Question

Hi I’ve been trying to fade from one image to another using trident java animation library, but haven’t quite grasped how you choose to interpolate a image. Any solutions?
Thanks anyway

Answer 1

I never used Trident for fading, but I’d suggest to read

1) basic Java 2D Graphics tutorial, and there is accesible to set transparency for JComponents that contains Icon or ImageGraphics

2) How to Create Translucent and Shaped Windows

3) for both ways you have to implements javax.swing.Timer

simple example for Graphics and Timer

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.Color;
import java.awt.AlphaComposite;
import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;

public class ButtonTest {

    private JFrame frame;
    private JButton opaqueButton1;
    private JButton opaqueButton2;
    private SoftJButton softButton1;
    private SoftJButton softButton2;
    private Timer alphaChanger;

    public void createAndShowGUI() {
        opaqueButton1 = new JButton("Opaque Button");
        opaqueButton2 = new JButton("Opaque Button");
        softButton1 = new SoftJButton("Transparent Button");
        softButton2 = new SoftJButton("Transparent Button");
        opaqueButton1.setBackground(Color.GREEN);
        softButton1.setBackground(Color.GREEN);
        frame = new JFrame();
        frame.getContentPane().setLayout(new java.awt.GridLayout(2, 2, 10, 10));
        frame.add(opaqueButton1);
        frame.add(softButton1);
        frame.add(opaqueButton2);
        frame.add(softButton2);
        frame.setSize(700, 300);
        frame.setLocation(150, 100);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
        alphaChanger = new Timer(30, new ActionListener() {

            private float incrementer = -.03f;

            @Override
            public void actionPerformed(ActionEvent e) {
                float newAlpha = softButton1.getAlpha() + incrementer;
                if (newAlpha < 0) {
                    newAlpha = 0;
                    incrementer = -incrementer;
                } else if (newAlpha > 1f) {
                    newAlpha = 1f;
                    incrementer = -incrementer;
                }
                softButton1.setAlpha(newAlpha);
                softButton2.setAlpha(newAlpha);
            }
        });
        alphaChanger.start();
        Timer uiChanger = new Timer(3500, new ActionListener() {

            private final LookAndFeelInfo[] laf = UIManager.getInstalledLookAndFeels();
            private int index = 1;

            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    UIManager.setLookAndFeel(laf[index].getClassName());
                    SwingUtilities.updateComponentTreeUI(frame);
                    opaqueButton1.setText(laf[index].getClassName());
                    softButton1.setText(laf[index].getClassName());
                } catch (Exception exc) {
                    exc.printStackTrace();
                }
                index = (index + 1) % laf.length;
            }
        });
        uiChanger.start();
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new ButtonTest().createAndShowGUI();
            }
        });
    }

    private static class SoftJButton extends JButton {

        private static final JButton lafDeterminer = new JButton();
        private static final long serialVersionUID = 1L;
        private boolean rectangularLAF;
        private float alpha = 1f;

        SoftJButton() {
            this(null, null);
        }

        SoftJButton(String text) {
            this(text, null);
        }

        SoftJButton(String text, Icon icon) {
            super(text, icon);
            setOpaque(false);
            setFocusPainted(false);
        }

        public float getAlpha() {
            return alpha;
        }

        public void setAlpha(float alpha) {
            this.alpha = alpha;
            repaint();
        }

        @Override
        public void paintComponent(java.awt.Graphics g) {
            java.awt.Graphics2D g2 = (java.awt.Graphics2D) g;
            g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha));
            if (rectangularLAF && isBackgroundSet()) {
                Color c = getBackground();
                g2.setColor(c);
                g.fillRect(0, 0, getWidth(), getHeight());
            }
            super.paintComponent(g2);
        }

        @Override
        public void updateUI() {
            super.updateUI();
            lafDeterminer.updateUI();
            rectangularLAF = lafDeterminer.isOpaque();
        }
    }
}