java学习笔记->画图板
简单画图板的制作
- 工具
- 步骤一：基本面板的创建
- 1.创建一个窗体
- 2.创建一个监听器类实现鼠标监听器
- 3.取到按下释放的x,y值，取到Graphics 对象
- 4.再将对象传递到监听器类中
- 运行效果
- 步骤二：基本画图功能的实现
- 代码，有注释哦
- 运行结果
- 中间遇到的问题
- Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 3
- 超出边界画图问题
- 步骤三：代码优化及功能丰富
- 效果展示
- 总结
- 更新代码
- 效果
环境：eclipse
工具
swing包（用于制作界面）
监听器：鼠标监听器MouseListener（用于监听鼠标动作）
绘制类：graphics类（用于画图）
步骤一：基本面板的创建
1.创建一个窗体
新建package命名为drawing_board,在其下新建class命名为board
package drawing_board;
import java.awt.FlowLayout;
import javax.swing.JFrame;
public class board {
public static void main(String[] args){
board bo = new board();
bo.initUI();
}
public void initUI() {
// top container -form JFrame instantiate object→create a form object
JFrame jf = new JFrame();
jf.setTitle("drawing board");
jf.setSize(1920, 1080);
//frame size自定义窗体大小
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// process close关闭进程
jf.setLocationRelativeTo(null);
// centered居中显示
FlowLayout fl = new FlowLayout();
// Fluid layout流式布局
jf.setLayout(fl);
jf.setVisible(true);// 可视化
}
}
2.创建一个监听器类实现鼠标监听器
新建class命名为DrawingListener，输入
package drawing_board;
import java.awt.event.MouseListener;
public class DrawingListener implements MouseListener{
}
将鼠标移到MouseListener，按F3，复制粘贴相关代码
package drawing_board;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
public class DrawListener implements MouseListener {
public void mouseClicked(MouseEvent e) {
}
public void mousePressed(MouseEvent e) {
}
public void mouseReleased(MouseEvent e) {
}
public void mouseEntered(MouseEvent e) {
}
public void mouseExited(MouseEvent e) {
}
}
3.取到按下释放的x,y值，取到Graphics 对象
继续补充代码
package drawing_board;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
import java.awt.Graphics;
public class DrawListener implements MouseListener {
int x1, x2, y1, y2;
Graphics g;
public void mouseClicked(MouseEvent e) {
System.out.println("点击");
}
public void mousePressed(MouseEvent e) {
System.out.println("按下");
x1 = e.getX();
y1 = e.getY();
}
public void mouseReleased(MouseEvent e) {
System.out.println("释放");
x2 = e.getX();
y2 = e.getY();
g.drawLine(x1, y1, x2, y2);
//to draw a line实现绘图功能
}
public void mouseEntered(MouseEvent e) {
System.out.println("进入");
}
public void mouseExited(MouseEvent e) {
System.out.println("离开");
}
}
4.再将对象传递到监听器类中
接下来，在board中实现它的方法，在jf.setVisible(true)前后分别增添如下代码
DrawListener dl = new DrawListener();
jf.addMouseListener(dl);
//调用接口方法
jf.setVisible(true);// 可视化
Graphics g = jf.getGraphics();
dl.g=g;
//传递画图对象
整个board代码如下
package drawing_board;
import java.awt.FlowLayout;
import java.awt.Graphics;
import javax.swing.JFrame;
public class board {
public static void main(String[] args){
board bo = new board();
bo.initUI();
}
public void initUI() {
// top container -form JFrame instantiate object→create a form object
JFrame jf = new JFrame();
jf.setTitle("drawing board");
jf.setSize(1920, 1080);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// process close关闭进程
jf.setLocationRelativeTo(null);
// centered居中显示
FlowLayout fl = new FlowLayout();
// Fluid layout流式布局
jf.setLayout(fl);
DrawListener dl = new DrawListener();
jf.addMouseListener(dl);
jf.setVisible(true);// 可视化
Graphics g = jf.getGraphics();
dl.g=g;
}
}
运行效果
由于录屏软件的问题，鼠标被自动隐藏了。
步骤二：基本画图功能的实现
代码，有注释哦
上面的程序只能画直线，这肯定是不够的，拿着只能画直线的东东有啥用嘛，还不如自己一支铅笔一张纸靠谱呢，是吧。ᐕ)⁾⁾
来，我们先看一看窗体的构建，打开eclipse，左上角，new file，然后new package，然后新建一个DrawPad2类（class）和一个Listener类
package DrawPad2;
import java.awt.FlowLayout;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JButton;
public class DrawPad {
Listener ls = new Listener();
public static void main(String[] args) {
