Layers, in graphic arts programs, give you a way of organizing objects in your documents and controlling their front-to-back stacking order. Illustrator, InDesign, and Photoshop all have layers, and share most basic layer features: you can create, move, hide, and show layers, and you can assign objects to layers. Illustrator and Photoshop have the ability to create layers within layers—“layer sets” or “layer groups.”
As is usual, the scripting model differs among the applications, so I’ll provide a set of wrapper functions that will take the same parameters, regardless of the host application. I’ll put all of the application-specific details inside these functions. I’ll make the functions work for Photoshop layer groups and Illustrator sub-layers, as well as for InDesign’s simpler layers. I don’t want to rebuild each application’s Layers panels, so I’ll provide simple buttons for putting the layer functions through their paces. (It seems to me unlikely that you’ll want to re-create the Layers panel, and more likely that you’ll want to add/assign/move layers without displaying a user interface at all. If I’m dead wrong, please let me know!)
This example is even more basic than the previous one—but I found a number of points that might trip up developers trying to work with layers in their extensions.
You can find the example project here: