The function find_focus_successor() is called when destroying a surface to find
a successor to the current focus. It, however, has the following issues:
- Its first parameter is the weston layer from which to search for a successor.
This is an unnecessary flexibility for our use, which only adds complexity to
the user of the function by having to make a call for each layer. We know
that we want to search for a successor first in the normal layer, and if that
fails, then in the inactive layer. So we change the signature of
find_focus_successor(), removing this first parameter.
- It includes logic to decide whether to do the search or not: if the destroyed
surface is different from the surface that currently has focus, and if their
outputs are the same, then abort and don't do the search. This returns NULL to
the calling function. The problem is that the function also returns NULL if
it does the search and finds no successor. The distinction for the failing
reason is lost, and the user of the function needs to add more logic to know
the reason for failure. To simplify, we take the logic out of
find_focus_successor() and inside the caller.
- It returns the successor view, although it receives surfaces and the client
has logic to retrieve the surface corresponding to the returned view. To
simplify and maintain symmetry, we change the signature so that the function
returns the surface corresponding to the successor view.
Fixes: #738
Signed-off-by: Sergio Gómez <sergio.g.delreal@gmail.com>
cc837eea61