Photoshop Scripting – Update Progress Bar in a Window

I want to show a progress bar for one of my Photoshop scripts. If I do work inside a button click event then I’m able to update the progress bar without any problems.

For this script, no user interaction is required. I want to: – Show the Window – Update the progress bar as work is done – Close the Window

var win = new Window("dialog{text:'Progress',bounds:[100,100,400,150], bar:Progressbar{bounds:[20,20,280,31] , value:0,maxvalue:100}};");
win.show();

for(...){
    //do work here

    //update progress
    win.bar.value = ...;
}

win.close();

The problem is, win.show(); blocks until the user closes the window. I’ve also tried to add an onClose handler then close the window immediately, but the window does not ever show.

Any ideas on how I could get a progress bar to work?

Answer

The window class dialog is a MODAL dialog and requires you to close it before the execution continues.

Use the class window to create a non-blocking window:

var win = new Window("window{text:'Progress',bounds:[100,100,400,150],bar:Progressbar{bounds:[20,20,280,31] , value:0,maxvalue:100}};");
win.show();

for(...){
    //do work here

    //update progress
    win.bar.value = ...;
}

win.close();

However, you will run into the next problem here. Depending on what you are doing in the loop, photoshop will not update the UI fast enough to see the progress bar moving. This is where I got stuck :/