【分形算法】Jason带你飞之3——java AWT菜单和button的事件响应
现在只剩下了最后10%的工作——添加菜单和按钮的功能。菜单栏可以选择两种模式：单一规则和随机规则模式；点击按钮实现单步迭代。
1、先来个简单的，菜单事件
1.1、问曰：什么是菜单事件？如何实现菜单事件？
答曰：我也不懂，但你一看下面的这个代码就懂了……{！参考http://blog.csdn.net/selena1122/article/details/37810579}
package myFenxing.release;
import java.awt.CheckboxMenuItem;
import java.awt.Frame;
import java.awt.Menu;
import java.awt.MenuBar;
import java.awt.MenuItem;
import java.awt.MenuShortcut;
import java.awt.TextArea;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
/**
* 简单的菜单项例子
* 菜单条-----菜单-----菜单项
* 其中，菜单中可以包含菜单，组成二级菜单
* @author elena
* @date 2014-7-15上午09:51:29
* @version 1.0
*/
public class SimpleMenu {
private Frame f = new Frame("菜单测试");
private MenuBar mb = new MenuBar();
Menu file = new Menu("文件");
Menu edit = new Menu("编辑");
MenuItem newItem = new MenuItem("新建");
MenuItem saveItem = new MenuItem("保存");
// 创建exititem菜单项，指定使用ctrl+x快捷键
MenuItem exitItem = new MenuItem("退出", new MenuShortcut(KeyEvent.VK_X));
CheckboxMenuItem autoWrap = new CheckboxMenuItem("自动换行");
MenuItem copyiItem = new MenuItem("复制");
MenuItem pasteItem = new MenuItem("粘贴");
Menu format = new Menu("格式");
// 创建commentem菜单项，指定使用ctrl+shift+/快捷键
MenuItem commentItem = new MenuItem("注释", new MenuShortcut(
KeyEvent.VK_SLASH, true));
MenuItem cancelItem = new MenuItem("取消注释");
private TextArea ta = new TextArea(6, 40);
public void init() {
// 以匿名内部类的形式创建菜单监听器
ActionListener menuListener = new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
String cmd = e.getActionCommand();
ta.append("单击" + cmd + "菜单" + "\n");
if (cmd.equals("退出")) {
System.exit(0);
}
}
};
commentItem.addActionListener(menuListener);
exitItem.addActionListener(menuListener);
// 为file菜单添加菜单项
file.add(newItem);
file.add(saveItem);
file.add(exitItem);
// 为edit菜单添加菜单项
edit.add(autoWrap);// 自动换行
// 使用addseparator方法来添加菜单分割线
edit.addSeparator();
edit.add(copyiItem);
edit.add(pasteItem);
// 为format菜单添加菜单项
format.add(commentItem);
format.add(cancelItem);
// 使用添加new menuitem（”-“）的方式添加菜单分割线
edit.add(new MenuItem("-"));
// 将format菜单组合到edit菜单中，从而形成二级菜单
edit.add(format);
// 将file edit菜单添加到mb菜单条中
mb.add(file);
mb.add(edit);
// 为窗体f设置菜单条
f.setMenuBar(mb);
// 以匿名内部类的形式创建事件监听器对象
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
ta.append("用户试图关闭窗口\n");
System.exit(0);
}
});
f.add(ta);
f.pack();
f.setVisible(true);
}
public static void main(String[] args) {
new SimpleMenu().init();
}
}
1.2、覆写actionPerformed方法
@Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
String cmd = e.getActionCommand();
if (cmd.equals("退出")) {
System.exit(0);
}else if(cmd.equals("单一规则")){
//System.out.print("单一规则");
this.statement= "F"; mode=1; itemChange=true;
this.statement= this.caluStatement1(4);
this.reinit();
}else if(cmd.equals("随机规则")){
this.statement= "F"; mode=2; itemChange=true;
this.statement= this.caluStatement2(5);
this.reinit();
}else if(cmd.equals("技术支持")){
try { Process process = Runtime.getRuntime().exec("explorer http://my.oschina.net/SnifferApache/blog/353418");
} catch (IOException IOe) {
IOe.printStackTrace();
}
}else if(cmd.equals("About 牛逼的树")){
JOptionPane.showMessageDialog(this, "LLC实验室制作\nhttp:gdauto.gdut.edu.cn/");
