Waiting for a button click.

[Sebouh]

Hi guys. I don't know how to implement this so i was hoping if any of you can help me.

I have a code like this one:

public static void main (String args[])
{
    //create frame and button
    ....
 
    frame.setVisible(true);
    frame.add(button);
 
    do {
         ....
        // wait for a button click
 
        //code to be executed after a button click
         .....
 
        }while (true);
}

So i want to do some stuff and wait for a button click to continue. I set up a mouse listener and add it to the button (although the listener does nothing). The problem is, how can i wait for a button click. If this were a non-GUI application, i'd use a scanner and wait for an input from the user, which automatically halts the program. I figured using sleep would hang the application.

Any thoughts?

thanks a lot.

[r035198x]

Hi guys. I don't know how to implement this so i was hoping if any of you can help me.

I have a code like this one:

public static void main (String args[])
{
    //create frame and button
    ....
 
    frame.setVisible(true);
    frame.add(button);
 
    do {
         ....
        // wait for a button click
 
        //code to be executed after a button click
         .....
 
        }while (true);
}

So i want to do some stuff and wait for a button click to continue. I set up a mouse listener and add it to the button (although the listener does nothing). The problem is, how can i wait for a button click. If this were a non-GUI application, i'd use a scanner and wait for an input from the user, which automatically halts the program. I figured using sleep would hang the application.

Any thoughts?

thanks a lot.

You don't use a mouselistener for listening for button clicks. Use an ActionListener instead. The code for handling the button click goes into the actionPerformed method.

[Sebouh]

Yes, you're right. I forgot about that.

But still, how would i get the application to wait for the click. I thought of something like this:

...
    boolean clicked = false;
    ...
    while (!clicked) {
        Thread.sleep(1000);
    }
 
    ...
}
 
actionPerformed() {
clicked = true;
}

But this would hang the application every time it sleeps.

[r035198x]

Yes, you're right. I forgot about that.

But still, how would i get the application to wait for the click. I thought of something like this:

...
    boolean clicked = false;
    ...
    while (!clicked) {
        Thread.sleep(1000);
    }
 
    ...
}
 
actionPerformed() {
clicked = true;
}

But this would hang the application every time it sleeps.

Just don't do anything until the actionPerformed method is called.

[Sebouh]

I'm not sure what you mean by do nothing. If the the code is:

x = 1 + 1;
//wait for button click
x = 1 + 2;

how can i do nothing? I have to put something in between to keep the app waiting, don't i?

[r035198x]

I'm not sure what you mean by do nothing. If the the code is:

x = 1 + 1;
//wait for button click
x = 1 + 2;

how can i do nothing? I have to put something in between to keep the app waiting, don't i?

x = 1 + 2

goes into the actionPerformed method.

[Sebouh]

x = 1 + 2

goes into the actionPerformed method.

I understand, but my original code had a while loop. I can't divide the while loop and put part of it in actionPerformed(), can i?

[r035198x]

I understand, but my original code had a while loop. I can't divide the while loop and put part of it in actionPerformed(), can i?

Like this?

while(true) {
    //some stuff
    if(clicked) {
         //do stuff
    }
}

and you set the clicked flag in actionPerformed

P.S Careful that you don't run yourself into an infinite loop

[Sebouh]

I'm afraid i will run to an infinite loop. If the player takes his time to click the button, then i'll constantly loop over the other part.

I was hoping to some sort of a "wait" solution that halts the application. I mean, how does the scanner work when i request input? Does it loop too, or blocks the program? I'm thinking more in terms of block and sleep - click button - interrupt - wake up thing.

[r035198x]

I'm afraid i will run to an infinite loop. If the player takes his time to click the button, then i'll constantly loop over the other part.

I was hoping to some sort of a "wait" solution that halts the application. I mean, how does the scanner work when i request input? Does it loop too, or blocks the program? I'm thinking more in terms of block and sleep - click button - interrupt - wake up thing.

Even then someone/thread has to keep checking to see if the button was clicked.
You ran into an infinite loop because you had not handled all the conditions and included a break point from the loop.
Perhaps if you post the full code you are using and explain what you want to achieve with it ...

[JosAH]

@OP: just for a little experiment: comment out that entire while loop in your main
method, i.e. that method only creates the frame and makes it visible. Run it and
see what happens.

kind regards,

Jos