try to fix looping. not there yet

engine/api.py

@@ -200,9 +200,39 @@ def startEngine(nsmClient):
     for track in session.data.tracks:
         callbacks._trackMetaDataChanged(track) #for colors, scale and simpleNoteNames
 
-    session.data.buildAllTracks()
+    session.data.buildAllTracks(buildSongDuration=True) #will set to max track length, we always have a song duration.
+
+    updatePlayback()
+
+
+def _loopOff():
+    session.data.buildSongDuration() #no parameter removes the loop
+    updatePlayback()
+    session.inLoopMode = None
+    callbacks._loopChanged(None, None, None)    
+
+def _loopNow():
+    now = cbox.Transport.status().pos_ppqn
+    _setLoop(now)
+
+def _setLoop(loopMeasureAroundPpqn):
+    if loopMeasureAroundPpqn < 0:
+        _loopOff()
+        return
+    
+    loopStart, loopEnd = session.data.buildSongDuration(loopMeasureAroundPpqn)
 
     updatePlayback()
+    session.inLoopMode = (loopStart, loopEnd)
+
+    assert loopStart <= loopMeasureAroundPpqn < loopEnd
+    if not playbackStatus():
+        cbox.Transport.play()
+
+    oneMeasureInTicks = (session.data.howManyUnits * session.data.whatTypeOfUnit) / session.data.subdivisions
+
+    measurenumber, rest = divmod(loopStart, oneMeasureInTicks)
+    callbacks._loopChanged(int(measurenumber), loopStart, loopEnd)
 
 def toggleLoop():
     """Plays the current measure as loop.
@@ -211,26 +241,9 @@ def toggleLoop():
     session.inLoopMode is a tuple (start, end)
     """
     if session.inLoopMode:
-        session.data.buildSongDuration() #no parameter removes the loop
-        updatePlayback()
-        session.inLoopMode = None
-        callbacks._loopChanged(None, None, None)
+        _loopOff()
     else:
-        now = loopMeasureAroundPpqn=cbox.Transport.status().pos_ppqn
-        loopStart, loopEnd = session.data.buildSongDuration(now)
-
-        updatePlayback()
-        session.inLoopMode = (loopStart, loopEnd)
-
-        assert loopStart <= now < loopEnd
-        if not playbackStatus():
-            cbox.Transport.play()
-
-        oneMeasureInTicks = (session.data.howManyUnits * session.data.whatTypeOfUnit) / session.data.subdivisions
-
-        measurenumber, rest = divmod(loopStart, oneMeasureInTicks)
-        callbacks._loopChanged(int(measurenumber), loopStart, loopEnd)
-
+        _loopNow()
 
 def seek(value):
     """override template one, which does not have a loop"""
@@ -262,6 +275,8 @@ def set_whatTypeOfUnit(ticks):
     if session.data.whatTypeOfUnit == ticks: return    
     session.data.whatTypeOfUnit = ticks
     session.data.buildAllTracks()
+    if session.inLoopMode:
+        _loopNow()
     updatePlayback()
     callbacks._timeSignatureChanged()
 
@@ -270,6 +285,8 @@ def set_howManyUnits(value):
     if session.data.howManyUnits == value: return        
     session.data.howManyUnits = value
     session.data.buildAllTracks()
+    if session.inLoopMode:
+        _loopNow()
     updatePlayback()
     callbacks._timeSignatureChanged()
     
@@ -278,6 +295,8 @@ def set_subdivisions(value):
     if session.data.subdivisions == value: return
     session.data.subdivisions = value
     session.data.buildAllTracks()
+    if session.inLoopMode:
+        _loopNow()
     updatePlayback()
     callbacks._subdivisionsChanged()
 
@@ -293,6 +312,8 @@ def convert_subdivisions(value, errorHandling):
             callbacks._patternChanged(tr)
     else:
         callbacks._subdivisionsChanged() #to reset the GUI value back to the working one.
+    if session.inLoopMode:
+        _loopNow()
     return result
 
 def set_numberOfMeasures(value):

engine/main.py

@@ -149,15 +149,22 @@ class Data(template.engine.sequencer.Score):
         return True
 
 
-    def buildAllTracks(self):
-        """Includes all patterns.
-        This still needs to be followed by buildSongDuration. Explicit is better than implicit."""
+    def buildAllTracks(self, buildSongDuration=False):
+        """Includes all patterns.        
+
+        buildSongDuration is True at least once in the programs life time, on startup.
+        If True it will reset the loop.  The api calls buildSongDuration directly when it sets
+        the loop.
+        """
         for track in self.tracks:
             track.pattern.buildExportCache()
             track.buildTrack()
-        self.buildSongDuration()
+        if buildSongDuration:
+            self.buildSongDuration()
 
     def buildSongDuration(self, loopMeasureAroundPpqn=None):
+        """Loop does not reset automatically. We keep it until explicitely changed.
+        If we do not have a loop the song duration is already maxTrackDuration, no update needed."""
         oneMeasureInTicks = (self.howManyUnits * self.whatTypeOfUnit) / self.subdivisions
         oneMeasureInTicks = int(oneMeasureInTicks)
         maxTrackDuration = self.numberOfMeasures * oneMeasureInTicks