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jjh08 says I see you jQuery :)

Posts I've Made

In Topic: Creating a Counter With "+" "-" Buttons

Posted 22 May 2013

@Cevo
This time, all your code is placed in main() but in the other case, the code logic was inside a constructor which would have created the infinite recursion GregBrannon was talking about. As I said before, from a practical standpoint, you don't want main() to have any code logic. You want the logic to be inside constructors and methods and have main() call those instead. Hope that helps

As far as the static keyword is concerned, you should ask yourself "Does it make sense to use this field or invoke this method without instantiating an object first?" In your case, it is unnecessary to use static because you do not have to put the code logic in main() but you chose to do so.
More resources : here and here
In Topic: Creating a Counter With "+" "-" Buttons

Posted 22 May 2013
Cevo, on 22 May 2013 - 03:48 PM, said:
i am not aware of all the methods you used there so i don't think i would be able to understand them fully at this moment.I used static because the variable was dropping to zero and starting another circle with the other button, so what i thought of making it static would bind the buttons to work together without the variable dropping.

That sample code g00se gave will create the GUI on the event dispatch thread. From the Java Tutorials:

Quote
In Swing programs, the initial threads don't have a lot to do. Their most essential job is to create a Runnable object that initializes the GUI and schedule that object for execution on the event dispatch thread. Once the GUI is created, the program is primarily driven by GUI events, each of which causes the execution of a short task on the event dispatch thread. Application code can schedule additionals tasks on the event dispatch thread (if they complete quickly, so as not to interfere with event processing) or a worker thread (for long-running tasks).

An initial thread schedules the GUI creation task by invoking javax.swing.SwingUtilities.invokeLater or javax.swing.SwingUtilities.invokeAndWait . Both of these methods take a single argument: the Runnable that defines the new task. Their only difference is indicated by their names: invokeLater simply schedules the task and returns; invokeAndWait waits for the task to finish before returning.

Hope that helps

Cevo, on 22 May 2013 - 03:59 PM, said:
@GregBrannon @jjh08
```
Click ClickCounter = new Click();
   stuff.add(lol);
   //+ button
   button.addActionListener(ClickCounter);
   stuff.add(button);
//- button
   stuff.add(button2);
   button2.addActionListener(ClickCounter);
```
So i think this will be right?
No, definitely use this like Greg said.
In Topic: Creating a Counter With "+" "-" Buttons

Posted 22 May 2013

GregBrannon, on 22 May 2013 - 03:52 PM, said:
@jjh08:

Your code is a design improvement, but you have two BIG mistakes that will cause the system to crash. The two errors are calling the constructor from the constructor. Instead of

// infinite recursion:
button.addActionListener( new Click() );

and

// infinite recursion:
button2.addActionListener( new Click() );

You do this:

button.addActionListener( this );
button2.addActionListener( this );

Thanks, I didn't even notice. My mistake

In Topic: Creating a Counter With "+" "-" Buttons

Posted 22 May 2013

Quote

If you declare them as class variables:

Great catch, Greg. I didn't see that at first but I did something like this:

public class Click implements ActionListener{
int sayac=0;
static JLabel lol=new JLabel("0 kere tıklandı");

JButton button = new JButton("+");
JButton button2 =new JButton("-");

public Click()
{
   JFrame frame=new JFrame("Counter");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.setSize(500,500);
   frame.setVisible(true);
   frame.setLayout(new FlowLayout());
   
 Container stuff=frame.getContentPane();
 
   stuff.add(lol);
   //+ button
   
   button.addActionListener(new Click());
   stuff.add(button);
//- button
   
   stuff.add(button2);
   button2.addActionListener(new Click());
}

public static void main(String[] args) {
        // TODO code application logic here
   new Click();
}
   @Override
 public void actionPerformed(ActionEvent e)
 {
   if(e.getSource().equals(button))       //problem is here &
     sayac++;
 
   else if(e.getSource().equals(button2)) //problem is here
         sayac--;
     
   lol.setText(sayac +" kere tıklandı");
 } 
}

Just took the code from main() and placed it inside a constructor for Click and had main() call it. I kept those two JButtons as instance variables. I didn't execute but no compile time errors.

In Topic: Creating a Counter With "+" "-" Buttons

Posted 22 May 2013

I just compiled the code in Eclipse. It says that "button" and "button2" cannot be resolved to a variable.
Basically, you declared button and button2 of type JButton in main() but you are trying to use them in another method called actionPerfomed(). You can't do this because those variables are local to main(). What you can do is take the two button variables out of main()'s scope and make them instance variables. Hope that helps

Also, you should make a constructor for Click and place all of the necessary code inside of that and then call it with main(). From a practical standpoint, main() should only have maybe 1 or 2 lines of code.