Python Hotkey in Maya

Coding
1

I want to create a hotkey using python. Normally I would just put the python or mel code directly into Hotkey editor command panel, but in this case I want to use a list to save names to. Obviously I don’t want to initialize the list every time I push the hotkey. So would think I need some sort of global list.

My first thought would be to make a python module that would be sourced at startup using either the userSetup.py or userSetup.mel and then the hotkey actually just calls a procedure in the module. Is this feasible? Is there a better way to accomplish this?

Thanks

2

Hook up the hotkey to a module.

import pymel.core as pm

pm.nameCommand( 'hotkeyTest', ann='Hotkey Test', c='python("import myScript;myScript.myFuction()")')
pm.hotkey( keyShortcut='a', ctrlModifier=True, name='hotkeyTest')

Not tested it, so not sure it works. To be honest, I am not sure I understand what you want to do either.
So if that doesn’t help you please elaborate what you want to do.

3

yeah I guess I worded that incorrectly. I do not want to create a hotkey using a python script. I want a maya hotkey to use a python script that will contain a list I can keep through out the session. Using a module and initializing it in a startup file seemed like it could work. I was just asking the best way to initialize the list the first time and then the hotkey would save object names to the list as the hotkey is pressed. I was trying to see if using the start-up files in conjunction with the python module was the way to go or if there was a slicker was to do it?

thanks for the reply!

4

I could be wrong, but I believe passing data between invocations of a hotkey will require the use of global variables.

“stuff” is not remembered between hotkey presses.

try making your list a global variable, each time you press the hotkey, it should append to the list.

5

There isn’t a way to save variable data between sessions either what I can remember, you will need to save the list in a file on disk I think.

Edit: Totally forgot about optionVar…

6

you can use an optionVar to save data between maya sessions.

7

you can use optionVar, or you can serialize data to your own file on disk as well. Personally i would serialize the data to my own file instead of cluttering up the optionVar.

8

Within a given session, you can implement memory like this:


Class ToolExample (object):

    ACTIVE = None

    def __init__(self):
         self.name = 'name'
         self.size = 1

    def run(self):
        print "my name is %s and my size is %s" % self.name, self.size"
        self.size += 1

    @classmethod
    def get_active(cls):
        if not cls.ACTIVE:
           cls.ACTIVE = ToolExample()
        return cls.ACTIVE

A runtimeCommand would invoke it like


ToolExample.get_active().run()

If you want to save settings or other state between sessions, you’d have to invent your own way to save or restore the state data; optionVars are good as long as what you want to save is simple:



    def __init__(self):
         saved_name = "name"
         if cmds.optionVar(exists = "ExampleToolName"):
            saved_name = cmds.optionVar(q=ExampleToolName)
         self.name = saved_name
         self.size = 1

You’d probably need to update any optionVars every time you change the command state since you won’t a notification or callback when Maya quits

9

Here is my solution.

you can implement this class somewhere in your scripts directory.


from pymel.util.common import path
import pickle
import pymel.core as pm


class Storage(object):
    def __init__(self):
        self.dumpPath = path('%s/storage.db' % pm.internalVar(usd=True))
        self.data = {}

    def __enter__(self):
        self.data = self.load()
        return self.data

    def __exit__(self, *args):
        self.dump()

    def dump(self):
        with open(self.dumpPath, 'wb') as f:
            pickle.dump(self.data, f)

    def load(self):
        if self.dumpPath.exists():
            with open(self.dumpPath, 'rb') as f:
                return pickle.load(f)
        else:
            self.dump()
            return self.data

Than when you want to persistently store data you can do something like this.


with Storage() as data:
    data['myData'] = [1, 2, 3, 4, 5, 6]

to retrieve said data


with Storage() as data:
    print data['myData']