/// <summary>
/// Returns the information if the given child is rendered at the given position.
/// Panels will check their children in the given render order.
/// Controls, which clip their render output at their boundaries or which hide individual children
/// will check if the given child is shown.
/// Other controls, wich don't clip their children's render output, will simply return the return value
/// of their parent's <see cref="IsChildRenderedAt"/> method with <c>this</c> as argument.
/// </summary>
/// <param name="child">Child to check.</param>
/// <param name="x">Absolute X coordinate to check.</param>
/// <param name="y">Absolute Y coordinate to check.</param>
/// <returns><c>true</c> if the given child of this element is rendered.</returns>
public virtual bool IsChildRenderedAt(UIElement child, float x, float y)
{
UIElement parent = VisualParent as UIElement;
return(parent == null ? true : parent.IsChildRenderedAt(this, x, y));
}
/// <summary>
/// Returns the information if the specified (absolute) coordinates are located in this element's range and
/// this control is visible at the given coords.
/// </summary>
/// <param name="x">Absolute X-coordinate.</param>
/// <param name="y">Absolute Y-coordinate.</param>
/// <returns><c>true</c> if the specified coordinates lay in this element's visible range.</returns>
public virtual bool IsInVisibleArea(float x, float y)
{
UIElement parent = VisualParent as UIElement;
return(IsInArea(x, y) && (parent == null || parent.IsChildRenderedAt(this, x, y)));
}
