Element(element, target, boundary Elementopt)
element relative to a
The position strategy used is as follows:
If adequate space is available, the element is positioned so the top left corner of the element is adjacent to the bottom left corner of the target.
If there is inadequate vertical space, the element is positioned so that the bottom left corner is adjacent to the top left corner of the target.
If there is inadequate horizontal space, the element is shifted left to fit.
The element to position.
Position relative to this element.
Position to fit within this element.