What is happening right now?

You could also write it like this in the act method: <Code Omitted>and add the following method to the World subclass: <Code Omitted>

My Animation class can be made to run exactly one cycle of images just by setting a cycle count field. My GifImage vs Animation scenario contains both the Animation class as well as the GifImage class provided by greenfoot and shows the various differences between them. Also, my Animation Support Class scenario demos a single cycle usage. Well, I see that it does 6 cycles (which looks like one visually) because the pattern repeats 6 times.

After moving, check the changed coordinate by comparing it to whatever limit you set for the direction moved. If passed the limit, move the actor back to that limit (using 'setLocation'). For example, to limit movement to the right so the actor does not go off the visible world: <Code Omitted>You can change the '1's to a larger value to put more of the actor in the world. Using 'getImage().getWidth()/2' instead of the '1's will place the actor at the edge and totally visible (no part of the actor passed the edge).