The callback functions are:
print - to be called from generate_text_internal()
iftest - same as print for ifblock objects (triggers jumping)
barval - same as above for bar objects (returns current bar value)
gaugeval - same as above for gauge objects
graphval - same as above for graph objects
percentage - for percentage objects, returns actual percentage
free - called in free_text_objects()
Until conversion is complete, if the function pointer is NULL the old
lookup by type is being done.
Note that it's possible to assign both 'print' and 'iftest' callbacks.
In this case, the code simply ignores the 'iftest' callback, though this
could easily be changed (always calling DO_JUMP at last, of course) in
order to allow ifblock objects to print something in addition to jumping
somewhere (or not).
The decision about whether to print ASCII or X11 bar is done from within
specials.c, so all those #ifdef + if () blocks can be dropped. This also
implicitly enables the ASCII bar for some bar printing objects which where
forgotten before.
In order to make life a bit easier, the struct mpd_s field "volume" has
been renamed to just "vol" to match the object's name (mpd_vol).
Although format_media_player_time() is probably meant to be used by all
supported media players, it's currently being used by mpd only. So for
now this function can reside statically in mpd.c
The IOError happens every time I close conky's normal own window, so I
guess the situation is not as abnormal as abort() indicates. Calling
exit() instead should really suffice and give the process a chance to
clean up (by calling destructor routines for instance).
Murphy hit me again: in my naive attempt to fix the clash between
ifblocks and objects parsing text objects due to the double use of the
'sub' field, I overlooked this problem with reusing the 'special_data'
field. So here comes the real thing (TM), donating ifblocks their own
field for pointing to the jump target.