DrawPad dp = new DrawPad();
dp.initUI();
}
public void initUI() {
JFrame jf = new JFrame();
jf.setSize(1280, 720);
jf.setLocationRelativeTo(null);
//居中center the frame
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JButton jb1 = new JButton("直线");
JButton jb2 = new JButton("矩形");
JButton jb3 = new JButton("圆");
JButton jb4 = new JButton("三角形");
JButton jb5 = new JButton("红色");
JButton jb6 = new JButton("蓝色");
JButton jb7 = new JButton("黄色");
JButton jb8 = new JButton("绿色");
JButton jb9 = new JButton("黑色");
FlowLayout fl = new FlowLayout();
//啦啦啦（∩△∩），老样子，流式布局
//Fiuid layout as usual
Listener ls = new Listener();
jb1.addActionListener(ls);
jb2.addActionListener(ls);
jb3.addActionListener(ls);
jb4.addActionListener(ls);
jb5.addActionListener(ls);
jb6.addActionListener(ls);
jb7.addActionListener(ls);
jb8.addActionListener(ls);
jb9.addActionListener(ls);
jf.addMouseListener(ls);
//调用Listener类，Listener继承了动作监听器和鼠标监听器的方法，等会会解释╰(*´︶`*)╯
//call the Listener class which implements ActionListener and MouseListener
jf.setLayout(fl);
jf.add(jb1);
jf.add(jb2);
jf.add(jb3);
jf.add(jb4);
jf.add(jb5);
jf.add(jb6);
jf.add(jb7);
jf.add(jb8);
jf.add(jb9);
jf.setVisible(true);
//没这个窗体都打不开哦，我经常忘记这个，十分尴尬<(。_。)>
Graphics g = jf.getGraphics();
ls.g=g;
//调用graphics类的方法，不然没法作图哟(*σ´∀`)σ
}
}
很简单，只是建立了几个按钮而已啦，仍然采用流式布局~
咳咳，接下来才是重点，我们一起来see see那个Listener类，先看代码
package DrawPad2;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
public class Listener implements ActionListener, MouseListener {
int x1, x2, y1, y2, x0, y0, w0, h0, y3, y4, y5, i = 0;
int tx[] = { 0, 0, 0 };
int ty[] = { 0, 0, 0 };
//这个如果不赋初值，有可能会报错的哟，大家可以自己试一试
Graphics g;
String intest = "";
public void actionPerformed(ActionEvent e) {
intest = e.getActionCommand();
if (intest.equals("红色"))
g.setColor(Color.RED);
if (intest.equals("蓝色"))
g.setColor(Color.BLUE);
if (intest.equals("黄色"))
g.setColor(Color.YELLOW);
if (intest.equals("绿色"))
g.setColor(Color.GREEN);
if (intest.equals("黑色"))
g.setColor(Color.BLACK);
//呐，这个很简单的啦，线条颜色设定嘛，问题不大
}
public void mouseClicked(MouseEvent e) {
System.out.println("点击");
//三角形方法一
if (intest.contentEquals("三角形")) {
tx[i] = e.getX();
ty[i] = e.getY();
i++;
if (i == 1) {
g.drawLine(tx[0], ty[0], tx[0], ty[0]);
}
else if (i == 2) {
g.drawLine(tx[0], ty[0], tx[1], ty[1]);
}
else if (i == 3) {
g.drawLine(tx[1], ty[1], tx[2], ty[2]);
g.drawLine(tx[2], ty[2], tx[0], ty[0]);
i = 0;
//重置计数
}
//这是一个，取两个点就画一条线的模式，待会儿会给大家演示的啦
//三角形方法二
// if (i == 3) {
// g.drawLine(tx[0], ty[0], tx[1], ty[1]);
// g.drawLine(tx[1], ty[1], tx[2], ty[2]);
// g.drawLine(tx[2], ty[2], tx[0], ty[0]);
// System.out.println(ty[0] + " " + tx[0]);
// System.out.println(ty[1] + " " + tx[1]);
// System.out.println(ty[2] + " " + tx[2]+" 3");
// System.out.println(ty[3] + " " + tx[3]);
////这几行是测试代码啦，我调值的时候遇到了老多波折了，哭唧唧，上面第一种方法，我把这四行代码复制了3遍，才搞清楚关系
// i = 0;
//
// }
//这是一个，取完三个点再一次性划线的模式
}
}
public void mousePressed(MouseEvent e) {
System.out.println("按下");
x1 = e.getX();
y1 = e.getY();
}
public void mouseExited(MouseEvent e) {
System.out.println("离开");
//其实这里没有必要的啦，但是，不加这串代码的话，会出问题的，就是鼠标出边界的时候，就画不了图了，等会给大家演示下哈
x2 = e.getX();
y2 = e.getY();
if (x1 > x2) {
x0 = x2;
w0 = x1 - x2;
} else {
x0 = x1;
w0 = x2 - x1;
}
if (y1 > y2) {
y0 = y2;
h0 = y1 - y2;
} else {
y0 = y1;
h0 = y2 - y1;
}
//大家看懂这波操作了嘛，看懂了？大佬大佬，我还是太嫩了，求大佬给些更好的意见。没看懂？来来来，首先啊，Graphics类，默认的坐标轴，是y轴向下的，同时左上角是原点，然后，Graphics作图的习惯是，取一个基准点（总是两个坐标中的最小值），然后规定长宽，同时Graphics类里的函数都不可以带负值，所以，我们要把长宽取绝对值，前后两个坐标的x和y分别取小的值，还不清楚可以留言问我哦
if (intest.equals("矩形")) {
g.drawRect(x0, y0, w0, h0);
} else if (intest.equals("圆")) {
g.drawOval(x0, y0, w0, h0);
}
}
