问题
I am making this java applet graphics with nodes and edges. I want to implement the fade-in and fade out effect on retrieval of the new nodes when one node is clicked, but I don't know how to write and implement the code. To clarify, for example animal node retrieves tiger and lion nodes. so when animal is clicked the node and the edge attached to it gradually fades away and the tiger and lion nodes gradually appear.
Thank you in advance
回答1:
This example uses AlphaComposite to do the fading. Alternatively, this example composes a color table based on saturation.
回答2:
You'll need to write an animation loop. Each time through the loop change the color of your edge and/or node. You can use either an alpha fade or a color fade to background. There are lots of tutorials on the web if you search for "java applet animation loop". One good article is here.
回答3:
Dear Friend here is the code that helps your problem
Kindly refer through it
/*Arpana*/
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import java.awt.color.ColorSpace;
import javax.swing.border.TitledBorder;
public class ImageColorEffect extends JFrame implements ActionListener {
DisplayPanel displayPanel;
JRadioButton brightButton, darkButton, contrastIButton, contrastDButton,
reverseButton, changeButton, resetButton;
public ImageColorEffect() {
super("Color Effect Example");
Container container = getContentPane();
container.setSize(500,500);
displayPanel = new DisplayPanel();
container.add(displayPanel);
JPanel panel = new JPanel();
panel.setLayout(new GridLayout(3, 2));
panel.setBorder(new TitledBorder("Click a Radio Button"));
ButtonGroup group = new ButtonGroup();
brightButton = new JRadioButton("Brightness",false);
panel.add(brightButton);
group.add(brightButton);
brightButton.addActionListener(this);
darkButton = new JRadioButton("Darkness",false);
panel.add(darkButton);
group.add(darkButton);
darkButton.addActionListener(this);
contrastIButton = new JRadioButton("Contrast in",false);
panel.add(contrastIButton);
group.add(contrastIButton);
contrastIButton.addActionListener(this);
contrastDButton = new JRadioButton("Contrast de",false);
panel.add(contrastDButton);
group.add(contrastDButton);
contrastDButton.addActionListener(this);
reverseButton = new JRadioButton("Negative",false);
panel.add(reverseButton);
group.add(reverseButton);
reverseButton.addActionListener(this);
changeButton = new JRadioButton("ChangeColor",false);
panel.add(changeButton);
group.add(changeButton);
changeButton.addActionListener(this);
resetButton = new JRadioButton("Reset",false);
panel.add(resetButton);
group.add(resetButton);
resetButton.addActionListener(this);
container.add(BorderLayout.NORTH, panel);
addWindowListener(new WindowEventHandler());
setSize(displayPanel.getWidth(), displayPanel.getHeight() + 25);
show();
}
class WindowEventHandler extends WindowAdapter {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
}
public static void main(String arg[]) {
new ImageColorEffect();
}
public void actionPerformed(ActionEvent e) {
JRadioButton rbutton = (JRadioButton) e.getSource();
if (rbutton.equals(brightButton)) {
displayPanel.brightenLUT();
displayPanel.applyFilter();
displayPanel.repaint();
} else if (rbutton.equals(darkButton)) {
displayPanel.darkenLUT();
displayPanel.applyFilter();
displayPanel.repaint();
} else if (rbutton.equals(contrastIButton)) {
displayPanel.contrastIncLUT();
displayPanel.applyFilter();
displayPanel.repaint();
} else if (rbutton.equals(contrastDButton)) {
displayPanel.contrastDecLUT();
displayPanel.applyFilter();
displayPanel.repaint();
} else if (rbutton.equals(reverseButton)) {
displayPanel.reverseLUT();
displayPanel.applyFilter();
displayPanel.repaint();
} else if (rbutton.equals(changeButton)) {
displayPanel.repaint();
displayPanel.grayOut();
} else if (rbutton.equals(resetButton)) {
displayPanel.reset();
displayPanel.repaint();
}
}
}
class DisplayPanel extends JPanel {
Image disImage;
BufferedImage image;
Graphics2D graph;
LookupTable lookup;
DisplayPanel() {
setBackground(Color.black);
loadImage();
setSize(disImage.getWidth(this), disImage.getWidth(this));
createBufferedImage();
}
public void loadImage() {
disImage = Toolkit.getDefaultToolkit().getImage(
"Desert.jpg");
MediaTracker media = new MediaTracker(this);
media.addImage(disImage, 1);
try {
media.waitForAll();
} catch (Exception e) {}
if (disImage.getWidth(this) == -1) {
System.out.println("file not found");
System.exit(0);
}
}
public void createBufferedImage() {
image = new BufferedImage(disImage.getWidth(this), disImage
.getHeight(this), BufferedImage.TYPE_INT_ARGB);
graph = image.createGraphics();
graph.drawImage(disImage, 0, 0, this);
}
public void brightenLUT() {
short brighten[] = new short[256];
for (int i = 0; i < 256; i++) {
short pixelValue = (short) (i + 10);
if (pixelValue > 255)
pixelValue = 255;
else if (pixelValue < 0)
pixelValue = 0;
brighten[i] = pixelValue;
}
lookup = new ShortLookupTable(0, brighten);
}
public void darkenLUT() {
short brighten[] = new short[256];
for (int i = 0; i < 256; i++) {
short pixelValue = (short) (i - 10);
if (pixelValue > 255)
pixelValue = 255;
else if (pixelValue < 0)
pixelValue = 0;
brighten[i] = pixelValue;
}
lookup = new ShortLookupTable(0, brighten);
}
public void contrastIncLUT() {
short brighten[] = new short[256];
for (int i = 0; i < 256; i++) {
short pixelValue = (short) (i * 1.2);
if (pixelValue > 255)
pixelValue = 255;
else if (pixelValue < 0)
pixelValue = 0;
brighten[i] = pixelValue;
}
lookup = new ShortLookupTable(0, brighten);
}
public void contrastDecLUT() {
short brighten[] = new short[256];
for (int i = 0; i < 256; i++) {
short pixelValue = (short) (i / 1.2);
if (pixelValue > 255)
pixelValue = 255;
else if (pixelValue < 0)
pixelValue = 0;
brighten[i] = pixelValue;
}
lookup = new ShortLookupTable(0, brighten);
}
public void reverseLUT() {
byte reverse[] = new byte[256];
for (int i = 0; i < 256; i++) {
reverse[i] = (byte) (255 - i);
}
lookup = new ByteLookupTable(0, reverse);
}
public void reset() {
graph.setColor(Color.black);
graph.clearRect(0, 0, image.getWidth(this), image.getHeight(this));
graph.drawImage(disImage, 0, 0, this);
}
public void grayOut() {
ColorConvertOp colorConvert = new ColorConvertOp(ColorSpace
.getInstance(ColorSpace.CS_GRAY), null);
colorConvert.filter(image, image);
}
public void applyFilter() {
LookupOp lop = new LookupOp(lookup, null);
lop.filter(image, image);
}
public void update(Graphics g) {
g.clearRect(0, 0, getWidth(), getHeight());
paintComponent(g);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2D = (Graphics2D) g;
g2D.drawImage(image, 0, 0, this);
}
}
来源：https://stackoverflow.com/questions/6165661/fade-in-and-fade-out-effect-in-java-applet