[Guide][JAVA] First GUI app

[Matim]

First JAVA app with Graphical User Interface

 

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First of all, I would like to note, that there are plenty of guides with similar subject (as always)

 

But it may be useful for community, and may improve this section a little bit.

 

Its step by step guide, to help newbies understand as much as possible.

 

1. General begining:

 

- Open your JAVA IDE (I will use Eclipse)

 

- Create new JAVA PROJECT (of course, project name doesn't matter!) and create your package, for example: eu.matim

 

 

- Create new Java Class file, for example Called GuiExample, and lets say Class called App

 

 

And now lets explain a bit, we have two Java classes:

 

• 1st one GuiExample will be used to build general GUI of the app.
  
• 2nd one App will contain main function, and will run our app
  

 

2. Building sample GUI:

 

- Open GuiExample class, at begining its just empty class:

 

package eu.matim;

/**
* @author Matim
* @version 1.0
*/
public class GuiExample 
{

}

 

- we will extend our class by JFrame, to do so write:

 

extends JFrame

 

next to the class name, also we will have to import this class (press ctrl+shift+o to organize import automatically)

 

also I will add default serialVersionUID (just to remove annoying warning)

 

- with next step, we will create constructor of our class + initializeGUI() function, so our class should look now something like this:

 

package eu.matim;

import javax.swing.JFrame;

/**
* @author Matim
* @version 1.0
*/
public class GuiExample extends JFrame
{
private static final long serialVersionUID = 1L;

public GuiExample()
{
	initializeGUI();
}

private void initializeGUI()
{

}
}

 

- Now we will add simple button, to do so, create new object of the JButton:

 

private JButton sampleButton = new JButton();

 

and add this code to the body of the initializeGUI() function:

 

sampleButton.setText("Click Me!");

add(sampleButton, BorderLayout.SOUTH);

 

With above lines, we have created, set text for new button, and added it to our Frame.

 

Ok, GUI class just for sample example is mostly ready, lets create claass which will show/open our app.

 

3. Running app:

 

- Open previously created class: App, we will have to add main function (to be able to run our example), add this:

 

public static void main(String[] args)

{

 

  }

 

Ok, now we will create new object of our already created class with GUI, we will setTitle, size and make it visible (at it into main void)

 

GuiExample window = new GuiExample();

window.setSize(200, 100);

window.setTitle("Sample Frame!");

window.setVisible(true);

 

Now you can run this app, simnply press Run -> Run as -> 1.Java Application in your eclipse

 

If everything is correct, your first app Window should appear:

 

 

By default, default Java look and feel is used (kinda shitty) you can change it of course (for example to System default, like win 7 ex.)

 

4. Adding simple button function:

 

- Ok lets say we want to print current Date after pressing our sample button, to do so, we need add ActionListener

 

once again open GuiExample class, and add this code into initializeGUI() function:

 

sampleButton.addActionListener(new ActionListener()

       {

public void actionPerformed(ActionEvent e)

{

Date d = new Date();

System.out.println("Current System date: " + d);

}

});

 

Seems it's self explanatory, but lets examplain:

 

• we have added new action listener for our button
  
• created new object of Date class
  
• printed created object
  

 

Done, now run your application once again, and press button, you should receive info with current date.

 

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Ok, it was short and simple sample for beginers, may be helpful I guess, if you want more detailed info, google it.

 

Also I would like to notice, that building Java GUI manualy is really boring (you will need a lot of time to create advanced GUI's)

 

So there is solution of course, use NetBeens, it has built in proffesional "drag and dropp" GUI builer.

 

If you have any question, feel free to ask me.

 

(its pointless to create more advanced Guide, now you can practice easily)

 

 

[FighterBoss]

You can't believe how much i love reading java guides,but i'm kinda lazy to practise ;X .

Good idea for a guide about gui.Keep up,you know ;D .

@for any misunderstanding from your topic,i will reply.

[Matim]

Practising in this case is the best way to improve your skills in my opinion (of course connected with good theory first aswell)

 

Anyway about Java GUI's (and not only), really good challenge is creating your own GUI Components, why?

 

Because java Swing library contains only basic components, which in most cases are too primitive for big projects.

 

For example, such extended version of the JTree component:

 

 

Took my long time to make it, but its really funny job (for example defaul JTree doesn't support reading from HDD, right mouse click actions)

 

etc.

 

 

[Azumaril$]

woaou you cant imagine how good is this tutorial xD. !! As fighterboss said i love to read these, especially if they are like it. really thank s