CODEWITHSUNDEEP
javauser-interface
Harminder Singh
Harminder Singh

Reputation: 67

Storing buttons to a variable

So for my program i have three buttons;

public void actionPerformed(ActionEvent e) {
        JButton b1= (JButton) e.getSource();
        JButton b2= (JButton) e.getSource();
        String button= b1.getText();
        String button2 = b2.getText();
        System.out.println("b1: " + button);
        System.out.println("b2: " + button2);

I'm trying to check which buttons are pressed and storing them into the variable. So when the user presses 8, button should be 8, and once they press any second button, button2 should get that button

Upvotes: 1

Views: 877

Answers (3)

Jacek Cz
Jacek Cz

Reputation: 1906

Every component can hold information on it, by putClientProperty(); This mechanism is kind of map, so can hold few named objects. We use only one. This obcjet (pie of information) is not visible for user, it is not text written on button like getText() in few tries, is only for consuming by algorithm. There can live not only primitives or strings, but live objects too.

class MyPanel extends JPanel{
    private JButton btn1, btn2;

    public MyPanel(){
        btn1 = new JButton("Button 1");
        btn1.putClientProperty("myinternalsense", 8); // <-- here

        btn2 = new JButton("Button 2");
        btn1.putClientProperty("myinternalsense", 5);  // <-- here
        btn1.putClientProperty("myfunctor", new MyFunctor() );  // <-- here

        ButtonHandler bn = new ButtonHandler();
        btn1.addActionListener(bh);
        btn2.addActionListener(bh);
    }
}

This information is accessible in any context, for example common event handler to many buttons.

private class ButtonHandler implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e){
        System.out.println((JButton)e.getSource().getClientPropertygetText("myinternasense"));  // <-- here
    }

}

Upvotes: 0

user3437460
user3437460

Reputation: 17454

Do i make a new ActionEvent?

Currently both your buttons refer to the same source (I.e the same button)

If the actions to be triggered are similar in nature (for example, the buttons in MineSweeper, they are different buttons, but the actions to be triggered are the same), then you don't have to create multiple action listeners for multiple buttons. You can let your buttons add the same action listener:

//Example
class MyPanel extends JPanel{
    private JButton btn1, btn2;

    public MyPanel(){
        btn1 = new JButton("Button 1");
        btn2 = new JButton("Button 2");
        ButtonHandler bn = new ButtonHandler();
        btn1.addActionListener(bh);
        btn2.addActionListener(bh);
    }
}

Infact, what you wanted to do is just a one-liner:

private class ButtonHandler implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent e){
        System.out.println((JButton)e.getSource().getText());
    }
}

However, if you have different actions for different buttons (for example, Start Game and Exit Game), then you can create separate action listeners for them.

Upvotes: 1

deHaar
deHaar

Reputation: 18578

So maybe you want to check the source of the event? Like:

public void actionPerformed(ActionEvent e) {
    if (e.getSource() == b1) {
        System.out.println("b1 pressed");
    } else if (e.getSource() == b2) {
        System.out.println("b2 pressed");
    } else {
        System.out.println("some other button pressed");
    }
}

and you should really create different buttons outside of the scope of this actionPerformed method!

EDIT The example solution by user3437460 is much better than this one…

Upvotes: 0

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