Free hand Drawring on JFrame, Color + Point[] Storage and rendering failing

Question

The following program is supposed to allow free hand drawing on the one frame and the other as a button to open the color selector. The code for the main class can be found:

package clickTesting;

import Desksnap.Utils.Line;

import javax.swing.*;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.LinkedList;
import java.util.List;


public class Main {
    public static Color currentColor = null;

    public static void main(String[] args) {
        Viewer gui = new Viewer();
        button gui1 = new button();
        gui.setVisible(true);
        gui1.setVisible(true);
        boolean lol = true;
        while (lol) {
            gui.repaint(500);
        }
    }


    static class Viewer extends JFrame implements MouseMotionListener, MouseListener {
        public List<Line> lines = new LinkedList<Line>();
        private int index = 0;
        private Point[] arr = new Point[100000];

        public Viewer() {
            addMouseListener(this);
            addMouseMotionListener(this);
        }

        private void initComponents() {
            PhotoWindow = new JFrame();
            setUndecorated(true);
            {
                Container PhotoWindowContentPane = PhotoWindow.getContentPane();
                PhotoWindowContentPane.setLayout(null);
                PhotoWindowContentPane.setPreferredSize(new Dimension(410, 539));
                PhotoWindow.pack();
                PhotoWindow.setLocationRelativeTo(PhotoWindow.getOwner());
                addMouseListener(this);


            }
        }

        private JFrame PhotoWindow;


        @Override
        public void mousePressed(MouseEvent e) {
            arr[index] = new Point(e.getX(), e.getY());
            index++;
            System.out.println(index);
        }

        @Override
        public void mouseReleased(MouseEvent e) {
            lines.add(new Line(Main.currentColor, arr));
            arr = new Point[100000];
            index = 0;
            System.out.println("Released");
        }

        @Override
        public void mouseDragged(MouseEvent e) {
            arr[index] = new Point(e.getX(), e.getY());
            index++;
            System.out.println(index);
        }


        @Override
        public void paint(Graphics g) {
            super.paintComponents(g);
            if (lines.size() >= 0) {
                for (Line z : lines) {
                    if (z != null) {
                        Point[] lel = z.getLine();
                        g.setColor(z.getColor());
                        if (lel != null) {
                            for (int i = 0; i < lel.length; i++)
                                if (lel[i] != null) {
                                    g.drawLine(lel[i].x, lel[i].y, lel[i + 1].x, lel[i + 1].y);
                                }
                        } else {
                            System.out.println("Nope");
                        }
                    }
                }
            } else {
                System.out.println("Nothing In List Yet!");
            }
        }


        //Unused
        @Override
        public void mouseEntered(MouseEvent e) {
        }

        @Override
        public void mouseExited(MouseEvent e) {
        }

        @Override
        public void mouseMoved(MouseEvent e) {
        }

        @Override
        public void mouseClicked(MouseEvent e) {
        }
    }


    public static class button extends JFrame implements MouseMotionListener, MouseListener {
        public button() {
            this.addMouseListener(this);
            this.addMouseMotionListener(this);
        }

        private void initComponents() {
            PhotoWindow = new JFrame();
            setUndecorated(true);
            {
                Container PhotoWindowContentPane = PhotoWindow.getContentPane();
                PhotoWindowContentPane.setLayout(null);
                PhotoWindowContentPane.setPreferredSize(new Dimension(410, 539));
                PhotoWindow.pack();
                PhotoWindow.setLocationRelativeTo(PhotoWindow.getOwner());
                addMouseListener(this);
            }
        }

        private JFrame PhotoWindow;


        @Override
        public void mousePressed(MouseEvent e) {
            JColorChooser color = new JColorChooser();
            Main.currentColor = color.showDialog(
                    button.this,
                    "Choose Background Color",
                    Color.BLACK);
        }

        @Override
        public void mouseReleased(MouseEvent e) {
        }

        @Override
        public void mouseEntered(MouseEvent e) {
        }

        @Override
        public void mouseExited(MouseEvent e) {
        }

        @Override
        public void mouseDragged(MouseEvent e) {
        }

        @Override
        public void mouseMoved(MouseEvent e) {
        }

        @Override
        public void mouseClicked(MouseEvent e) {
        }
    }
}

This class supports the drawing, recording of the lines and the main loop:

package Desksnap.Utils;

import java.awt.*;
import java.util.*;
import java.util.List;


public class Line {
    Color color = null;
    Point[] points = null;

 public Line(Color color, Point[] points){
     color = this.color;
     points = this.points;
 }

    public Color getColor(){
        return color;
    }
    public Point[] getLine(){
        return points;
    }


}

This is the line class used.

After drawing a line the program just prints 'Nope' into the console.

Output: Nope x 10000000

Please help me understand what I've done wrong.

Answer 1

To start with, NEVER do this...

while (lol) {
    gui.repaint(500);
}

You do not control the paint process, that is the domain of the RepaintManager. If you want your component updated, use repaint ONCE and let the RepaintManager figure it out.

The core of your problem is here...

public Line(Color color, Point[] points) {
    color = this.color;
    points = this.points;
}

You are assigning the values of this.color to color and this.points to points, which has no effect. You should be assigning them the other way around (color to this.color)

You will, also want to take a closer look at:

• The Use of Multiple JFrames, Good/Bad Practice?
• Painting in AWT and Swing
• Performing Custom Painting

Calling super.paintComponents from within paint is a bad idea, you should be calling super.paint and let it take care of the appropriate paint calls.

Actually, you shouldn't be overriding paint without a really good reason, espically of top level containers. Instead, start by extending your paint class from a JPanel and override it's paintComponent method instead.

You can then add this component to what ever container you want.