help on image slider

[fatfatpopo]

Anyone who understand the codes below, can you please kindly explain to me by adding comments.. thanks in advance

 
// <applet code="ImageSlider" width="400" height="400"></applet>
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.event.*;
 
public class ImageSlider extends JApplet implements ChangeListener {
BufferedImage[] images;
JLabel label;
 
public void init() {
images = getImages();
getContentPane().setLayout(new BorderLayout());
getContentPane().add(getLabelComponent());
getContentPane().add(getSlider(), "Last");
}
 
public void stateChanged(ChangeEvent e) {
JSlider slider = (JSlider)e.getSource();
int index = slider.getValue() -1;
label.setIcon(new ImageIcon(images[index]));
}
 
private JScrollPane getLabelComponent() {
label = new JLabel(new ImageIcon(images[0]));
label.setHorizontalAlignment(JLabel.CENTER);
return new JScrollPane(label);
}
 
private JSlider getSlider() {
JSlider slider = new JSlider(1, 4, 1);
slider.setPaintTicks(true);
slider.setPaintLabels(true);
slider.setMajorTickSpacing(1);
slider.setSnapToTicks(true);
slider.addChangeListener(this);
return slider;
}
 
private BufferedImage[] getImages() {
BufferedImage[] images = new BufferedImage[4];
for(int j = 0; j < images.length; j++) {
try {
String path = "images/t" + (j+1) + ".gif";
images[j] = ImageIO.read(new File(path));
} catch(IOException e) {
System.out.println("Read error: " + e.getMessage());
}
}
return images;
}
}
 
 

[r035198x]

Anyone who understand the codes below, can you please kindly explain to me by adding comments.. thanks in advance

 
// <applet code="ImageSlider" width="400" height="400"></applet>
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.event.*;
 
public class ImageSlider extends JApplet implements ChangeListener {
BufferedImage[] images;
JLabel label;
 
public void init() {
images = getImages();
getContentPane().setLayout(new BorderLayout());
getContentPane().add(getLabelComponent());
getContentPane().add(getSlider(), "Last");
}
 
public void stateChanged(ChangeEvent e) {
JSlider slider = (JSlider)e.getSource();
int index = slider.getValue() -1;
label.setIcon(new ImageIcon(images[index]));
}
 
private JScrollPane getLabelComponent() {
label = new JLabel(new ImageIcon(images[0]));
label.setHorizontalAlignment(JLabel.CENTER);
return new JScrollPane(label);
}
 
private JSlider getSlider() {
JSlider slider = new JSlider(1, 4, 1);
slider.setPaintTicks(true);
slider.setPaintLabels(true);
slider.setMajorTickSpacing(1);
slider.setSnapToTicks(true);
slider.addChangeListener(this);
return slider;
}
 
private BufferedImage[] getImages() {
BufferedImage[] images = new BufferedImage[4];
for(int j = 0; j < images.length; j++) {
try {
String path = "images/t" + (j+1) + ".gif";
images[j] = ImageIO.read(new File(path));
} catch(IOException e) {
System.out.println("Read error: " + e.getMessage());
}
}
return images;
}
}
 
 

Why not read an Applet and a Swing tutorial, then you can even comment it yourself.

[fatfatpopo]

Why not read an Applet and a Swing tutorial, then you can even comment it yourself.

I had read it, but still don't quit understand.So im here to see anyone who can give me any assistance.

[r035198x]

I had read it, but still don't quit understand.So im here to see anyone who can give me any assistance.

Which part do you not understand then?

[fatfatpopo]

Which part do you not understand then?

Do you have any tutorial guide to recommend for all these codes? Other than javasun.. Thanks

[r035198x]

Do you have any tutorial guide to recommend for all these codes? Other than javasun.. Thanks

Sun's swing tutorial is the best one for it and that's the only one I'll recommend.

[fatfatpopo]

Which part do you not understand then?

I don't really understand the code below.. But i know is setting the layout in the applet.

getContentPane().setLayout(new BorderLayout());
getContentPane().add(getLabelComponent());
getContentPane().add(getSlider(), "Last");
 

[r035198x]

I don't really understand the code below.. But i know is setting the layout in the applet.

getContentPane().setLayout(new BorderLayout());
getContentPane().add(getLabelComponent());
getContentPane().add(getSlider(), "Last");
 

The first line sets the layout to be BorderLayout, the next two lines add two things first a JScrollPane and then a JSlider. Both of these are discussed in the swing tutorial link that I gave you. The methods getLabelComponent() and getSlider() which reaturn these components are there in the ImageSlider applet that you have.

