Computes a matrix suitable to describe a transformation from this's coordinate system into target
's coordinate system.
The transform can not be computed in certain cases, for example when this and target
do
not share a common ancestor. In that case out_transform
gets set to the identity matrix.
this |
a `GtkWidget` |
target |
the target widget that the matrix will transform to |
out_transform |
location to store the final transformation |
true if the transform could be computed, false otherwise |