How to enlarge the textfield in a swing panel?

Question

I'm trying to expand the textfield in my simple calculator program. I tried to increase the value of

JTextField text1= new JTextField (400); but nothing happened.

Answers will be appreciated. Please help...

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Carl extends JFrame{
    JTextField text1= new JTextField (400);
    JLabel label1= new JLabel (" ");
    JButton button1= new JButton ("1");
    JButton button2= new JButton ("2");
    JButton button3= new JButton ("3");
    JButton button4= new JButton ("4");
    JButton button5= new JButton ("5");
    JButton button6= new JButton ("6");
    JButton button7= new JButton ("7");
    JButton button8= new JButton ("8");
    JButton button9= new JButton ("9");
    JButton button10= new JButton ("0");
    JButton button11= new JButton ("+");
    JButton button12= new JButton ("-");
    JButton button13= new JButton ("*");
    JButton button14= new JButton ("/");
    JButton button15= new JButton ("=");
    JButton button16= new JButton ("C");
    JLabel blank1 = new JLabel("");
    JLabel blank2 = new JLabel("");
    JLabel blank3 = new JLabel("");
    JLabel blank4 = new JLabel(""); 
    Font times= new Font ("Times New Roman", Font.BOLD, 14);
    int operation1;
    int operation2;
    int operation3;
    int operation4;
    String n1,n2;
    JPanel p1 = new JPanel();
    JPanel p2 = new JPanel();

public Carl(){
        setResizable(true);
        setVisible(true);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setTitle("CARL DARWIN PAMINTUAN");
        setSize(300,300);           
        button1.setForeground(Color.BLACK);
        button2.setForeground(Color.BLACK);
        button3.setForeground(Color.BLACK);
        button4.setForeground(Color.BLACK);
        button5.setForeground(Color.BLACK);
        button6.setForeground(Color.BLACK);
        button7.setForeground(Color.BLACK);
        button8.setForeground(Color.BLACK);
        button9.setForeground(Color.BLACK);
        button10.setForeground(Color.BLACK);
        button11.setForeground(Color.BLACK);
        button12.setForeground(Color.BLACK);
        button13.setForeground(Color.BLACK);
        button14.setForeground(Color.BLACK);
        button15.setForeground(Color.BLACK);
        button16.setForeground(Color.BLACK);
        button1.setBackground(Color.BLUE);
        button2.setBackground(Color.BLUE);
        button3.setBackground(Color.BLUE);
        button4.setBackground(Color.BLUE);
        button5.setBackground(Color.BLUE);
        button6.setBackground(Color.BLUE);
        button7.setBackground(Color.BLUE);
        button8.setBackground(Color.BLUE);
        button9.setBackground(Color.BLUE);
        button10.setBackground(Color.BLUE);
        button11.setBackground(Color.BLUE);
        button12.setBackground(Color.BLUE);
        button13.setBackground(Color.BLUE);
        button14.setBackground(Color.BLUE);
        button15.setBackground(Color.BLUE);
        button16.setBackground(Color.BLUE);
        button1.setToolTipText ("one");
        button2.setToolTipText ("two");
        button3.setToolTipText ("three");
        button4.setToolTipText ("four");
        button5.setToolTipText ("five");
        button6.setToolTipText ("six");
        button7.setToolTipText ("seven");
        button8.setToolTipText ("eight");
        button9.setToolTipText ("nine");
        button10.setToolTipText ("zero");
        button11.setToolTipText ("addition");
        button12.setToolTipText ("subtraction");
        button13.setToolTipText ("multiplication");
        button14.setToolTipText ("division");
        button15.setToolTipText ("equal");
        button16.setToolTipText ("clear");
        button1.setFont(times);
        button2.setFont(times);
        button3.setFont(times);
        button4.setFont(times);
        button5.setFont(times);
        button6.setFont(times);
        button7.setFont(times);
        button8.setFont(times);
        button9.setFont(times);
        button10.setFont(times);
        button11.setFont(times);
        button12.setFont(times);
        button13.setFont(times);
        button14.setFont(times);
        button15.setFont(times);
        button16.setFont(times);
        label1.setFont(times);
        setLayout(new BorderLayout());
        add(p1,BorderLayout.CENTER);
        p1.setLayout(new GridLayout(6,3,2,2));
        p1.add(p2,BorderLayout.CENTER);
        p1.add(label1);
        p1.add(text1);
        p1.add(blank3);
        p1.add(button7);
        p1.add(button8);
        p1.add(button9);
        p1.add(button11);
        p1.add(button4);
        p1.add(button5);
        p1.add(button6);
        p1.add(button12);
        p1.add(button1);
        p1.add(button2);
        p1.add(button3);
        p1.add(button13);
        p1.add(button10);
        p1.add(button16);
        p1.add(button15);
        p1.add(button14);

