So i got this class that inherited from JPanel and a Thread that instantiates a Image object and making it move horizontally. The problem is the Image is just drawn using the Graphics class and the drawImage() method but stays still and not moving.
MyJPanel.java
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Point;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class MyJPanel extends JPanel implements ActionListener,Runnable
{
private static final long serialVersionUID = 1L;
private Timer timer;
private Image backgroundImage;
private Image player;
private int playerX, playerY;
private int projectileX,projectileY;
private Image projectileImage;
private ArrayList<Image> projectiles = new ArrayList<Image>();
boolean flag = false;
public MyJPanel(Image backgroundImage, Image player,Image projectileImage)
{
this.backgroundImage = backgroundImage;
this.player = player;
this.projectileImage = projectileImage;
this.setLayout(null);
timer = new Timer(50, this);
timer.start();
this.addKeyListener(new KeyAdapter() // Listens for a keyboard event
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_SPACE) // If pressing space - shoot
{
ProjectileThread projectileThread = new ProjectileThread(playerX,playerY);
projectileThread.start(); // Create a Thread and call run() method
}
repaint();
}
});
// Mouse listener
this.addMouseMotionListener(new MouseMotionListener()
{
@Override
public void mouseMoved(MouseEvent e)
{
playerX = e.getX();
playerY = e.getY();
}
@Override
public void mouseDragged(MouseEvent e)
{
}
});
hideMouseCursor();
this.setFocusable(true);
this.setVisible(true);
} // End of JPanel constructor
public void paintComponent(Graphics graphics)
{
super.paintComponent(graphics);
graphics.drawImage(backgroundImage,0,0,this.getWidth(),this.getHeight(),null); // Draw the background
graphics.drawImage(player,playerX,playerY,null); // Draw the player
graphics.drawImage(projectileImage,projectileX,projectileY,null);
}
public void moveProjectile()
{
while (projectileX < this.getWidth())
{
this.projectileX += 2;
}
}
public void hideMouseCursor() // Hides the mouse cursor
{
//Transparent 16 x 16 pixel cursor image.
BufferedImage cursorbackgroundImgage = new BufferedImage(16, 16, BufferedImage.TYPE_INT_ARGB);
// Create a new blank cursor.
Cursor blankCursor = Toolkit.getDefaultToolkit().createCustomCursor(
cursorbackgroundImgage, new Point(0, 0), "Blank Cursor");
// Set the blank cursor to the JPanel.
this.setCursor(blankCursor);
}
@Override
public void actionPerformed(ActionEvent actionEvent) // Without the method and the repaint() the mouse listener will not work
{
repaint();
}
public class ProjectileThread extends Thread
{
Graphics graphics;
public ProjectileThread(int playerX,int playerY)
{
projectileX = playerX + player.getWidth(null);
projectileY = playerY + player.getHeight(null) / 2;
}
@Override
public void run()
{
graphics.drawImage(projectileImage,projectileX,projectileY,null);
while (projectileX < getWidth())
{
projectileX += 2;
}
try
{
Thread.sleep(500);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
public static void main(String[] args)
{
JFrame frame = new JFrame("A Game by me");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setExtendedState(JFrame.MAXIMIZED_BOTH); // Making the frame take a full screen
ImageIcon backgroundImageIcon = new ImageIcon("space_background_2.jpg");
Image backgroundImgage = backgroundImageIcon.getImage();
ImageIcon playerImageIcon = new ImageIcon("spaceship_1.png");
Image playerImage = playerImageIcon.getImage();
ImageIcon projectileIcon = new ImageIcon("spaceship_projectile_1.png");
Image projectileImage = projectileIcon.getImage();
frame.add(new MyJPanel(backgroundImgage,playerImage,projectileImage));
frame.setVisible(true);
}
@Override
public void run()
{
}
} // End of MyJPanel
there are some variables and Objects that i don't use so don't mind them please.
The CS:
Thread:
public class ProjectileThread extends Thread
{
Graphics graphics;
public ProjectileThread(int playerX,int playerY)
{
projectileX = playerX + player.getWidth(null);
projectileY = playerY + player.getHeight(null) / 2;
}
@Override
public void run()
{
graphics.drawImage(projectileImage,projectileX,projectileY,null);
while (projectileX < getWidth())
{
projectileX += 2;
}
try
{
Thread.sleep(500);
}
catch (InterruptedException e)
{
e.printStackTrace();
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
Starting the Thread each space bar click:
this.addKeyListener(new KeyAdapter() // Listens for a keyboard event
{
public void keyPressed(KeyEvent e)
{
if (e.getKeyCode() == KeyEvent.VK_SPACE) // If pressing space - shoot
{
ProjectileThread projectileThread = new ProjectileThread(playerX,playerY);
projectileThread.start(); // Create a Thread and call run() method
}
repaint();
}
});
I have been to this problem for quiet a lot and i don't seem to recall why it is not moving if i clearly say this.projectileX += 2;?
Any suggestions would be very appreciated. Thanks.
