(MEL) how to build UI that list groups and children ?

onionhead_o

Im trying to build a UI for my script that list Groups and children  similar to Outliner. The issue Im having is that I  just needs a list where users can add items to the list. Not a global list that list all the objects in scene.  I search the MEL documentation already but unsure as to which command i should be using.

sprunghunt

you can filter your list by types in the LS command

eg: 
string $listOfTransforms[] = `ls -tr`; //this gets all transforms in the scene
string $listOfTransforms[] = `ls -dag`; //this gets all DAG objects in the scene
string $selectList[] = `ls -as`; // this gets all top level transforms in the scene

https://help.autodesk.com/cloudhelp/2016/ENU/Maya-Tech-Docs/Commands/ls.html

to add to your list you can use appendStringArray()
https://download.autodesk.com/us/maya/2011help/Commands/appendStringArray.html

Deadly Nightshade

You need these components
1) Getting a list of the things you want - such as transforms. See above answer.
2) Create a window
3) Create a layout (columnLayout should be perfectly ok here)
4) Create a UI control for displaying the data. A textScrollList sounds like what you want to use here
5) Loop over the list of things you wanna display and append them to the textScrollList
6) When the user adds a new thing, you do the same: append to the textScrollList
7) For refreshing the UI you want to destroy all children of the textScrollList and then rebuild them. This is how all UI-refreshing code works. Destroy - Rebuild.
(Don't destroy the parent textScrollList)

The official docs have some boilerplate code you can try (bottom): http://download.autodesk.com/us/maya/2009help/commandspython/show.html?textScrollList.html&cat=Windows

You can switch to MEL in the upper right corner.

(And the sooner you can transition to Python from MEL, the better for your sanity. MEL is a garbage language).