/******************************************************************************* * * * File: Applet_06.java Revision: 1.0 * * * * Contents: shows the applet's state in an external window * * * * Creation: 11.09.2000 Last Modification: 23.04.2002 * * * * Platform: IBM-compatible PC running Windows 98SE * * * * Environment: Java 1.4 * * * * Author: Andreas Rozek Phone: ++49 (711) 6770682 * * Kirschblütenweg 15 Fax: - * * D-70569 Stuttgart EMail: Andreas.Rozek@T-Online.De * * Germany * * * * URL: http://www.Andreas-Rozek.de/ * * * * Copyright: this software is published under the "GNU General Public Li- * * cense" (see "http://www.gnu.org/copyleft/gpl.html" for addi- * * tional information) * * * * Comments: (none) * * * *******************************************************************************/ import java.applet.*; // basic applet classes import java.awt.*; // basic AWT classes (& interfaces) import java.awt.event.*; // AWT event handling import java.awt.image.*; // image processing classes public class Applet_06 extends java.applet.Applet { /**** information about author, version and copyright of this applet ****/ final static String AppletInfo = "Applet_06 - shows the applet's state in an external window\n" + "\n" + "Andreas Rozek\n" + "Kirschblütenweg 15\n" + "D-70569 Stuttgart\n" + "Germany\n" + "\n" + "Phone: ++49 (711) 6770682\n" + "Fax: -\n" + "EMail: Andreas.Rozek@T-Online.De\n" + "URL: http://www.Andreas-Rozek.de"; /**** information about foreseen applet parameters ****/ final static String[][] ParameterInfo = null; /******************************************************************************* * * * Non-Public Instance Variables * * * *******************************************************************************/ /**** bitmaps for state display ****/ Image after_Constructor, after_init, after_start, after_stop; /**** user interface components ****/ Button WindowButton; // opens an external window StateDisplayFrame ExternalFrame; // an external window for the applet's state /******************************************************************************* * * * Public Instance Variables * * * *******************************************************************************/ Image actualState; // refers to the image which reflects the actual state /******************************************************************************* * * * Constructor * * * *******************************************************************************/ public Applet_06 () { super(); // just to be complete /**** initialize internal variables ****/ after_Constructor = null; // bitmaps cannot be loaded yet: browser may... after_init = null; // ...crash within "getDocumentBase()" after_start = null; after_stop = null; actualState = after_Constructor; WindowButton = null; ExternalFrame = null; }; /******************************************************************************* * * * Public Instance Methods * * * *******************************************************************************/ /******************************************************************************* * * * destroy clean up before the applet will be unloaded * * * *******************************************************************************/ public void destroy () { if (ExternalFrame != null) { ExternalFrame.dispose(); }; }; /******************************************************************************* * * * getAppletInfo provides information about author, version and copyright * * * *******************************************************************************/ public String getAppletInfo () { return AppletInfo; // see above for definition of "AppletInfo" }; /******************************************************************************* * * * getParameterInfo provides information about foreseen applet parameters * * * *******************************************************************************/ public String[][] getParameterInfo () { return ParameterInfo; // see above for definition of "ParameterInfo" }; /******************************************************************************* * * * init initialize an applet each time it's loaded or reloaded * * * *******************************************************************************/ public void init () { /**** unify the visual appearance of an applet on different platforms ****/ setBackground(Color.lightGray); setFont(new Font("Helvetica", Font.PLAIN, 11)); /**** load botmaps ****/ after_Constructor = getImage(getCodeBase(),"after_Constructor.gif"); prepareImage(after_Constructor, this); // force loading after_init = getImage(getCodeBase(),"after_init.gif"); prepareImage(after_init, this); // force loading after_start = getImage(getCodeBase(),"after_start.gif"); prepareImage(after_start, this); // force loading after_stop = getImage(getCodeBase(),"after_stop.gif"); prepareImage(after_stop, this); // force loading /**** prepare user interface ****/ setLayout(new BorderLayout()); WindowButton = new Button("Open State Window"); WindowButton.setFont(new Font("Helvetica", Font.BOLD, 12)); WindowButton.setEnabled(ExternalFrame == null); WindowButton.addActionListener(new ActionListener() { public void actionPerformed (ActionEvent Event) { if (ExternalFrame == null) { Applet_06 Context = (Applet_06) ((Button) Event.getSource()).getParent(); ExternalFrame = new StateDisplayFrame(Context); WindowButton.setEnabled(false); }; }; }); add(WindowButton,"Center"); /**** resize and show applet ****/ // resize(preferredSize()); setVisible(true); /**** update the state display ****/ actualState = after_init; if (ExternalFrame != null) { ExternalFrame.repaint(); }; }; /******************************************************************************* * * * start start an applet when the accompanying document has been entered * * * *******************************************************************************/ public synchronized void start () { // may be called several times! actualState = after_start; if (ExternalFrame != null) { ExternalFrame.repaint(); }; }; /******************************************************************************* * * * stop stop an applet when the accompanying document has been left * * * *******************************************************************************/ public synchronized void stop () { // may be called several times! actualState = after_stop; if (ExternalFrame != null) { ExternalFrame.repaint(); }; }; }; /******************************************************************************* * * * Additional Classes * * * *******************************************************************************/ class StateDisplay extends Component { Applet_06 Context; // a reference to the associated applet Dimension DisplaySize; // the only acceptable size for this display public StateDisplay (Applet_06 Context) { super(); this.Context = Context; // keep a reference to the associated applet DisplaySize = new Dimension(352,105); setSize(DisplaySize); }; public Dimension getMaximumSize() {return DisplaySize;}; public Dimension getMinimumSize() {return DisplaySize;}; public Dimension getPreferredSize() {return DisplaySize;}; public void paint (Graphics Graf) { if (Context.actualState != null) { Graf.drawImage(Context.actualState, 0,0, this); }; }; }; class StateDisplayFrame extends Frame { Applet_06 Context; // a reference to the associated applet public StateDisplayFrame (Applet_06 Context) { super("Applet_06 - State Display"); /**** keep a reference to the associated applet ****/ this.Context = Context; /**** enable window event processing ****/ enableEvents(AWTEvent.WINDOW_EVENT_MASK); /**** prepare user interface ****/ setLayout(new BorderLayout()); Component Display = new StateDisplay(Context); add(Display,"Center"); /**** resize and show the frame ****/ pack(); setVisible(true); /**** inhibit further size changes ****/ setResizable(false); }; protected void processWindowEvent (WindowEvent Event) { super.processWindowEvent(Event); if (Event.getID() == WindowEvent.WINDOW_CLOSING) { Context.ExternalFrame = null; Context.WindowButton.setEnabled(true); dispose(); // remove this window }; }; };