button1.addActionListener(new Listener1());
        button2.addActionListener(new Listener2());
        button3.addActionListener(new Listener3());
        button4.addActionListener(new Listener4());
        button5.addActionListener(new Listener5());
        button6.addActionListener(new Listener6());
        button7.addActionListener(new Listener7());
        button8.addActionListener(new Listener8());
        button9.addActionListener(new Listener9());
        button10.addActionListener(new Listener0());
        button11.addActionListener(new ListenerAdd());
        button12.addActionListener(new ListenerSub());
        button13.addActionListener(new ListenerMul());
        button14.addActionListener(new ListenerDiv());
        button15.addActionListener(new ListenerEqual());
        button16.addActionListener(new ListenerClear());
}

    private class Listener1 implements ActionListener{
        public void actionPerformed (ActionEvent a){
            n1= text1.getText ();                   
            text1.setText (n1+"1");
        }
    }


private class Listener2 implements ActionListener{
        public void actionPerformed (ActionEvent b){
            n1= text1.getText ();
            text1.setText (n1+"2");
        }
    }   
    private class Listener3 implements ActionListener{
        public void actionPerformed (ActionEvent c){
            n1= text1.getText ();
            text1.setText (n1+"3");
        }
    }   
    private class Listener4 implements ActionListener{
        public void actionPerformed (ActionEvent d){
            n1= text1.getText ();
            text1.setText (n1+"4");
        }
    }   
    private class Listener5 implements ActionListener{
        public void actionPerformed (ActionEvent e){
            n1= text1.getText ();
            text1.setText (n1+"5");
        }
    }   

private class Listener6 implements ActionListener{
        public void actionPerformed (ActionEvent f){
            n1= text1.getText ();
            text1.setText (n1+"6");
        }
    }   
    private class Listener7 implements ActionListener{
        public void actionPerformed (ActionEvent g){
            n1= text1.getText ();
            text1.setText (n1+"7");
        }
    }   
    private class Listener8 implements ActionListener{
        public void actionPerformed (ActionEvent h){
            n1= text1.getText ();
            text1.setText (n1+"8");
        }
    }   
    private class Listener9 implements ActionListener{
        public void actionPerformed (ActionEvent i){
            n1= text1.getText ();
            text1.setText (n1+"9");
        }
    }

private class Listener0 implements ActionListener{
        public void actionPerformed (ActionEvent j){
            n1= text1.getText ();
            text1.setText (n1+"0");
        }
    }
    private class ListenerAdd implements ActionListener{
        public void actionPerformed (ActionEvent k){
            n2= text1.getText ();
            operation1=1;
            text1.setText ("");
        }
    }   
    private class ListenerSub implements ActionListener{
        public void actionPerformed (ActionEvent l){
            n2= text1.getText ();
            operation2=2;
            text1.setText ("");
        }
    }

private class ListenerMul implements ActionListener{
        public void actionPerformed (ActionEvent m){
            n2= text1.getText ();
            operation3=3;
            text1.setText ("");
        }
    }

    private class ListenerDiv implements ActionListener{
        public void actionPerformed (ActionEvent n){
            n2= text1.getText ();
            operation4=4;
            text1.setText ("");         
        }
    }
    private class ListenerEqual implements ActionListener{
        public void actionPerformed (ActionEvent o){
            if(operation1==1){
                int a=Integer.parseInt(n2);
                int b=Integer.parseInt(text1.getText());
                int sum = (a + b);  
                String sum1 = Integer.toString(sum);
                text1.setText(sum1);
            }

