Java help

nogono · #1 (**permalink**) 07-25-2007, 06:15 PM

what is addactionListener(this) means.....what exactly this means over here....

thanks

HelloWorld · #2 (**permalink**) 07-25-2007, 06:33 PM

this means the class that you're working on...
addActionListener(this) then means that you're passing this class into ActionListener, which I don't think would work...

Lee · #3 (**permalink**) 07-26-2007, 08:16 AM

Quote:

Originally Posted by HelloWorld

this means the class that you're working on...
addActionListener(this) then means that you're passing this class into ActionListener, which I don't think would work...

I think that line was an example and to know what that part ment he put this there so that it was clear to others trying to help

nogono · #4 (**permalink**) 07-27-2007, 02:06 PM

What is pane,panel,getcontentpane,container.......want meaning + Example...

HelloWorld · #5 (**permalink**) 07-27-2007, 02:27 PM

Quote:

Originally Posted by nogono

What is pane,panel,getcontentpane,container.......want meaning + Example...

Here's quote from Java API

Quote:

ContainergetContentPane()
Returns the contentPane object for this frame.

That's from javax.swing.JFrame package.

For panel, the only one that I usually use is JPanel, that will create the container of objects (which can be anything... example: JButton, another JPanel, JToolbar, etc)

Container is basically an Object that can be JFrame itself, which is the outermost of your panel, or JPanel... I'm not sure if there's another type of container, but those two are the most commonly used. You may want to check Java APIs for what are classes that inherits from the java.awt.Container package to see different kind of containers that Java offers

You may want to see my previous tutorial for the JFrame example

http://www.programmerstalk.net/thread692.html

nogono · #6 (**permalink**) 07-27-2007, 03:31 PM

SocketClient frame =

new SocketClient();
frame.setTitle("Client Program");
WindowListener l = new WindowAdapter() {
publicvoid windowClosing(WindowEvent e) {
System.exit(0);
}
};

frame.addWindowListener(l);
frame.pack();
frame.setVisible(true);
frame.listenSocket();

Can u understand me whole program........

HelloWorld · #7 (**permalink**) 07-27-2007, 03:38 PM

Quote:

Originally Posted by nogono

SocketClient frame =

new SocketClient();

frame.setTitle("Client Program");
WindowListener l = new WindowAdapter() {
publicvoid windowClosing(WindowEvent e) {
System.exit(0);
}
};

frame.addWindowListener(l);
frame.pack();
frame.setVisible(true);
frame.listenSocket();

Can u understand me whole program........

From the code that you gave me, it doesn't give me much information of what kind of application are you trying to create. But you named your class pretty well so I guess you're trying to create some kind of networking application. However, what does:

Code:

frame.listenSocket();

that do in your program?
The rest of your code is just the general setup for GUI

nogono · #8 (**permalink**) 07-27-2007, 07:59 PM

SocketClient frame =
new SocketClient();
frame.setTitle("Client Program");
WindowListener l = new WindowAdapter() {
publicvoid windowClosing(WindowEvent e) {
System.exit(0);
}
};

frame.addWindowListener(l);
frame.pack();
frame.setVisible(true);

i know it s a part of code(GUI)...I just want to understand this code......i am familiar with some concepts...but i am not clear about the syntax.....specially window adapter function......

HelloWorld · #9 (**permalink**) 07-27-2007, 10:55 PM

Before the explanation about WindowAdapter. Just to let you know that those lines of codes may also be replaced with this one and do the exact same thing:

PHP Code:

  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

And I hope that code is more readable than the one that you have (although it's actually better to use the one what you have because it's more explicit) "Better" in the sense that you have much more control to what do you want your GUI to do when the close "X" button is pressed.. lol.. I played with this around with my friend by poping up another window each time it's pressed!!!

Anyways, WindowAdapter and WindowListener are basically (almost) the same thing with actionListener that you have with other objects such as buttons. When you say

PHP Code:

  WindowListener l = new WindowAdapter() {

}

that means that you're calling the instance of WindowListener (the action listener for the GUI's window). As you may realize, Java divided your GUI into 3 parts: Window, Frames, and Panel. The Window will be the outer most of your GUI, the Frame will be the one that's within the Window (the content), and the Panel will be what is within the Frames (you can add JPanel within Frame).

WindowAdapter however is one method that must be overridden when you called WindowListener (It's an abstract method). And WindowAdapter class has a method called windowClosing that takes a WindowEvent.

PHP Code:

  System.exit(0); // you can change "0" to whatever you wanted

This code is the one that's going to close the System process of the JVM. Be careful with this when you run 2 Java program at the same time, because both of them will be closed when this function is called. It will basically turned off the JVM process.

Please note that I haven't personally research that deep to these matters, so I can't give you more detailed explanation than what I understood. Hopefully this would help

nogono · #10 (**permalink**) 07-28-2007, 11:15 AM

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