}
}
注意：选中某个模式之后，需要重新计算statement，并重新画图。同时还要改变按钮显示文字，所以要在reinit方法中添加
canvas.setStatement(statement);
canvas.repaint();
if(this.itemChange){
this.itemChange= false;
this.step= 1;//重置步骤数
button_step.setLabel("单步迭代");
label_step.setText(" ");
}
而Canvas的repaint方法是在当前参数基础上重新画图，不满足需要，所以我们也要覆写repaint，添加
//清除旧的图像
repaint(0, 0, 0, getWidth(), getHeight());
//重置画图参数
pStartX =320; //原始起始点340,20
pStartY =20;
direction_init =90; // 作画时的初始方向
direction =direction_init;
lengthF =4.5; //步长
rotation =30; //给定转角
2、单步迭代功能
根据当前的模式来决定单步实现哪个规则，计算新的statement，再次画图即可
//button的响应事件
public boolean action(Event ev, Object arg){
if ( ev.target instanceof Button) {
String button = (String) arg;
if (button.equals("单步迭代")) {
button_step.setLabel("迭代一步");
label_step.setText("第"+step+"步");
this.statement= "F";
if(mode== 1){
this.caluStatement1(1);
}else{
this.caluStatement2(1);
}
this.reinit();
}
if (button.equals("迭代一步")){
step++;
label_step.setText("第"+step+"步");
this.statement= "F";
if(mode== 1){
this.caluStatement1(step);
}else{
this.caluStatement2(step);
}
this.reinit();
}
return true;
}else return false;
}
3、最终版的全部源码和功能截图
package myFenxing.UI;
/**
* @author Jason
* @Corp LLC lab
* @version LS grammar implementation
*/
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import java.io.IOException;
import java.util.Vector;
import javax.swing.JOptionPane;
//画布
class MyCanvas extends Canvas{
String statement; //LS文法表达式
int pStartX =320; //起始点340,20
int pStartY =20;
double direction_init =90; // 作画时的初始方向
double direction =direction_init;
double lengthF =4.5;
double rotation =30;
int StartDepth =7; //画图深度
doublePoint a, b; // 画线段所需的两点
MyCanvas(){
setBackground(Color.black);
}
public void setStatement(String s){
this.statement= s;
}
//改变窗口大小的时候会调用此方法重新绘图
public void paint(Graphics g){
//System.out.print("\n"+this.statement);
a = new doublePoint(pStartX,pStartY); // 起始点
g.setColor(new Color(110,170,60)); // 定义画笔的颜色绿色
draw(g,this.statement);
}
//核心方法
public void draw(Graphics g, String statement){
Vector aPoint = new Vector();//用堆栈记录[]中的内容
Vector aDirection = new Vector();
String sDirection;
int i;
int j;
char c; //System.out.print("\ndraw length "+statement.length());
for (i=0;i<statement.length();i++) {
//获取公理中第i个字符，即解释instruction
c = statement.charAt(i);
if (c=='F') {
double rad = 2*Math.PI*direction/360 ; // 角度转换
double p = lengthF * Math.cos(rad);
double q = lengthF * Math.sin(rad);
b = new doublePoint(a.x+p, a.y+q);
//g=this.getGraphics();
g.drawLine((int)(a.x), (int)(400-a.y), (int)(b.x) ,(int)(400-b.y));
a = b; // 前一线段的终点为后一线段的起始点
}
else if (c=='+') direction += rotation; //逆时针转角度
else if (c=='-') direction -= rotation; //顺时针转角度
else if (c=='[') { //入栈
aPoint.addElement(a);
sDirection = String.valueOf(direction);
aDirection.addElement(sDirection);
}
else if (c==']') { //出栈
a=(doublePoint)(aPoint.elementAt(aPoint.size()-1));
sDirection=(String)(aDirection.elementAt(aDirection.size()-1));
direction=Double.valueOf(sDirection).doubleValue();
aPoint.removeElementAt(aPoint.size()-1);
aDirection.removeElementAt(aDirection.size()-1);
}
}//System.out.print("\ndraw over;");
}
@Override
