桂林工学院 案例 案例五：跳动的文字_Java程序设计及应用

案例五：跳动的文半 设计要求 文字按顺序从右到左跳动最示，需要显示的文字，文字的颜色、字体、大小，青景色， 字体大小。出残的速度均由用户指定。 实例效果 【查看源文件] import java.applet Applet: import java.awt. import java.util.NoSuchElementException: import java.util.Vector; public class TextBouncer extends Applet implements Runnable private int delay. private int type: private int hspeed; private double bounce: private int gravity: private int randomg: private int fontSize; private Font txtFont: private String fontName; private int fontStyle: private String txtStrings[ private Color txtColors[: private Color beColor: private int txtH;

案例五：跳动的文字 设计要求： 文字按顺序从右到左跳动显示，需要显示的文字、文字的颜色、字体、大小、背景色、 字体大小、出现的速度均由用户指定。 实例效果 [查看源文件] import java.applet.Applet; import java.awt.*; import java.util.NoSuchElementException; import java.util.Vector; public class TextBouncer extends Applet implements Runnable { private int delay; private int type; private int hspeed; private double bounce; private int gravity; private int randomg; private int fontSize; private Font txtFont; private String fontName; private int fontStyle; private String txtStrings[]; private Color txtColors[]; private Color bgColor; private int txtH;

private int txtN: private int txtwl: private int txtx知i private int txtvx: private double txtY: private double txtVYIl private double txtAll: Thread drawThread: private boolean froren; private Dimension affD; private Image offl; private Graphics offG: public TextBouncer[) 1 frozen false; 1 public void init) int k =0; String s getParameter("fps"l try 4 if's !null) k-Integer.parselnt(s]: catch(Exception_e{】 dehy=k<=0?75:1000/k s=getParameter["text"]: 作到

private int txtN; private int txtW[]; private int txtX[]; private int txtVX[]; private double txtY[]; private double txtVY[]; private double txtA[]; Thread drawThread; private boolean frozen; private Dimension offD; private Image offI; private Graphics offG; public TextBouncer() { frozen = false; } public void init() { int k = 0; String s = getParameter("fps"); try { if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } delay = k <= 0 ? 75 : 1000 / k; s = getParameter("text"); if(s == null)

s ="Bennet Uk's|TextBouncer Applet"; Vector vector new Vector int i; for[k =0:k <s.length(k =i+1) 1 i=s.indexofl'',k): -到 i=s.length(): String s1=s.substring(k il: vector.addElement/s1) 1 txtStrings new String[vector.size)l: vector.copylnto(txtStrings): vector new VectorD: s=getParameter("textcolor"): if's I=null) 1 nt出 for[k =0:k <s.length(k =j+1) 1 j=s.indexofl'l',k]: 附0 j=s.length(: String s2=s.substring(k止： Color color decodeColor(s2) if color !=null) vector.addElement(colorl: else try

s = "Bennet Uk's|TextBouncer Applet"; Vector vector = new Vector(); int i; for(k = 0; k < s.length(); k = i + 1) { i = s.indexOf('|', k); if(i == -1) i = s.length(); String s1 = s.substring(k, i); vector.addElement(s1); } txtStrings = new String[vector.size()]; vector.copyInto(txtStrings); vector = new Vector(); s = getParameter("textcolor"); if(s != null) { int j; for(k = 0; k < s.length(); k = j + 1) { j = s.indexOf('|', k); if(j == -1) j = s.length(); String s2 = s.substring(k, j); Color color = decodeColor(s2); if(color != null) vector.addElement(color); else try {

vector.addElement(vector.lastElement()): catchNoSuchElementException ex) vector.addElement(Color.blue): 1 \ forlk vector.size(l:kc tatStrings-length:k] try 1 vector.addElement/vector.lastElement(): 1 catch/NoSuchElementException ex) vector.addElement(Color.blue) txtCalors=new Calorlvector.size vector.copyintotxtColors): s-getParameter["fontname"): 华=nu ontName■s: if fontName =null) fontName -"Helvetica"; s=getParameter("bgcolor"): f华=nu bgColor=decodeColor(s); if(bgColor .nul间 beColor Color.white: k=0

vector.addElement(vector.lastElement()); } catch(NoSuchElementException _ex) { vector.addElement(Color.blue); } } } for(k = vector.size(); k < txtStrings.length; k++) try { vector.addElement(vector.lastElement()); } catch(NoSuchElementException _ex) { vector.addElement(Color.blue); } txtColors = new Color[vector.size()]; vector.copyInto(txtColors); s = getParameter("fontname"); if(s != null) fontName = s; if(fontName == null) fontName = "Helvetica"; s = getParameter("bgcolor"); if(s != null) bgColor = decodeColor(s); if(bgColor == null) bgColor = Color.white; k = 0;

s=意etParameterlfontsi2e门： try 4 作=nu k =Integer-parselnt(s); catch(Exception_e国{】 font5ae=k<=0？14:k k=心 s=getParameter["fontstyle"]: try 1 作=nu k =Integer-parselnt(s): 1 catch[Exception_e{】 fontStyle =k <=0?1:k; k=0; s=getParameter["type"): try f华：nu k-Integer-parselnt(s]: catch[Exception_e{】 type=kc=071:k灯 k=0; s getParameter("hspeed"l try

s = getParameter("fontsize"); try { if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } fontSize = k <= 0 ? 14 : k; k = 0; s = getParameter("fontstyle"); try { if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } fontStyle = k <= 0 ? 1 : k; k = 0; s = getParameter("type"); try { if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } type = k <= 0 ? 1 : k; k = 0; s = getParameter("hspeed"); try {

