Auto-switch Image Editor image when painting multiple textured Materials

( if this isn't already the case... if it is, ignore...)

I'd like the appropriate image file to be displayed in the Image Editor when I'm painting on a mesh and switch Materials when I ALT+LCLK.

This would eliminate the slow and awkward action of using the menu to switch images.

But only when I ALT+LCLC (or other), I don't want it switching as the brush passes over different Materials.