Java Cookbook

Program: PlotterAWT

In Section 8.12, we discussed a series of Plotter classes. The PlotterAWT class shown in Example 12-7 extends that to provide a “plot preview” service: before being plotted on a (probably slow) plotter, the plot is displayed in an AWT window using the Graphics drawing primitives.

Example 12-7. PlotterAWT.java

import java.awt.*; import java.awt.event.*; /** * A Plotter subclass for drawing into an AWT Window. Reflecting back * to AWT gives us a "known working" plotter to test on. * You can also steal this as a basis for your own plotter driver! */ public class PlotterAWT extends Plotter { Frame f; Image os; PCanvas p; Graphics g; Font font; FontMetrics fontMetrics; PlotterAWT( ) { super( ); f = new Frame("Plotter"); p = new PCanvas(os, MAXX, MAXY); f.add(p); f.pack( ); f.setVisible(true); f.addWindowListener(new WindowAdapter( ) { public void windowClosing(WindowEvent e) { // If we do setVisible and dispose, then the Close completes PlotterAWT.this.f.setVisible(false); PlotterAWT.this.f.dispose( ); System.exit(0); } }); g = p.getOsGraphics( ); } public void drawBox(int w, int h) { g.drawRect(curx, cury, w, h); p.repaint( ); } public void rmoveTo(int incrx, int incry){ moveTo(curx += incrx, cury += incry); } public void moveTo(int absx, int absy){ if (!penIsUp) g.drawLine(curx, cury, absx, absy); curx = absx; cury = absy; } public void setdir(float deg){} void penUp( ){ penIsUp = true; } void penDown( ){ penIsUp = false; } void penColor(int c){ switch(c) { case ...