Java 1996 August/Java - Summer 1996.iso/windows/doc/ui/layout/example/appletbutton.java

Java Source | 1996-02-26 | 5.2 KB | 170 lines

/*
 * Copyright (c) 1994 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL purposes and without
 * fee is hereby granted provided that this copyright notice
 * appears in all copies. Please refer to the file "copyright.html"
 * for further important copyright and licensing information.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 */
//TO DO: Close all windows when you leave the page?

import java.awt.*;
import java.util.*;
import java.applet.Applet;

public class AppletButton extends Applet implements Runnable {
    int frameNumber = 1;
    String windowClass;
    String buttonText;
    String windowText;
    int requestedWidth = 0;
    int requestedHeight = 0;
    Button button;
    Thread windowThread;
    Label label;
    boolean pleaseCreate = false;

    public void init() {
    windowClass = getParameter("WINDOWTYPE");
    if (windowClass == null) {
        windowClass = "TestWindow";
    }

    buttonText = getParameter("BUTTONTEXT");
    if (buttonText == null) {
        buttonText = "Click here to bring up a " + windowClass;
    }

    windowText = getParameter("WINDOWTEXT");
    if (windowText == null) {
        windowText = windowClass;
    }

        String windowWidthString = getParameter("WINDOWWIDTH");
        if (windowWidthString != null) {
            try {
                requestedWidth = Integer.parseInt(windowWidthString);
            } catch (NumberFormatException e) {
                requestedWidth = 0;
            }
        }

        String windowHeightString = getParameter("WINDOWHEIGHT");
        if (windowHeightString != null) {
            try {
                requestedHeight = Integer.parseInt(windowHeightString);
            } catch (NumberFormatException e) {
                requestedHeight = 0;
            }
        }

    setLayout(new GridLayout(2,0));
    add(button = new Button(buttonText));
        button.setFont(new Font("Helvetica", Font.PLAIN, 14));

    add(label = new Label("", Label.CENTER));
    }

    public void start() {
    if (windowThread == null) {
        windowThread = new Thread(this, "Bringing Up " + windowClass);
        windowThread.start();
    }
    }

    public synchronized void run() {
    Class windowClassObject = null;
    Class tmp = null;
    String name = null;

    // Make sure the window class exists and is really a Frame.
    // This has the added benefit of pre-loading the class,
    // which makes it much quicker for the first window to come up.
    try {
        windowClassObject = Class.forName(windowClass);
    } catch (Exception e) {
        // The specified class isn't anywhere that we can find.
        label.setText("Can't create window: Couldn't find class "
                  + windowClass);
        button.disable();
    }

    // Find out whether the class is a Frame.
    for (tmp = windowClassObject, name = tmp.getName();
         !( name.equals("java.lang.Object") ||
            name.equals("java.awt.Frame") ); ) {
        tmp = tmp.getSuperclass();
        name = tmp.getName();
    }
    if ((name == null) || name.equals("java.lang.Object")) {
        //We can't run; ERROR; print status, never bring up window
        label.setText("Can't create window: "
                  + windowClass +
              " isn't a Frame subclass.");
        button.disable();
    } else if (name.equals("java.awt.Frame")) {
        //Everything's OK. Wait until we're asked to create a window.
        while (windowThread != null) {
            while (pleaseCreate == false) {
            try {
                wait();
            } catch (InterruptedException e) {
            }
            }

            //We've been asked to bring up a window.
            pleaseCreate = false;
            Frame window = null;
            try {
                window = (Frame)windowClassObject.newInstance();
            } catch (Exception e) {
            label.setText("Couldn't create instance of class "
                      + windowClass);
            }
        if (frameNumber == 1) {
                window.setTitle(windowText);
        } else {
                window.setTitle(windowText + ": " + frameNumber);
        }
            frameNumber++;

        //Set the window's size.
            window.pack();
                if ((requestedWidth > 0) | (requestedHeight > 0)) {
                    window.resize(Math.max(requestedWidth,
                       window.size().width),
                  Math.max(requestedHeight,
                       window.size().height));
                }

            window.show();
            label.setText("");
        }
    }
    }

    public synchronized boolean action(Event event, Object what) {
    if (event.target instanceof Button) {
        //signal the window thread to build a window
        label.setText("Please wait while the window comes up...");
        pleaseCreate = true;
        notify();
    }
    return false;
    }
}

class TestWindow extends Frame {
    public TestWindow() {
    resize(300, 300);
    }
}