Press [enter] to start the game, no error

Question

I am trying to get a function where, when you press enter, you start the game, but it isn't working. There is no error. I have followed a tutorial.

here is my code:

import greenfoot.*;

/**
 * Write a description of class Menu here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class Menu extends World
{

    /**
     * Constructor for objects of class Menu.
     * 
     */
    public Menu()
    {    
        // Create a new world with 600x400 cells with a cell size of 1x1 pixels.
        super(800, 500, 1); 

        prepare();
    }

     public void start()
    {
        {
            if(Greenfoot.isKeyDown("ENTER"))
            {
                MinionWorld MinionWorld= new MinionWorld();
                Greenfoot.setWorld(MinionWorld);
            }
        }
    }

    /**
     * Prepare the world for the start of the program. That is: create the initial
     * objects and add them to the world.
     */
    private void prepare()
    {
        Controls controls = new Controls();
        addObject(controls, 300, 100);
        controls.setLocation(175, 50);
    }
}

You have not provided the dependencies such as `Greenfoot`, `MinionWorld` and `Controls`. — Jagger, Sep 21 '15 at 09:02
Please add "greenfoot" as tags. Also checkout my answer below. — mirmdasif, Sep 21 '15 at 09:10

Pouriya Zarbafian · Answer 1 · 2015-09-21T09:09:44.613

0

Your code check if the Enter button is pressed at the moment it is run. You should use a KeyListener to catch the 'Enter' pressed event. If you are not using a GUI you can just use a Scanner and wait for the user to press Enter:

Scanner scanner = new Scanner(System.in);
scanner.nextLine();

This will wait until the user press Enter.

edited Sep 21 '15 at 09:09

answered Sep 21 '15 at 09:02

Pouriya Zarbafian

506
4
11

I am new at this, so i don't really know what you mean? :) – Julie Iburg Sep 21 '15 at 09:04
Do you use a GUI or only command line, in which case I edited my response. – Pouriya Zarbafian Sep 21 '15 at 09:11
Should i then just add the code about scanner to my world or? shall i also make an actor called Scanner with some other codes in? – Julie Iburg Sep 21 '15 at 09:26

score 0 · Answer 2 · answered Sep 21 '15 at 09:06

0

if(Greenfoot.isKeyDown("ENTER"))

Change this line to

if(Greenfoot.isKeyDown("enter"))

Key name for Enter is "enter" all small-caps.

answered Sep 21 '15 at 09:06

mirmdasif

6,014
2
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28

I think this is the right answer. "enter" is the right string, not "Enter" – TheLostMind Sep 21 '15 at 09:07
I have now changed the line, but it is still not working – Julie Iburg Sep 21 '15 at 09:09
This method checks if Enter is down at the moment it is run. It will not do anything if the user press Enter. – Pouriya Zarbafian Sep 21 '15 at 09:13

score 0 · Answer 3 · answered Sep 21 '15 at 09:56

With your actual code now, what's happening is that when you call start(), it's checking ONCE, at the time you called start() if the user pressed enter.

One thing you can do is to put the code of your start method in a while loop, which will make it checking if the user pressed enter all the time, and when the condition is met, you can break the while loop to end the start method.

Here is an example of code:

public void start()
{
    while(true){
        if(Greenfoot.isKeyDown("ENTER"))
        {
            MinionWorld MinionWorld= new MinionWorld();
            Greenfoot.setWorld(MinionWorld);
            break; // Ends the loop
        }
    }
}

Press [enter] to start the game, no error

3 Answers3