Hi!
I don't think there is a good documentation on this, or atleast I haven't found it...
As a rule of thumb:
Most Fields pass the value entered
Most Buttons pass True or False
Most state buttons (radio, checkbox) have an on command (True) and off command (False)
Script Elements pass the script entered.
I made a habit out of just querying the output first whenever I use a UI element I'm not familiar with, this way:
# If one value is passed
#command
lambda x: output(x)
#function
def output(x):
print("Printed: {0}".format(x))
#if no value is passed
#command
outputFree
#function
def outputFree():
print("I ran therefore no args were passed")
#If multiple arguments are passed
#command
lambda *x: multiOutput(*x)
#function
def multiOutput(*args):
print(args)
One of these three will work and tell you what the passed argument was.
I don't do a lot of UI scripting but the UI elements I most often use and therefore wrote down at some point pass the following arguements:
button -> False
symbolButton -> False
iconTextButton -> Nothing is passed
textfield -> tx
intfield -> v
radioButtonGrp -> cc= True, on = True, of = False
radioButton -> cc= True, onc = True, ofc = False
checkBoxGrp -> cc= True, on = True, of = False
checkBox -> cc= True, onc = True, ofc = False
intSlider -> v
colorIndexSliderGrp -> dc = Nothing is passed
scriptTable -> (tableRowIndex, tableColumnIndex, cellValue) (int,int,string)
This list is far from complete ofcourse, but it's a startingpoint at least^^
I hope it helps!