1 files changed, 73 insertions, 0 deletions
diff --git a/blc2/functions/multichaser.py b/blc2/functions/multichaser.py
new file mode 100644
index 0000000..558112e
--- /dev/null
+++ b/blc2/functions/multichaser.py
@@ -0,0 +1,73 @@
+from ..constants import MULTICHASER, ONESHOT
+from .function import Function
+
+class MultiChaser(Function):
+    type = MULTICHASER 
+
+    def __init__(self, w, id_ = None, name = None):
+        super().__init__(w=w, id_=id_, name=name)
+        self._tracks = []
+
+        self._duration = 0
+        self._actual_duration = 0
+        self._scope = frozenset()
+        self._audio_scope = frozenset()
+        self._advance_mode = ONESHOT
+        ## Order is of the format:
+        ##   (track 1 step number, track 2 step number, ... )
+        self._order = []
+
+    @property
+    def audio_scope(self):
+        return self._audio_scope
+
+    @property
+    def scope(self):
+        return self._scope
+
+    @property 
+    def tracks(self):
+        """Return the multichaser's tracks."""
+        return tuple(self._tracks)
+
+    def _recalculate(self, update=True):
+        self._duration = max(0, *(i.duration for i in self._tracks))
+        self._actual_duration = max(0, *(i.actual_duration for i in self._tracks))
+        self._scope = frozenset().union(*(i.scope for i in self._tracks))
+        self._audio_scope = frozenset().union(*(i.audio_scope for i in self._tracks))
+        if update:
+            self.w.function_changed(self)
+
+    @property
+    def duration(self):
+        return self._duration
+
+    @property
+    def actual_duration(self):
+        return self._actual_duration
+
+    def register_track(self, track):
+        """Register a new track. 
+
+        Should only be called in the MultiChaserTrack constructor. 
+        """
+        self._tracks.append(track)
+        self.w.register_function_delete_callback(track, self._track_deleted, self)
+        self.w.register_function_change_callback(track, self._track_changed, self)
+        self._order = [(*i, 0) for i in self._order]
+        self._recalculate()
+
+    def _track_changed(self, _):
+        ## May need to fix up indexes
+        pass
+
+    def _track_deleted(self, track):
+        i = self._tracks.index(track)
+        self._order = 
+        self._tracks.remove(track)
+        self._recalculate()
+
+    def delete(self):
+        for track in self._tracks:
+            track.delete()
+        super().delete()