Contoh AWT Event Model

Contoh script sederhana :

import java.awt.*;
import java.awt.event.*;
public class SimpleAWT extends java.applet.Applet
implements ActionListener, ItemListener {
private Button button = new Button("Push Me!");
private Checkbox checkbox = new Checkbox("Check Me!");
private Choice choice = new Choice();
private Label label = new Label("Pick something!");
public void init() {
button.addActionListener(this);
checkbox.addItemListener(this);
choice.addItemListener(this);
// An Applet is a Container because it extends Panel.
setLayout(new BorderLayout());
choice.addItem("Red");
choice.addItem("Green");
choice.addItem("Blue");
Panel panel = new Panel();
panel.add(button);
panel.add(checkbox);
panel.add(choice);
add(label, "Center");
add(panel, "South");
}





FontTest.java



import java.awt.*;
import java.awt.event.*;
import java.util.Enumeration;
import COM.ociweb.awt.ColorMap;
public class FontTest extends java.applet.Applet
implements ActionListener, AdjustmentListener, ItemListener, MouseListener {
static final String DEFAULT_FONT = "Helvetica";
static final String DEFAULT_TEXT = "FontTest";
static final int DEFAULT_SIZE = 24;
private static final int BOX_SIZE = 3;
private static final int MIN_SIZE = 6;
private static final int MAX_SIZE = 250;
private CheckboxGroup styleGroup = new CheckboxGroup();
private Checkbox boldRadio = new Checkbox("Bold", false, styleGroup);
private Checkbox bothRadio = new Checkbox("Both", false, styleGroup);
private Checkbox italicRadio =
new Checkbox("Italic", false, styleGroup);
private Checkbox plainRadio = new Checkbox("Plain", true, styleGroup);
private Choice fontChoice = new Choice();
private List colorList = new List(4, false);
private MyCanvas myCanvas = new MyCanvas();
private PopupMenu popup = new PopupMenu("Font");
private Scrollbar scrollbar =
new Scrollbar(Scrollbar.HORIZONTAL, DEFAULT_SIZE, BOX_SIZE,
MIN_SIZE, MAX_SIZE + BOX_SIZE);
private TextField sizeField =
new TextField(String.valueOf(DEFAULT_SIZE), 3);
private TextField textField = new TextField(DEFAULT_TEXT, 40);

public void init() {
fontChoice.addItem("TimesRoman");
fontChoice.addItem("Helvetica");
fontChoice.addItem("Courier");
fontChoice.select(DEFAULT_FONT);
Panel fontPanel = new Panel();
fontPanel.add(new Label("Font:"));
fontPanel.add(fontChoice);
Panel stylePanel = new Panel();
stylePanel.add(plainRadio);
stylePanel.add(boldRadio);
stylePanel.add(italicRadio);
stylePanel.add(bothRadio);
Enumeration e = ColorMap.getColorNames();
while (e.hasMoreElements()) {
colorList.addItem((String) e.nextElement());
}
colorList.select(0);
Panel sizePanel = new Panel();
sizePanel.add
(new Label("Size (" + MIN_SIZE + "-" + MAX_SIZE + ")"));
sizePanel.add(sizeField);
Panel westPanel = new Panel(new GridLayout(0, 1));
westPanel.add(fontPanel);
westPanel.add(stylePanel);
westPanel.add(colorList);
westPanel.add(sizePanel);

setLayout(new BorderLayout());
add(myCanvas, "Center");
add(westPanel, "West");
add(textField, "North");
add(scrollbar, "South");
fontChoice.addItemListener(this);
plainRadio.addItemListener(this);
boldRadio.addItemListener(this);
italicRadio.addItemListener(this);
bothRadio.addItemListener(this);
colorList.addItemListener(this);
sizeField.addActionListener(this);
textField.addActionListener(this);
scrollbar.addAdjustmentListener(this);
fontPanel.addMouseListener(this);
stylePanel.addMouseListener(this);
sizePanel.addMouseListener(this);
myCanvas.addMouseListener(this);
MenuItem timesRomanItem = new MenuItem("TimesRoman");
MenuItem helveticaItem = new MenuItem("Helvetica");
MenuItem courierItem = new MenuItem("Courier");
timesRomanItem.addActionListener(this);
helveticaItem.addActionListener(this);
courierItem.addActionListener(this);
popup.add(timesRomanItem);
popup.add(helveticaItem);
popup.add(courierItem);
add(popup);
}

public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == textField) {
myCanvas.setText(textField.getText());
} else if (source == sizeField) {
int size = Integer.parseInt(sizeField.getText());
scrollbar.setValue(size);
setFont();
} else if (source instanceof MenuItem) {
MenuItem menuItem = (MenuItem) source;
if (menuItem.getParent() == popup) {
fontChoice.select(e.getActionCommand());
setFont();
}
}
}
public void adjustmentValueChanged(AdjustmentEvent e) {
if (e.getSource() == scrollbar) {
sizeField.setText(String.valueOf(scrollbar.getValue()));
setFont();
}
}
public void itemStateChanged(ItemEvent e) {
Object source = e.getSource();
if (source == fontChoice) {
setFont();
} else if (source instanceof Checkbox) {
Checkbox checkbox = (Checkbox) source;
if (checkbox.getCheckboxGroup() == styleGroup) {
setFont();
}
} else if (source == colorList) {
Color color = ColorMap.getColor(colorList.getSelectedItem());
myCanvas.setColor(color);
}
}

// MouseListener methods that need no action.
public void mouseEntered(MouseEvent e) {}
public void mouseExited(MouseEvent e) {}
public void mouseClicked(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void mousePressed(MouseEvent e) {
popup.show((Component) e.getSource(), e.getX(), e.getY());
}
private void setFont() {
int style = Font.PLAIN;
Checkbox styleRadio = styleGroup.getSelectedCheckbox();
if (styleRadio == plainRadio) {
style = Font.PLAIN;
} else if (styleRadio == boldRadio) {
style = Font.BOLD;
} else if (styleRadio == italicRadio) {
style = Font.ITALIC;
} else if (styleRadio == bothRadio) {
style = Font.BOLD + Font.ITALIC;
}
Font font =
new Font(fontChoice.getSelectedItem(),
style,
Integer.parseInt(sizeField.getText()));
myCanvas.setFont(font);
}
}

class MyCanvas extends Canvas {
private Color color = Color.black;
private Font font =
new Font(FontTest.DEFAULT_FONT,
Font.PLAIN,
FontTest.DEFAULT_SIZE);
private String text = FontTest.DEFAULT_TEXT;
public void setColor(Color color) {
this.color = color;
repaint();
}
public void setFont(Font font) {
this.font = font;
repaint();
}
public void setText(String text) {
this.text = text;
repaint();
}
public void paint(Graphics g) {
g.setColor(color);
g.setFont(font);
g.drawString(text, 10, 200);
}
}