Java Virtual Keyboard Using Robot, Toolkit and JToggleButton Classes

https://www.facebook.com/Oxus20
oxus20@gmail.com JAVA
Virtual
Keyboard
» Exception
Handling
» JToggleButton Class
» Robot Class
» Toolkit Class
Prepared By: Nahid Ahmadi
Edited By: Abdul Rahman Sherzad

Agenda
» Virtual Keyboard
» Exception Handling
» JToggleButton Class
» Robot Class
» Toolkit Class
» Virtual Keyboard Implementation
2

3

Virtual Keyboard Using JAVA
4

Introduction to Virtual Keyboard
» A virtual keyboard is considered to be a
component to use on computers without a
real keyboard e.g.
˃ touch screen computer
» A mouse can utilize the keyboard
functionalities and features. 5

Virtual Keyboard Usage
» It is possible to obtain keyboards for the
following specific purposes:
˃ Keyboards to fill specific forms on sites
˃ Special key arrangements
˃ Keyboards for dedicated commercial sites
˃ etc.
» In addition, Virtual Keyboard used for the
following subjects:
˃ Foreign Character Sets
˃ Touchscreens
˃ Bypass key loggers
6

7

Exception Handling
» A program can be written assuming that nothing unusual or
incorrect will happen.
˃ The user will always enter an integer when prompted to do so.
˃ There will always be a nonempty list for a program that takes an entry from the list.
˃ The file containing the needed information will always exist.
» Unfortunately, it isn't always so.
» Once the core program is written for the usual, expected
case(s), Java's exception-handling facilities should be
added to accommodate the unusual, unexpected case(s).
8

Exception Hierarchy
9

Exception Handling Demo
Source code
public class ExceptionHandlingDemo {
public static void main(String args[]) {
try {
int scores[] = { 90, 85, 75, 100 };
System.out.println("Access element nine:" + scores[9]);
} catch (ArrayIndexOutOfBoundsException e) {
System.out.println("Exception thrown:" + e);
}
System.out.println("nWithout Exception Handling I was
not able to execute and print!");
}
}
10

Exception Handling Demo
OUTPUT
Exception
thrown:java.lang.ArrayIndexOutOfBoundsEx
ception: 9
Without Exception Handling I was not
able to execute and print!
11

12

JToggleButton Class
» JToggleButton is an implementation of a two-state
button and is used to represent buttons that can be
toggled ON and OFF
» The JRadioButton and JCheckBox classes are
subclasses of this class.
» The events fired by JToggleButtons are slightly
different than those fired by JButton. 13

JToggleButton Demo
» The following example on next slide demonstrates
a toggle button. Each time the toggle button is pressed,
its state is displayed in a label.
» Creating JToggleButton involves these steps:
1. Create an instance of JToggleButton.
2. Register an ItemListener to handle item events generated by the button.
3. To determine if the button is on or off, call isSelected().
14

JToggleButton Demo
Source Code
import java.awt.FlowLayout;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JToggleButton;
class JToggleButtonDemo {
JLabel lblOutput;
JToggleButton btnOnOff;
JFrame win;
JToggleButtonDemo() {
// JFrame Customization
win = new JFrame("Using JToggleButton");
win.setLayout(new FlowLayout());
win.setSize(300, 80);
win.setLocationRelativeTo(null);
win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
15

// JToggleButton and JLabel Customization
lblOutput = new JLabel("State : OFF");
btnOnOff = new JToggleButton("On / Off", false);
// Add item listener for JToggleButton.
btnOnOff.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
if (btnOnOff.isSelected()) {
lblOutput.setText("State : ON");
} else {
lblOutput.setText("State : OFF");
}
}
});
// Add toggle button and label to the content pane.
win.add(btnOnOff);
win.add(lblOutput);
win.setVisible(true);
}
new JToggleButtonDemo();
}
} 16

JToggleButton Demo
OUTPUT
17

18

Java Robot Class
» This class is used to generate native
system input events for the
purposes of
˃ test automation
˃ self-running demos
˃ and other applications where control of the mouse
and keyboard is needed.
» This class has three main
functionalities:
˃ mouse control
˃ keyboard control
˃ and screen capture.
19

Robot Class Demo
» Perform keyboard operation with help of java Robot class.
» The following example on next slide will demonstrate the
Robot class usage to handle the keyboard events.
» The program will write the word "OXUS20" inside the
TextArea automatically after running the program.
» The word "OXUS20" will be written character by character
with one second delay between each on of the
characters. 20

