Creates a new javafx.beans.binding.DoubleBinding that contains the element of an javafx.collections.ObservableList at the specified position. The DoubleBinding will hold 0.0 if the index is outside of the ObservableList.

Parameters:

op		the ObservableList
index		the position in the List, converted to int

Returns:  the new DoubleBinding

Exceptions:

NullPointerException

if the ObservableList or index is null

Since:  JavaFX 8.0