public void mouseReleased(MouseEvent e) {
System.out.println("释放");
x2 = e.getX();
y2 = e.getY();
if (x1 > x2) {
x0 = x2;
w0 = x1 - x2;
} else {
x0 = x1;
w0 = x2 - x1;
}
if (y1 > y2) {
y0 = y2;
h0 = y1 - y2;
} else {
y0 = y1;
h0 = y2 - y1;
}
//跟上面一样的操作啦（＞ｙ＜）
if (intest.equals("直线")) {
g.drawLine(x1, y1, x2, y2);
} else if (intest.equals("矩形")) {
g.drawRect(x0, y0, w0, h0);
} else if (intest.equals("圆")) {
g.drawOval(x0, y0, w0, h0);
}
// else
}
public void mouseEntered(MouseEvent e) {
System.out.println("进入");
}
}
//下面是之前的旧代码啦，有点冗余，先得出变量结果再进入画的东西就很方便啦
//旧矩形
//if (x2 > x1) {
//
// if (y2 > y1)
// g.drawRect(x1, y1, x2 - x1, y2 - y1);
// else
// g.drawRect(x1, y2, x2 - x1, y1 - y2);
//} else {
// if (y2 > y1)
// g.drawRect(x2, y1, x1 - x2, y2 - y1);
// else
// g.drawRect(x2, y2, x1 - x2, y1 - y2);
//}
//旧圆
//if (x2 > x1) {
//
// if (y2 > y1)
// g.drawOval(x1, y1, x2 - x1, y2 - y1);
// else
// g.drawOval(x1, y2, x2 - x1, y1 - y2);
//} else {
// if (y2 > y1)
// g.drawOval(x2, y1, x1 - x2, y2 - y1);
// else
// g.drawOval(x2, y2, x1 - x2, y1 - y2);
//}
运行结果
中间遇到的问题
Exception in thread “AWT-EventQueue-0” java.lang.ArrayIndexOutOfBoundsException: 3
这个问题出现的可能有很多，原因都是计算机中出现了未定义的变量之类的，我给大家示范一下
大家看，为什么点击三下之后报错呢，因为去掉i=1后，i会无限增加，但我一这个监听器方法里必须i=1,2，3，三角形方法失效了，就会出错，如果有同学遇到了一样的报错提示，去找找自己的变量问题吧~good luck了您嘞（＾ω＾）
超出边界画图问题
我先给大家示范一下这个问题哈
大家注意到了嘛，那么方法就是，把我注释掉的东西加回来咯，啦啦啦~，不过这个方法也有弊端，有同学可能也在上面运行结果图中看到了，就是，碰到按钮它也会触发离开方法，这个问题，等我们明天学个新框框，就可以解决啦
步骤三：代码优化及功能丰富
步骤二中的代码过于冗杂，大家可以看到 按钮界面 我傻傻的从前往后疯狂加。。。非常浪费时间和空间，我们先来看看升级后的代码，新的代码优化了布局，还增加了两个新物件。
首先新建一个package取名DrawPad，其下有两个class，DrawPad3和Listener3（为什么要加数字呢。。。因为本人之前做了个非常傻的事情。。。我有两个DrawPad包，然后我调试bug的时候疯狂修改第一个的Listener，妄图解决第二个DrawPad的问题。。。那能解决掉么。。。被身边的同学嘲笑了半天，真的是无地自容(Ｔ▽Ｔ)），好了，看代码吧，首先是DrawPad3
package com_0905_DrawPad;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
public class DrawPad3 {
public static void main(String[] args) {
DrawPad3 dp = new DrawPad3();
dp.initUI();
}
public void initUI() {
JFrame jf = new JFrame();
BorderLayout bl = new BorderLayout();
FlowLayout fl = new FlowLayout();
Listener3 ls = new Listener3();
// 创建窗体
jf.setSize(1280, 720);
jf.setLayout(bl);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// 设置大小属性，使用边框布局，
JPanel jp1 = new JPanel();
jp1.setPreferredSize(new Dimension(1280, 50));
jp1.setLayout(fl);
jp1.setBackground(Color.gray);
// 北方向jp1采用流式布局
JPanel jp2 = new JPanel();
jp2.setBackground(Color.white);
JPanel jp3 = new JPanel();
jp3.setBackground(Color.gray);
JPanel jp4 = new JPanel();
jp4.setBackground(Color.gray);
JPanel jp5 = new JPanel();
jp5.setBackground(Color.gray);
// 设置东西南北中五个方向的属性颜色
JPanel jp1_2 = new JPanel();
jp1_2.setLayout(fl);
// jp1_2.setPreferredSize(new Dimension(640,50));
jp1_2.setBackground(Color.gray);
//设置颜色区属性
JPanel jp1_1 = new JPanel();
jp1_1.setLayout(fl);
// jp1_1.setPreferredSize(new Dimension(640,50));
jp1_1.setBackground(Color.gray);
//设置功能区属性
jp1.add(jp1_1);
jp1_1.setPreferredSize(new Dimension(600, 50));
// 在北方向jp1的窗口中创建按钮西方向的窗口，采用流式布局
jp1.add(jp1_2);
jp1_2.setPreferredSize(new Dimension(600, 50));
// 在北方向jp1的窗口中创建东方向的窗口，采用流式布局
JButton jb1 = new JButton("功能区");
jp1_1.add(jb1);
String[] btnstr = { "直线", "矩形", "圆", "三角形", "哆啦A梦", "小章鱼" };
for (int i = 0; i < btnstr.length; i++) {
JButton btn = new JButton(btnstr[i]);
jp1_1.add(btn);
btn.addActionListener(ls);
//调用动作监听器
}
// 在jp1的西方向窗口创建功能区按钮
JButton jb2 = new JButton("颜色区");
jp1_2.add(jb2);
Color[] btnco = { Color.red, Color.blue, Color.yellow, Color.green, Color.black };
for (int i = 0; i < btnco.length; i++) {
JButton btn = new JButton("");
btn.setBackground(btnco[i]);