[fatfatpopo]

The first line sets the layout to be BorderLayout, the next two lines add two things first a JScrollPane and then a JSlider. Both of these are discussed in the swing tutorial link that I gave you. The methods getLabelComponent() and getSlider() which reaturn these components are there in the ImageSlider applet that you have.

I would like to ask regarding "getLabelComponent() ", how i know what name should i put after "get"

[r035198x]

I would like to ask regarding "getLabelComponent() ", how i know what name should i put after "get"

It depends on what you've called the method in the class. See my reply #8 again.

[fatfatpopo]

It depends on what you've called the method in the class. See my reply #8 again.

Kindly tell me what is going on in the codes below

for(int j = 0; j < images.length; j++) {
            try {
                String path = "images/t" + (j+1) + ".gif";
                images[j] = ImageIO.read(new File(path));
            } catch(IOException e) {
                System.out.println("Read error: " + e.getMessage());
 

[r035198x]

Kindly tell me what is going on in the codes below

for(int j = 0; j < images.length; j++) {
            try {
                String path = "images/t" + (j+1) + ".gif";
                images[j] = ImageIO.read(new File(path));
            } catch(IOException e) {
                System.out.println("Read error: " + e.getMessage());
 

Dry run it on a piece of paper with sample values and tell us what you think it's doing.

[fatfatpopo]

Dry run it on a piece of paper with sample values and tell us what you think it's doing.

Can anyone tell me, how come im not able to view it at the browser? Thanks alot..

[r035198x]

Can anyone tell me, how come im not able to view it at the browser? Thanks alot..

Did you manage to run it on some simple editor like Textpad?
How are you running it on the browser and what does it do when you run it?

[fatfatpopo]

Did you manage to run it on some simple editor like Textpad?
How are you running it on the browser and what does it do when you run it?

Do you know what does the error mean?
Below is the error message shown in Java Console:


java.security.AccessControlException: access denied (java.io.FilePermission images\t1.gif read)
at java.security.AccessControlContext.checkPermission (Unknown Source)
at java.security.AccessController.checkPermission(Unk nown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkRead(Unknown Source)
at java.io.File.canRead(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)
at ImageSlider.getImages(ImageSlider.java:48)
at ImageSlider.init(ImageSlider.java:15)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

[r035198x]

Do you know what does the error mean?
Below is the error message shown in Java Console:


java.security.AccessControlException: access denied (java.io.FilePermission images\t1.gif read)
at java.security.AccessControlContext.checkPermission (Unknown Source)
at java.security.AccessController.checkPermission(Unk nown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkRead(Unknown Source)
at java.io.File.canRead(Unknown Source)
at javax.imageio.ImageIO.read(Unknown Source)
at ImageSlider.getImages(ImageSlider.java:48)
at ImageSlider.init(ImageSlider.java:15)
at sun.applet.AppletPanel.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

Read an applet tutorial and find out about how to display images on an applet. Applets are not allowed to open files on your computer unless they are signed. You need to use a URL and the code base for the path of the images.

[fatfatpopo]

Read an applet tutorial and find out about how to display images on an applet. Applets are not allowed to open files on your computer unless they are signed. You need to use a URL and the code base for the path of the images.

hmmm. i cannot signed for my applet because they give it to company but im only individual.

[r035198x]

hmmm. i cannot signed for my applet because they give it to company but im only individual.

Read my reply again. If you read the tutorial you will know how to display the images without needing to sign the applet.

[fatfatpopo]

Read my reply again. If you read the tutorial you will know how to display the images without needing to sign the applet.

Can tell me what changes must i make? because i view it very nicely at my appletviewer.. Thanks again

[r035198x]

Can tell me what changes must i make? because i view it very nicely at my appletviewer.. Thanks again

Please read* my responses.

*Reading - an extinct art that students used to get information (paraphrased from Jos)

We're not going anywhere here. I really would like it for you to read those tutorials.

[fatfatpopo]

Please read* my responses.

*Reading - an extinct art that students used to get information (paraphrased from Jos)

We're not going anywhere here. I really would like it for you to read those tutorials.

I have read from java tutorial and lots more.. But im quite confused over my problem.. If not i won't have stucked in the problem for so long..