Подробное руководство по программированию на Java



             

Листинг 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; } }

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