btn.setPreferredSize(new Dimension(50, 30));
//设置单个按钮大小
jp1_2.add(btn);
btn.addActionListener(ls);
//调用动作监听器
}
// 在jp1的东方向按钮中创建颜色区按钮
jf.add(jp1, BorderLayout.NORTH);
jf.add(jp2, BorderLayout.CENTER);
jf.add(jp3, BorderLayout.SOUTH);
jf.add(jp4, BorderLayout.EAST);
jf.add(jp5, BorderLayout.WEST);
// 将东西南北中四个组件添加到jf中
jf.setVisible(true);
// 可视化
jp2.addMouseListener(ls);
//在绘画面板中加入鼠标监听器
Graphics g = jp2.getGraphics();
ls.g = g;
//调用graphics类的画图功能
}
}
然后是Listener
package DrawPad;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JButton;
public class Listener3 implements ActionListener, MouseListener {
int x1, x2, y1, y2, x0, y0, w0, h0, y3, y4, y5, i = 0;
int tx[] = { 0, 0, 0 };
int ty[] = { 0, 0, 0 };
Graphics g;
String intest = "三角形";
public void actionPerformed(ActionEvent e) {
intest = e.getActionCommand();
System.out.println(" 点击按钮 ");
if ("".equals(intest)) {
JButton btn = (JButton) e.getSource();
Color c = btn.getBackground();
g.setColor(c);
System.out.println(c);
//如果按钮是空文本，就取背景颜色
}
}
public void mouseClicked(MouseEvent e) {
System.out.println("点击");
tx[i] = e.getX();
ty[i] = e.getY();
i++;
if (intest.equals("三角形")) {
if (i == 1) {
g.drawLine(tx[0], ty[0], tx[0], ty[0]);
} else if (i == 2) {
g.drawLine(tx[0], ty[0], tx[1], ty[1]);
} else if (i == 3) {
g.drawLine(tx[1], ty[1], tx[2], ty[2]);
g.drawLine(tx[2], ty[2], tx[0], ty[0]);
i = 0;
}
}
}
public void mousePressed(MouseEvent e) {
System.out.println("按下");
x1 = e.getX();
y1 = e.getY();
}
public void mouseExited(MouseEvent e) {
System.out.println("离开");
}
public void mouseReleased(MouseEvent e) {
System.out.println("释放");
x2 = e.getX();
y2 = e.getY();
if (x1 > x2) {
x0 = x2;
w0 = x1 - x2;
} else {
x0 = x1;
w0 = x2 - x1;
}
if (y1 > y2) {
y0 = y2;
h0 = y1 - y2;
} else {
y0 = y1;
h0 = y2 - y1;
}
if (intest.equals("直线")) {
g.drawLine(x1, y1, x2, y2);
} else if (intest.equals("矩形")) {
g.drawRect(x0, y0, w0, h0);
} else if (intest.equals("圆")) {
g.drawOval(x0, y0, w0, h0);
} else if (intest.equals("哆啦A梦")) {
g.setColor(Color.blue);
g.fillOval(x0, y0, w0, h0);
// 脸部大圆
g.setColor(Color.white);
g.fillOval((int) (x0 + w0 * 0.075), (int) (y0 + h0 * 0.075), (int) (w0 * 0.85), (int) (h0 * 0.85));
// 脸部小圈
g.setColor(Color.white);
g.fillOval((int) (x0 + w0 / 2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g.fillOval((int) (x0 + w0 / 2 - w0 * 0.2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g.setColor(Color.black);
g.drawOval((int) (x0 + w0 / 2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g.drawOval((int) (x0 + w0 / 2 - w0 * 0.2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
// 眼睛外轮廓
g.setColor(Color.black);
g.fillOval((int) (x0 + w0 / 2), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05), (int) (h0 * 0.05));
g.fillOval((int) (x0 + w0 / 2 - w0 * 0.05), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05),
(int) (h0 * 0.05));
// 黑眼球
g.setColor(Color.black);
g.drawLine((int) ((x0 + w0 / 2 - w0 * 0.025) + w0 * 0.05 / 2),
(int) ((y0 * 1.2 + h0 * 0.375) + h0 * 0.05 / 2), (int) (x0 + w0 * 0.25 + w0 * 0.5 / 2),
(int) (y0 + h0 / 3 + h0 / 2));
g.drawArc((int) (x0 + w0 * 0.25), (int) (y0 + h0 / 3), (int) (w0 * 0.5), (int) (h0 / 2), 0, -180);
// 嘴巴微笑
g.setColor(Color.red);
g.fillOval((int) (x0 + w0 / 2 - w0 * 0.025), (int) (y0 * 1.2 + h0 * 0.375), (int) (w0 * 0.05),
(int) (h0 * 0.05));
// 鼻子
g.setColor(Color.black);
} else if (intest.equals("小章鱼")) {
g.drawOval(x0, y0, w0, h0);
// 脸部大圆
g.drawOval((int) (x0 + w0 / 2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g.drawOval((int) (x0 + w0 / 2 - w0 * 0.2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g.fillOval((int) (x0 + w0 / 2), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05), (int) (h0 * 0.05));
