Swing, ActionEvent can't see button...

[Jacob Morehouse]

Hello!

I've been lurking for a few months, first post... In Eclipse, the error is on: e.getSource() == calculate_button. "calculate_button cannot be resolved to a variable." Any ideas? I've been stuck here for a few hours, but I'm sure it is probably something simple.

Thank you very much for any help of comments provided!

Daragaaz

import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.*;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;


public class haakon_calc_main extends JFrame implements ActionListener {
	
	JPanel the_panel = new JPanel(new GridBagLayout());
	static int weight = 0;
	static int freight = 0;
	static int surcharge = 0;
	static int fsc = 0;
	static int the_total = 0;


	
	
	//build window
	public haakon_calc_main()
	{
		//define frame
		super("Haakon Calculator");
		setSize(370, 250);
		setResizable(false);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLocationRelativeTo(null);
		
		GridBagConstraints gbc = new GridBagConstraints();
		//gbc.fill = GridBagConstraints.HORIZONTAL;
		gbc.insets = new Insets(3,3,3,3);
		gbc.anchor = GridBagConstraints.WEST;
		//gbc.weightx = 0.5;
		
		
		
		JLabel weight_label = new JLabel("Weight: ");
		gbc.gridx = 0;
		gbc.gridy = 0;
		the_panel.add(weight_label, gbc);
		
		JTextField weight_field = new JTextField(5);
		gbc.gridx = 1;
		gbc.gridy = 0;
		the_panel.add(weight_field, gbc);
		
		JLabel spacer_label = new JLabel(" ");
		spacer_label.setPreferredSize(new Dimension(60,1));
		gbc.gridx = 2;
		gbc.gridy = 0;
		the_panel.add(spacer_label, gbc);
		
		JLabel freight_label = new JLabel("Freight: ");
		gbc.gridx = 3;
		gbc.gridy = 1;
		the_panel.add(freight_label, gbc);
		
		JTextField freight_field = new JTextField(5);
		gbc.gridx = 4;
		gbc.gridy = 1;
		the_panel.add(freight_field, gbc);
		
		JLabel surcharge_label = new JLabel("Surcharge: ");
		gbc.gridx = 3;
		gbc.gridy = 2;
		the_panel.add(surcharge_label, gbc);
		
		JTextField surcharge_field = new JTextField(5);
		gbc.gridx = 4;
		gbc.gridy = 2;
		the_panel.add(surcharge_field, gbc);
		
		JLabel fsc_label = new JLabel("FSC: ");
		gbc.gridx = 3;
		gbc.gridy = 3;
		the_panel.add(fsc_label, gbc);
		
		JTextField fsc_field = new JTextField(5);
		gbc.gridx = 4;
		gbc.gridy = 3;
		the_panel.add(fsc_field, gbc);
		
		JLabel vertspace_label = new JLabel(" ");
		gbc.gridx = 0;
		gbc.gridy = 4;
		the_panel.add(vertspace_label, gbc);
		
		JButton calculate_button = new JButton("Calculate");
		gbc.gridwidth = 2;
		gbc.gridx = 0;
		gbc.gridy = 5;
		the_panel.add(calculate_button, gbc);
		
		JLabel total_label = new JLabel("Total: ");
		gbc.gridwidth = 2;
		gbc.gridx = 2;
		gbc.gridy = 5;
		the_panel.add(total_label, gbc);
		
		JTextField total_field = new JTextField(5);
		gbc.gridwidth = 2;
		gbc.gridx = 3;
		gbc.gridy = 5;
		the_panel.add(total_field, gbc);
		

		//add panels to frame
		getContentPane().add(the_panel,BorderLayout.NORTH);
		
		//set the listeners
		calculate_button.addActionListener(this); 
		
	}

	

	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub

		if (e.getSource() == calculate_button) {
			//do things...
		}	

	}
	
	
	
	public static void main(String[] args) {
		new haakon_calc_main().setVisible(true);
	}
}

[Janeice DelVecchio]

You're using the calculate_button reference outside the scope from where it's declared. I can elaborate if you don't know what that means.

Welcome to CodeRanch!

[Jacob Morehouse]

Janeice DelVecchio wrote:You're using the calculate_button reference outside the scope from where it's declared. I can elaborate if you don't know what that means.

Welcome to CodeRanch!

