Movable Objects

[Steven Gibbs]

Hi there

I have a JFrame with a JPanel placed on it. The JFrame is 400x400 and the JPanel is 300x300.

I now want to put an object on the panel ie, a rectangle in horizontal position sized at a height of 50 and length of 100.

Basically the JPanel is to be imagined as a 6x6 grid. Its the beginning stages of the Rush Hour game - I want to first get one object moving and then once that is sorted i will then edit it and take it further by adding other cars (rectangles in this case)

I have no idea how to add a rectangle shape to the panel that is moveable by clicking on it and dragging. I know I need to use a MouseListener. I want the rectangle to be able to move in incriments of 50 as 300/6 is obviously 50.

I have made a drawing program before using dragging/rubber banding but this is obviously going to be a bit different.

Here is the code I have at the moment coded in Netbeans - Any help anyone could give me would be much appreciated as at the moment I am at a dead end.

    
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
 
/**
 *
 * @author  Steven Gibbs
 */
public class RushJFrame extends javax.swing.JFrame {
    
    /** Creates new form RushJFrame */
    public RushJFrame() {
        initComponents();
    }
    
     /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">                          
    private void initComponents() {
        gamePanel = new javax.swing.JPanel();
 
        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setAlwaysOnTop(true);
        gamePanel.setBackground(new java.awt.Color(255, 255, 255));
        gamePanel.setBorder(javax.swing.BorderFactory.createLineBorder(new java.awt.Color(0, 0, 0)));
        gamePanel.setPreferredSize(new java.awt.Dimension(400, 400));
 
        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(42, 42, 42)
                .addComponent(gamePanel, javax.swing.GroupLayout.PREFERRED_SIZE, 300, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(42, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addGap(31, 31, 31)
                .addComponent(gamePanel, javax.swing.GroupLayout.PREFERRED_SIZE, 300, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(33, Short.MAX_VALUE))
        );
        java.awt.Dimension screenSize = java.awt.Toolkit.getDefaultToolkit().getScreenSize();
        setBounds((screenSize.width-400)/2, (screenSize.height-400)/2, 400, 400);
    }// </editor-fold>                        
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new RushJFrame().setVisible(true);
            }
        });
    }
    
    // Variables declaration - do not modify                     
    private javax.swing.JPanel gamePanel;
    // End of variables declaration     

[ November 08, 2007: Message edited by: Steven Gibbs ]

[Brandon Broschinsky]

Well just quickly putting something together you could do something like this. This gives a simple example of moving objects around the screen in a grid like fashion. Just click and drag the squares around. Hope this helps.

    
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
 
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
 

public class test extends JPanel{
 
/**
 * 
 */
private static final long serialVersionUID = 1L;
private ArrayList<moveObject> list = new ArrayList<moveObject>();
public static int size = 50;
 

/**
 * @param args
 */
public test(){
addAll();
}

public void addAll(){
list.add(new moveObject(0,0,Color.orange));
list.add(new moveObject(50,50,Color.pink));
list.add(new moveObject(200,100,Color.green));
list.add(new moveObject(300,250,Color.black));
}



/* (non-Javadoc)
 * @see javax.swing.JComponent#paintComponent(java.awt.Graphics)
 */
@Override
protected void paintComponent(Graphics g) {
// TODO Auto-generated method stub
super.paintComponent(g);
for(moveObject o : list){
Point p = convertToGrid(o.getX(), o.getY());
g.drawImage(o.getImage(),p.x,p.y,null);
}
}

public Point convertToGrid(int x, int y){
Point p = new Point();
int factor = x/size;
p.x=factor*size;

int yfactor = y/size;
p.y=yfactor*size;

return p;
}
 

 
public static void main(String[] args) {
JFrame f = new JFrame("test");
test t = new test();
f.setContentPane(t);
f.pack();
f.setLocationRelativeTo(null);
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.setSize(new Dimension(500,500));
f.setVisible(true);

}

public class moveObject implements MouseListener,MouseMotionListener{
int x=-1;
int y=-1;
Color color = Color.red;
BufferedImage image = null;
boolean pressed = false;
int width = size;
int height = size;

public moveObject(int x, int y,Color color){
this.x=x;
this.y=y;
this.color = color;
image = getMoveImage();
addMouseListener(this);
addMouseMotionListener(this);
}

public BufferedImage getMoveImage(){
BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
Graphics2D g = image.createGraphics();
g.setColor(color);
g.fillRect(0,0,image.getWidth(),image.getHeight());
return image;
}
 
/**
 * @return the color
 */
public Color getColor() {
return color;
}
 
/**
 * @param color the color to set
 */
public void setColor(Color color) {
this.color = color;
}
 
/**
 * @return the image
 */
public BufferedImage getImage() {
return image;
}
 
/**
 * @param image the image to set
 */
public void setImage(BufferedImage image) {
this.image = image;
}
 
/**
 * @return the x
 */
public int getX() {
return x;
}
 
/**
 * @param x the x to set
 */
public void setX(int x) {
this.x = x;
}
 
/**
 * @return the y
 */
public int getY() {
return y;
}
 
/**
 * @param y the y to set
 */
public void setY(int y) {
this.y = y;
}
 
public void mouseClicked(MouseEvent e) {
// TODO Auto-generated method stub

}
 
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub

}
 
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub

}
 
public void mousePressed(MouseEvent e) {
java.awt.Rectangle rect = new java.awt.Rectangle(x,y,width,height);
if(rect.contains(new Point(e.getX(),e.getY()))){
pressed = true;
}

}
 
public void mouseReleased(MouseEvent e) {
if(pressed){
x=e.getX();
y=e.getY();
repaint();
}
pressed=false;

}
 
public void mouseDragged(MouseEvent e) {
if(pressed){
x=e.getX();
y=e.getY();
repaint();
}

}
 
public void mouseMoved(MouseEvent e) {
// TODO Auto-generated method stub

}

}
 
}