Latch and Transport Functionality

Hello again Rui,

Wow! You rock! I was able to map my transport controls to the transport menu items and things work. It looks like the mods are permanent (not per session), which is what I want. Funny thing: I was going to suggest that MIDI controls be mappable to any UI element as a general purpose idea, but was afraid to suggest it because I thought it would take too much time to put into the existing code AND YOU DID IT ALREADY!

Now for the bad news: Button releases on the Launchkey still cause the mapped action to turn off. I hacked together a mididings script that swallows CC events with an event value of 0, which results in the action I want:

from mididings       import *
from mididings.event import *

buttonState = [0] * 128;

####################################################################################################
# buttonCtrl:  Toggle outgoing CC event value when the incoming value is non-zero
####################################################################################################
#
# Convert the momentary on/off buttons to mode toggle events when the button press occurs
#

def buttonCtrl (event):
  button = event.ctrl;
  value  = event.value;

  if (value != 0):
    state = buttonState [button] = value if (buttonState [button] == 0) else 0;
    event = CtrlEvent (event.port, event.channel, button, state);
    print (" - Ctrl (%d, %d) => Ctrl (%d, %d)" % (button, value, button, state));
    return event;
  else:
    print (" - Ctrl (%d, %d) => *IGNORED*" % (button, value));
    return None;

####################################################################################################
# midiCtrl:  Route the incoming MIDI messages to the event filter
####################################################################################################

def midiCtrl (event):
  button = event.ctrl;
  if   (button >=  51 and button <=  59):  return (buttonCtrl (event));
  elif (button == 104 or  button == 105):  return (buttonCtrl (event));
  elif (button >= 112 and button <= 117):  return (buttonCtrl (event));
  return event;

run (
  Filter (CTRL) % Process (midiCtrl)
)

But what would be nice is if Qtractor could somehow do this natively. I also looked into the hook function, but I don't think it does what I want. Perhaps I'm being daft.

Hope I'm not being a pain about this.

Bruce

Hi again Rui,

Thanks for your responses. I was able to use the Hook option successfully with the sliders/faders on the Launchkey, which is exactly what I wanted out those buggers. I'm still a little unclear about how latch works, but no matter, the mididings script fixes things up quite nicely for me.

As I mentioned before, and after having even *more* time to think about it, I think integrating mididings into Qtractor would be a really nice feature. Here's my proposal: How about adding a "Run mididings script" options to the General tab of the View/Options menu? If a file is specified, and it exists, spawn a mididings process using QProcess. I'm not sure if I would rather have the user connect the mididings output to the Qtractor input via Qjackctl, or have it done automagically (I'm leaning more toward having the user perform the connections). What's nice about this is that mididings can be used a shim between various pieces of hardware and Qtractor and probably saves you some time in the long run: "Hey Rui, I have a SoundBlaster 3000 combination MIDI controller/latte machine and can't get button XYZ to work. Fix it!"

If it's OK with you, I'd like to open a feature request ticket on GitHub just so that we have a record of the request. And again, I'm willing to help with coding.

I hope you and your family had a wonderful Christmas, and I wish you a Happy New Year.

Bruce