g.fillOval((int) (x0 + w0 / 2 - w0 * 0.05), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05),
(int) (h0 * 0.05));
// 两个眼睛
g.drawOval((int) (x0 + w0 * 0.5 - w0 * 0.25 / 2), (int) (y0 + h0 / 2 + h0 / 4 - h0 * 0.25),
(int) (w0 * 0.25), (int) (h0 * 0.25));
g.drawOval((int) (x0 + w0 * 0.5 - w0 * 0.15 / 2), (int) (y0 + h0 / 2 + h0 / 4 - h0 * 0.1875),
(int) (w0 * 0.15), (int) (h0 * 0.15));
// 嘴巴
g.drawArc((int) (x0), (int) (y0 + h0 / 2), (int) (w0), (int) (h0 / 2), 0, -180);
g.drawArc((int) (x0), (int) (y0 + 3 * h0 / 4), (int) (w0), (int) (h0 / 4), 0, -180);
g.drawArc((int) (x0), (int) (y0 + 5 * h0 / 6), (int) (w0), (int) (h0 / 6), 0, -180);
// 小腿
}
}
public void mouseEntered(MouseEvent e) {
System.out.println("进入");
}
}
效果展示
咳咳，这哆啦A梦和那个章鱼，丑是丑了点，这只是测试版本嘛，有能力的同学设计了更好看的图像可以在下面留个言，让我学习一下丫，和上面第二步代码的区别，在注释里我都标注了，我总结一下，就是按钮用循环来写，以及用数学方法设计组合图形。
总结
鼠标监听器可以记录鼠标的点击，按压，释放，进入和离开（界面），graphics类可以帮助我们画图，配合动作监听器获取坐标，结合一个窗体便是完整的画图板咯，更多进阶功能，可以自行开发呀兄弟萌。✧٩(ˊωˋ*)و✧
更新代码
新增了一个可以控制画笔大小的滑块儿，及一些分型功能，左上角新建了菜单（但没有赋予实际功能）。
DrawPad3.java
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.JButton;
public class DrawPad3 {
public static void main(String[] args) {
DrawPad3 dp = new DrawPad3();
dp.initUI();
}
public void initUI() {
JFrame jf = new JFrame();
BorderLayout bl = new BorderLayout();
FlowLayout fl = new FlowLayout();
Listener3 ls = new Listener3();
//create a new frame
jf.setSize(1920, 1280);
// set the size;
jf.setLayout(bl);
// set the main frame as borderlayout
jf.setLocationRelativeTo(null);
//set the location to center
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//set the close button
JMenuBar menuBar = new JMenuBar();
jf.setJMenuBar(menuBar);
JMenu menu1 = new JMenu("file");
menu1.addActionListener(ls);
JMenu menu2 = new JMenu("edit");
JMenu menu3 = new JMenu("window");
menuBar.add(menu1);
menuBar.add(menu2);
menuBar.add(menu3);
JMenuItem item1 = new JMenuItem("open");
JMenuItem item2 = new JMenuItem("save");
JMenuItem item3 = new JMenuItem("save as");
JMenuItem item4 = new JMenuItem("exit");
menu1.add(item1);
menu1.add(item2);
menu1.add(item3);
menu1.addSeparator();
menu1.add(item4);
//create a simple menu
JPanel jp1 = new JPanel();
jp1.setPreferredSize(new Dimension(1920, 100));
jp1.setLayout(fl);
jp1.setBackground(Color.gray);
// set jp1 in north as flowlayout
JPanel jp2 = new JPanel();
jp2.setBackground(Color.white);
JPanel jp3 = new JPanel();
jp3.setBackground(Color.gray);
JPanel jp4 = new JPanel();
jp4.setBackground(Color.gray);
JPanel jp5 = new JPanel();
jp5.setBackground(Color.gray);
// set other four panels
JPanel jp1_2 = new JPanel();
jp1_2.setLayout(fl);
jp1_2.setPreferredSize(new Dimension(400, 50));
jp1_2.setBackground(Color.gray);
// set the color section as flowlayout
JPanel jp1_1 = new JPanel();
jp1_1.setLayout(fl);
jp1_1.setPreferredSize(new Dimension(1200, 50));
jp1_1.setBackground(Color.gray);
// set the funtion section as flowlayout
// int con=1;
// BasicStroke size = new BasicStroke (con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);
//set the size of pen
JSlider jp1_3 = new JSlider(0,20,1);
jp1_3.setPreferredSize(new Dimension(200, 50));
jp1_3.addChangeListener(ls);
//add changelistener
// 设置主刻度间隔
jp1_3.setMajorTickSpacing(5);
// 设置次刻度间隔
jp1_3.setMinorTickSpacing(1);
// 绘制 刻度 和 标签
jp1_3.setPaintTicks(true);
jp1_3.setPaintLabels(true);
jp1_3.addChangeListener(ls);
//set a new bar
jp1.add(jp1_1);
jp1.add(jp1_2);
jp1.add(jp1_3);
// add the two scetions blow to jp1
