src/mxmMidi/experimental/MidiOutStreamBase.py

   1 class MidiOutStreamBase:
   2
   3
   4     """
   5
   6     MidiOutStreamBase is Basically an eventhandler. It is the most central
   7     class in the Midi library. You use it both for writing events to
   8     an output stream, and as an event handler for an input stream.
   9
  10     This makes it extremely easy to take input from one stream and
  11     send it to another. Ie. if you want to read a Midi file, do some
  12     processing, and send it to a midiport.
  13
  14     All time values are in absolute values from the opening of a
  15     stream. To calculate time values, please use the MidiTime and
  16     MidiDeltaTime classes.
  17
  18     """
  19
  20     def __init__(self):
  21
  22         # the time is rather global, so it needs to be stored
  23         # here. Otherwise there would be no really simple way to
  24         # calculate it. The alternative would be to have each event
  25         # handler do it. That sucks even worse!
  26         self._absolute_time = 0
  27         self._relative_time = 0
  28         self._current_track = 0
  29
  30     # time handling event handlers. They should overwritten with care
  31
  32     def update_time(self, new_time=0, relative=1):
  33         """
  34         Updates the time, if relative is true, new_time is relative,
  35         else it's absolute.
  36         """
  37         if relative:
  38             self._relative_time = new_time
  39             self._absolute_time += new_time
  40         else:
  41             self._absolute_time = new_time
  42             self._relative_time = new_time - self._absolute_time
  43
  44     def rel_time(self):
  45         "Returns the relative time"
  46         return self._relative_time
  47
  48     def abs_time(self):
  49         "Returns the absolute time"
  50         return self._absolute_time
  51
  52     # track handling event handlers
  53
  54     def set_current_track(self, new_track):
  55         "Sets the current track number"
  56         self._current_track = new_track
  57
  58     def get_current_track(self):
  59         "Returns the current track number"
  60         return self._current_track
  61
  62
  63     #####################
  64     ## Midi events
  65
  66
  67     def channel_message(self, message_type, channel, data):
  68         """The default event handler for channel messages"""
  69         pass
  70
  71
  72     #####################
  73     ## Common events
  74
  75     def system_exclusive(self, data):
  76
  77         """The default event handler for system_exclusive messages"""
  78         pass
  79
  80
  81     def system_common(self, common_type, common_data):
  82
  83         """The default event handler for system common messages"""
  84         pass
  85
  86
  87     #########################
  88     # header does not really belong here. But anyhoo!!!
  89
  90     def header(self, format, nTracks, division):
  91
  92         """
  93         format: type of midi file in [1,2]
  94         nTracks: number of tracks
  95         division: timing division
  96         """
  97         pass
  98
  99
 100     def start_of_track(self, n_track=0):
 101
 102         """
 103         n_track: number of track
 104         """
 105         pass
 106
 107
 108     def eof(self):
 109
 110         """
 111         End of file. No more events to be processed.
 112         """
 113         pass
 114
 115
 116     #####################
 117     ## meta events
 118
 119
 120     def meta_event(self, meta_type, data, time):
 121
 122         """The default event handler for meta_events"""
 123         pass
 124
 125
 126
 127
 128 if __name__ == '__main__':
 129
 130     midiOut = MidiOutStreamBase()
 131     midiOut.update_time(0,0)
 132     midiOut.note_on(0, 63, 127)
 133     midiOut.note_off(0, 63, 127)
 134
 135