Loading...
Logo
Processing Forum
Programming Questions
danieljay
danieljay

State Machines

in Programming Questions  •  10 months ago  
So I am trying to put together a state machine, and am running into some difficultly. 

I created a tab in my sketch called "states.java" with the following lines, 

Copy code
  1. public enum states { STATE_1, STATE_2, STATE_3, STATE_4, STATE_5, STATE_6, MAX_STATES };

  3. states state = new states;
Then in my main sketch tab I have the flow like so:

Copy code
  1. switch (state){

  3. case STATE_1 : 
  4. // if this does that, do something
  5. }
  6. state = STATE_2;
  7. break;

  9. case STATE_2: 
  10. // if this does that, do something
  11. }
  12. state = STATE_3;
  13. break;
  14. //etc etc

but I am receiving an error saying "cannot find anything named "state". What am I missing?

Cheers!



Replies(9)

PhiLho
PhiLho

Re: State Machines

10 months ago
There is no "new states", these are kind of constants, not instantiable. Just declare:
states state;
Suggestion: write States instead, to show it is a type of your own, akin to classes.
danieljay
danieljay

Re: State Machines

10 months ago
tried this. I get a NullPointerException error
Chrisir
Chrisir

Re: State Machines

10 months ago


Do you have

Copy code
  1. public enum States { STATE_1, STATE_2, STATE_3, STATE_4, STATE_5, STATE_6, MAX_STATES };

  3. States state ;


Where do you get a NullPointerException error?      

danieljay
danieljay

Re: Re: State Machines

10 months ago
Copy code
  1. public enum States { STATE_1, STATE_2, STATE_3, STATE_4, STATE_5, STATE_6, MAX_STATES };

  3. States state ;

that above approach gives me the error, "cannot find state" in my main tab.
Chrisir
Chrisir

Re: State Machines

10 months ago


I don't use enums, I don't know how it is...

Copy code
  1. // -------------------------------------------
  2. // program
  3. final int statePlay     =0;
  4. final int stateWon      =1;
  5. final int stateDead     =2;
  6. final int statePause    =3;
  7. final int stateStartUp  =4;
  8. final int stateNewLevel =5;
  9. //

  11. int stateOfGame = stateStartUp;

  13. //
  14. // -------------------------------------------
quarks
quarks

Re: State Machines

10 months ago
This works

States.java
Copy code
  1. public enum States { STATE_1, STATE_2, STATE_3, STATE_4, STATE_5, STATE_6, MAX_STATES };

Main sketch tab

Copy code
  1. States state = States.STATE_2;

  3. switch (state) {
  4. case STATE_1 :
  5.   println("STATE 1");
  6.   break;
  7. case STATE_2:
  8.   println("STATE 2");
  9.   break;
  10. case STATE_3:
  11.   println("STATE 3");
  12.   break;
  13. }
Try changing the state in line 1 to prove it works.
danieljay
danieljay

Re: State Machines

10 months ago
Thanks everyone!

I am going with quarks solution which is working great for me!
PhiLho
PhiLho

Re: State Machines

10 months ago
Coming back late, but indeed, you still need to give an initial state. I didn't assign it because I don't know what your logic is, and I thought it was obvious... My bad.
BTW, I hope you are going to give more descriptive names to your states. 
danieljay
danieljay

Re: Re: State Machines

10 months ago
No problem! Thanks for the suggestion. 

Yes, depending on my loops, they should have more descriptive names :)


Top Reply

Statistics

  • 9 Replies
  • 799  Views
  • 1 Followers

Actions

Related Posts