Member Avatar for osean

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?

  • 2 Contributors
  • 2 Replies
  • 105 Views
  • 6 Hours Discussion Span
  • Latest Post Latest Post by Dark_Omen

Recommended Answers

All 2 Replies

Member Avatar for Dark_Omen

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;
  }
}
Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.