How do I use the -exists flag from "window" command? - mel

Question

The maya manual does not describe how -exists flag in window command is used. I tried many ways of using it and it does not budge.
I've been fiddling and googling for 2 days, it wasn't going anywhere. I was only trying to detect if one of my window is opened or not.
Here's the test code I've got so far:
string $something = `window -title "name of the window" -widthHeight 200 150`;
columnLayout -adjustableColumn false;
button -label "detect this window" -command "dothis_1";
showWindow $something;
proc dothis_1()
{
if (`window -ex $something` == true)
{
print "window detected!\n";
}
else
{
print "window detection failed!\n";
}
}
//--------
So...I assumed I did something wrong somewhere or I simply misunderstood what -exists does? What did I do wrong and how do I detect whether my window is opened or not?

Answer 1

Your procedure has a variable scope issue, where it doesn't know what $something is, because it's defined outside of it.
You could make your procedure accept an argument for a window name you want to check against, create your window, then pass its name to the button's command:
string $something = `window -title "name of the window" -widthHeight 200 150`;
columnLayout -adjustableColumn false;
button -label "detect this window" -command ("dothis_1 " + $something); // Pass window name to proc.
showWindow $something;
proc dothis_1(string $win) {
if (`window -ex $win` == true) {
print "window detected!\n";
} else {
print "window detection failed!\n";
}
}
Alternatively you should be able to create a global variable so that it's accessible within the procedure too.
Although your use case is a bit weird. You can only click the button if the window exists!