Q: Is there a function to test whether an element is in front or in
back of another element?
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A: Page 'Elements' are always returned in the order they are painted
(i.e. from back to front). As a result, there is no need for an
explicit function to check Z order of an element (in case you do need
to assign a Z-index to an element you can maintain a counter variable
in the Element extract loop and assign a unique value to each
element).
In case you need to find if two elements overlap, you can check for
intersection between their bounding boxes (element.GetBBox(rect1); ...
res.IntersectRect(rect1, rect2)).