//: BadTechnique.java
//////////////////////////////////////////////////
// Copyright (c) Bruce Eckel, 1998
// Source code file from the book "Thinking in Java"
// All rights reserved EXCEPT as allowed by the
// following statements: You can freely use this file
// for your own work (personal or commercial),
// including modifications and distribution in
// executable form only. Permission is granted to use
// this file in classroom situations, including its
// use in presentation materials, as long as the book
// "Thinking in Java" is cited as the source.
// Except in classroom situations, you cannot copy
// and distribute this code; instead, the sole
// distribution point is http://www.BruceEckel.com
// (and official mirror sites) where it is
// freely available. You cannot remove this
// copyright and notice. You cannot distribute
// modified versions of the source code in this
// package. You cannot use this file in printed
// media without the express permission of the
// author. Bruce Eckel makes no representation about
// the suitability of this software for any purpose.
// It is provided "as is" without express or implied
// warranty of any kind, including any implied
// warranty of merchantability, fitness for a
// particular purpose or non-infringement. The entire
// risk as to the quality and performance of the
// software is with you. Bruce Eckel and the
// publisher shall not be liable for any damages
// suffered by you or any third party as a result of
// using or distributing software. In no event will
// Bruce Eckel or the publisher be liable for any
// lost revenue, profit, or data, or for direct,
// indirect, special, consequential, incidental, or
// punitive damages, however caused and regardless of
// the theory of liability, arising out of the use of
// or inability to use software, even if Bruce Eckel
// and the publisher have been advised of the
// possibility of such damages. Should the software
// prove defective, you assume the cost of all
// necessary servicing, repair, or correction. If you
// think you've found an error, please email all
// modified files with clearly commented changes to:
// Bruce@EckelObjects.com. (Please use the same
// address for non-code errors found in the book.)
/////////////////////////////////////////////////
// It's possible to override components this way,
// but the listener approach is much better, so
// why would you?
import java.awt.*;
import java.awt.event.*;
class Display {
public static final int
EVENT = 0, COMPONENT = 1,
MOUSE = 2, MOUSE_MOVE = 3,
FOCUS = 4, KEY = 5, ACTION = 6,
LAST = 7;
public String[] evnt;
Display() {
evnt = new String[LAST];
for(int i = 0; i < LAST; i++)
evnt[i] = new String();
}
public void show(Graphics g) {
for(int i = 0; i < LAST; i++)
g.drawString(evnt[i], 0, 10 * i + 10);
}
}
class EnabledPanel extends Panel {
Color c;
int id;
Display display = new Display();
public EnabledPanel(int i, Color mc) {
id = i;
c = mc;
setLayout(new BorderLayout());
add(new MyButton(), BorderLayout.SOUTH);
// Type checking is lost. You can enable and
// process events that the component doesn't
// capture:
enableEvents(
// Panel doesn't handle these:
AWTEvent.ACTION_EVENT_MASK |
AWTEvent.ADJUSTMENT_EVENT_MASK |
AWTEvent.ITEM_EVENT_MASK |
AWTEvent.TEXT_EVENT_MASK |
AWTEvent.WINDOW_EVENT_MASK |
// Panel can handle these:
AWTEvent.COMPONENT_EVENT_MASK |
AWTEvent.FOCUS_EVENT_MASK |
AWTEvent.KEY_EVENT_MASK |
AWTEvent.MOUSE_EVENT_MASK |
AWTEvent.MOUSE_MOTION_EVENT_MASK |
AWTEvent.CONTAINER_EVENT_MASK);
// You can enable an event without
// overriding its process method.
