public class LineDraw extends Applet
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>