JButton jb1 = new JButton("functional zone");
jp1_1.add(jb1);
String[] btnstr = { "line", "rectangle", "circle", "triangle", "Doraemon", "little octopus","wired triangle","chaos" ,"leaves","maple","ITStree","move ball"};
for (int i = 0; i < btnstr.length; i++) {
JButton btn = new JButton(btnstr[i]);
jp1_1.add(btn);
btn.addActionListener(ls);
}
// create functional zone
JButton jb2 = new JButton("color");
JButton jb3 = new JButton("selfchoose");
jp1_2.add(jb2);
jp1_2.add(jb3);
jb3.addActionListener(ls);
Color[] btnco = { Color.red, Color.blue, Color.yellow, Color.green, Color.black };
for (int i = 0; i < btnco.length; i++) {
JButton btn = new JButton("");
btn.setBackground(btnco[i]);
btn.setPreferredSize(new Dimension(50, 30));
jp1_2.add(btn);
btn.addActionListener(ls);
}
// create color zone
jf.add(jp1, BorderLayout.NORTH);
jf.add(jp2, BorderLayout.CENTER);
jf.add(jp3, BorderLayout.SOUTH);
jf.add(jp4, BorderLayout.EAST);
jf.add(jp5, BorderLayout.WEST);
// add jp1 to jp5 to main frame
jf.setVisible(true);
// visible
jp2.addMouseListener(ls);
Graphics2D g2 = (Graphics2D) jp2.getGraphics();
ls.g2 = g2;
}
}
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.lang.Math;
import java.util.EventListener;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Listener3 implements ActionListener, MouseListener, ChangeListener {
int x1, x2, y1, y2, x0, y0, w0, h0, y3, y4, y5, i = 0;
int tx[] = { 0, 0, 0 };
int ty[] = { 0, 0, 0 };
int x[] = { 0, 0, 0, 0, 0 };
int y[] = { 0, 0, 0, 0, 0 };
Graphics2D g2;
String intest = "";
int con = 1;
// BasicStroke size = new BasicStroke(con, BasicStroke.CAP_ROUND , BasicStroke.JOIN_BEVEL);
// the original size of the pen
// public interface ChangeListener extends EventListener {
//
// void stateChanged(ChangeEvent e);
//
//
// }
public void stateChanged(ChangeEvent e) {
JSlider js = (JSlider) e.getSource();
con = js.getValue();
// con=(int) e.getSource();
System.out.println("当前值: " + con);
g2.setStroke(new BasicStroke(con, BasicStroke.CAP_ROUND, BasicStroke.JOIN_BEVEL));
}
public void actionPerformed(ActionEvent e) {
intest = e.getActionCommand();
System.out.println(" click button ");
if ("".equals(intest)) {
JButton btn = (JButton) e.getSource();
Color c = btn.getBackground();
g2.setColor(c);
System.out.println(c);
} else if ("file".equals(intest)) {
} else if ("selfchoose".contentEquals(intest)) {
Color color = new Color(200, 200, 200);
Color c = JColorChooser.showDialog(null, "please choose your color", color);
g2.setColor(c);
}
}
public void mouseClicked(MouseEvent e) {
System.out.println("click");
if (intest.equals("triangle")) {
tx[i] = e.getX();
ty[i] = e.getY();
i++;
if (i == 1) {
g2.drawLine(tx[0], ty[0], tx[0], ty[0]);
} else if (i == 2) {
g2.drawLine(tx[0], ty[0], tx[1], ty[1]);
} else if (i == 3) {
g2.drawLine(tx[1], ty[1], tx[2], ty[2]);
g2.drawLine(tx[2], ty[2], tx[0], ty[0]);
i = 0;
}
}
}
public void mousePressed(MouseEvent e) {
System.out.println("press");
x1 = e.getX();
y1 = e.getY();
}
public void mouseExited(MouseEvent e) {
System.out.println("leave");
}
public void mouseReleased(MouseEvent e) {
System.out.println("release");
x2 = e.getX();
y2 = e.getY();
if (x1 > x2) {
x0 = x2;
w0 = x1 - x2;
} else {
x0 = x1;
w0 = x2 - x1;
}
if (y1 > y2) {
y0 = y2;
h0 = y1 - y2;
} else {
y0 = y1;
h0 = y2 - y1;
}
if (intest.equals("line")) {
g2.drawLine(x1, y1, x2, y2);
} else if (intest.equals("rectangle")) {
g2.drawRect(x0, y0, w0, h0);
} else if (intest.equals("circle")) {
g2.drawOval(x0, y0, w0, h0);
} else if (intest.equals("Doraemon")) {
drawDoraemon(x0,y0,w0,h0);
