Цвет краски программы не сохраняет цвет

Question

Я действительно застрял. Я не могу понять, почему предыдущий цвет моего paintComponent продолжает меняться. Я считаю, что проблема в моем arraylist, но я не знаю, как изменить arraylist, чтобы он мог принимать разные цвета.

public class Drawing extends JPanel { 
    private JRadioButton red, yellow, blue, erase; 
    private JButton button; 
    private Color c; 
    private ArrayList<Point> pointList; 
    private int counter = 0; 
    private boolean isDrawingMode = true; 
    private boolean eraser, isBlue; 
    private HashMap test; 


    public Drawing() { 
     setLayout(new FlowLayout()); 
     setBackground(Color.white); 
     JPanel pane = new JPanel(); 
     pointList = new ArrayList<Point>(); 
     addMouseListener(new MouseTrackerListener()); 

     red = new JRadioButton("Red"); 
     yellow = new JRadioButton("Yellow"); 
     blue = new JRadioButton("Blue"); 
     erase = new JRadioButton("Erase"); 
     button = new JButton("Clear Drawing"); 

     red.addActionListener(new ColorActionListener()); 
     yellow.addActionListener(new ColorActionListener()); 
     blue.addActionListener(new ColorActionListener()); 
     erase.addActionListener(new ColorActionListener()); 
     button.addActionListener(new ColorActionListener()); 

     pane.add(red); 
     pane.add(yellow); 
     pane.add(blue); 
     pane.add(erase); 
     pane.add(button); 
     add(pane); 
     pane.setBackground(Color.gray); 

     ButtonGroup group = new ButtonGroup(); 
     group.add(red); 
     group.add(yellow); 
     group.add(blue); 
     group.add(erase); 

     setPreferredSize(new Dimension(500, 500)); 
    } 

    public void paintComponent(Graphics pen) { 
     super.paintComponent(pen); 

     pen.setColor(Color.red); 
     pen.setColor(c); 



     for (int i = 0; i < pointList.size(); i++) { 

      Point p = pointList.get(i); 

      pen.fillOval(p.x, p.y, 10, 10); 

      if (eraser = true) { 


       p = pointList.get(i); 
       pen.drawOval(p.x, p.y, 10, 10); 
      } 

     } 

    } 

    private class MouseTrackerListener extends MouseInputAdapter { 
     public void mouseClicked(MouseEvent e) { 

      counter++; 
      if (counter % 2 != 0) { 
       addMouseMotionListener(new MouseTrackerListener()); 
       isDrawingMode = true; 

      } else { 
       isDrawingMode = false; 
      } 

     } 

     public void mouseMoved(MouseEvent e) { 
      if (isDrawingMode) { 
       Point point = e.getPoint(); 
       pointList.add(point); 

       repaint(); 
      } 
     } 
    } 

    private class ColorActionListener implements ActionListener { 
     public void actionPerformed(ActionEvent e) { 

      if (e.getSource() == red) { 
       c = Color.red; 
      } else if (e.getSource() == yellow) { 

       c = Color.yellow; 

      } else if (e.getSource() == blue) { 
       isBlue=true; 
       c = Color.blue; 
      } else if (e.getSource() == erase) { 
       eraser = true; 
       c=Color.white; 
      } else if (e.getSource() == button) { 
       pointList.clear(); 
       repaint(); 

      } 

     } 
    } 

    public static void main(String[] args) { 
     Drawing draw = new Drawing(); 
     JFrame frame = new JFrame("Draw Something!"); 

     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(draw); 
     frame.setSize(450, 450); 
     frame.setVisible(true); 
    } 

} 

Answer 1

Создайте пользовательский класс, который может содержать информацию о том, что рисовать и как покрасить его (цвет и форма)

public class Dot { 

    private Point p; 
    private Color color; 

    public Dot(Point p, Color color) { 
     this.p = p; 
     this.color = color; 
    } 

    public void draw(Graphics g) { 
     g.setColor(color); 
     g.drawOval(p.x, p.y, 10, 10); 
    } 

} 

Используйте это вместо того, чтобы хранить Points ...

public void mouseMoved(MouseEvent e) { 
    if (isDrawingMode) { 
     Point point = e.getPoint(); 
     pointList.add(new Dot(point, c)); 

     repaint(); 
    } 
} 

(Вам необходимо будет обновить pointList, чтобы принять Dot вместо Point)

Тогда просто покрасить "точки" ....

