Fading Jpanels in and out in a JFrame

I would like to make a game with multiple JPanels in a single global JFrame. I would like to switch these JPanels but with a nice animation like fade in and fade out. How would you be able to fade a JPanel out, switch the JPanel to a new o开发者_StackOverflow社区ne, and fade the new in (preferably without an external library)?

Thanks a lot

Maybe http://filthyrichclients.org/
has some nice ideas and examples(online) to get started. It contains many swing animation details.

Could possibly do something like this on the panel and components to make them fade out:

Color bgColor = getBackground();

for(int alpha = bgColor.getAlpha(); alpha > = 0; alpha--)
{
    setBackground(new Color(
    bgColor.getRed(),
    bgColor.getGreen(),
    bgColor.getBlue(),
    alpha));
}

You will probably need to throw a Thread.sleep() in there.

Also have a look at:

com.sun.awt.AWTUtilities.setWindowOpacity(this,opacity );

But note that this does the entire application

For reference, FlashTest shows how to fade by changing a color's saturation, while AlphaTest shows how to fade by changing a color's alpha.

I suggest creating a dummy javafx node, setting an animation for it, and binding the opacity property of the dummy node with your swing item. it would be something like this

import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.util.Duration;    
import javax.swing.*;

class transitions
{
    Button fade_reference = new Button();
    transitions.fade fade_transistion;
    JFrame frame = new JFrame();
    transitions()
    {
        fade_transistion = new fade(fade_reference, 250, 0.2, 0.9);
        fade_reference.opacityProperty().addListener(observable-> {
            frame.setOpacity((float)fade_reference.getOpacity());
        });
    }

    class fade
    {
        private final Timeline show_timeline, hide_timeline;
        Node node;
        double min_opacity;
        double max_opacity;
        int annimation_duration;

        fade(Node node, int annimation_duration, double min_opacity, double max_opacity)
        {
            this.min_opacity = min_opacity;
            this.max_opacity = max_opacity;
            this.node = node;
            this.annimation_duration = annimation_duration;
            show_timeline = setupShowTransition();
            hide_timeline = setupDismissTransition();

        }

        private Timeline setupShowTransition()
        {
            return create_timeline(max_opacity);
        }

        private Timeline setupDismissTransition()
        {
            return create_timeline(min_opacity);
        }

        private Timeline create_timeline(double target_opacity)
        {
            Timeline tl = new Timeline();

            KeyValue kv1 = new KeyValue(node.opacityProperty(), node.getOpacity());
            KeyFrame kf1 = new KeyFrame(Duration.ZERO, kv1);

            KeyValue kv2 = new KeyValue(node.opacityProperty(), target_opacity);
            KeyFrame kf2 = new KeyFrame(Duration.millis(annimation_duration), kv2);

            tl.getKeyFrames().addAll(kf1, kf2);
            return tl;
        }

        void fade_up()
        {
            show_timeline.play();
        }

        void fade_down()
        {
            hide_timeline.play();
        }
    }
}