Java -практика использования


          

Программа рисования с всплывающим меню



Листинг 13.2. Программа рисования с всплывающим меню

import j ava.awt.* ;

import j ava.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);
 

}



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