There was already an undocumented mechanism provided by
mp.set_key_bindings and other functions, but this was relatively
verbose, and also weird. It was mainly to make the OSC happy (including
being efficient and supporting weird corner cases), while the new
functions try to be a bit simpler.
This also provides a way to let users rebind script-provided commands.
(This mechanism is less efficient, because it's O(n^2) for n added key
bindings, but it shouldn't matter.)
Instead, chain them.
Note that there's no logic to prevent the other event handlers to be run
from an event handler (like it's popular in GUI toolkits), because I
think that's not very useful for this purpose.
This is partial only, and it still accesses some MPContext internals.
Specifically, chapter and track lists are still read directly, and OSD
access is special-cased too.
The OSC seems to work fine, except using the fast-forward/backward
buttons. These buttons behave differently, because the OSC code had
certain assumptions how often its update code is called.
The Lua interface changes slightly.
Note that this has the odd property that Lua script and video start
at the same time, asynchronously. If this becomes an issue, explicit
synchronization could be added.
When the Lua code was written, the core didn't have names for log levels
yet (just numbers). The only user visible change is that "verbose"
becomes "v", since this level had different names.
wm4