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Thread: How to use multiple actionlisteners

  1. #1
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    Default How to use multiple actionlisteners

    Hi,
    I am trying to make a code that has multiple buttons, but the only way i know how to make action listeners are to either use inner classes (which require variable to be final, which isnt good for me), or to use AddActionListener(this), which only allows for one action listener.
    Ive heard somehting about getSource(), but cant find any good examples of how its used... Are there any other ways to use multiple action listeners?

    This is a code i was experimenting with getSource on, but i kept on getting an error:
    import java.awt.*;
    import javax.swing.*;
    import java.awt.event.ActionListener;
    import java.awt.event.ActionEvent;
    public class FindAddPage implements ActionListener
    {
        public static void main (String[] args)
        {
            int counter = 0;
            //set up frame
            GridLayout myLayout = new GridLayout (2,1);
            JFrame myFrame = new JFrame ("Add/Find");
            myFrame.setSize(400,200);
            JPanel myPanel = new JPanel();
            myPanel.setLayout(myLayout);
     
            //make buttons
            JButton add = new JButton ("Add A Tutor");
            JButton find = new JButton ("Find A Tutor");
     
            if(event.getSource()==add){
                counter++;
            }
     
            myFrame.setVisible(true);
        }
    }


  2. #2
    Super Moderator Norm's Avatar
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    Default Re: How to use multiple actionlisteners

    You can also make an inner class that extends ActionListener, create an instance of that and add it as a listener.
    Does your usage of getSource() work? Where is the object: event defined and given a value?
    Do a search on the forum for getSource() for some code samples.

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    Default Re: How to use multiple actionlisteners

    May be if our forum Vip means this try it
    public void actionPerformed(ActionEvent event)
    {
    if(event.getSource()==add){
    counter++;}
    }

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    Default Re: How to use multiple actionlisteners

    What does event.getSource() returns???
    Why don't you try casting it?

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    Default Re: How to use multiple actionlisteners

    Hi,
    I tried using this:
     ActionListener al = new ActionListener(){
            public void actionPerformed(ActionEvent event){
                if(event.getSource()==add){
                    counter++;
                }
            }
     };

    However it still gave me the error that "add" and "counter" would need to be made final... Is there a way to get around this?

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    Default Re: How to use multiple actionlisteners

    try to make add and counter Class variable

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    Default Re: How to use multiple actionlisteners

    Well, it's saying you coz i guess you are drawing buttons in your main() method, am i right?
    If so, remember, main() is a static method and you can't reference the object from static context like that.
    Well, can you give your whole code? Or is that all?

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    Default Re: How to use multiple actionlisteners

    I will suggest you some things.
    1. Draw the GUI in constructor.
    2. And then add an actionevent to the button, you want to.
    3. Make an object of GUI class in your main and set it to visible.

  9. #9
    Super Moderator Norm's Avatar
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    Default Re: How to use multiple actionlisteners

    Move the code out of the main method into the constructor for the class and have the only code in the main method call that constructor. Then you can use class variables.

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    Default Re: How to use multiple actionlisteners

    Hey,
    I got it to work. I made the GUI in a constructor method and then used main to create the new GUI. Thank You for the help

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