Swing Introduction

Swing:-

It is an enhancement of AWT component because the AWT component provides limited component only for the simple user interface.AWT component had been developed by C and Cpp programming language hence it's performance is slow as compare to swing.

Swing component was implemented by JFC(Java Foundation Class) , It provides a rich set of component to create an advanced graphical user interface.

Swing provides javax.swing package to contain swing component.


Swing component use J char in front of all Classes .J means Java Foundation Class.

JButton,JLabel,JTextField,JFrame,JPanel

Swing Architecture:-

Q)Create a Hello World Program using Swing without using GUI Tools?



import java.awt.Color;
import java.awt.Container;
import java.awt.HeadlessException;
import javax.swing.*;
/**
 *
 * @author SHIVA
 */
public class SwingBasic extends JFrame {

    JLabel lbl;
    public SwingBasic()
    {
        setVisible(true);
        setSize(400,400);
        setLayout(null);
        Container c = getContentPane();
        c.setBackground(Color.orange);
        lbl = new JLabel("Hello World");
        lbl.setBounds(100, 50, 100,30);
        add(lbl);
     
   }
    public static void main(String[] args) {
        SwingBasic obj = new SwingBasic();
    }

 
}

Toggle Button:-

It provides Button UI but works similarly to checkbox using click and unclick event both.

private void jToggleButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                             
        // TODO add your handling code here:
        if(jToggleButton1.isSelected())
            jLabel1.setText("On");
        else
            jLabel1.setText("OFF");
    } 


isSelected():- It returns true and false when we click and  unclick to button.



RadioButton and CheckBox Component in Swing:-


SWING Provide RadioButton Class to create RadioButton, RadioButton always will be linked with Button Group Class to choose a single option.


How we integrate with ButtonGroup to radio button?

RightClick on RadioButton and Select ButtonGroupname to logically grouping the button.


A CheckBox is similar to Awt it only contains a different method for selection.

Method for CheckBox and RadioButton:-

isSelected():-   it returns true when radiobutton and checkbox will be checked otherwise return false.

..............................................................................................................................................................

Combobox and ListBox:-

Swing Provide JCombobox class to store multiple items but we can select a single item at a time.

Combobox item can be inserted by Model Property using right-click on combobox.

Combobox use ItemStateChanged Event and getSelectItem() to get data.


private void jComboBox1ItemStateChanged(java.awt.event.ItemEvent evt) {                                            
        // TODO add your handling code here:
        jLabel1.setText(jComboBox1.getSelectedItem().toString());

    }  


ListBox:-

It is used to select multiple items in a group of item, ListBox will be implemented by JList Class.

How we add an element in List?

Right-click on List and Change Model Property.

Default event of ListBox is listselection value changed, it will be appear when we right-click on listbox and choose events option.

Code to display ListBox Element:-

 private void jList1ValueChanged(javax.swing.event.ListSelectionEvent evt) {                                    
       Object str[] = jList1.getSelectedValues();
       String s="";
       for(Object s1:str)
       {
           s=s+s1+" " ;
       }
       jLabel2.setText(s);
       

    }





How we Add element dynamically in ListBox and Combobox?

LISTBOX provide DefaultListModel class and Comobox provide DefaultComboBoxModel to add and remove element.


1)First, initialize it

DefaultComboBoxModel cbm;
    DefaultListModel   dlm;
    public SwingExample5() {
        initComponents();
        cbm = (DefaultComboBoxModel)jComboBox1.getModel();
        dlm = new DefaultListModel();

    }




2) write code for add and delete
 private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        cbm.addElement(jTextField1.getText());
        jComboBox1.setModel(cbm);
        dlm.addElement(jTextField1.getText());
        jList1.setModel(dlm);
    }                                        

    private void jButton2ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        cbm.removeElement(jTextField1.getText());
        jComboBox1.setModel(cbm);
        dlm.removeElement(jTextField1.getText());
        jList1.setModel(dlm);
    }