Thank you Janeice!!! I wasn't expecting an immediate response!

I'm stubborn, I'll spend a few minutes to see if I can figure it out... I usually remember those painful 'eureka' moments better, lol.

Daragaaz

[Janeice DelVecchio]

Jacob Morehouse wrote:Thank you Janeice!!! I wasn't expecting an immediate response!

I'm glad you appreciate the fast response.

Post again if you want more pointers.

[Jacob Morehouse]

Thank you Janeice, that did the trick. You are correct. It didn't immediately click what that meant, but as I looked it over it makes sense. In case anyone else get's stuck, the corrected version of my code is below.


Daragaaz

import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.*;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;


public class haakon_calc_main extends JFrame implements ActionListener {
	
	JPanel the_panel = new JPanel(new GridBagLayout());
	static int weight = 0;
	static int freight = 0;
	static int surcharge = 0;
	static int fsc = 0;
	static int the_total = 0;

	JLabel weight_label = new JLabel("Weight: ");
	JTextField weight_field = new JTextField(5);
	JLabel spacer_label = new JLabel(" ");
	JLabel freight_label = new JLabel("Freight: ");
	JTextField freight_field = new JTextField(5);
	JLabel surcharge_label = new JLabel("Surcharge: ");
	JTextField surcharge_field = new JTextField(5);
	JLabel fsc_label = new JLabel("FSC: ");
	JTextField fsc_field = new JTextField(5);
	JLabel vertspace_label = new JLabel(" ");
	JButton calculate_button = new JButton("Calculate");
	JLabel total_label = new JLabel("Total: ");
	JTextField total_field = new JTextField(5);
	
	
	//build window
	public haakon_calc_main()
	{
		//define frame
		super("Haakon Calculator");
		setSize(370, 250);
		setResizable(false);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLocationRelativeTo(null);
		
		GridBagConstraints gbc = new GridBagConstraints();
		//gbc.fill = GridBagConstraints.HORIZONTAL;
		gbc.insets = new Insets(3,3,3,3);
		gbc.anchor = GridBagConstraints.WEST;
		//gbc.weightx = 0.5;
		
		
		gbc.gridx = 0;
		gbc.gridy = 0;
		the_panel.add(weight_label, gbc);
		
		
		gbc.gridx = 1;
		gbc.gridy = 0;
		the_panel.add(weight_field, gbc);
		
		spacer_label.setPreferredSize(new Dimension(60,1));
		gbc.gridx = 2;
		gbc.gridy = 0;
		the_panel.add(spacer_label, gbc);
		
		
		gbc.gridx = 3;
		gbc.gridy = 1;
		the_panel.add(freight_label, gbc);
		
		
		gbc.gridx = 4;
		gbc.gridy = 1;
		the_panel.add(freight_field, gbc);
		
		
		gbc.gridx = 3;
		gbc.gridy = 2;
		the_panel.add(surcharge_label, gbc);
		
		
		gbc.gridx = 4;
		gbc.gridy = 2;
		the_panel.add(surcharge_field, gbc);
		
		
		gbc.gridx = 3;
		gbc.gridy = 3;
		the_panel.add(fsc_label, gbc);
		
		
		gbc.gridx = 4;
		gbc.gridy = 3;
		the_panel.add(fsc_field, gbc);
		
		
		gbc.gridx = 0;
		gbc.gridy = 4;
		the_panel.add(vertspace_label, gbc);
		
		
		gbc.gridwidth = 2;
		gbc.gridx = 0;
		gbc.gridy = 5;
		the_panel.add(calculate_button, gbc);
		
		
		gbc.gridwidth = 2;
		gbc.gridx = 2;
		gbc.gridy = 5;
		the_panel.add(total_label, gbc);
		
		
		gbc.gridwidth = 2;
		gbc.gridx = 3;
		gbc.gridy = 5;
		the_panel.add(total_field, gbc);
		

		//add panels to frame
		getContentPane().add(the_panel,BorderLayout.NORTH);
		
		//set the listeners
		calculate_button.addActionListener(this); 
		
	}

	

	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub

		if (e.getSource() == calculate_button) {
			//do things...
		}	

	}
	
	
	
	public static void main(String[] args) {
		new haakon_calc_main().setVisible(true);
	}
}

[Janeice DelVecchio]

Lovely and beautiful!