}
// To eliminate flicker:
public void update(Graphics g) {
paint(g);
}
public void paint(Graphics g) {
g.setColor(c);
Dimension s = getSize();
g.fillRect(0, 0, s.width, s.height);
g.setColor(Color.black);
display.show(g);
}
public void processEvent(AWTEvent e) {
display.evnt[Display.EVENT]= e.toString();
repaint();
super.processEvent(e);
}
public void
processComponentEvent(ComponentEvent e) {
switch(e.getID()) {
case ComponentEvent.COMPONENT_MOVED:
display.evnt[Display.COMPONENT] =
"Component moved";
break;
case ComponentEvent.COMPONENT_RESIZED:
display.evnt[Display.COMPONENT] =
"Component resized";
break;
case ComponentEvent.COMPONENT_HIDDEN:
display.evnt[Display.COMPONENT] =
"Component hidden";
break;
case ComponentEvent.COMPONENT_SHOWN:
display.evnt[Display.COMPONENT] =
"Component shown";
break;
default:
}
repaint();
// Must always remember to call the "super"
// version of whatever you override:
super.processComponentEvent(e);
}
public void processFocusEvent(FocusEvent e) {
switch(e.getID()) {
case FocusEvent.FOCUS_GAINED:
display.evnt[Display.FOCUS] =
"FOCUS gained";
break;
case FocusEvent.FOCUS_LOST:
display.evnt[Display.FOCUS] =
"FOCUS lost";
break;
default:
}
repaint();
super.processFocusEvent(e);
}
public void processKeyEvent(KeyEvent e) {
switch(e.getID()) {
case KeyEvent.KEY_PRESSED:
display.evnt[Display.KEY] =
"KEY pressed: ";
break;
case KeyEvent.KEY_RELEASED:
display.evnt[Display.KEY] =
"KEY released: ";
break;
case KeyEvent.KEY_TYPED:
display.evnt[Display.KEY] =
"KEY typed: ";
break;
default:
}
int code = e.getKeyCode();
display.evnt[Display.KEY] +=
KeyEvent.getKeyText(code);
repaint();
super.processKeyEvent(e);
}
public void processMouseEvent(MouseEvent e) {
switch(e.getID()) {
case MouseEvent.MOUSE_CLICKED:
requestFocus(); // Get FOCUS on click
display.evnt[Display.MOUSE] =
"MOUSE clicked";
break;
case MouseEvent.MOUSE_PRESSED:
display.evnt[Display.MOUSE] =
"MOUSE pressed";
break;
case MouseEvent.MOUSE_RELEASED:
display.evnt[Display.MOUSE] =
"MOUSE released";
break;
case MouseEvent.MOUSE_ENTERED:
display.evnt[Display.MOUSE] =
"MOUSE entered";
break;
case MouseEvent.MOUSE_EXITED:
display.evnt[Display.MOUSE] =
"MOUSE exited";
break;
default:
}
display.evnt[Display.MOUSE] +=
", x = " + e.getX() +
", y = " + e.getY();
repaint();
super.processMouseEvent(e);
}
public void
processMouseMotionEvent(MouseEvent e) {
switch(e.getID()) {
case MouseEvent.MOUSE_DRAGGED:
display.evnt[Display.MOUSE_MOVE] =
"MOUSE dragged";
break;
case MouseEvent.MOUSE_MOVED:
display.evnt[Display.MOUSE_MOVE] =
"MOUSE moved";
break;
default:
}
display.evnt[Display.MOUSE_MOVE] +=
", x = " + e.getX() +
", y = " + e.getY();
repaint();
super.processMouseMotionEvent(e);
}
}
class MyButton extends Button {
int clickCounter;
String label = "";
public MyButton() {
enableEvents(AWTEvent.ACTION_EVENT_MASK);
}
public void paint(Graphics g) {
g.setColor(Color.green);
Dimension s = getSize();
g.fillRect(0, 0, s.width, s.height);
g.setColor(Color.black);
g.drawRect(0, 0, s.width - 1, s.height - 1);
drawLabel(g);
}
private void drawLabel(Graphics g) {
FontMetrics fm = g.getFontMetrics();
int width = fm.stringWidth(label);
int height = fm.getHeight();
int ascent = fm.getAscent();
int leading = fm.getLeading();
int horizMargin =
(getSize().width - width)/2;
int verMargin =
(getSize().height - height)/2;
g.setColor(Color.red);
g.drawString(label, horizMargin,
verMargin + ascent + leading);
}
public void processActionEvent(ActionEvent e) {
clickCounter++;
label = "click #" + clickCounter +
" " + e.toString();
repaint();
super.processActionEvent(e);
}
}
public class BadTechnique extends Frame {
BadTechnique() {
setLayout(new GridLayout(2,2));
add(new EnabledPanel(1, Color.cyan));
add(new EnabledPanel(2, Color.lightGray));
add(new EnabledPanel(3, Color.yellow));
// You can also do it for Windows:
enableEvents(AWTEvent.WINDOW_EVENT_MASK);
}
public void processWindowEvent(WindowEvent e) {
System.out.println(e);
if(e.getID() == WindowEvent.WINDOW_CLOSING) {
System.out.println("Window Closing");
System.exit(0);
}
}
public static void main(String[] args) {
Frame f = new BadTechnique();
f.setTitle("Bad Technique");
f.setSize(700,700);
f.setVisible(true);
}
} ///:~ |
