//: GoodTechnique.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.)
/////////////////////////////////////////////////
// Your first choice when overriding components
// should be to install listeners. The code is
// much safer, more modular and maintainable.
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);
addComponentListener(new CL());
addFocusListener(new FL());
addKeyListener(new KL());
addMouseListener(new ML());
addMouseMotionListener(new MML());
}
// 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);
}
// Don't need to enable anything for this:
public void processEvent(AWTEvent e) {
display.evnt[Display.EVENT]= e.toString();
repaint();
super.processEvent(e);
}
class CL implements ComponentListener {
public void componentMoved(ComponentEvent e){
display.evnt[Display.COMPONENT] =
"Component moved";
repaint();
}
public void
componentResized(ComponentEvent e) {
display.evnt[Display.COMPONENT] =
"Component resized";
repaint();
}
public void
componentHidden(ComponentEvent e) {
display.evnt[Display.COMPONENT] =
"Component hidden";
repaint();
}
public void componentShown(ComponentEvent e){
display.evnt[Display.COMPONENT] =
"Component shown";
repaint();
}
}
class FL implements FocusListener {
public void focusGained(FocusEvent e) {
display.evnt[Display.FOCUS] =
"FOCUS gained";
repaint();
}
public void focusLost(FocusEvent e) {
display.evnt[Display.FOCUS] =
"FOCUS lost";
repaint();
}
}
class KL implements KeyListener {
public void keyPressed(KeyEvent e) {
display.evnt[Display.KEY] =
"KEY pressed: ";
showCode(e);
}
public void keyReleased(KeyEvent e) {
display.evnt[Display.KEY] =
"KEY released: ";
showCode(e);
}
public void keyTyped(KeyEvent e) {
display.evnt[Display.KEY] =
"KEY typed: ";
showCode(e);
}
void showCode(KeyEvent e) {
int code = e.getKeyCode();
display.evnt[Display.KEY] +=
KeyEvent.getKeyText(code);
repaint();
}
}
class ML implements MouseListener {
public void mouseClicked(MouseEvent e) {
requestFocus(); // Get FOCUS on click
display.evnt[Display.MOUSE] =
"MOUSE clicked";
showMouse(e);
}
public void mousePressed(MouseEvent e) {
display.evnt[Display.MOUSE] =
"MOUSE pressed";
showMouse(e);
}
public void mouseReleased(MouseEvent e) {
display.evnt[Display.MOUSE] =
"MOUSE released";
showMouse(e);
}
public void mouseEntered(MouseEvent e) {
display.evnt[Display.MOUSE] =
"MOUSE entered";
showMouse(e);
}
public void mouseExited(MouseEvent e) {
display.evnt[Display.MOUSE] =
"MOUSE exited";
showMouse(e);
}
void showMouse(MouseEvent e) {
display.evnt[Display.MOUSE] +=
", x = " + e.getX() +
", y = " + e.getY();
repaint();
}
}
class MML implements MouseMotionListener {
public void mouseDragged(MouseEvent e) {
display.evnt[Display.MOUSE_MOVE] =
"MOUSE dragged";
showMouse(e);
}
public void mouseMoved(MouseEvent e) {
display.evnt[Display.MOUSE_MOVE] =
"MOUSE moved";
showMouse(e);
}
void showMouse(MouseEvent e) {
display.evnt[Display.MOUSE_MOVE] +=
", x = " + e.getX() +
", y = " + e.getY();
repaint();
}
}
}
class MyButton extends Button {
int clickCounter;
String label = "";
public MyButton() {
addActionListener(new AL());
}
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);
}
class AL implements ActionListener {
public void actionPerformed(ActionEvent e) {
clickCounter++;
label = "click #" + clickCounter +
" " + e.toString();
repaint();
}
}
}
public class GoodTechnique extends Frame {
GoodTechnique() {
setLayout(new GridLayout(2,2));
add(new EnabledPanel(1, Color.cyan));
add(new EnabledPanel(2, Color.lightGray));
add(new EnabledPanel(3, Color.yellow));
}
public static void main(String[] args) {
Frame f = new GoodTechnique();
f.setTitle("Good Technique");
f.addWindowListener(
new WindowAdapter() {
public void windowClosing(WindowEvent e){
System.out.println(e);
System.out.println("Window Closing");
System.exit(0);
}
});
f.setSize(700,700);
f.setVisible(true);
}
} ///:~ |
