【发布时间】：2012-05-10 10:25:33
【问题描述】：
我有以下这个类，它刷新第 0 层中的 jpeg 文件，第 1 层用于绘制/绘画/素描与粉碎事物相关的任何内容。但是在我的绘图中，当我想做一条细线时，它会断裂。因为鼠标光标移动需要更慢。
如何解决鼠标快速移动，线保持连接？
Annotation.java
package test;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Annotation {
// Image
private static Image backgroundImage;
private static BufferedImage _bufImage = null;
// Enum
public static enum Shape { RECTANGLE, OVAL, LINE }
private static enum State { IDLE, DRAGGING }
private static final Shape INIIIAL_SHAPE = Shape.RECTANGLE;
private static final Color INITIAL_COLOR = Color.RED;
private static Shape _shape = INIIIAL_SHAPE;
private static Color _color = INITIAL_COLOR;
private static State _state = State.IDLE;
private static Point _start = null;
private static Point _end = null;
// JPanel
private static JPanel p;
private static JPanel mp;
/* Run: */
public static void main(String args[]) {
c();
}
/* GUI */
public static void c() {
try {
backgroundImage = ImageIO.read(new File("/var/tmp/test.jpeg"));
} catch (IOException e) {
e.printStackTrace();
}
myTimer();
loadAnnotation();
loadBackground();
JFrame f;
f = new JFrame();
f.setLayout(new BorderLayout());
f.add(mp);
f.pack();
f.setVisible(true);
}
/* 5 seconds to load picture */
public static void myTimer() {
javax.swing.Timer t = new javax.swing.Timer(5000, new ActionListener() {
public void actionPerformed(ActionEvent ae) {
try {
backgroundImage = ImageIO.read(new File("/var/tmp/test.jpeg"));
mp.repaint();
} catch (IOException e) {
e.printStackTrace();
}
}
});
t.start();
}
/* Layer 0:
* Load background picture */
public static void loadBackground() {
mp = new JPanel() {
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(backgroundImage, 0, 0, 1024, 600, null);
}
public Dimension getPreferredSize() {
return new Dimension(1024, 600);
}
};
mp.add(p);
}
/* Layer 1:
* Annotation: Draw on top of background picture anything! */
public static void loadAnnotation() {
p = new JPanel() {
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D)g;
g2.setColor(Color.RED);
if (_bufImage == null) {
int w = this.getWidth();
int h = this.getHeight();
_bufImage = new BufferedImage(1024,600, BufferedImage.TRANSLUCENT);
Graphics2D gc = _bufImage.createGraphics();
}
g2.drawImage(_bufImage, null, 0, 0);
if (_state == State.DRAGGING) {
g2.drawLine(_start.x, _start.y, _end.x , _end.y);
}
}
public Dimension getPreferredSize() {
return new Dimension(1024, 600);
}
};
p.setLayout(new FlowLayout());
p.addMouseListener(new MouseListener() {
@Override
public void mouseClicked(MouseEvent me) {
}
@Override
public void mousePressed(MouseEvent me) {
}
@Override
public void mouseReleased(MouseEvent me) {
//_state = State.IDLE;
_state = State.IDLE;
}
@Override
public void mouseEntered(MouseEvent me) {
}
@Override
public void mouseExited(MouseEvent me) {
}
});
p.addMouseMotionListener(new MouseMotionListener() {
@Override
public void mouseDragged(MouseEvent me) {
System.out.println("drag");
_state = State.DRAGGING;
_start = me.getPoint();
_end = _start;
if (_state == State.DRAGGING) {
Graphics2D g2 = _bufImage.createGraphics();
g2.setColor(Color.red);
g2.setStroke(new BasicStroke(90));
g2.fillOval(_start.x, _start.y, 10, 10);
p.repaint();
}
}
@Override
public void mouseMoved(MouseEvent me) {
System.out.println("move");
}
});
JButton pm = new JButton("+");
pm.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent ae) {
}
});
p.add(pm);
p.setOpaque(true);
}
}
【问题讨论】：
标签： java image swing graphics2d