Simple Java Paint Program: How to change the color without changing the previous painted

Question

I am writing simple Paint program, where you paint whatever you want by dragging the mouse. You can change the color and the size of the brush, but in this version, when I change the color or the size of the brush, everything painted before is changed too when I start to draw again by dragging the mouse. I have tried with getGraphics method in the paintComponent method, but I probably did it wrong way because it did not help me.. Any ideas how to deal with this issue? Thank you.

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import javax.swing.JPanel;

public class PaintPanel extends JPanel{
    private int pointCount = 0;
    private Point points[] = new Point[10000];
    private Color currentColor;
    private int pointSize;

    public PaintPanel(){
        setBackground(Color.WHITE);
        setDefaultColor();
        setDefaultPointSize();
        addMouseMotionListener(
                new MouseMotionAdapter() {

                    public void mouseDragged(MouseEvent event){

                        if(pointCount < points.length){
                            points[pointCount] = event.getPoint();
                            pointCount++;
                            repaint();
                        }
                    }
        }
      );

    }

    public void setColor(Color newColor){
        currentColor = newColor;
    }

    public void setDefaultColor(){
        currentColor = Color.BLACK;
    }

    public void setPointSize(int size){
        pointSize = size;
    }

    public void setDefaultPointSize(){
        pointSize = 6;
    }

    public void paintComponent(Graphics g){
        super.paintComponent(g);
        g.setColor(currentColor);
        for(int i = 0; i < pointCount; i++)
            g.fillOval(points[i].x,points[i].y,pointSize,pointSize);
    }
}

Any option to do it without Collections?

Answer 1

Everything is colored currentColor You need two levels of storage. First of all, use an ArrayList to store your points. Then use an array list of array lists to store your "curves." Each "curve" should know its color.