L'esempio, editato nel file grafDemo.java è:
import java.awt.Graphics;
import java.awt.Color;
import java.awt.Button;
import java.awt.borderLayout;
import java.awt.GridLayout;
import java.awt.FlowLayout;
import java.awt.Panel;
import java.awt.Label;
import java.awt.Choice;
import java.awt.font;
import java.awt.Toolkit;
import java.awt.Checkbox;
import java.awt.Scrollbar;
import java.awt.GraphicsEnvironment;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.AdjustmentListener;
import java.awt.event.AdjustmentEvent;
import java.applet.*;
public class grafDemo extends Applet
{
Scrollbar R=new Scrollbar(Scrollbar.VERTICAL, 0, 1, 0, 255);
Scrollbar G=new Scrollbar(Scrollbar.VERTICAL, 0, 1, 0, 255);
Scrollbar B=new Scrollbar(Scrollbar.VERTICAL, 0, 1, 0, 255);
Choice FN=new Choice();
Choice GR=new Choice();
Checkbox F=new Checkbox("Figure chiuse piene",false);
int [] puntiX={1,100,200,300,399,300,200,100};
int [] puntiY={200,150,50,150,200,100,250,130};
int punti=8;
public void init()
{
// Calcolo i font del sistema:
// String[] NOMI=GraphicsEnvironment.
// getLocalGraphicsEnvironment().
// getAvailablefontFamilyNames();
/*
Per Java presente sui browser
String [] NOMI=Toolkit.getdefaultToolkit().getfontList();
*/
String [] NOMI=Toolkit.getdefaultToolkit().getfontList();
try
{
int indice=0;
while (true)
{
FN.addItem(NOMI[indice++]);
}
}
catch (ArrayIndexOutOfBoundsException e)
{};
setLayout(new borderLayout());
Panel np=new Panel(new GridLayout(1,3));
Panel rosso=new Panel(new FlowLayout());
rosso.add(new Label("Rosso"));
rosso.add(R);
np.add(rosso);
Panel verde=new Panel(new FlowLayout());
verde.add(new Label("Verde"));
verde.add(G);
np.add(verde);
Panel blu=new Panel(new FlowLayout());
blu.add(new Label("Blu"));
blu.add(B);
np.add(blu);
R.setUnitIncrement(10);
R.setValue(255);
G.setUnitIncrement(10);
G.setValue(255);
B.setUnitIncrement(10);
B.setValue(255);
add(np,borderLayout.SOUTH);
GR.addItem("Linea");
GR.addItem("Rettangolo");
GR.addItem("Rettangolo 3D");
GR.addItem("Rettangolo Arrotondato");
GR.addItem("Cerchio");
GR.addItem("Ellisse");
GR.addItem("Poligono generico");
GR.addItem("Testo");
GR.addItem("Arco");
Panel up=new Panel(new GridLayout(1,3));
up.add(GR);
up.add(FN);
up.add(F);
add(up,borderLayout.NORTH);
R.addAdjustmentListener(new AL());
G.addAdjustmentListener(new AL());
B.addAdjustmentListener(new AL());
GR.addItemListener(new IL());
FN.addItemListener(new IL());
F.addItemListener(new IL());
}
public void paint(Graphics g)
{
g.setColor(new Color(255-R.getValue(),
255-G.getValue(),
255-B.getValue()
));
g.setfont(new font(FN.getSelectedItem(),0,40));
boolean filled=F.getState();
int pg=GR.getSelectedIndex();
g.drawString(GR.getSelectedItem(),1,300);
if (pg==0)
{
g.drawLine(1,100,399,300);
return;
}
if (pg==1)
{
g.drawRect(50,100,250,100);
if (filled) g.fillRect(50,100,250,100);
return;
}
if (pg==2)
{
g.draw3DRect(50,100,250,100,true);
return;
}
if (pg==3)
{
g.drawRoundRect(50,100,300,100,20,20);
if (filled) g.fillRoundRect(50,100,300,100,20,20);
return;
}
if (pg==4)
{
g.drawOval(100,100,200,200);
if (filled) g.fillOval(100,100,200,200);
return;
}
if (pg==5)
{
g.drawOval(100,100,200,100);
if (filled) g.fillOval(100,100,200,100);
return;
}
if (pg==6)
{
g.drawPolygon(puntiX,puntiY,punti);
if (filled) g.fillPolygon(puntiX,puntiY,punti);
return;
}
if (pg==7)
{
g.drawString("Questa è una stringa",1,200);
return;
}
if (pg==8)
{
g.drawArc(1,50,398,200,10,270);
if (filled) g.fillArc(1,50,398,200,10,270);
return;
}
}
public class IL implements ItemListener
{
public void itemStateChanged(ItemEvent e)
{
repaint();
}
}
public class AL implements AdjustmentListener
{
public void adjustmentValueChanged(AdjustmentEvent e)
{
repaint();
}
}
}