} else if (intest.equals("little octopus")) {
drawOctopus(x0, y0, w0, h0);
} else if (intest.equals("wired triangle")) {
System.out.println("click");
for (int i = 0; i < x.length; i++) {
x[i] = (int) (0 + Math.random() * (1200 - 0 + 1));
y[i] = (int) (0 + Math.random() * (700 - 0 + 1));
System.out.println(x[i] + " " + y[i] + " ");
// g.fillOval(x[i], y[i], 5, 5);
g2.drawLine(x[i], y[i], x[i], y[i]);
}
for (int i = 0; i < 10000; i++) {
int c = (int) (0 + Math.random() * (2 - 0 + 1));
x[x.length - 1] = (int) (x[c] / 2 + x[x.length - 1] / 2);
y[y.length - 1] = (int) (y[c] / 2 + y[y.length - 1] / 2);
System.out.println(c);
g2.drawLine(x[x.length - 1], y[y.length - 1], x[x.length - 1], y[y.length - 1]);
}
} else if (intest.equals("chaos")) {
drawDream(g2);
} else if (intest.equals("leaves")) {
drawLeaves(g2, x1, y1);
} else if (intest.equals("maple")) {
drawMaple(g2, x1, y1);
} else if (intest.equals("ITStree")) {
drawITStree(g2, x1, y1);
} else if (intest.equals("move ball")) {
BallGame();
}
}
public void mouseEntered(MouseEvent e) {
System.out.println("in");
}
private void drawDoraemon(int x0,int y0,int w0,int h0) {
g2.setColor(Color.blue);
g2.fillOval(x0, y0, w0, h0);
// big circle of face
g2.setColor(Color.white);
g2.fillOval((int) (x0 + w0 * 0.075), (int) (y0 + h0 * 0.075), (int) (w0 * 0.85), (int) (h0 * 0.85));
// small circle of face
g2.setColor(Color.white);
g2.fillOval((int) (x0 + w0 / 2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g2.fillOval((int) (x0 + w0 / 2 - w0 * 0.2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g2.setColor(Color.black);
g2.drawOval((int) (x0 + w0 / 2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g2.drawOval((int) (x0 + w0 / 2 - w0 * 0.2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
// outer eye contour
g2.setColor(Color.black);
g2.fillOval((int) (x0 + w0 / 2), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05), (int) (h0 * 0.05));
g2.fillOval((int) (x0 + w0 / 2 - w0 * 0.05), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05),
(int) (h0 * 0.05));
// black eyes
g2.setColor(Color.black);
g2.drawLine((int) ((x0 + w0 / 2 - w0 * 0.025) + w0 * 0.05 / 2),
(int) ((y0 * 1.2 + h0 * 0.375) + h0 * 0.05 / 2), (int) (x0 + w0 * 0.25 + w0 * 0.5 / 2),
(int) (y0 + h0 / 3 + h0 / 2));
g2.drawArc((int) (x0 + w0 * 0.25), (int) (y0 + h0 / 3), (int) (w0 * 0.5), (int) (h0 / 2), 0, -180);
// smile
g2.setColor(Color.red);
g2.fillOval((int) (x0 + w0 / 2 - w0 * 0.025), (int) (y0 * 1.2 + h0 * 0.375), (int) (w0 * 0.05),
(int) (h0 * 0.05));
// nose
g2.setColor(Color.black);
}
private void drawDream(Graphics g) {
double x = 0f;
double y = 0f;
// a,b,c,d
double a = -1.8, b = -2.0, c = -0.5, d = -0.9;
for (int i = 0; i < 25500; i++) {
// formula
double temx = Math.sin(a * y) + c * Math.cos(a * x);
double temy = Math.sin(b * x) + d * Math.cos(b * y);
// change the shape of x1,x2,enlarge them and move to screen coordinates
int x1 = (int) (temx * 130 + 500);
int y1 = (int) (temy * 130 + 400);
System.out.println("x1: " + x1 + " y1: " + y1);
// colors are deepened according to iteration coefficients
g.setColor(new Color(0, 0, i / 100));
g.drawLine(x1, y1, x1, y1);
x = temx;
y = temy;
}
}
private void drawOctopus(int x0,int y0,int w0,int h0){
g2.drawOval(x0, y0, w0, h0);
// face
g2.drawOval((int) (x0 + w0 / 2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g2.drawOval((int) (x0 + w0 / 2 - w0 * 0.2), (int) (y0 * 1.2), (int) (w0 * 0.2), (int) (h0 * 0.2));
g2.fillOval((int) (x0 + w0 / 2), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05), (int) (h0 * 0.05));
