How can I move an image based on a timer?

Question

How can I move an image based on a timer? I'm trying to get the image to move without any user input but I've done something wrong because I cant get the image to move.

Am I incorrectly calling the method AnimationPanel that I've built to actually move the image? I have a feeling it has something to do with that.

Here's what I've tried so far: The Overloaded Constructor is so that I can call AnimationPanel with ease from this particular class.

public class ClassC extends Component {
    int x; int y;
    BufferedImage img;

    public void paint(Graphics g) {
        g.drawImage(img, x, y, null);
    }

    public ClassC() {
        try {
            img = ImageIO.read(new File("RobotFrame1.png"));
        } catch (IOException e) {
        }
    }

    public ClassC(int x)
    {}

    public Dimension getPreferredSize() {
        if (img == null) {
            return new Dimension(100,100);
        } else {
            return new Dimension(img.getWidth(null)+900, img.getHeight(null)+900);
        }
    }

    public void AnimationPanel() {

        javax.swing.Timer timer = new javax.swing.Timer(20, new ActionListener() {
            public void actionPerformed(ActionEvent arg0) {
                x++;
                y++;
                repaint();
            }
        });
        timer.start();
    }

    public static void main(String[] args) {

        JFrame f = new JFrame("Load Image Sample");
        f.addWindowListener(new WindowAdapter(){
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        f.add(new ClassC());
        f.pack();
        f.setVisible(true);
        ClassC callanimation = new ClassC(1);
        callanimation.AnimationPanel();
    }
}

Related [example](http://stackoverflow.com/a/13795187/1057230) :-) — nIcE cOw, Jul 15 '13 at 03:32

score 4 · Accepted Answer · answered Jul 15 '13 at 01:55

4

The component that is on the screen is not the component that you are animating...

// Create first instance here...
f.add(new ClassC());
f.pack();
f.setVisible(true);
// Create second instance here...
ClassC callanimation = new ClassC(1);
callanimation.AnimationPanel();

Instead, this will get you started

ClassC callanimation = new ClassC();
callanimation.AnimationPanel();
f.add(callanimation);
f.pack();
f.setVisible(true);

ps- I'd also be very careful, you are mixing frameworks. While AWT and Swing share some parts of the library, they don't always play nice together ;)

answered Jul 15 '13 at 01:55

MadProgrammer

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Im so sorry for wasting your time. My mind must not be in the right mode today. Thank you very much. – moonbeamer2234 Jul 15 '13 at 02:12
Welcome to my world :P – MadProgrammer Jul 15 '13 at 02:16
@moonbeamer2234 : Instead of adding a `WindowListener` to the `JFrame`, it would be wise, if you just write `f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE)`, that will do almost the same task :-) – nIcE cOw Jul 15 '13 at 03:19
@nIcEcOw `java.awt.Frame` doesn't have `setDefaultCloseOperation`. This would assume that the OP was using Swing ;) – MadProgrammer Jul 15 '13 at 03:21
@MadProgrammer : But inside the main method I am watching `JFrame` being used ... – nIcE cOw Jul 15 '13 at 03:26
@nIcEcOw Sorry, you're right, keep getting caught on the "using AWT" part, my bad - another reason the OP should be using a `JPanel` – MadProgrammer Jul 15 '13 at 03:42

Francis Fuerte · Answer 2 · 2013-07-15T08:32:16.087

3

public ClassC(int x)
{

}

why is this empty? what is x for?

f.add(new ClassC()); <-- you created a ClassC() here
f.pack();
f.setVisible(true);
ClassC callanimation = new ClassC(1); <-- you created a new ClassC here

these two are different because you created them again..

try doing:

ClassC callanimation = new ClassC(1);
f.add(callanimantion); 
f.pack();
f.setVisible(true);
callanimation.AnimationPanel();

edited Jul 15 '13 at 08:32

answered Jul 15 '13 at 02:05

Francis Fuerte

254
1
9

How can I move an image based on a timer?

2 Answers2