Java, change boolean from another class

Question

This question is different because it's about creating a 3D world editor.. at the moment I want to get the updated positions of my models to work..

so I've worked my way up to a rather simple problem. In order to update the scene I want to have a boolean look if a specific input was given and then change from false to true once this input was given.. my problem though is that the Input method has to be in another class and I don't know how I can affect the boolean from there.. here's the code:

public class EngineSetup extends Game
{
    public boolean doStuff = true;

    public void Init()
    {   
        CreationTool updateCoords = new CreationTool(this);
        while(doStuff == true) { updateCoords.Environment(); doStuff = false; }
    }
}

This is what happens when the engine starts. It's going to run the Environment method in my CreationTool class only once, because after the first execution doStuff changes to false.

public class CreationTool extends GameComponent
{
    public void Input(float delta)
    {   
        if(Input.GetKeyUp(getCoords))
        // change the boolean value in EngineSetup to true
    }
}

In the CreationTool class I have this Input method and getCoords is just a variable for the enter key.

So the idea is once I hit the enter key the boolean in the EngineSetup class is set to true and the Environment method is being executed once again and the boolean is changed back to false again.

How can I change the boolean value from within the CreationTool class as decribed above?

Thanks a lot for any help!

EDIT: I've gotten some answers but none of them worked..

public class EngineSetup extends Game
{   
    private static EngineSetup INSTANCE;
    public boolean doStuff = true;

    public void Init()
    {    
        INSTANCE = this;
        CreationTool updateCoords = new CreationTool(this);
        while(doStuff == true) { System.out.println("Work"); doStuff = false; }
}

public class CreationTool extends GameComponent
{
    public void Input(float delta)
    {   
        if(Input.GetKeyUp(getCoords))
            { EngineSetup.getInstance().doStuff=true; }
    }
}

It works the first time around when the program starts but when I hit the enter nothing happens.

public class EngineSetup extends Game
{   
    public static boolean doStuff = true;

    public void Init()
    {    
        CreationTool updateCoords = new CreationTool(this);
        while(doStuff == true) { System.out.println("Work"); doStuff = false; }
}

public class CreationTool extends GameComponent
{
    public void Input(float delta)
    {   
        if(Input.GetKeyUp(getCoords))
            EngineSetup.doStuff = true;
    }
}

Also this didn't work, the first time around when the program start everything's fine but when I hit enter: nothing..

How to fix..?

It looks like CreationTool takes an instance of EngineSetup as an argument in its constructor. Why not utilize this to set the boolean? — JamesB, Jul 23 '15 at 22:46
I don't thik this is really a duplicate. The answer there is specialized for that post. I think my answer is more generic and better. — Roberto Anić Banić, Jul 23 '15 at 22:46

score 0 · Answer 1 · answered Jul 24 '15 at 16:10

Okay, I've restructured my code a little and got the booleans to work the way I wanted. I moved the boolean from the EngineSetup class to the CreationTool class, where the Input is and change the booelans from there:

public class EngineInput extends Game
{       
    public void Init()
    {           
        if(CreationTool.doStuff == true) {
        System.out.println("updateVegetation "+CreationTool.doStuff);       
            this.UpdateVegetation(); // method that updates coordinates
        } else
        if(CreationTool.doStuff == false) 
        System.out.println("updateVegetation "+CreationTool.doStuff);           
    }
}

and in my CreationTool class I can affect the boolean:

public class CreationTool extends GameComponent
{   
    public static boolean doStuff = true;

    EngineInput updateVegetation = new EngineInput();

    public void Input(float delta)
    {           
        if(doStuff == true) { if(Input.GetKeyUp(getCoords)) { System.out.println(doStuff); doStuff = false; updateVegetation.UpdateVegetation(); } } else
        if(doStuff == false) { if(Input.GetKeyUp(getCoords)) { System.out.println(doStuff); doStuff = true; updateVegetation.UpdateVegetation(); } }
    }
}

Thanks for your help! The coordinates are now being read from a text file once I hit the enter key, however the updated positions are still only rendered after restarting the program, this is another riddle I need to solve.

score -1 · Answer 2 · answered Jul 23 '15 at 22:42

-1

Ok so let's suppose the EngineSetup class is a Singleton. There will only be 1 object of it created.

You should create a static instance variable, and a get method!

public class EngineSetup extends Game
{
    private static EngineSetup INSTANCE;
    public boolean doStuff = true;

    public void Init()
    {   
        INSTANCE = this;
        CreationTool updateCoords = new CreationTool(this);
        while(doStuff == true) { updateCoords.Environment(); doStuff = false; }
    }

    public static EngineSetup getInstance(){
        return INSTANCE;
    }
}

Now you just need to do this: EngineSetup.getInstance().doStuff=true;

answered Jul 23 '15 at 22:42

Roberto Anić Banić

1,411
10
21

Thanks a lot, I will try it out.. Sure I think EngineSetup is only created once.. as far as understand at least.. – DisasterCoder Jul 23 '15 at 22:48
@DisasterCoder if this solves your problem please mark my answer as correct and upvote if you can! I am currently question banned, so I can only answer XD. – Roberto Anić Banić Jul 23 '15 at 22:50
1

You already have an instance of EngineSetup being passed to CreationTool, just set it as state within CreationTool and set the boolean when required. There is no need for any statics here. – JamesB Jul 23 '15 at 22:51
Did not know that @JamesB, but I still think this is a valid answer. – Roberto Anić Banić Jul 23 '15 at 22:52
Could I know the reason of voting down my answer? DisasterCoder did it not work? And @JamesB with this method he can change it from anywhere – Roberto Anić Banić Jul 23 '15 at 22:58
1

Yes but this can be achieved without using static methods and variables. – JamesB Jul 23 '15 at 23:00
I didn't downVote anything but still your method didn't work for some reason.. I'll edit my answer and include the things that didn't work.. anyone an idea how to find out why I'm unable to change the boolean? – DisasterCoder Jul 23 '15 at 23:01
You do have a point there, but only one question, did you downvote it? @JamesB – Roberto Anić Banić Jul 23 '15 at 23:01
Are votes that important? well I'll give you an up vote if you can solve my problem.. so any ideas? – DisasterCoder Jul 23 '15 at 23:11
I think the problem is not in the code I gave you, could you check if the keypress even registers? – Roberto Anić Banić Jul 23 '15 at 23:27

score -2 · Answer 3 · answered Jul 23 '15 at 22:40

-2

You can make doStuff static (public static boolean doStuff = true;) so that it can be accessed without having an instance of the EngineSetup class.

Then, in your CreationTool.Input(float) method you can say EngineSetup.doStuff = true;.

answered Jul 23 '15 at 22:40

Jashaszun

9,207
3
29
57

@DisasterCoder You tested it with a `println` *where*? Show some code. – Jashaszun Jul 23 '15 at 22:55
I'm going to edit my answer now and show what I tried out but still didn't work.. – DisasterCoder Jul 23 '15 at 23:01

Java, change boolean from another class

3 Answers3