An image view does not “retain” a reference to the image currently being displayed in it. This is unnecessary overhead for the object class, as it’s job is to show the image data… not image files… so keeping track of files is not within it’s scope. This is left to you, the programmer, to add to your code. When you use “load image…” to insert an image into the view, ASS does all of the dirty work of generating image data from the file and preparing it for inserting it into the view for you, something you would have to do a bit more explicitly in obj-c. Once you create an image data object and place it into the view, it’s no longer a file… it’s data. So going back and asking it to tell you what the image file that the data came from is not possible.
You’ll have to use a property variable in your code to retain a reference to the file you’re currently viewing, and use that reference when you need to. Whenever you load (or drop) a file into your image view set your variable to the path… name… or both of the image so you can get at it later.
As far as the matrix question goes, try using the “current row” or “current column” property of the matrix to get the index of the clicked cell. Also, see apple’s control view doc for more explanation and properties.