Layout Tree Updates

[Isabella Swift]

I am not able to understand layout tree updates. can someone please help.

I have one DIV and it has 3 children when I add a new child just above the first child in this div then all the older 3 children present in this div will move below in terms of y-position.

So this will cause change in their AbsoluteBoundingBoxRect, which is present in layout object. I wanted to know where wxactly the AbsoluteBoundingBoxRect changes.

As per the flow I have found following functions -

1) StyleEngine::UpdateStyleAndLayoutTree

2) StyleEngine::RebuildLayoutTree

3) Element::RebuildLayoutTree

But in all of these functions the AbsoluteBoundingBoxRect has older values of x,y,width and height. Where can I find the updated values of AbsoluteBoundingBoxRect.

Also does layout change occur node by node ?

Please provide any information that you may have related to layout updates. Thank you.