OOP2 : Form & Event Handler (Bab 9)

Dalam event handling pada Java ada empat bagian penting yang harus diketahui:

1. Event Object merupakan object yang mendiskripsikan sebuah event yang di-trigger oleh event source.
2. Event Handler merupakan method yang menerima event object dan melakukan respond yang sesuai dengan event object tersebut.
3. Event Listener merupakan interface yang akan meng-handle event yang terjadi. setiap type event mempunyai interface yang bersesuaian. Listener tersebut harus diimplementasikan oleh class yang akan meng-handle event
4. Event Source merupakan pembangkit / trigger sebuah event objects

setiap event object mempunyai  type event yang berbdea beda. sehingga kita harus menentukan type event sebelum menentukan jenis interface listener. karena setiap type event mempunyai jenis interface listener yang bersesuaian.

C#

/*
 * Created by SharpDevelop.
 * User: ceplez
 * Date: 7/8/2012
 * Time: 12:32 AM
 *
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace form2c_
{
    /// <summary>
    /// Description of MainForm.
    /// </summary>
    public partial class MainForm : Form
    {
        public MainForm()
        {
            //
            // The InitializeComponent() call is required for Windows Forms designer support.
            //
            InitializeComponent();
           
            //
            // TODO: Add constructor code after the InitializeComponent() call.
            //
        }
       
        void HasilClick(object sender, EventArgs e)
        {
            string user=input1.Text.ToString();
            string pas=input2.Text.ToString();
            if (user=="akhlis" && pas=="123456")
            {
                MessageBox.Show("Selamat anda telah login");
                this.Close();
            }
            else
            {
                MessageBox.Show("Username atau password salah"+"\n"+"Silahkan ulangi lagi...");
                this.input1.ResetText();
                this.input2.ResetText();
                this.input1.Focus();
            }
           
           
        }
    }
}

 

Java

package formjava;

import javax.swing.JOptionPane;

public class NewJPanel extends javax.swing.JPanel {

    public NewJPanel() {

        initComponents();

    }

    @SuppressWarnings("unchecked")

    // <editor-fold defaultstate="collapsed" desc="Generated Code">

    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();

        buton1 = new javax.swing.JButton();

        input1 = new javax.swing.JTextField();

        jLabel2 = new javax.swing.JLabel();

        input2 = new javax.swing.JPasswordField();

        jLabel1.setText("Username");

        buton1.setText("Login");

        buton1.setName("login"); // NOI18N

        buton1.addActionListener(new java.awt.event.ActionListener() {

            public void actionPerformed(java.awt.event.ActionEvent evt) {

                buton1ActionPerformed(evt);

            }

        });

        input1.setName("input1"); // NOI18N

        jLabel2.setText("Password");

        input2.setName("input2"); // NOI18N

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(this);

        this.setLayout(layout);

        layout.setHorizontalGroup(

            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

            .addGroup(layout.createSequentialGroup()

                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

                    .addGroup(layout.createSequentialGroup()

                        .addGap(60, 60, 60)

                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

                            .addComponent(jLabel1)

                            .addComponent(jLabel2))

                        .addGap(30, 30, 30)

                        .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)

                            .addComponent(input2)

                            .addComponent(input1, javax.swing.GroupLayout.DEFAULT_SIZE, 109, Short.MAX_VALUE)))

                    .addGroup(layout.createSequentialGroup()

                        .addGap(147, 147, 147)

                        .addComponent(buton1)))

                .addContainerGap(153, Short.MAX_VALUE))

        );

        layout.setVerticalGroup(

            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)

            .addGroup(layout.createSequentialGroup()

                .addGap(52, 52, 52)

                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)

                    .addComponent(jLabel1)

                    .addComponent(input1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))

                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)

                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)

                    .addComponent(jLabel2)

                    .addComponent(input2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))

                .addGap(38, 38, 38)

                .addComponent(buton1)

                .addContainerGap(141, Short.MAX_VALUE))

        );

    }// </editor-fold>

    private void buton1ActionPerformed(java.awt.event.ActionEvent evt) {

       String  usr= input1.getText();

       String pass=input2.getText();

       if (usr.equals("akhlis")&&pass.equals("123456"))

        {

           JOptionPane.showMessageDialog(buton1, "berhasil");

        }

       else

       {

           JOptionPane.showMessageDialog(buton1, "gagal");

       }

    }

    // Variables declaration - do not modify

    private javax.swing.JButton buton1;

    private javax.swing.JTextField input1;

    private javax.swing.JPasswordField input2;

    private javax.swing.JLabel jLabel1;

    private javax.swing.JLabel jLabel2;

    // End of variables declaration

}