mGui Window testing from within a class

Coding
1

I’m adapting some UI classes to mGui -which is wonderful - and I’m bumping up against the old “how do I test if the window exists?” issue.
The mGui docs have this idiom:

if my_window:
    my_window.show()
else:
    my_window = Window(....)
    my_window.show()

but how does this work when my_window is scoped into a class?

import pymel.core as pm
from mGui.gui import *
from mGui.forms import *

class UI(object):

    def __init__(self, data=None):
        self.window = None

    def create_window(self):
        # create
        with Window('UI') as window:
            with FooterForm() as main:
                with VerticalForm() as form:
                    text = Text("hello")
                with HorizontalStretchForm() as footer:
                    btn_1 = Button('command')

        window.main.footer.btn_1.command += self.test
        return window

    def test(self, *args, **kwargs):
        print "{}, {}".format(args,kwargs)

    def run(self):
    
    	# is pm.window the best way here?
        if pm.window('UI',query=True, exists=True):
            pm.deleteUI('UI')

        if not self.window:
            self.window = self.create_window()
        self.window.show()

ui=UI()
ui.run()

The pm.window('UI',query=True, exists=True): test feels clunky, but the mGui Window() class doesn’t seem to work like that. Does mGui have a more elegant solution? Is there a better approach?

2

Couldn’t you just do:

if self.window:
    cmds.deleteUI(self.window)
self._window = self.create_window()

I think that is vaguely how I handled it in the past. I’d need to go digging through some of my code at home to be sure though.

3

that did not seem to work for me.
It causes the RuntimeError Object's name 'UI' is not unique. # if you run() with the window already created.

the class instance doesn’t seem to know about windows outside of itself, without querying via pm.window()

4

Oh yeah good catch.
Also I totally forgot to look into how I was handling this. Hopefully I remember tonight.
Now that I’m actually thinking about it.
Odds are good that I probably set the name somewhere and did an cmds.window(self._name, exist=True) check.

I might have gotten crazy and did if Window.wrap('UI'): check to stay more in the universe of mGui.

5

I generally don’t bother with naming windows at all, that way I don’t have to worry about accidental name collisions. What happens if you just don’t name the window explictly?

6

My UI scripts typically get called this way:

ui = UI()
ui.run()

Without the name & pm.window() query, I get multiple windows as I test.
Makes sense, as I’m creating a new instance of the class each time,
and one instance won’t know about another’s .window attribute.

Instead of looking inside my window class for a solutions,
What’s needed is to test if an instance of the UI Class itself already exists:

if not ui:
    ui = UI()
ui.run()

And then all work as advertised. Pretty Obvious, just needed to think it through.

PS mGui is wonderful, thanks to both of you for your efforts

7

You could tweak the truth-test of the UI class:

     class UI(Object):
            
            ....

           def __nonzero__(self):
                 return bool(self.window)