CODEWITHSUNDEEP
javaimageswingjframejslider
user7489721
user7489721

Reputation:

Preloading images to use as JLabel icon

I want to have a simple JFrame with a JLabel (to show images as an icon) and a JSlider (to switch between 40 images).

When I load the new images on a StateChange event of the slider, the program gets very slow, especially when I slide fast.

So I was thinking of preloading the 40 images and replacing them via the slider. Is this smart and possible?

Upvotes: 0

Views: 194

Answers (1)

Sergiy Medvynskyy
Sergiy Medvynskyy

Reputation: 11327

I assume, you have something like this:

public class MyClass {
    // other declarations
    private JLabel label;
    // other methods
    public void stateChange(ChangeEvent e) {
        label.setIcon(new ImageIcon(...)); // here is code to determine name of the icon to load.
                timer = null;
    }
}

What you need is to change your code as following:

public class MyClass {
    // other declarations
    private JLabel label;
    private Timer timer; // javax.swing.Timer
    // other methods
    public void stateChange(ChangeEvent e) {
        if (timer != null) {
            timer.stop();
        }
        timer = new Timer(250, new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                label.setIcon(new ImageIcon(...)); // here is code to determine name of the icon to load.
                timer = null;
            }
        });
        timer.setRepeats(false);
        timer.start();
    }
}

Upvotes: 2

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