//animatordemo.java
import java.util.*;
import java.awt.*;
import java.applet.*;
import java.text.*;
public class animatordemo extends applet implements runnable
{
thread timer; // 用于显示时钟的线程
int lastxs, lastys, lastxm,
lastym, lastxh, lastyh;
simpledateformat formatter; //格式化时间显示
string lastdate; // 保存当前时间的字符串
font clockfacefont; //设置显示时钟里面的数字的字体
date currentdate; // 显示当前时间
color handcolor; // 用于显示时针、分针和表盘的颜色
color numbercolor; // 用于显示秒针和数字的颜色
public void init()
{
int x,y;
lastxs = lastys = lastxm = lastym = lastxh = lastyh = 0;
formatter = new simpledateformat ("yyyy eee mmm dd hh:mm:ss ");
currentdate = new date();
lastdate = formatter.format(currentdate);
clockfacefont = new font("serif", font.plain, 14);
handcolor = color.blue;
numbercolor = color.darkgray;
try {
setbackground(new color(integer.parseint(getparameter("bgcolor"),16)));
} catch (exception e) { }
try {
handcolor = new color(integer.parseint(getparameter("fgcolor1"),16));
} catch (exception e) { }
try {
numbercolor = new color(integer.parseint(getparameter("fgcolor2"),16));
} catch (exception e) { }
resize(300,300); // 设置时钟窗口大小
}
// 计算四分之一的圆弧
public void plotpoints(int x0, int y0, int x, int y, graphics g)
{
g.drawline(x0+x,y0+y,x0+x,y0+y);
g.drawline(x0+y,y0+x,x0+y,y0+x);
g.drawline(x0+y,y0-x,x0+y,y0-x);
g.drawline(x0+x,y0-y,x0+x,y0-y);
g.drawline(x0-x,y0-y,x0-x,y0-y);
g.drawline(x0-y,y0-x,x0-y,y0-x);
g.drawline(x0-y,y0+x,x0-y,y0+x);
g.drawline(x0-x,y0+y,x0-x,y0+y);
}
// 用bresenham算法来画圆，其中(x0,y0)是圆的中心，r为圆半径
public void circle(int x0, int y0, int r, graphics g)
{
int x,y;
float d;
x=0;
y=r;
d=5/4-r;
plotpoints(x0,y0,x,y,g);
while (y＞x) {
if (d＜0) {
d=d+2*x+3;
x++;
}
else {
d=d+2*(x-y)+5;
x++;
y--;
}
plotpoints(x0,y0,x,y,g);
}
}
public void paint(graphics g)
{
int xh, yh, xm, ym, xs, ys, s = 0, m = 10, h = 10, xcenter, ycenter;
string today;
currentdate = new date();
simpledateformat formatter = new simpledateformat("s",locale.getdefault());
try {
s = integer.parseint(formatter.format(currentdate));
} catch (numberformatexception n) {
s = 0;
}
formatter.applypattern("m");
try {
m = integer.parseint(formatter.format(currentdate));
} catch (numberformatexception n) {
m = 10;
}
formatter.applypattern("h");
try {
h = integer.parseint(formatter.format(currentdate));
} catch (numberformatexception n) {
h = 10;
}
formatter.applypattern("eee mmm dd hh:mm:ss yyyy");
today = formatter.format(currentdate);
//设置时钟的表盘的中心点为(80,55)
xcenter=80;
ycenter=55;
// a= s* pi/2 - pi/2 (to switch 0,0 from 3:00 to 12:00)
// x = r(cos a) + xcenter, y = r(sin a) + ycenter
xs = (int)(math.cos(s * 3.14f/30 - 3.14f/2) * 45 + xcenter);
ys = (int)(math.sin(s * 3.14f/30 - 3.14f/2) * 45 + ycenter);
xm = (int)(math.cos(m * 3.14f/30 - 3.14f/2) * 40 + xcenter);
ym = (int)(math.sin(m * 3.14f/30 - 3.14f/2) * 40 + ycenter);
xh = (int)(math.cos((h*30 + m/2) * 3.14f/180 - 3.14f/2) * 30 + xcenter);
yh = (int)(math.sin((h*30 + m/2) * 3.14f/180 - 3.14f/2) * 30 + ycenter);
//画时钟最外面的圆盘其中心在(xcenter,ycenter)半径为50
g.setfont(clockfacefont);
g.setcolor(handcolor);
circle(xcenter,ycenter,50,g);
//画时钟表盘里的数字
g.setcolor(numbercolor);
g.drawstring("9",xcenter-45,ycenter+3);
g.drawstring("3",xcenter+40,ycenter+3);
g.drawstring("12",xcenter-5,ycenter-37);
g.drawstring("6",xcenter-3,ycenter+45);
// 如果必要的话抹去然后重画
g.setcolor(getbackground());
if (xs != lastxs || ys != lastys) {
g.drawline(xcenter, ycenter, lastxs, lastys);
g.drawstring(lastdate, 5, 125);
}
if (xm != lastxm || ym != lastym) {
g.drawline(xcenter, ycenter-1, lastxm, lastym);
g.drawline(xcenter-1, ycenter, lastxm, lastym); }
if (xh != lastxh || yh != lastyh) {
g.drawline(xcenter, ycenter-1, lastxh, lastyh);
g.drawline(xcenter-1, ycenter, lastxh, lastyh); }
g.setcolor(numbercolor);
g.drawstring("", 5, 125);
g.drawstring(today, 5, 125);
g.drawline(xcenter, ycenter, xs, ys);
g.setcolor(handcolor);
g.drawline(xcenter, ycenter-1, xm, ym);
g.drawline(xcenter-1, ycenter, xm, ym);
g.drawline(xcenter, ycenter-1, xh, yh);
g.drawline(xcenter-1, ycenter, xh, yh);
lastxs=xs; lastys=ys;
lastxm=xm; lastym=ym;
lastxh=xh; lastyh=yh;
lastdate = today;
currentdate=null;
}
//applet的启动方法
public void start()
{
timer = new thread(this);
timer.start();
}
// applet的停止方法
public void stop()
{
timer = null;
}
//线程的run方法
public void run()
{
thread me = thread.currentthread();
while (timer == me) {
try {
thread.currentthread().sleep(1000);
}
catch (interruptedexception e) {
}
repaint();
}
}
//注意：这里重写了update()方法，只是调用了paint()方法来消除闪烁现象
public void update(graphics g)
{
paint(g);
}
}
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