g2.fillOval((int) (x0 + w0 / 2 - w0 * 0.05), (int) (y0 * 1.2 + h0 * 0.075), (int) (w0 * 0.05),
(int) (h0 * 0.05));
// two eyes
g2.drawOval((int) (x0 + w0 * 0.5 - w0 * 0.25 / 2), (int) (y0 + h0 / 2 + h0 / 4 - h0 * 0.25),
(int) (w0 * 0.25), (int) (h0 * 0.25));
g2.drawOval((int) (x0 + w0 * 0.5 - w0 * 0.15 / 2), (int) (y0 + h0 / 2 + h0 / 4 - h0 * 0.1875),
(int) (w0 * 0.15), (int) (h0 * 0.15));
// mouth
g2.drawArc((int) (x0), (int) (y0 + h0 / 2), (int) (w0), (int) (h0 / 2), 0, -180);
g2.drawArc((int) (x0), (int) (y0 + 3 * h0 / 4), (int) (w0), (int) (h0 / 4), 0, -180);
g2.drawArc((int) (x0), (int) (y0 + 5 * h0 / 6), (int) (w0), (int) (h0 / 6), 0, -180);
// legs
}
private void drawLeaves(Graphics g, int x1, int y1) {
double x = 0f;
double y = 0f;
// a,b,c,d
double a[] = { 0.0000, 0.7248, 0.1583, 0.3386 };
double b[] = { 0.2439, 0.0337, -0.1297, 0.3694 };
double c[] = { 0.0000, -0.0253, 0.3550, 0.2227 };
double d[] = { 0.3053, 0.7426, 0.3676, -0.0756 };
double e[] = { 0.0000, 0.2060, 0.1383, 0.0679 };
double f[] = { 0.0000, 0.2538, 0.1750, 0.0826 };
for (int i = 0; i < 25500; i++) {
int t = (int) (0 + Math.random() * (3 - 0 + 1));
double temx = a[t] * x + b[t] * y + e[t];
double temy = c[t] * x + d[t] * y + f[t];
int x6 = (int) (temx * 400 + x1);
int y6 = (int) (temy * 400 + y1);
System.out.println("x6: " + x6 + " y6: " + y6);
//
g.setColor(new Color(50, (i / 100), 50));
g.drawLine(x6, y6, x6, y6);
// g.fillOval(x6, y6, 30, 30);
x = temx;
y = temy;
}
}
private void drawMaple(Graphics g, int x1, int y1) {
double x = 0f;
double y = 0f;
// a,b,c,d
double a[] = { 0.1400, 0.4300, 0.4500, 0.4900 };
double b[] = { 0.0100, 0.5200, -0.4900, 0.0000 };
double c[] = { 0.0000, -0.4500, 0.4700, 0.0000 };
double d[] = { 0.5100, 0.5000, 0.4700, 0.5100 };
double e[] = { -0.0800, 1.4900, -1.6200, 0.0200 };
double f[] = { -1.3100, -0.7500, -0.7400, 1.6200 };
for (int i = 0; i < 25500; i++) {
int t = (int) (0 + Math.random() * (3 - 0 + 1));
double temx = a[t] * x + b[t] * y + e[t];
double temy = c[t] * x + d[t] * y + f[t];
int x6 = (int) (temx * 80 + x1);
int y6 = (int) (temy * 80 + y1);
System.out.println("x6: " + x6 + " y6: " + y6);
g.setColor(new Color(150, 75, 0));
g.drawLine(x6, y6, x6, y6);
x = temx;
y = temy;
}
}
private void drawITStree(Graphics g, int x1, int y1) {
double x = 0f;
double y = 0f;
double a[] = { 0.0500, -0.0500, 0.0300, -0.0300, 0.5600, 0.1900, -0.3300 };
double b[] = { 0.0000, 0.0000, -0.1400, 0.1400, 0.4400, 0.0700, -0.3400 };
double c[] = { 0.0000, 0.0000, 0.0000, 0.0000, -0.3700, -0.1000, -0.3300 };
double d[] = { 0.4000, -0.4000, 0.2600, -0.2600, 0.5100, 0.1500, 0.3400 };
double e[] = { -0.0600, -0.0600, -0.1600, -0.1600, 0.3000, -0.2000, -0.5400 };
double f[] = { -0.4700, -0.4700, -0.0100, -0.0100, 0.1500, 0.2800, 0.3900 };
for (int i = 0; i < 25500; i++) {
int t = (int) (0 + Math.random() * (6 - 0 + 1));
double temx = a[t] * x + b[t] * y + e[t];
double temy = c[t] * x + d[t] * y + f[t];
int x6 = (int) (temx * 300 + x1);
int y6 = (int) (temy * 300 + y1);
System.out.println("x6: " + x6 + " y6: " + y6);
g.setColor(new Color(50, (i / 100), 50));
g.drawLine(x6, y6, x6, y6);
x = temx;
y = temy;
}
}
private void BallGame () {
int changex, changey;
while(true){
g2.setColor(Color.WHITE);
g2.fillOval(x2, y2, 100, 100);
x2++;
y2++;
int r,b,j;
r= (int) (0 + Math.random() * (255 - 0 + 1));
b= (int) (0 + Math.random() * (255 - 0 + 1));
j= (int) (0 + Math.random() * (255 - 0 + 1));
g2.setColor(Color.getHSBColor(r,b,j));
g2.fillOval(x2, y2, 100, 100);
// sleep 100ms
try {
Thread.sleep(100);
}catch (InterruptedException e1) {
e1.printStackTrace();
}
}
}
}
效果