else{
            text1.getText();
            }
            if(operation2==2){
                int a=Integer.parseInt(n2);
                int b=Integer.parseInt(text1.getText());
                int dif = (a - b);
                String dif1 = Integer.toString(dif);
                text1.setText(dif1);
            }
            else{
            text1.getText();
            }
            if(operation3==3){
                int a=Integer.parseInt(n2);
                int b=Integer.parseInt(text1.getText());
                int product = (a * b);  
                String product1 = Integer.toString(product);
                text1.setText(product1); 
            }

else{
            text1.getText();
            }
            if(operation4==4){
                double a=Double.parseDouble(n2);
                double b=Double.parseDouble(text1.getText());
                double quo = (a/b); 
                String quo1 = Double.toString(quo);
                text1.setText(quo1); 
            }
            else{
            text1.getText();
            }       
        }
    }   
    private class ListenerClear implements ActionListener{
        public void actionPerformed (ActionEvent p){
            text1.setText("");
        }
    }   
public static void main(String[]args){
    Carl frame= new Carl();     
}
}

Answer 1

All components in a GridLayout have the same size. You may have to use a different LayoutManager. But you should consider ... restructuring ... your program anyhow.

Answer 2

As @dic19 answer's that you don't have to use setSize(300,300) as it is bad practice. Instead you have to use different Layout Managers.

One more thing I notice in your code you are using setVisible(true) before adding any component to your frame that is also bad practice . Instead you need to use setVisible(true) at last after you done with adding your all components to frame.

To use JTextField text1= new JTextField (400); this line you have to use different layout, you can't do it with your current layout manager you are using.

Look at this sample example here you can see how to use JTextField text1= new JTextField (400); and make appropriate changes

public class Calculator extends JFrame{
    private JButton button1;
    private final JPanel numPanel,labelPanel;
    Calculator(){
        button1 = new JButton("1");
        JButton button2 = new JButton("2");
        JButton button3 = new JButton("3");
        JButton button_plus = new JButton("+");

        JButton button4 = new JButton("4");
        JButton button5 = new JButton("5");
        JButton button6 = new JButton("6");
        JButton button_minus = new JButton("-");

        JButton button7 = new JButton("7");
        JButton button8 = new JButton("8");
        JButton button9 = new JButton("9");
        JButton button_multiple = new JButton("*");

        JButton button0 = new JButton("0");
        JButton clear = new JButton("clear");
        JButton delete = new JButton("delete");
        JButton button_divide = new JButton("/");
        JButton button_equals = new JButton("=");

        final TextField text = new TextField(15);

        JFrame frame = new JFrame("CALCULATOR");
        frame.setSize(300, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        numPanel = new JPanel();
        labelPanel = new JPanel();

        numPanel.setLayout(new GridLayout(4, 4));
        labelPanel.setLayout(new FlowLayout());

        numPanel.add(button1);
        button1.addActionListener(new ActionListener() {
                 public void actionPerformed(ActionEvent ae) {
                         text.setText(button1.getText());
                 }
        });

        numPanel.add(button2);
        button2.addActionListener(null);

        numPanel.add(button3);
        button3.addActionListener(null);

        numPanel.add(button_plus);
        button_plus.addActionListener(null);

        numPanel.add(button4);
        button4.addActionListener(null);

        numPanel.add(button5);
        button5.addActionListener(null);

        numPanel.add(button6);
        button6.addActionListener(null);

        numPanel.add(button_minus);
        button_minus.addActionListener(null);

        numPanel.add(button7);
        button7.addActionListener(null);

        numPanel.add(button8);
        button8.addActionListener(null);

        numPanel.add(button9);
        button9.addActionListener(null);

        numPanel.add(button_multiple);
        button_multiple.addActionListener(null);

        numPanel.add(button0);
        button0.addActionListener(null);

        numPanel.add(clear);
        clear.addActionListener(null);

        numPanel.add(delete);
        delete.addActionListener(null);

        numPanel.add(button_divide);
        button_divide.addActionListener(null);

        labelPanel.add(new JLabel("Answer"));
        labelPanel.add(text);
        labelPanel.add(button_equals);
        button_equals.addActionListener(null);

        frame.add(numPanel,BorderLayout.CENTER);
        frame.add(labelPanel, BorderLayout.SOUTH);
        frame.setVisible(true);
    }
    public static void main(String args[]) {
        new Calculator();
    }
}

Output: