Laborejo/engine/midiinput/stepmidiinput.py

#! /usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Copyright 2022, Nils Hilbricht, Germany ( https://www.hilbricht.net )

This file is part of the Laborejo Software Suite ( https://www.laborejo.org ),
more specifically its template base application.

This application is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
"""

import logging; logging.info("import {}".format(__file__))

#Python Standard Library

#Third Party Modules

#Template Modules
from template.engine.input_midi import MidiInput

#Our Modules
import engine.api as api

"""
This file is used directly. It is a global part of the engine (see bottom of the file)
that uses the api directly, which in turn triggers the GUI.
"""


class StepMidiInput(MidiInput):
    """We initialize with everything switched off. This makes it easier for a complex system
    of engine, GUI and midiinput to start up and get the order of operations right

    For chord entry we use the first note only as indicator. The indicator was a set() at one time,
    which means that as long as one of the chord notes would still be down the chord was still "on".
    That is not as robust and convenient as using the starting note, which is counter intuitive,
    therefore documented here.

    Up until 2022 we used the midi in active toggle just on/off. So the template bypass.
    But now we never switch midi processing off, we just reroute input vs. setting the pitch cursor
    """

    def __init__(self):
        #No super init in here! This is delayed until self.start
        self.firstActiveNote = None #for chord entry.
        self._currentlyActiveNotes = set()
        self.ready = False #Program start
        self.inputitemTrueCursorpitchFalse = False #start with just

    def start(self):
        """Call this manually after the engine and an event loop have started.
        For example from the GUI. It is currently started by mainwindow.py start()
        But it could be started from a simple command line interface as well."""
        assert api.laborejoEngineStarted
        super().__init__(session=api.session, portName="in")
        self.midiProcessor.active = True #never off.
        self.ready = True #Program start

        #Connect the template midi input with Laborejo api calls.
        #self.midiProcessor.notePrinter(True)
        self.midiProcessor.register_NoteOn(self._insertMusicItemFromMidi)
        self.midiProcessor.register_NoteOff(self._pop)

        api.callbacks.setCursor.append(self._setMidiThru) #When the track changes re-route cbox RT midi thru
        api.callbacks._setCursor(destroySelection = False) #Force once to trigger a cursor export which calls our midi thru setter

    @property
    def midiInIsActive(self):
        """
        try:
            return self.midiProcessor.active
        except AttributeError: #during startup
            return False
        """
        return self.inputitemTrueCursorpitchFalse

    def _insertMusicItemFromMidi(self, timeStamp, channel, midipitch, velocity):
        keysig = api.session.data.currentTrack().state.keySignature()
        pitchToInsert = api.pitchmath.fromMidi(midipitch, keysig)
        if self.inputitemTrueCursorpitchFalse:
            if self._currentlyActiveNotes: #Chord
                api.left()
                api.addNoteToChord(pitchToInsert)
                api.right()
            else: #Single note
                baseDuration = api.session.data.cursor.prevailingBaseDuration
                api.insertChord(baseDuration, pitchToInsert)
        else:
            api.session.data.cursor.cursorWasMovedAfterChoosingPitchViaMidi = False
            api.toPitch(pitchToInsert)

        self._currentlyActiveNotes.add(midipitch) #This needs to be at the end of the function for chord-detection to work

    def _pop(self, timeStamp, channel, midipitch, velocity):
        self._currentlyActiveNotes.remove(midipitch)

    def setMidiInputActive(self, state:bool):
        #self.midiProcessor.active = state
        self.inputitemTrueCursorpitchFalse = state
        api.callbacks._prevailingBaseDurationChanged(api.session.data.cursor.prevailingBaseDuration)

    def toggleMidiIn(self):
        #self.setMidiInputActive(not self.midiInIsActive)
        self.setMidiInputActive(not self.inputitemTrueCursorpitchFalse)

    def _setMidiThru(self, cursorExport):
        """We don't need to react to deleted tracks because that does reset the cursor.
        The template midi in does _not_ check if the routed output ports still exist.
        however, that is a low risk state that needs changes in the program"""
        self.setMidiThru(cursorExport["cboxMidiOutUuid"])
        self.setMidiThruChannel(cursorExport["midiChannel"]+1) #cursor midi channel is 0 based

stepMidiInput = StepMidiInput() #global to use in other parts of Laborejo