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Java Source | 2000-05-25 | 8.4 KB | 277 lines |
- //: 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);
- }
- } ///:~