Программирование на Java.Подробное руководство

         

Исходный текст аплета LineDraw


Исходный текст аплета LieDrnaw вы найдете в листинге 1.

Листинг 1. Файл LieDrnaw.java

import java.applet.*; import java.awt.*; import java.util.*;

public class LineDraw extends Applet { Dimension dmDown; Dimension dmUp; Dimension dmPrev; boolean bDrawing; Vector lines;

public String getAppletInfo() { return "Name: LineDraw"; }

public void init() { bDrawing = false; lines = new Vector(); }

public void paint(Graphics g) { Dimension dimAppWndDimension = getSize();

setBackground(Color.yellow); g.setColor(Color.black); g.drawRect(0, 0, dimAppWndDimension.width - 1, dimAppWndDimension.height - 1);

for (int i=0; i < lines.size(); i++) { Rectangle p = (Rectangle)lines.elementAt(i); g.drawLine(p.width, p.height, p.x, p.y); g.drawString("<" + p.width + "," + p.height + ">", p.width, p.height); g.drawString("<" + p.x + "," + p.y+ ">", p.x, p.y); } bDrawing = false; }

public boolean mouseDown(Event evt, int x, int y) { if(evt.clickCount > 1) { lines.removeAllElements(); repaint(); return true; }

dmDown = new Dimension(x, y); dmPrev = new Dimension(x, y); bDrawing = false; return true; }

public boolean mouseUp(Event evt, int x, int y) { if(bDrawing) { dmUp = new Dimension(x, y); lines.addElement( new Rectangle(dmDown.width, dmDown.height, x, y)); repaint(); bDrawing = false; } return true; }

public boolean mouseDrag(Event evt, int x, int y) { Graphics g = getGraphics(); bDrawing = true;

g.setColor(Color.yellow); g.drawLine(dmDown.width, dmDown.height, dmPrev.width, dmPrev.height);

g.setColor(Color.black); g.drawLine(dmDown.width, dmDown.height, x, y);

dmPrev = new Dimension(x, y); return true; }

public boolean mouseMove(Event evt, int x, int y) { bDrawing = false; return true; } }

Исходный текст документа HTML, подготовленного системой JavaWorkshop, представлен в листинге 2.

Листинг 2. Файл LineDraw.tmp.html

<applet name="LineDraw" code="LineDraw" codebase= "file:/e:/Sun/Articles/vol5/src/LineDraw" width="500" height="600" align="Top" alt="If you had a java-enabled browser, you would see an applet here."> </applet>





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