This fixes#511
It allows the virtualenv plugin to call back and tell the airline plugin
to update the statusline. Therefore, the new function
airline#extensions#virtualenv#update() is provided. However, to properly
fix this issue, the virtualenv plugin needs to call this function.
Second, depending on $VIRTUAL_ENV is not safe, since the virtualenv
plugin might define it itsself when calling :VirtualEnvActivate
Therefore skip this test and just test for existance of he
:VirtualEnvList command.
This fixes issue #858
previously, the the on_window_changed() function returned early when the
popupmenu was visible, which also means, that a new preview window
created by the popup menu would not be rendered correctly until one
moves into this window.
Therefore, I made it not return early, even if the popup menu was opened
to make sure, it will be rendered. However, since the popup menu is
open, this might have unwanted consequences, if some plugin or other
function from airline calls some normal mode command (e.g. wordcount
which should not be enabled for preview windows). So this might break
subtile in other areas later.
An alternative might be to just document the fact, that airline won't
color preview windows at all. But I don't like that either.
Prior to this change airline set the function for getting hunks only once,
which works as long as you don't use simlar plugins for different VCS at the
same time.
If that was the case, only one plugin would have won, depending on the first
buffer handled by these plugins. And although the code for the other plugin
was run every time, you would never see the actual line changes, since airline
didn't even bother checking.
Now these plugins can be used side-by-side in the same Vim instance, e.g.
gitgutter for, well, git and signify for the rest.
The difference as per documentation of :statusline
f S Path to the file in the buffer, as typed or relative to current
directory.
F S Full path to the file in the buffer.
