CODEWITHSUNDEEP
javaswingjframejbuttonjlabel
God
God

Reputation: 1248

JButton not shown on screen

Im trying to make an application that will change the state of a traffic light in the click of a button. My code: Main

import javax.swing.*;

public class PP416 
{
    public static void main(String[] args)
    {
        JFrame frame = new JFrame("Traffic light");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.getContentPane().add(new TrafficPanel());
        frame.pack();
        frame.setVisible(true);
    }
}

JPanel Class:

import javax.swing.*;
import java.awt.*;
import java.awt.Event;

public class TrafficPanel extends JPanel 
{
    private JButton button;
    private int indicator = 0; // Light is off

    public TrafficPanel()
    {
        button = new JButton("Change");

        this.add(button);
    }

    public void paint(Graphics g)
    {
        if (indicator == 0)
        {
            g.drawOval(30, 40, 30, 30);
            g.drawOval(30, 70, 30, 30);
            g.drawOval(30, 100, 30, 30);
        }
    }

}

the button just not appearing , just the ovalls. anyone can help me with this?

Upvotes: 1

Views: 59

Answers (1)

Hovercraft Full Of Eels
Hovercraft Full Of Eels

Reputation: 285405

Don't override paint but rather paintComponent and Most important, call the super's method. Your lack of a super call may be preventing your JPanel from drawing its child components well.

e.g.,

@Override
protected void paintComponent(Graphics g) {
   super.paintComponent(g);
   if (indicator == 0) {
       g.drawOval(30, 40, 30, 30);
       g.drawOval(30, 70, 30, 30);
       g.drawOval(30, 100, 30, 30);
   }
}

Upvotes: 2

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