link-actionlistener

import java.awt.*;

import java.awt.event.*;

import javax.swing.*;

public class Responding extends JPanel {

Rectangle target = new Rectangle(125,100,75,75);

protected void paintComponent(Graphics g) {

super.paintComponent(g);

Graphics2D g2 = (Graphics2D)g;

g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,

RenderingHints.VALUE_ANTIALIAS_ON);

g2.draw(target);

}

public static void main(String[] args) {

Responding test = new Responding();

test.addMouseListener(test.ml);

JFrame f = new JFrame();

f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f.getContentPane().add(test);

f.setSize(400,400);

f.setLocation(200,200);

f.setVisible(true);

}

private MouseListener ml = new MouseAdapter() {

public void mousePressed(MouseEvent e) {

if(target.contains(e.getPoint())) {

// Here you can:

// change to another card in a CardLayout

// load another JPanel into the content pane

// show content in a JDialog or a JOptionPane

System.out.println("target selected");

}

}

};

}

crwooda at 2007-7-9 5:31:44 >

Iwant to create jpeg file by users request,

A little confusing...

the jpeg will show a number of rectangles(nodes) and arcs(relations) connecting two

rectangles.

Okay.

I wanted to know how can i add actionlisteners to each rectangle,

Technically, you cannot add an ActionListener but we'll try to get the effect of one.

so if users wants more information about that node they can click on the rectangle and

say a new jsp page opens with additional information.

Can't help on the jsp page but I'll try to advise you on options for the graphics part.

So let's say you have the jpeg image containing rectangles connected by arcs. To get this

to respond to user mouse clicks you will need to store the location/size of each

rectangle (as a Rectangle) and use this information to determine which rectangle was

selected by the user, just like above. You can keep an array of Rectangles to use for

determining the selections and another (parallel) array with the URLs or data to use for

your jsp pages. Or you could make a Map with the Rectangles (or array index) as keys and

info objects (such as URL or a data store class) as the value. The Rectangle location

will have to be relative to the image in case it is shown in a larger component - another

detail. You add a MouseListener to the component showing the image, identify the selected

Rectangle in the mousePressed method and use the index of the Rectangle in its array to

access the info in the parallel array or use the Rectangle (or its array index) to get

the info from the map.

crwooda at 2007-7-9 5:31:44 >