public void repaint(){
//清除旧的图像
repaint(0, 0, 0, getWidth(), getHeight());
//重置画图参数
pStartX =320; //起始点340,20
pStartY =20;
direction_init =90; // 作画时的初始方向
direction =direction_init;
lengthF =4.5;
rotation =30;
this.paint(getGraphics());
}
}
//窗口
class MyWindow extends Frame implements ActionListener{
MyCanvas canvas= new MyCanvas();
//在画布中绘图的起始点340，20
int pStartX =320;
int pStartY =20;
Panel pSouth= new Panel();
MenuBar menubar= new MenuBar();
Menu menu1= new Menu("文件"); Menu mn_mode= new Menu(); Menu help= new Menu("帮助");
MenuItem item1= new MenuItem("退出");
MenuItem mn_mode_1= new MenuItem(); MenuItem mn_mode_2= new MenuItem();
MenuItem help_1= new MenuItem("技术支持"); MenuItem help_2= new MenuItem("About 牛逼的树");
Choice choice= new Choice();
Button button_step= new Button("单步迭代");
Label label_step= new Label(" ");
Label info= new Label("LLC LAB");
//LS文法需要的变量
String statement,replacement;
int step=1;//单步迭代的步骤
int mode=2;//模式1：单一规则，模式2：随机规则
boolean itemChange= false;//false表示item没有改变
String sStart; //公理；起始字符串
String sRule[][]; //存储规则
//构造方法
MyWindow(){
//默认状态下的公理
sStart = "F";//给公理赋值
statement= sStart; replacement= "F[+F]F[-F]F" ;
//用来随机抽取，绘制随机植物
sRule = new String [10][2];
//设置UI
setBackground(Color.lightGray);
choice.addItem("牛逼的树");
pSouth.add(choice);
pSouth.add(button_step);
pSouth.add(label_step);
pSouth.add(info);
add(canvas,BorderLayout.CENTER);
add(pSouth,BorderLayout.SOUTH);
//设置menu
this.setMenuBar(menubar);
menubar.add(menu1); menubar.add(mn_mode); menubar.add(help);
menu1.add(item1);
mn_mode.add(mn_mode_1); mn_mode.add(mn_mode_2); help.add(help_1); help.add(help_2);
mn_mode.setLabel("生成模式");
mn_mode_1.setLabel("单一规则"); mn_mode_2.setLabel("随机规则");
item1.addActionListener(this);
mn_mode_1.addActionListener(this);
mn_mode_2.addActionListener(this);
help_1.addActionListener(this);
help_2.addActionListener(this);
}
@Override
public void actionPerformed(ActionEvent e) {
//略
}
//button的响应事件
public boolean action(Event ev, Object arg){
if ( ev.target instanceof Button) {
String button = (String) arg;
//略
}else return false;
}
//响应关闭操作
protected void processWindowEvent(WindowEvent e) {
super.processWindowEvent(e);
if (e.getID() == WindowEvent.WINDOW_CLOSING) {
System.exit(0);
}
}
//窗口名称
public synchronized void setTitle(String title) {
super.setTitle(title);
enableEvents(AWTEvent.WINDOW_EVENT_MASK);
}
public void init() {
//将计算出的statement传递给画布
canvas.setStatement(statement);
this.setSize(pStartX*2,550);
//获得屏幕长和宽，dimension类在一个单一对象中封装组建的宽和高
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
this.setLocation((d.width - this.getSize().width) / 2, (d.height - this.getSize().height) / 2);
this.setVisible(true);
}
//操作之后刷新
public void reinit(){
//将计算出的statement传递给画布
canvas.setStatement(statement);
canvas.repaint();
if(this.itemChange){
this.itemChange= false;
this.step= 1;//重置步骤数
button_step.setLabel("单步迭代");
label_step.setText(" ");
}
}
/**计算LS表达式*/
//略
/**Main method*/
public class randomLS {
public static void main(String args[]){
MyWindow instance= new MyWindow();
instance.setTitle("牛逼的树");
instance.statement= instance.caluStatement2(5);
instance.init();
}
}
效果图
