Question

I would like to create a program where the Jframe is able to move freely on it’s own. Kind of like a translation / transition.

For example,

1. Click on program to begin.

2. Jframe spawns at location (0,0).

3. Automatically move (animate) 100 pixels to the right so that the new coordinates are (100,0).

I know there’s the setLocation(x,y) method that sets the initial position once the program runs but is there a way to move the entire Jframe after the program starts?

Answer 1

The basic concept would look something like this…

public class MoveMe01 {

    public static void main(String[] args) {
        new MoveMe01();
    }

    public MoveMe01() {

        EventQueue.invokeLater(
                new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }

                final JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new JLabel("Use the Force Luke"));
                frame.pack();
                frame.setLocation(0, 0);
                frame.setVisible(true);

                Timer timer = new Timer(40, new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        Point location = frame.getLocation();
                        Point to = new Point(location);
                        if (to.x < 100) {
                            to.x += 4;
                            if (to.x > 100) {
                                to.x = 100;
                            }
                        }
                        if (to.y < 100) {
                            to.y += 4;
                            if (to.y > 100) {
                                to.y = 100;
                            }
                        }

                        frame.setLocation(to);

                        if (to.equals(location)) {
                            ((Timer)e.getSource()).stop();
                        }
                    }
                });
                timer.setRepeats(true);
                timer.setCoalesce(true);
                timer.start();

            }
        });
    }
}

This is a pretty straight, linear animation. You’d be better of investigating one of the many animation engines available for Swing, this will provide you with the ability to change the speed of the animation based on the current frame (doing things like slow-in and slow-out for example)

I would take a look at

• Timing Framework
• Trident
• Universla Tween Engine

Updated with a “variable time” solution

This is basically an example of how you might do a variable time animation. That is, rather then having a fixed movement, you can adjust the time and allow the animation to calculate the movement requirements based on the run time of the animation…

public class MoveMe01 {

    public static void main(String[] args) {
        new MoveMe01();
    }

    // How long the animation should run for in milliseconds
    private int runTime = 500;
    // The start time of the animation...
    private long startTime = -1;

    public MoveMe01() {

        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }

                final JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new JLabel("Use the Force Luke"));
                frame.pack();
                frame.setLocation(0, 0);
                frame.setVisible(true);

                Timer timer = new Timer(40, new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {

                        if (startTime < 0) {
                            // Start time of the animation...
                            startTime = System.currentTimeMillis();
                        }
                        // The current time
                        long now = System.currentTimeMillis();
                        // The difference in time
                        long dif = now - startTime;
                        // If we've moved beyond the run time, stop the animation
                        if (dif > runTime) {
                            dif = runTime;
                            ((Timer)e.getSource()).stop();
                        }
                        // The percentage of time we've been playing...
                        double progress = (double)dif / (double)runTime;

                        Point location = frame.getLocation();
                        Point to = new Point(location);

                        // Calculate the position as perctange over time...
                        to.x = (int)Math.round(100 * progress);
                        to.y = (int)Math.round(100 * progress);
                        // nb - if the start position wasn't 0x0, then you would need to
                        // add these to the x/y position above...

                        System.out.println(to);

                        frame.setLocation(to);
                    }
                });
                timer.setRepeats(true);
                timer.setCoalesce(true);
                timer.start();

            }
        });
    }
}