Retrieves a Cairo context to be used to draw on the `GdkSurface` of context.
A call to [[email protected]_frame] with this context must have been done or this function will return
null.
The returned context is guaranteed to be valid until [[email protected]_frame] is called.
| this |
a `GdkCairoContext` that is currently drawing |
|
a Cairo context to draw on `GdkSurface |