How to listen for events on contained components?
I'm a relative newbie to Java and to Swing components. I've managed to figure out quite a lot in a few weeks from reading and looking at forums, but there's one thing I want to accomplish that I just can't seem to find or understand.
I want to be able to create whole banks of groups of 5-7 radio buttons. These will fit into categories, say three groups of buttons in one category, five groups in another, etc. I have written a class to create a group of buttons on a JPanel, then assign the buttons to a ButtonGroup, and I have implemented listeners in the class, one for each button, which sets a variable to a numeric value depending on which radio button is selected.
With formatting and variable declarations omitted to save space, here it is:
/* ButtonPanel.java
*/
import java.awt.*;
import javax.swing.*;
import java.awt.Event.*;
public class ButtonPanel extends javax.swing.JPanel {
public ButtonPanel(String header) {
this.setLayout(new java.awt.GridBagLayout());
this.add(jLabel1, gridBagConstraints);
jRadioButton1.setText("1");
this.add(jRadioButton1, gridBagConstraints);
jRadioButton2.setText("2");
this.add(jRadioButton2, gridBagConstraints);
jRadioButton3.setText("3");
this.add(jRadioButton3, gridBagConstraints);
jRadioButton4.setText("4");
this.add(jRadioButton4, gridBagConstraints);
jRadioButton5.setText("5");
this.add(jRadioButton5, gridBagConstraints);
jRadioButton6.setText("6");
this.add(jRadioButton6, gridBagConstraints);
jRadioButton7.setText("7");
this.add(jRadioButton7, gridBagConstraints);
ButtonGroup btg = new ButtonGroup();
btg.add(jRadioButton1);
btg.add(jRadioButton2);
btg.add(jRadioButton3);
btg.add(jRadioButton4);
btg.add(jRadioButton6);
btg.add(jRadioButton5);
btg.add(jRadioButton7);
jRadioButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton1ActionPerformed(evt);
}
});
jRadioButton2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton2ActionPerformed(evt);
}
});
jRadioButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton3ActionPerformed(evt);
}
});
jRadioButton4.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton4ActionPerformed(evt);
}
});
jRadioButton5.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton5ActionPerformed(evt);
}
});
jRadioButton6.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton6ActionPerformed(evt);
}
});
jRadioButton7.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRadioButton7ActionPerformed(evt);
}
});
// pack();
}// </editor-fold>
private void jRadioButton7ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 7;
}
private void jRadioButton6ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 6;
}
private void jRadioButton2ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 2;
}
private void jRadioButton3ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 3;
}
private void jRadioButton5ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 5;
}
private void jRadioButton4ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 4;
}
private void jRadioButton1ActionPerformed(java.awt.event.ActionEvent evt) {
outval = 1;
}
public int pickedButton(){
return outval;
}
}
This simple class seems to work well. My next idea is that I create a new class to implement a category of buttons. The name of the category of buttons can vary, and the labels next to each row (group) of buttons can vary. I implement this by passing an array of labels into the class, using the first as a category header, and the remaining ones as labels for the rows of buttons. The entire category is placed on a JPanel.
/*
* CategoryOfButtons.java
*/
import java.awt.*;
import java.awt.Event.*;
import javax.swing.*;
public class CategoryOfButtons extends javax.swing.JPanel {
public CategoryOfButtons(String[] labels) {
this.setLayout(new java.awt.GridLayout(labels.length+1,1));
this.setBorder(javax.swing.BorderFactory.createEtchedBorder());
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel1.setFont(new java.awt.Font("Arial Black", 0, 14));
jLabel1.setText(labels[0]);
testBut = new ButtonPanel[labels.length - 1]; //array of button panels
this.add(jLabel1); // the category header
for (i=1;i<=labels.length-1;i++){
testBut[i-1] = new ButtonPanel(labels);
this.add(testBut[i-1]);
};
this.add(jLabel2);
}
// variable declarations omitted to save space
}
From a main class, I will create categories of buttons as needed. Here's what I can't figure. I would like to put a label on the CategoryOfButtons JPanel that keeps a running sum of the selected button from each ButtonPanel, and I want to display that running sum in jLabel2. The obvious solution would seem to be to sum up the testBut[].pickedButton() values over the indices of the testBut array. That works to show an initial value of 0, but I can't figure how to get the value to update. I don't want to have to install a separate button on CategoryOfButtons to cause a fresh evaluation of the sum of the values from the radio buttons.
I tried setting up a mouse clicked action event on CategoryOfButtons, and having the event handler sum up the testBut[].pickedButton() values, but clicking the mouse on a radio button in a contained ButtonPanel doesn't seem to create an event in the CategoryOfButtons container.How can I get a value in the container (CategoryOfButtons) to respond to an event in the contained component (ButtonPanel)?
I hope this makes sense....
