I'm reading this in two different ways:
1 - when you press your touch controls the actor disappears from the screen 2 - when you press the touch control the actor moves along the x-axis and out of the screen
For the sake of argument I'm going to assume that we're talking about number two.
What you'll need to do is restrict the actors movement to the boundaries of the current screen. You can do this is two ways with Gamesalad
1 - create an invisible barrier for your actor to collide against 2 - use a behaviour to prevent your actor from going beyond the screen boundary
I'll explain both:
1, Invisible barriers What you'll do is create a new actor, and set it to collide with the actor that your controlling. You'll create a few instances of this actor to create a walled area for your actor. Although this works, it's a little cludgy and using additional actors in a scene take a little performance away from your application.
2, using a behaviour In my opinion the better way is to use the given behaviours in Gamesalad itself. To stop the player actor from moving off screen you can use a combination of Rules and the Constrain Attribute behaviour to achieve this.
The first thing to know is your screen size; for an iPad I believe it's 1074 along the x-axis.
So to stop the actor moving off either side of the screen you'll need to do the following:
Open up the player actor the click on the "Create Rule" button on the top right. A new rule window will appear, but default the first dropdown will say "Actor receives event" change this to "Attribute".
Next select the attribute to use the rule against, since we're interested in the x-axis we'll want to query that player attribute which will be:
(also known as self) > Position > X
Select the greater than symbol (">") and then enter the maximum width of the screen minus whatever border value you want, so I'll use 1014 (1024 - 10).
Find and drag the Constrain Attribute behaviour into your rule a set the actors X position to 1014.
This will stop the actor from going beyond one side of the screen, now copy the rule and amend the settings to that if the actor goes less than, say 10, it will constrain the actors X position to 10.
I'd post an image, but alas my Karma isn't large enough right now! Hence the large explanation!
Hope this is what you're looking for!
