点击激活笔的Java画图

Question

所以我在java中做了一个画图应用程序。然而，不要点击并按住，然后拖动来画东西。相反，我想点击激活我的画笔/笔，它将绘制到我带上鼠标的位置，然后再次单击以取消激活画笔/笔。

public class DrawArea extends JComponent { 

private Image image; 
private Graphics2D g2; 

// Mouse coordinates 
private int currentX, currentY, oldX, oldY;  


public DrawArea() { 

addMouseListener(new MouseAdapter() { 
    public void mousePressed(MouseEvent e) { 
     // save coord x,y when mouse is pressed 
     oldX = e.getX(); 
     oldY = e.getY(); 
    } 
}); 

addMouseMotionListener(new MouseMotionAdapter() { 
    public void mouseDragged(MouseEvent e) { 
     // coord x,y when drag mouse 
     currentX = e.getX(); 
     currentY = e.getY(); 

     if (g2 != null) { 
     // draw oval if g2 context not null 
     g2.drawOval(oldX, oldY, 20, 20); 
     g2.fillOval(oldX, oldY, 20, 20); 

     // refresh draw area to repaint 
     repaint(); 
     // store current coords x,y as olds x,y 
     oldX = currentX; 
     oldY = currentY; 
     } 
    } 
}); 

Answer 1

创建一个变量，当您单击时激活，直到您再次单击，将该变量设置为false。这就是我所做的。