Help Me Please :(

Collision detection has to be done in the class of one of the colliding actors. In order to move back off any hit grass, the actor needs to know where it was moved from. Therefore, the setting of the actor's location should also be done in its class. Make your world class act method simply this: Then, in each of the four called methods, use code similar to the following example: Line 4 will prevent the actor from moving onto any grass objects. Finally, remove the 'nabrak_atas' method from the Imun class.

wow this very simple and work. thank you master, one more question, if i want make the button right, left or up like method isKeyDown, you know if button pressed, the actor move but if button not pressed, actor stop. how make that??

That would not be as simple as just replacing the four conditions in the act method because you only would want one direction at a time (you were only able to click on one button at a time as originally coded, so this was not a issue with that). To allow only one direction at a time you need code as follows:

that code for game computer master. Greenfoot.isKeyDown not work to android. i use code mousePressed... how method mousePressed like isKeyDown. :) if i push the button left in game or i pressed the button left in game, that condition same with i push the button left in keyboard. and if i lost the button in game, that condition same with i lost the button left inkeyboard. this mousePressed master :)

I will respond here since you asked for me specifically. Unfortunately, I am not at all familiar with the workings of android to help as far as screen sizing or what compiling program might work for you -- sorry.