For clarity and other reasons, I'd avoid making the class implements ActionListener. Just add an anonymous ActionListener to each JComboBox. Something like this
JComboBox comboFont;
JLabel label = new JLabel("label");
String fontString = "ariel";
int fontWeight = Font.PLAIN;
int fontSize = 16;
Font font = new Font(fontString, fontWeight, fontSize);
Color textColor = Color.BLACK
public JPanel contentPane() {
comboFont = new JComboBox(fontStrings);
comboFont.addActionListener(new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
fontString = (String)comboFont.getSelectedItem();
font = new Font(fontString, fontWeight, fontSize);
label.setFont(font);
}
});
}
What this will do is dynamically change the font when a new font is selected from the combobox. You should have global values for Font, fontSize and fontWeight so that each different combobox can make use of them and change the font accordingly in the actionPerformed
Also, take a look at this answer from AndrewThompson, showing the actual rendered font style in the JComboBox, with all the fonts obtained from the system fonts. Here's a glimpse. Don't forget to up-vote the answer in the link!
Give this a try. I revamped your code
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class textchanger {
//String[] fontStrings = {"Arial", "Arial Black", "Helvetica", "Impact", "Times New Roman"};
Integer[] fontSizes = {10, 12, 14, 16, 18, 20, 22, 24};
String[] colorStrings = {"Red", "Blue", "Green", "Yellow", "Orange"};
String[] bgStrings = {"Red", "Blue", "Green", "Yellow", "Orange"};
String[] fontStyle = {"BOLD", "Italic", "Plain"};
JPanel panel;
JLabel labelText, labelFont, labelSize, labelColor, labelBG, labelOutput;
JTextField textField;
JComboBox comboFont, comboSize, comboColor, comboBG;
JButton btnOk, btnCancel;
String fontString;
int fontWeight = Font.PLAIN;
int fontSize;
Font font = new Font(fontString, Font.PLAIN, fontSize);
Color textColor;
Color bgColor;
static String text = "Text";
static JLabel textLabel = new JLabel(text);
JPanel textLabelPanel = new JPanel(new GridBagLayout());
public JPanel contentPane() { //Creates the GUI
panel = new JPanel();
panel.setLayout(new GridLayout(7, 8, 10, 10));
textLabelPanel.setPreferredSize(new Dimension(500, 50));
labelText = new JLabel("Enter Text:");
textField = new JTextField(10);
textField.setText(text);
textField.getDocument().addDocumentListener(new DocumentListener() {
@Override
public void insertUpdate(DocumentEvent e) {
String newText = textField.getText();
textLabel.setText(newText);
}
@Override
public void removeUpdate(DocumentEvent e) {
String newText = textField.getText();
textLabel.setText(newText);
}
@Override
public void changedUpdate(DocumentEvent e) {
}
});
labelFont = new JLabel("Select font type:");
GraphicsEnvironment ge = GraphicsEnvironment.
getLocalGraphicsEnvironment();
String[] fonts = ge.getAvailableFontFamilyNames();
comboFont = new JComboBox(fonts);
fontString = (String) comboFont.getItemAt(0);
comboFont.setSelectedIndex(0);
comboFont.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
fontString = (String) comboFont.getSelectedItem();
font = new Font(fontString, fontWeight, fontSize);
textLabel.setFont(font);
}
});
labelSize = new JLabel("Select font size:");
comboSize = new JComboBox(fontSizes);
comboSize.setSelectedIndex(0);
fontSize = (Integer) comboSize.getItemAt(0);
comboSize.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
fontSize = (Integer) comboSize.getSelectedItem();
font = new Font(fontString, fontWeight, fontSize);
textLabel.setFont(font);
}
});
labelColor = new JLabel("Select font color:");
comboColor = new JComboBox(colorStrings);
comboColor.setSelectedIndex(0);
textColor = Color.RED;
textLabel.setForeground(textColor);
comboColor.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String colorString = (String) comboColor.getSelectedItem();
switch (colorString) {
case "Red":
textColor = Color.RED;
break;
case "Blue":
textColor = Color.BLUE;
break;
case "Green":
textColor = Color.GREEN;
break;
case "Yellow":
textColor = Color.YELLOW;
break;
case "Orange":
textColor = Color.ORANGE;
break;
default:
textColor = Color.RED;
}
textLabel.setForeground(textColor);
}
});
labelBG = new JLabel("Select a background color:");
comboBG = new JComboBox(bgStrings);
comboBG.setSelectedIndex(1);
bgColor = Color.BLUE;
textLabelPanel.setBackground(bgColor);
comboBG.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String bgColorString = (String) comboBG.getSelectedItem();
switch (bgColorString) {
case "Red":
bgColor = Color.RED;
break;
case "Blue":
bgColor = Color.BLUE;
break;
case "Green":
bgColor = Color.GREEN;
break;
case "Yellow":
bgColor = Color.YELLOW;
break;
case "Orange":
bgColor = Color.ORANGE;
break;
default:
bgColor = Color.RED;
}
textLabelPanel.setBackground(bgColor);
}
});
btnOk = new JButton("Ok");
btnCancel = new JButton("Cancel");
labelOutput = new JLabel("");
panel.add(labelText);
panel.add(textField);
panel.add(labelFont);
panel.add(comboFont);
panel.add(labelSize);
panel.add(comboSize);
panel.add(labelColor);
panel.add(comboColor);
panel.add(labelBG);
panel.add(comboBG);
panel.add(btnOk);
panel.add(btnCancel);
panel.add(labelOutput);
JPanel mainPanel = new JPanel(new BorderLayout());
mainPanel.add(panel);
textLabelPanel.add(textLabel);
mainPanel.add(textLabelPanel, BorderLayout.SOUTH);
return mainPanel;
}
class FontCellRenderer extends DefaultListCellRenderer {
public Component getListCellRendererComponent(
JList list,
Object value,
int index,
boolean isSelected,
boolean cellHasFocus) {
JLabel label = (JLabel) super.getListCellRendererComponent(
list, value, index, isSelected, cellHasFocus);
Font font = new Font((String) value, Font.PLAIN, 20);
label.setFont(font);
return label;
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame("Fonts, Colors and Sizes");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(650, 350);
textchanger txtObj = new textchanger();
frame.setContentPane(txtObj.contentPane());
frame.setVisible(true);
}
});
}
}
