Mouse drag and draw

   
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class MouseDragActionPanel extends JPanel implements MouseMotionListener {
  private static final int SquareWidth = 10;

  private static final int Max = 100;

  private Rectangle[] squares = new Rectangle[Max];

  private int squareCount = 0;

  private int currentSquareIndex = -1;

  public MouseDragActionPanel() {
    addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent evt) {
        int x = evt.getX();
        int y = evt.getY();
        currentSquareIndex = getSquare(x, y);
        if (currentSquareIndex < 0) // not inside a square
          add(x, y);
      }

      public void mouseClicked(MouseEvent evt) {
        int x = evt.getX();
        int y = evt.getY();

        if (evt.getClickCount() >= 2) {
          remove(currentSquareIndex);
        }
      }
    });
    addMouseMotionListener(this);
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    for (int i = 0; i < squareCount; i++)
      ((Graphics2D)g).draw(squares[i]);
  }

  public int getSquare(int x, int y) {
    for (int i = 0; i < squareCount; i++)
      if(squares[i].contains(x,y))
        return i;
    return -1;
  }

  public void add(int x, int y) {
    if (squareCount < Max) {
      squares[squareCount] = new Rectangle(x, y,SquareWidth,SquareWidth);
      currentSquareIndex = squareCount;
      squareCount++;
      repaint();
    }
  }

  public void remove(int n) {
    if (n < 0 || n >= squareCount)
      return;
    squareCount--;
    squares[n] = squares[squareCount];
    if (currentSquareIndex == n)
      currentSquareIndex = -1;
    repaint();
  }

  public void mouseMoved(MouseEvent evt) {
    int x = evt.getX();
    int y = evt.getY();

    if (getSquare(x, y) >= 0)
      setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
    else
      setCursor(Cursor.getDefaultCursor());
  }

  public void mouseDragged(MouseEvent evt) {
    int x = evt.getX();
    int y = evt.getY();

    if (currentSquareIndex >= 0) {
      Graphics g = getGraphics();
      g.setXORMode(getBackground());
      ((Graphics2D)g).draw(squares[currentSquareIndex]);
      squares[currentSquareIndex].x = x;
      squares[currentSquareIndex].y = y;
      ((Graphics2D)g).draw(squares[currentSquareIndex]);
      g.dispose();
    }
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.setTitle("MouseTest");
    frame.setSize(300, 200);
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });

    Container contentPane = frame.getContentPane();
    contentPane.add(new MouseDragActionPanel());

    frame.show();
  }
}

1.	Drags within the image
2.	Mouse Wheel Event Demo
3.	Move Shape with mouse
4.	MouseMotion Event: mouse move and drag
5.	MouseDrag -- implement simple mouse drag in a window
6.	MouseDragClip -- implement simple mouse drag in a window. Speed up by using clipping regions
7.	Swing Mouse Motion Event Demo
8.	Mouse Event Demo
9.	Handle mouse motion event
10.	Handle mouse button click event?
11.	Move and scale graphical objects with a mouse on the panel
12.	Detecting Double and Triple Clicks
13.	InputEvent.BUTTON1_MASK (for left mouse button)
14.	InputEvent.BUTTON2_MASK (for middle mouse button)
15.	InputEvent.BUTTON3_MASK (for right mouse button)
16.	Handling Mouse Clicks
17.	Handling Mouse Motion
18.	extends MouseAdapter and implements MouseMotionListener to create a mouse drawing programm

Mouse drag and draw : Mouse « Event « Java

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