public WinUINativeDrawingContext(IUIElement uiElement)
{
if (uiElement is not Microsoft.UI.Xaml.UIElement winUIUIElement)
{
throw new InvalidOperationException($"uiElement is of type {uiElement.GetType()}, not of expected type Microsoft.UI.Xaml.UIElement");
}
_compositor = ElementCompositionPreview.GetElementVisual(winUIUIElement).Compositor;
}
/// <summary>
/// Returns a <see cref="Media.Rectangle"/> that represents the layout partition that is reserved for a child element<para></para>
/// It is equivalent to the rectangle returned by the <see cref="IUIElement.RenderTarget"/> property, modified to include eventual padding values
/// </summary>
/// <param name="element">The <see cref="IUIElement"/> instance to compute the layout slot of</param>
/// <returns>A <see cref="Media.Rectangle"/> that represents the layout partition that is reserved for a child element</returns>
public static Media.Rectangle GetLayoutSlot(IUIElement element)
{
IPaddedElement paddedElement;
Media.Point layoutSlotPosition;
Media.Size layoutSlotSize;
Media.Rectangle layoutSlot;
layoutSlotPosition = element.RenderTarget.Position;
layoutSlotSize = element.RenderTarget.Size;
if (typeof(IPaddedElement).IsAssignableFrom(element.GetType()))
{
paddedElement = (IPaddedElement)element;
layoutSlotPosition += new Media.Point(paddedElement.Padding.Left, paddedElement.Padding.Top);
layoutSlotSize = new Media.Size(layoutSlotSize.Width - paddedElement.Padding.Left - paddedElement.Padding.Right, layoutSlotSize.Height - paddedElement.Padding.Top - paddedElement.Padding.Bottom );
}
layoutSlot = new Media.Rectangle(layoutSlotPosition, layoutSlotSize);
return layoutSlot;
}
