Иллюстрированный самоучитель по Java

Создание меню

Листинг 13.2. Программа рисования с всплывающим меню.

import java.awt.*;
import java.awt.event.*;
public class PopupMenuScribble extends Frame{
public PopupMenuScribble(String s){ super (s);
ScrollPane pane = new ScrollPane();
pane.setSize(300, 300);
add(pane, BorderLayout.CENTER);
Scribble scr = new Scribble(this, 500, 500);
pane.add(scr);
addWindowListener(new WinClose());
pack ();
setVisible(true);
}
class WinClose extends WindowAdapter{
public void windowClosing(WindowEvent e){
System.exit(0);
}
}
public static void main(String[] args){
new PopupMenuScribble(" \"Рисовалка\" с всплывающим меню");
}
}
class ScriBble extends Component implements ActionListener{
protected int lastX, lastY, w, h;
protected Color currColor = Color.black;
protected Frame f;
protected PopupMenu c;
public Scribble(Frame frame, int width, int height)!{
f = frame; w = width; h = height;
enableEvents(AWTEvent.MOUSE_EVENT_MASK |
AWTEvent.MOUSEJtoTIONJEVENT_MASK);
с = new PopupMenu ("Цвет");
add(c);
Menultera clear = new Menultem("Очистить",
new MenuShortcut(KeyEvent.VK_D));
Menultem red = new Menultem("Красный");
Menultem green = new Menultem("Зеленый");
Menultem blue = new Menultern("Синий");
Menultem black = new Menultem("Черный");
c.add(red); c.add(green); c.add(blue);
c.add(black); с.addSeparator(); с.add(clear);
red.addActionListener(this);
green.addActionListener(this);
blue.addActionListener(this);
black.addActionListener(this);
clear.addActionListener(this);
}
public Dimension getPreferredSize()
{
return new Dimension(w, h);
}
public void actionPerformed(ActionEvent event){
String s = event.getActionCommand();
if (s.equals("Очистить")) repaint();
else if (s.equals("Красный")) currColor = Color.red;
else if (s.equals("Зеленый")) currColor = Color.green;
else if (s.equals("Синий")) currColor = Color.blue;
else if (s.equals("Черный")) currColor = Color.black;
}
public void processMouseEvent(MouseEvent e){
if (e.isPopupTrigger())
c.show(e.getComponent (), e.getXO, e.getY());
else if (e.getlDO == MouseEvent.MOUSE_PRESSED){
lastX = e.getX(); lastY = e.getY(); }
else super.processMouseEvent(e); }
public void processMouseMotionEvent(MouseEvent e){
if (e.getlDO = MouseEvent.MOUSE_DRAGGED){
Graphics g = getGraphics();
g.setColor(currColor);
g.drawLinedastX, lastY, e.getX(), e.getY());
lastX = e.getX(); lastY = e.getY();
}
else super.processMouseMotionEvent(e);
}
}

Рис. 13.3. Программа рисования с всплывающим меню