Robot Class Demo
Source Code
import java.awt.AWTException;
import java.awt.BorderLayout;
import java.awt.Robot;
import java.awt.event.KeyEvent;
import javax.swing.JTextArea;
public class RobotDemo extends JFrame {
public RobotDemo() {
// JFrame with TextArea Settings
setTitle("OXUS20 Robot Demo");
setSize(400, 200);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLocationRelativeTo(null);
JTextArea txtOXUS = new JTextArea();
add(txtOXUS, BorderLayout.CENTER);
setVisible(true);
} 21

public static void main(String[] args) {
new RobotDemo();
// Store Keystrokes "OXUS20" in an array
int keyInput[] = { KeyEvent.VK_O, KeyEvent.VK_X, KeyEvent.VK_U,
KeyEvent.VK_S, KeyEvent.VK_2, KeyEvent.VK_0 };
try {
Robot robot = new Robot();
// press the shift key
robot.keyPress(KeyEvent.VK_SHIFT);
// This types the word 'OXUS20' in the TextArea
for (int i = 0; i < keyInput.length; i++) {
if (i > 0) {
robot.keyRelease(KeyEvent.VK_SHIFT);
}
robot.keyPress(keyInput[i]);
// pause typing for one second
robot.delay(1000);
}
} catch (AWTException e) {
System.err.println("Exception is happening!");
}
} // end of main()
} // end of RobotDemo class 22

23

Toolkit class
» Toolkit is an AWT class acting as a base class for all
implementations of AWT.
» This class offers a static method getDefaultToolkit() to return
a Toolkit object representing the default implementation of
AWT.
» You can use this default toolkit object to get information of the
default graphics device, the local screen, and other purposes.
» Next slide demonstrate an example finding out the actual size
and resolution of your screen. 24

Toolkit Class Demo
Source Code
import java.awt.Dimension;
import java.awt.Toolkit;
public class ToolkitDemo {
public static void main(String[] a) {
Toolkit tk = Toolkit.getDefaultToolkit();
Dimension d = tk.getScreenSize();
System.out.println("Screen size: " + d.width + "x" + d.height);
System.out.println("nScreen Resolution: " +
tk.getScreenResolution());
}
}
25

Toolkit Class Demo
OUTPUT
Screen Size: 1366x768
Screen Resolution: 96
26

Another Toolkit Example
» Change the state of the Caps Lock key
˃ If Caps Lock key is ON turn it OFF
˃ Otherwise, if Caps Lock key is OFF turn it ON
» Toolkit.getDefaultToolkit().setLockingKeyState(
KeyEvent.VK_CAPS_LOCK, false);
˃ This line of code will change the state of the Caps Lock key OFF.
» Toolkit.getDefaultToolkit().setLockingKeyState(
KeyEvent.VK_CAPS_LOCK, true);
˃ This line of code will change the state of the Caps Lock key ON.
» Accordingly the keyboard LEDs flash will become
ON or OFF. 27

Another Toolkit Class Demo
Source Code
import java.awt.FlowLayout;
class ChangeCapsLockStateDemo {
JLabel lblOutput;
JToggleButton btnOnOff;
JFrame win;
ChangeCapsLockStateDemo() {
// JFrame Customization
win = new JFrame("Using JToggleButton");
win.setLayout(new FlowLayout());
win.setSize(300, 80);
win.setLocationRelativeTo(null);
win.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 28

// JToggleButton and JLabel Customization
lblOutput = new JLabel("CapsLock : OFF");
Toolkit.getDefaultToolkit().setLockingKeyState(KeyEvent.VK_CAPS_LOCK, false);
btnOnOff = new JToggleButton("On / Off", false);
// Add item listener for JToggleButton.
btnOnOff.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent ie) {
if (btnOnOff.isSelected()) {
lblOutput.setText("CapsLock : ON");
Toolkit.getDefaultToolkit().setLockingKeyState(KeyEvent.VK_CAPS_LOCK, true);
} else {
lblOutput.setText("CapsLock : OFF");
Toolkit.getDefaultToolkit().setLockingKeyState(KeyEvent.VK_CAPS_LOCK, false);
}
}
});
// Add toggle button and label to the content pane.
win.add(btnOnOff);
win.add(lblOutput);
win.setVisible(true);
}
new ChangeCapsLockStateDemo();
}
}
29

Another Toolkit Class Demo
OUPUT
30

31

Java Virtual Keyboard
Source Code
import java.awt.AWTException;
import java.awt.Color;
import java.awt.Robot;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JPanel;
public class JavaVirtualKeyboard implements ActionListener, ItemListener {
32

Java Virtual Keyboard
OUTPUT
33

Complete Source Code will
be published very soon
Check Our Facebook Page
(https://www.facebook.com/Oxus20)
34

END
35

Java Virtual Keyboard Using Robot, Toolkit and JToggleButton Classes

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