.GetNSObject(objc_getAssociatedObject(view.Handle, YogaNodeKey.Handle)) as YogaLayout;
if (yoga == null)
{
yoga = new YogaLayout(view);
objc_setAssociatedObject(view.Handle, YogaNodeKey.Handle, yoga.Handle, AssociationPolicy.RETAIN_NONATOMIC);
}
return(yoga);
}
static bool NodeHasExactSameChildren(YogaNode node, NativeView[] subviews)
{
if (node.Count != subviews.Length)
{
return(false);
}
for (int i = 0; i < subviews.Length; i++)
{
YogaLayout yoga = subviews[i].Yoga() as YogaLayout;
if (node[i] != yoga._node)
{
return(false);
}
}
return(true);
}
static void AttachNodesFromViewHierachy(NativeView view)
{
YogaLayout yoga = view.Yoga() as YogaLayout;
var node = yoga._node;
// Only leaf nodes should have a measure function
if (yoga.IsLeaf)
{
RemoveAllChildren(node);
node.SetMeasureFunction(MeasureView);
}
else
{
node.SetMeasureFunction(null);
// Create a list of all the subviews that we are going to use for layout.
var subviewsToInclude = new List <NativeView>();
foreach (var subview in view.Subviews)
{
if (subview.Yoga().IsIncludeInLayout)
{
subviewsToInclude.Add(subview);
}
}
if (!NodeHasExactSameChildren(node, subviewsToInclude.ToArray()))
{
RemoveAllChildren(node);
for (int i = 0; i < subviewsToInclude.Count; i++)
{
YogaLayout yogaSubview = subviewsToInclude[i].Yoga() as YogaLayout;
node.Insert(i, yogaSubview._node);
}
}
foreach (var subView in subviewsToInclude)
{
AttachNodesFromViewHierachy(subView);
}
}
}
static void ApplyLayoutToViewHierarchy(NativeView view)
{
//TODO : "Framesetting should only be done on the main thread."
YogaLayout yoga = view.Yoga() as YogaLayout;
if (!yoga.IsIncludeInLayout)
{
return;
}
var node = yoga._node;
ApplyLayoutToNativeView(view, node);
if (!yoga.IsLeaf)
{
for (int i = 0; i < view.Subviews.Length; i++)
{
ApplyLayoutToViewHierarchy(view.Subviews[i]);
}
}
}
SizeF CalculateLayoutWithSize(YogaLayout layout, float width, float height)
{
//TODO : Check thread access
if (!layout.IsEnabled)
{
System.Diagnostics.Debug.WriteLine("Doesn't use Yoga");
}
NativeView view = null;
if (_viewRef.TryGetTarget(out view))
{
AttachNodesFromViewHierachy(view);
}
var node = layout._node;
node.CalculateLayout(width, height);
return(new SizeF {
Width = node.LayoutWidth, Height = node.LayoutHeight
});
}