@Override 
protected void paintComponent(Graphics pen) { 
    super.paintComponent(pen); 
    for (int i = 0; i < pointList.size(); i++) { 

     Dot p = pointList.get(i); 
     p.draw(pen); 

    } 
} 

Пример

import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.FlowLayout; 
import java.awt.Graphics; 
import java.awt.Point; 
import java.awt.event.ActionEvent; 
import java.awt.event.ActionListener; 
import java.awt.event.MouseEvent; 
import java.util.ArrayList; 
import java.util.HashMap; 
import javax.swing.ButtonGroup; 
import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JRadioButton; 
import javax.swing.event.MouseInputAdapter; 

public class Drawing extends JPanel { 

    private JRadioButton red, yellow, blue, erase; 
    private JButton button; 
    private Color c; 
    private ArrayList<Dot> pointList; 
    private int counter = 0; 
    private boolean isDrawingMode = true; 
    private boolean eraser, isBlue; 
    private HashMap test; 

    public Drawing() { 
     setLayout(new FlowLayout()); 
     setBackground(Color.white); 
     JPanel pane = new JPanel(); 
     pointList = new ArrayList<Dot>(); 
     addMouseListener(new MouseTrackerListener()); 

     red = new JRadioButton("Red"); 
     yellow = new JRadioButton("Yellow"); 
     blue = new JRadioButton("Blue"); 
     erase = new JRadioButton("Erase"); 
     button = new JButton("Clear Drawing"); 

     red.addActionListener(new ColorActionListener()); 
     yellow.addActionListener(new ColorActionListener()); 
     blue.addActionListener(new ColorActionListener()); 
     erase.addActionListener(new ColorActionListener()); 
     button.addActionListener(new ColorActionListener()); 

     pane.add(red); 
     pane.add(yellow); 
     pane.add(blue); 
     pane.add(erase); 
     pane.add(button); 
     add(pane); 
     pane.setBackground(Color.gray); 

     ButtonGroup group = new ButtonGroup(); 
     group.add(red); 
     group.add(yellow); 
     group.add(blue); 
     group.add(erase); 

     setPreferredSize(new Dimension(500, 500)); 
    } 

    public void paintComponent(Graphics pen) { 
     super.paintComponent(pen); 
     for (int i = 0; i < pointList.size(); i++) { 

      Dot p = pointList.get(i); 
      p.draw(pen); 

     } 

    } 

    private class MouseTrackerListener extends MouseInputAdapter { 

     public void mouseClicked(MouseEvent e) { 

      counter++; 
      if (counter % 2 != 0) { 
       addMouseMotionListener(new MouseTrackerListener()); 
       isDrawingMode = true; 

      } else { 
       isDrawingMode = false; 
      } 

     } 

    public void mouseMoved(MouseEvent e) { 
     if (isDrawingMode) { 
      Point point = e.getPoint(); 
      pointList.add(new Dot(point, c)); 

      repaint(); 
     } 
    } 
    } 

    private class ColorActionListener implements ActionListener { 

     public void actionPerformed(ActionEvent e) { 

      if (e.getSource() == red) { 
       c = Color.red; 
      } else if (e.getSource() == yellow) { 
       c = Color.yellow; 
      } else if (e.getSource() == blue) { 
       c = Color.blue; 
      } else if (e.getSource() == erase) { 
       eraser = true; 
       c = Color.white; 
      } else if (e.getSource() == button) { 
       pointList.clear(); 
      } 
      repaint(); 

     } 
    } 

    public class Dot { 

     private Point p; 
     private Color color; 

     public Dot(Point p, Color color) { 
      this.p = p; 
      this.color = color; 
     } 

     public void draw(Graphics g) { 
      g.setColor(color); 
      g.drawOval(p.x, p.y, 10, 10); 
     } 

    } 

    public static void main(String[] args) { 
     Drawing draw = new Drawing(); 
     JFrame frame = new JFrame("Draw Something!"); 

     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().add(draw); 
     frame.setSize(450, 450); 
     frame.setVisible(true); 
    } 
}