activityindicator.java

J2ME MIDP_Example_Applications

// Copyright 2003 Nokia Corporation.
//
// THIS SOURCE CODE IS PROVIDED 'AS IS', WITH NO WARRANTIES WHATSOEVER,
// EXPRESS OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY, FITNESS
// FOR ANY PARTICULAR PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE
// OR TRADE PRACTICE, RELATING TO THE SOURCE CODE OR ANY WARRANTY OTHERWISE
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// SUPPORT. FURTHERMORE, NOKIA MAKES NO WARRANTY THAT EXERCISE OF THE
// RIGHTS GRANTED HEREUNDER DOES NOT INFRINGE OR MAY NOT CAUSE INFRINGEMENT
// OF ANY PATENT OR OTHER INTELLECTUAL PROPERTY RIGHTS OWNED OR CONTROLLED
// BY THIRD PARTIES
//
// Furthermore, information provided in this source code is preliminary,
// and may be changed substantially prior to final release. Nokia Corporation
// retains the right to make changes to this source code at
// any time, without notice. This source code is provided for informational
// purposes only.
//
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// Corporation.
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// Sun Microsystems, Inc.
// Other product and company names mentioned herein may be trademarks or
// trade names of their respective owners.
//
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// granted to the Licensee to download, print, reproduce and modify the
// source code. The licensee has the right to market, sell, distribute and
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package whiteboard;

import javax.microedition.lcdui.*;

class ActivityIndicator
    extends Form
    implements Runnable, CommandListener
{
    private final static int TICK_TIME_MILLIS = 300;

    private final Command exitCommand;
    private final Command cancelCommand;
    private final ImageItem progressMeter;
    private final Image progress0;
    private final Image progress1;

    private volatile boolean aborting = false;
    private volatile boolean doAnimation = false;

    private Thread thread = null;
    private int progressCount = 0;

    private final WhiteboardMIDlet parent;

    ActivityIndicator(WhiteboardMIDlet parent)
    {
        super("Status");
        this.parent = parent;

        // Initialize progress meter
        progress0 = WhiteboardMIDlet.makeImage("/progress0.png");
        progress1 = WhiteboardMIDlet.makeImage("/progress1.png");
        int anchor = (ImageItem.LAYOUT_LEFT | ImageItem.LAYOUT_NEWLINE_AFTER);
        progressMeter = new ImageItem("Connecting", progress0, anchor, "");
        append(progressMeter);

        // Screen commands
        exitCommand = new Command("Exit", Command.EXIT, 1);
        cancelCommand = new Command("Cancel", Command.SCREEN, 2);
        addCommand(exitCommand);
        addCommand(cancelCommand);
        setCommandListener(this);
    }

    // Runnable: this method is used by our thread
    public void run()
    {
        while ((Thread.currentThread() == thread) && !aborting)
        {
            if (doAnimation)
            {
                Image image = ((progressCount % 2) == 0) ? progress0 : progress1;

                progressMeter.setImage(image);
                progressCount++;
            }

            try
            {
                synchronized (this)
                {
                    wait(TICK_TIME_MILLIS);
                }
            }
            catch (InterruptedException e)
            {
            }
        }
    }


    public void commandAction(Command command, Displayable d)
    {
        if (command == exitCommand)
        {
            parent.notifyDestroyed();
        }
        else if (command == cancelCommand)
        {
            parent.abortRequest();
            stopProgressMeter();
        }
    }

    // add an animated progressMeter to the Form
    void startProgressMeter()
    {
        if (size() == 2)
        {
            insert(0, progressMeter);
        }

        // start animation
        aborting = false;
        doAnimation = true;
        thread = new Thread(this);
        thread.start();
    }


    // Stop the progressMeter's animation and remove from Form
    void stopProgressMeter()
    {
        // stop animation
        aborting = true;
        doAnimation = false;

        if (size() == 3)
        {
            delete(0);
        }
    }

    void setText(String text)
    {
        progressMeter.setLabel(text);
    }
}