James Gosling: idealism, the Internet and Java, Pt I

Saturday 23 July 2011

JForm: Fill the form with style

After understanding and using swing toolkit, I understood that there is a allot of scope to develop Custom components easily.
I have developed a component called JForm which basically a button and its selection pops up a window if it is not visible.

Technically the JForm component is a combination of 2 components they are:

1. JButton
2. Window

JButton is a API of swing toolkit where as Window is a API of AWT.

Behaviour of JForm:

JForm is a usual button like JButton. but it is glued to a Window component. this Window takes a JPanel class as an arguments.

In the given example has 2 components they are 1. JTextArea  2. JButton [Submit] which are appended to a JPanel..

The below image shows the effect before selecting the JForm:






This image shown is the effect after selecting the JForm:

                                     



the below code is an example which includes code for JForm custom component and main() includes usage of JForm.


import java.awt.Color;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Point;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentEvent;
import java.awt.event.ComponentListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;

public class JForm extends JButton {

Point location;
int X = 0;
int Y = 0;
int W = 0;
int H = 0;
JFrame frame;
MyWindow window;

public JForm(JFrame frame, JPanel panel) {

this.frame = frame;
this.setBackground(Color.gray);
this.setText("click me!...");
JForm.this.window = new MyWindow();
JForm.this.window.add(panel);
this.addActionListener(new ActionListener() {

@Override
public void actionPerformed(ActionEvent e) {

if (window.isVisible() == false) {
JForm.this.window.setSize(10, 20);
location = getLocationOnScreen();
X = location.x;
Y = location.y;
JForm.this.window.setLocation(X - 5, Y + JForm.this.getHeight());
window.pack();
window.setVisible(true);
}else{
window.setVisible(false);
}
}
});
}

class MyWindow extends Window {
public MyWindow() {
super(JForm.this.frame);
frame.addComponentListener(new ComponentListener() {
public void componentResized(ComponentEvent evt) {
if (JForm.this.isShowing() == true) {
location = JForm.this.getLocationOnScreen();
X = location.x;
Y = location.y;
JForm.this.window.setLocation(X - 5, Y + JForm.this.getHeight());
}
}

@Override
public void componentHidden(ComponentEvent arg0) {
if (JForm.this.isShowing() == true) {
location = JForm.this.getLocationOnScreen();
X = location.x;
Y = location.y;
JForm.this.window.setLocation(X - 5, Y + JForm.this.getHeight());
}
}

@Override
public void componentMoved(ComponentEvent arg0) {
if (JForm.this.isShowing() == true) {
location = JForm.this.getLocationOnScreen();
X = location.x;
Y = location.y;
JForm.this.window.setLocation(X - 5, Y + JForm.this.getHeight());
}
}

@Override
public void componentShown(ComponentEvent arg0) {
if (JForm.this.isShowing() == true) {
location = JForm.this.getLocationOnScreen();
X = location.x;
Y = location.y;
JForm.this.window.setLocation(X - 5, Y + JForm.this.getHeight());
}
}
});
}

}

public static void main(String[] args) {
JFrame frame = new JFrame();

GridBagLayout l = new GridBagLayout();

GridBagConstraints c = new GridBagConstraints();
c.gridwidth = 40;
c.gridheight = 20;
frame.setLayout(l);
JPanel panel = new JPanel();
GridBagLayout pl = new GridBagLayout();
GridBagConstraints pC = new GridBagConstraints();
JTextArea ta = new JTextArea(5, 10);
panel.add(ta, pC);
JButton button = new JButton("Submit");
pC.gridx = 50;
pC.gridy = 40;
panel.add(button, pC);

panel.setBackground(Color.gray);
JForm form = new JForm(frame, panel);
l.setConstraints(form, c);
frame.getContentPane().add(form, c);
frame.setSize(200, 200);
frame.pack();
frame.setVisible(true);
}
}

Next time I will come up with a JForm with different shapes like rounded, rounded corners etc..  

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