on
Called whenever the document in the fragment scrolled. Values are expressed in an arbitrary unit and may change with every call. Also maxX and maxY are not guaranteed to remain the same between two calls.
Parameters
curr
Current scroll amount X.
curr
Current scroll amount Y.
max
Maximum scroll amount of the X dimension.
max
Maximum scroll amount of the Y dimension.
extend
Extend of the visible content in the X dimension.
extend
Extend of the visible content in the Y dimension.