Program for dynamically creating and adding JLabels

In this tutorial, we will create a JFrame that contains JTextField, JPanel and JLabels. We have to add the number of JLabels that are entered in JTextField. For example, if we have entered number 4 then four labels will be added in JPanel.





To accomplish this task we have used here CaretListener interface and its method caretUpdate( ).

 SOURCE CODE 
import java.awt.Color;
import javax.swing.*;
import javax.swing.event.*;

class CreateLabelsDynamically extends JFrame implements CaretListener {
 
 JTextField jtf;
 JPanel jpan;
 
 public CreateLabelsDynamically() {
  
  jtf = new JTextField(10);
  jpan = new JPanel();
  
  setLayout(null);
  
  jtf.setBounds(50, 20, 50, 30);
  jtf.addCaretListener(this);
  
  jpan.setBounds(50, 80, 200, 200);
  jpan.setOpaque(true);
  jpan.setBackground(Color.CYAN);
  
  add(jtf);
  add(jpan);
 }
 
 public void caretUpdate(CaretEvent ce)  {
  
  String str = jtf.getText();
  
  jpan.removeAll();
  
  if(!str.equals("")) {
   int num = Integer.parseInt(str);
   JLabel jlabels[] = new JLabel[num];
   
   for(int i = 0; i < jlabels.length; i++) {
    jlabels[i] = new JLabel("Label" + i);
    jpan.add(jlabels[i]);
   }
  }
  jpan.validate();
  jpan.repaint();
 }
 
 public static void main(String args[]) {
  
  CreateLabelsDynamically c = new CreateLabelsDynamically();
  c.setTitle("My Frame");
  c.setSize(300,350);
  c.setVisible(true);
 }
}

OUTPUT 

 C:\>javac CreateLabelsDynamically.java 
C:\>java CreateLabelsDynamically


Popular posts from this blog

Program to define a class 'employee' with data members as empid, name and salary. Accept data for 5 objects using Array of objects and print it.

This program demonstrates you the array of objects.  Array of object  is the collection of objects of the same class. The given syntax will define an array of reference therefore assign object to individual reference in the array to declare the array of object. The syntax to define array of object is: <class-name> <array-name> [size]; For example, the following statement will define an array of object having size 6 references to the class  Box . Box b[6]; For creating an array of objects (allocating memory) you have to write down the following statements for (int i=0; i<6; i++) { b[i] = new Box(); // Assigning object to individual reference in the array. } PROGRAM import java.util.Scanner; public class Employee { int empid; String name; float salary; public void getInput() { Scanner in = new Scanner(System.in); System.out.print("Enter the empid :: "); empid = in.nextInt(); System.out.print("Enter the name :: ");...
Read more

First Android App | Android Development | Java

Image
Develop an android application to display “Hello World!” on screen Introduction In this tutorial, you learn how to start android development with the very first android project. You also create and run your first Android app Hello World, on emulator or physical device. Before you start writing your first program using Android Studio, you have to make sure that you have set-up your Android development environment properly. Also it is assumed that you have a little bit of working knowledge with Android studio. What you should already know Basic understanding of object-oriented programming Basic understanding of Java programming language What you'll need A computer running Windows or Linux, or a Mac running macOS. Android Studio should be installed, if it’s not ready, please download it from the Official Website. ...
Read more

Program to design an applet which draws a circle (having color BLUE) inside a triangle (having color YELLOW)

Image
Given program will draw a circle inside a triangle. The color of circle is "blue" and triangle having color "yellow". To fill circle with respective colours first we have to set the colour using  setColor(Color c)  method of  Graphics  class and then use the fillPolygon() and fillOval( )  method. The  fillPolygon( )  method Fills a closed polygon defined by arrays of x and y coordinates.
Read more