?
Solved

Add ActionListener to change TextArea

Posted on 2006-10-31
7
Medium Priority
?
1,700 Views
Last Modified: 2012-06-21
Here is my code so far:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;        

public class TestModule {
      public static void main(String[] args) {
            new Window();         
      }
}
class Window extends JFrame {
      public Window() {
            super ("Thermostat");
            setSize(600, 500);
            setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            setVisible(true);
            Container ca = getContentPane();
            ca.setBackground(Color.lightGray);
            GridBagLayout gblm = new GridBagLayout();
            GridBagConstraints gbc = new GridBagConstraints();
            gbc.fill = GridBagConstraints.HORIZONTAL;
            ca.setLayout(gblm);
            
            //DISPLAY TEMPERATURE      
            JTextArea tempView = new JTextArea("76", 25, 25);
            gbc.gridx = 0;
            gbc.gridy = 0;
            ca.add(tempView,gbc);
                        
            //WARMER      BUTTON
            JButton warmer = new JButton("Warmer");
            gbc.gridx = 0;
            gbc.gridy = 1;
            ca.add(warmer,gbc);
            //?????   warmer.addActionListener(this);    ?????            
            
            //COOLER BUTTON
            JButton cooler = new JButton("Cooler");
            gbc.gridx = 0;
            gbc.gridy = 2;
            ca.add(cooler,gbc);      
                //?????   cooler.addActionListener(this);    ?????      
            
            setContentPane(ca);      
      }
      public void warmerActionPerformed(ActionEvent event) {
            //CHANGE TextArea up one degree      
      }
      
      public void coolerActionPerformed(ActionEvent event) {
            //CHANGE TextArea down one degree      
      }
}                  

Can someone please help me understand the ActionListener event ... how I can add it to the button ... capture the content of the text area, add or subtract 1 to it then redisplay it.  Also, please feel free to comment on how I have this set up ... I am new to JAVA and just trying to get a grasp on this process of actions.

Thanks in advance,
Rocky
0
Comment
Question by:rockymagee
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 4
  • 3
7 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 17843997
You need to add this method to your class

public void actionPerformed(ActionEvent e) {
      if ("Cooler".equals(e.getActionCommand()) ) {
            coolerActionPerformed(e);
      }
      else if ("Warmer".equals(e.getActionCommand()) ) {
            warmerActionPerformed(e);
      }
}
0
 
LVL 6

Author Comment

by:rockymagee
ID: 17844425
How to I reference the method from public Window()?

I added the recommended code .... and uncommented

warmer.addActionListener(this);
AND
cooler.addActionListener(this);

I get the following error:

addActionListener(java.awt.event.ActionListener) in javax.swing.AbstractButton cannot be applied to (Window)
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 17844596
extends JFrame implements ActionListener
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 6

Author Comment

by:rockymagee
ID: 17844700
Thanks, that works!

If I could ask on more thing:

This is my modification to your actionPerformed(...):

public void actionPerformed(ActionEvent e) {
     if ("Cooler".equals(e.getActionCommand()) ) {
       tempValue = tempView.getText();
       tempValue = (int) tempValue;
       tempValue  = tempValue + 1;
//
       tempView.setText(tempValue);      
     }
     else if ("Warmer".equals(e.getActionCommand()) ) {
       tempValue = tempView.getText();
       tempValue = (int) tempValue;
       tempValue  = tempValue + 1;
       tempView.setText(tempValue);
     }
}

Questions:  Can I read out the string from the TextArea, cast it to an int | add or subtract | recast as string and set the new value back into the text area .... ?

I really appreciate the help, you got me around a big curve with the ActionListener that I could not figure out !
0
 
LVL 86

Accepted Solution

by:
CEHJ earned 2000 total points
ID: 17845119
>>
Questions:  Can I read out the string from the TextArea, cast it to an int | add or subtract | recast as string and set the new value back into the text area .... ?
>>

Sure

//Let text area contain 100

tempView.setText("" + Integer.parseInt(tempView.getText()));
0
 
LVL 6

Author Comment

by:rockymagee
ID: 17845430
Perfect Thanks !

Thanks for the quick responses ...

A++
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 17845996
:-)
0

Featured Post

Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Java had always been an easily readable and understandable language.  Some relatively recent changes in the language seem to be changing this pretty fast, and anyone that had not seen any Java code for the last 5 years will possibly have issues unde…
Introduction This article is the last of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers our test design approach and then goes through a simple test case example, how …
Viewers learn about the third conditional statement “else if” and use it in an example program. Then additional information about conditional statements is provided, covering the topic thoroughly. Viewers learn about the third conditional statement …
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…
Suggested Courses

719 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question