hi,
i created a listbox
List list = new List();
list.addItem(".....:P");
list.addItem("...:(");
add(list);
list.makeVisible(1);
setVisible(true);how can i make the listbox enabled (readable, but not disabled), so the user can't select anything from it?
also, does anyone know of any good sites with full tutorials for beginners, for java?
Have to add an eventListener to your code so you can use it.
Take a look at my calc app i made for a project, I used a listbox.
import java.awt.*;
import javax.swing.*;
public class CalculatorDriver{
public static void main(String[] args){
DisplayWindow d = new DisplayWindow();
CalculatorPanel p = new CalculatorPanel();
d.add(p);
d.showFrame();
}
}import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class CalculatorPanel extends JPanel implements ActionListener{
//Creating GUI components
//Buttons for program
//math function buttons P1
JButton plus = new JButton("+");
JButton minus = new JButton("-");
JButton times = new JButton("x");
JButton divide = new JButton("/");
JButton sqRoot = new JButton("sqrt");
//Program functions p2
JButton submit = new JButton("Submit");
JButton save = new JButton("Save");
JButton quit = new JButton("Quit");
JButton reset = new JButton("Reset");
//list button functions p3
JButton use = new JButton("Use Value");
JButton deleteVal = new JButton("Delete Value");
JButton clear = new JButton("Clear All");
//Label
JLabel enterLabel = new JLabel("enter: ");
JLabel result = new JLabel("0.0");
JLabel saveLabel = new JLabel("Save the answer");
JLabel savedLabel = new JLabel("Saved Values");
//Textfield
JTextField enter = new JTextField(8);
//list object to store values in
List saveList = new List(5);
//Panels for grids
JPanel p1 = new JPanel();
JPanel p2 = new JPanel();
JPanel p3 = new JPanel();
JPanel p4 = new JPanel();
//Event types to be passed to MathControls
private int functionChoice;
final int PLUS = 0;
final int MINUS = 1;
final int TIMES = 2;
final int DIVIDE = 3;
final int SQRT = 4;
//Constructor for MathControls
MathControls m = new MathControls();
//Enter values
double x = 0.0;
double y = 0.0;
double z = 0.0;
//placeholder
String stringHolder;
public CalculatorPanel(){
//GridLayout 4 by 1 with red borders
setLayout(new GridLayout(4,1));
p1.setBorder(BorderFactory.createLineBorder(Color.red));
p2.setBorder(BorderFactory.createLineBorder(Color.red));
p3.setBorder(BorderFactory.createLineBorder(Color.red));
p4.setBorder(BorderFactory.createLineBorder(Color.red));
//add components to panels
p1.add(plus);
p1.add(minus);
p1.add(times);
p1.add(divide);
p1.add(sqRoot);
p2.add(enterLabel);
p2.add(enter);
p2.add(result);
p2.add(submit);
p2.add(reset);
p2.add(saveLabel);
p2.add(save);
p3.add(savedLabel);
p3.add(saveList);
p3.add(use);
p3.add(deleteVal);
p3.add(clear);
p4.add(quit);
//add buttons to ActionListener
plus.addActionListener(this);
minus.addActionListener(this);
times.addActionListener(this);
divide.addActionListener(this);
sqRoot.addActionListener(this);
submit.addActionListener(this);
save.addActionListener(this);
saveList.addActionListener(this);
quit.addActionListener(this);
reset.addActionListener(this);
use.addActionListener(this);
deleteVal.addActionListener(this);
clear.addActionListener(this);
//adding the panels to main frame
add(p1);
add(p2);
add(p3);
add(p4);
}
public void actionPerformed(ActionEvent e){
//Quit function
if(e.getSource() == quit){
System.exit(0);
}
//plus functionality
else if(e.getSource() == plus){
//get x
stringHolder = enter.getText();
x = (Double.parseDouble(enter.getText()));
//use x as the label for the moment
result.setText(stringHolder);
//set the function choice
functionChoice = PLUS;
//clear the textField for the next number
enter.setText("");
}
//minus functionality
else if(e.getSource() == minus){
//get x
stringHolder = enter.getText();
x = (Double.parseDouble(enter.getText()));
//use x as the label for the moment
result.setText(stringHolder);
//set the function choice
functionChoice = MINUS;
//clear the textField for the next number
enter.setText("");
}
//times functionality
else if(e.getSource() == times){
//get x
stringHolder = enter.getText();
x = (Double.parseDouble(enter.getText()));
//use x as the label for the moment
result.setText(stringHolder);
//set the function choice
functionChoice = TIMES;
//clear the textField for the next number
enter.setText("");
}
//divide functionality
else if(e.getSource() == divide){
//get x
stringHolder = enter.getText();
x = (Double.parseDouble(enter.getText()));
//use x as the label for the moment
result.setText(stringHolder);
//set the function choice
functionChoice = DIVIDE;
//clear the textField for the next number
enter.setText("");
}
//Square Root functionality
else if(e.getSource() == sqRoot){
//get x
stringHolder = enter.getText();
x = (Double.parseDouble(enter.getText()));
//use x as the label for the moment
result.setText(stringHolder);
//set the function choice
functionChoice = SQRT;
z = m.Control(functionChoice, x, 0);
String stringHolder1 = Double.toString(z);
result.setText(stringHolder1);
//clear the textField for the next number
enter.setText("");
}
//Submit button function
else if(e.getSource() == submit){
//get y
y = (Double.parseDouble(enter.getText()));
//send information to get z
z = m.Control(functionChoice, x, y);
//put z to the label
stringHolder = Double.toString(z);//convert z to string
//set the text of the label to the result
result.setText(stringHolder);
//clear the textfield for more information
enter.setText("");
}
//reset button function
else if(e.getSource() == reset){
//sets the result back to "0.0"
result.setText("0.0");
}
//save button function
else if(e.getSource() == save){
saveList.add(result.getText());
}
//use item button function from list
else if(e.getSource() == use){
enter.setText(saveList.getSelectedItem());
}
//delete item from list function
else if(e.getSource() == deleteVal){
saveList.remove(saveList.getSelectedItem());
}
//clear all values from list
else if(e.getSource() == clear){
saveList.removeAll();
}
}
}import java.awt.*;
import javax.swing.*;
public class DisplayWindow extends JFrame{
private Container c;
public DisplayWindow(){
super("Calculator");
c = this.getContentPane();
}
public void addPanel(JPanel p){
p.setPreferredSize(new Dimension(2000, 2000));
c.add(p);
}
public void showFrame(){
this.pack();
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}public class MathControls{
private int control;
public MathControls(){
}
public double Control(int type, double a, double b){
control = type;
//Add
if(control == 0){
return (a+b);
}
//Subtract
if(control == 1){
return (a-b);
}
//Times
if(control == 2){
return (a * b);
}
//Divide
if(control == 3){
return (a / b);
}
//SQ ROOT
if(control == 4){
return (Math.sqrt(a));
}
return 0.0;
}
}o yeah, you can also look at the java api, it's very useful to figure out how to make objects work.
Here is the one for the listbox:
http://java.sun.com/j2se/1.5.0/docs/api/java/awt/List.html
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