SynthWeaver
SynthWeaver

Reputation: 21

Player sprite won't move in Java 2D game (repaint)

I am new to Java and I am trying to make a simple game for fun. I first tried to put repaint into paintComponent(), it worked until I tried to add some background. Does anyone know how to let my player move with or without 'repaint'?

Screen class

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

class Frame extends JFrame implements KeyListener
{
Map map;

public static void main(String[] args)
{
    Frame frame = new Frame();
    frame.addKeyListener(new Frame());
    frame.setVisible(true);
}

public Frame()
{
    setInit();
}

private void setInit()
{
    map = new Map();
    add(map);

    setSize(800, 800);//frame size 300 width and 300 height
    setTitle("Eerste Game");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setLocationRelativeTo(null);

    setResizable(false);
    setLayout(new GridLayout(1,1,0,0));
    setFocusable(true);
    setVisible(true);
}

public void keyPressed(KeyEvent e) {
    int keyCode = e.getKeyCode();

    map.movePlayer(keyCode);
}

public void keyReleased(KeyEvent e)
{

}

public void keyTyped(KeyEvent e)
{

}
}  

Map class

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;

class Map extends JPanel
{
   Player player;
   BufferedImage map;

    public Map() {
        player = new Player();
        try{map = ImageIO.read(new File("img/map.png"));}catch (Exception e){};
    }

    public void movePlayer(int keyPressed)
    {
        player.move(keyPressed);
        revalidate();
        repaint();
    }

    @Override
    public void paintComponent(Graphics g)
    {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.drawImage(player.img,player.getX(),player.getY(), null);
    }

}

Player class

import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;

class Player
{
    BufferedImage img = null;
    private int x = 100;
    private int y = 100;

    public Player()
    {
        try{img = ImageIO.read(new File("img/bob.png"));}catch (Exception e){}
    }

    public int getX()
    {
        return x;
    }

    public int getY()
    {
        return y;
    }

    public void move(int keyPressed)
    {
        if(keyPressed == KeyEvent.VK_W) {
            // handle up
            y = y - 5;
        }
        if (keyPressed == KeyEvent.VK_A) {
            // handle links
            x = x - 5;
        }
        if (keyPressed == KeyEvent.VK_S) {
            // handle onder
            y = y + 5;
        }
        if (keyPressed == KeyEvent.VK_D ) {
            // handle right
            x = x + 5;
        }

    }
}

Upvotes: 1

Views: 261

Answers (2)

Zoe - Save the data dump
Zoe - Save the data dump

Reputation: 28238

You do:

frame.addKeyListener(new Frame());

Which creates a new frame instead of adding the current frame as the Listener.

So you change it tO

 frame.addKeyListener(frame);

Upvotes: 0

Hovercraft Full Of Eels
Hovercraft Full Of Eels

Reputation: 285405

You're unnecessarily creating a new Frame object as the KeyListener, and so the KeyListener events all go to a different Frame instance, not the one being shown. Change

frame.addKeyListener(new Frame());

to:

frame.addKeyListener(frame);

So that now the KeyListener drives the true displayed Frame instance of interest.


Other issues, this is not good:

catch (Exception e){}

Always catch specific exceptions and almost always, you should handle them. At least do something like this:

catch (IOException e) {
    e.printStacktrace();
}

Upvotes: 1

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