ifs !null) k-Integer-parselnt(s]: catchException_e{】 hspeed =kc0?1:k k=D; s-getParameter["bounce"): try 作senu k=Integer.parselnt(s): catch(Exception_e{】 bounce =k<=0 ?1.0D:Math.sqrt((double)k 100D) k=D; s"getParameter["gravity") try 1 f华enu kInteger.parselntis]: catchException_e{】 gravity=k <=0?10:k k=0 s=getParameter("randomg") try 1 作nu k=Integer-parselnt(s):

if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } hspeed = k <= 0 ? 1 : k; k = 0; s = getParameter("bounce"); try { if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } bounce = k <= 0 ? 1.0D : Math.sqrt((double)k / 100D); k = 0; s = getParameter("gravity"); try { if(s != null) k = Integer.parseInt(s); } catch(Exception _ex) { } gravity = k <= 0 ? 10 : k; k = 0; s = getParameter("randomg"); try { if(s != null) k = Integer.parseInt(s); }

catch(Exception_e{】 randomg=k0可 randomg++; txtN =0; private Color decodeColor(String s) boolean flag fake: try nt好 if作startswith"0x刀 i=Integer.parselnt(ssubstring(2)16): eke in(s-startswith["]) i=Integer.parseint(s.substring(1)16): ekse ifs-startswith0门&&s.length()>1】 i=Integer.parseint(s.substring(1)8): else i=Integer.parselnt(s,10% return new Color(间 1 catch(NumberformatExceptionex) return null

catch(Exception _ex) { } randomg = k 0) randomg++; txtN = 0; } private Color decodeColor(String s) { boolean flag = false; try { int i; if(s.startsWith("0x")) i = Integer.parseInt(s.substring(2), 16); else if(s.startsWith("#")) i = Integer.parseInt(s.substring(1), 16); else if(s.startsWith("0") && s.length() > 1) i = Integer.parseInt(s.substring(1), 8); else i = Integer.parseInt(s, 10); return new Color(i); } catch(NumberFormatException _ex) { return null; } }

blic void s到ar0 iR(lfrozen) 1 if(drawThread=anu画 drawThread new Thread this]: drawThread.start(l: public void stopl) d由WThread=null: repaint( public boolean mouseDown(Event event,int i,int j) if frozen) { frozen false start(): 】clso frozen true; stop(l: return true: public void run( lone I=System.currentTimeMilis(l:

public void start() { if(!frozen) { if(drawThread == null) drawThread = new Thread(this); drawThread.start(); } } public void stop() { drawThread = null; repaint(); } public boolean mouseDown(Event event, int i, int j) { if(frozen) { frozen = false; start(); } else { frozen = true; stop(); } return true; } public void run() { long l = System.currentTimeMillis();

while(Thread.currentThread(=drawThread) animateText(l: repaint( try I+-delay: Thread.sleep(Math.max0LI-System.currentTimeMilis(; catchllnterruptedException_ex) return; 】 private int squarelint i returni*ic 1 private synchronized void initText 1 int i txtStrings[txtN].length): iftxtFont =null) txtFont new Font fontName,fontStyle,fontsue): offG.setFont(txtFont): 1 FontMetrics fontmetrics-olG.getFontMetrics( txtH fontmetrics.getAscent() txtW=new int[可g

while(Thread.currentThread() == drawThread) { animateText(); repaint(); try { l += delay; Thread.sleep(Math.max(0L, l - System.currentTimeMillis())); } catch(InterruptedException _ex) { return; } } } private int square(int i) { return i * i; } private synchronized void initText() { int i = txtStrings[txtN].length(); if(txtFont == null) { txtFont = new Font(fontName, fontStyle, fontSize); offG.setFont(txtFont); } FontMetrics fontmetrics = offG.getFontMetrics(); txtH = fontmetrics.getAscent(); txtW = new int[i];

txtX new int]: txtvx new inti]: txtY=new double]: txtVY=new double[i txtA new double int l: int k]; switch(type] case3:∥003y intj=0: for[int1=C:1<e1+小 txtxji1]-j: txtVx[i1]hspeed; txtA[i1]txtVY[i1]=(2D*(double )(offD.height-txtH))/(doublesquare(intK(Math.random() (double]randomg)+gravity): txtY[1]=(doubleltxtH txtA[i1]: try j+=ttwil]fontmetrics.charWidth(txtStrings[txtN].charAt[i1]l: catch/StringindexOutOfBoundsException ex][} return; case4:∥V004 int k =0; for[int jl=0:jl cjl++) txtx[j1]=k:

txtX = new int[i]; txtVX = new int[i]; txtY = new double[i]; txtVY = new double[i]; txtA = new double[i]; int l; int k1; switch(type) { case 3: // '\003' int j = 0; for(int i1 = 0; i1 < i; i1++) { txtX[i1] = j; txtVX[i1] = hspeed; txtA[i1] = txtVY[i1] = (2D * (double)(offD.height - txtH)) / (double)square((int)(Math.random() * (double)randomg) + gravity); txtY[i1] = (double)txtH + txtA[i1]; try { j += txtW[i1] = fontmetrics.charWidth(txtStrings[txtN].charAt(i1)); } catch(StringIndexOutOfBoundsException _ex) { } } return; case 4: // '\004' int k = 0; for(int j1 = 0; j1 < i; j1++) { txtX[j1] = k;