Applets and Images!

[usman ahmad]

Hi!
I am using an Image in my applet. It runs fine when I view it on my Computer. But when I uploaded it to my server it stopped running.Only the Image portion.Rest of the applet is running fine.I also uploaded the Image which I am using in my applet.
Any answers...
Regards
Usman

[Nathan Pruett]

Usman,
It would help alot if you posted the source code...
It could be alot of problems... image not in the place where the applet is looking for it, server lag, or the way you are trying to get the image...
-Nate

[usman ahmad]

here is the code
import java.awt.*;
import java.applet.*;
public class LoadImage extends Applet
{
private Image egg;
public void init()
{
egg = getImage(getDocumentBase(),"egg.gif");
}
public void paint(Graphics g)
{
setBackground(Color.white);
g.drawImage(egg,1,1,this);
g.drawString("Planning to Develop your WebSite!",100,50);
g.drawString("Give Usman Ahmad a crack at it.",100,300);
}

}
I hope this is helpful.
Thanks& Regards.
Usman

[Nathan Pruett]

Hmmm... the code works fine...
Can you post the URL of where you have this on the Internet?
Is the image or applet in a subdirectory?
-Nate

[usman ahmad]

here is the url where it is
http://www.angelfire.com/yt2/resume1/testthread.htm
check it out.
Regards
Usman

[This message has been edited by usman ahmad (edited March 23, 2001).]

[usman ahmad]

Originally posted by usman ahmad:
here is the url where it is
http://www.angelfire.com/yt2/resume1/testthread.htm
check it out.
Regards
Usman

[usman ahmad]

Actually there are two applets running on this page.
Both the class file and the image and the html page are in the same Directory.
Regards
Usman

[Nathan Pruett]

Hmmm.... I am not sure why the Image is not showing up... try the following code to see if it helps any, but if it doesn't I am stumped...
Using MediaTracker like this helps to ensure that Images are loaded completely before they are displayed...

import java.awt.*;
import java.applet.*;
public class LoadImage extends Applet
{
    private Image egg;
    
    public void init()
    {
        egg = getImage(getCodeBase(),"egg.gif");
        MediaTracker tracker = new MediaTracker( this );
        tracker.addImage( egg, 0 );
        try
        {
            tracker.waitForID( 0 );
        }
        catch( InterruptedException x )
        {
            System.err.println( "Error loading image with MediaTracker" );
        }
    }
    public void paint(Graphics g)
    {
        setBackground(Color.white);
        g.drawImage(egg,1,1,this);
        g.drawString("Planning to Develop your WebSite!",100,50);
        g.drawString("Give Usman Ahmad a crack at it.",100,300);
    }
}

[usman ahmad]

Tried this also but the image part is missing still.
Thanks anyways!
Regards
Usman

[usman ahmad]

Hi! What now I did is explicitly called the img.
you can check it here
http://www.angelfire.com/resume1/testthread.htm
But the image still won't run in the applet.
Any help!
Regards
Usman

[Nathan Pruett]

Usman,
Ah ha! Now I know what the problem is! But I don't think you will like the answer....
Java does not directly support animated gifs... the first frame of the animated gif is blank, and so your applet is displaying only the first, blank frame of the gif you are trying to load...
To get your applet to work, what you'll basically have to do is have two images... the whole egg and the broken egg... have a thread to control the animation... start the animation with the whole egg at the top of the screen, move the egg down the screen, and when it reaches a certain point switch the image to the broken egg and stop moving the egg down...
Is this explaination is good enough for you to figure out what to do? If not, post again, and I will try to post some code that will help you out...
HTH,
-Nate

[usman ahmad]

Thanks Nate, But shouldn't it then not display when I view it in the browser on my computer. But I can see it. Anyways, show me the code with which I can do that.
Thanks!
Regards,
Usman

[Nathan Pruett]

Usman,
I checked out what you said, and sure enough... I was wrong... I dl'ed your egg image from the web and ran it in appletviewer and in IE4... and it worked! Guess I have egg on my face, eh? However, I uploaded the graphic to my crappy free webpage and tried it and... it didn't run! I then changed the code to load and display a static gif and the code worked... ( Check it out here at... http://members.fortunecity.com/nepruett/UsmanImage.html my crappy website ) I have no idea what is wrong... but the problem seems to be with the image and not the applet...
HTH,
-Nate
P.S. - I am working on the code that will take the animation out of the image and put it into the applet... I think this may solve your problem...
[This message has been edited by Nathan Pruett (edited March 28, 2001).]

[Matt DeLacey]

Hmmm....I'm using Netscape and it works fine for me!
With Respect,
Matt

[Matt DeLacey]

Maybe you need to clear your caches. In IE I can't figure out how to do it (I know how you're supposed to be able to do it), but in Netscape, it's pretty straightforward. Give that a shot...maybe it's already fixed and you're just seeing an old copy.
Matt

[Nathan Pruett]

Usman,
Here is the updated java source for animating with an applet and not with an image... just a quick and dirty example, but it works...

import java.awt.*;
import java.applet.*;
public class UsmanImage extends Applet implements Runnable
{
    private Image[] egg;    // Array of egg images
    private int showingPic; // The egg picture currently showing
    private int eggX;       // The x point to draw the egg picture
    private int eggY;       // The y point to draw the egg picture
    private int reset;      // Do we need to reset the animation loop?
    // Backbuffer used in double buffering and it's graphic context.
    private Image backBuffer;
    private Graphics bg;
    // Thread to control the animation, and a boolean to stop it.
    private Thread animationThread;
    private boolean animating;
    // Applet initializer.  Sets defaults for all attributes and loads all
    // images.
    public void init()
    {
        // Set defaults for attributes.
        egg = new Image[ 6 ];
        showingPic = 0;
        eggX = 10;
        eggY = 0;
        // Use MediaTracker to ensure image loading.
        MediaTracker tracker = new MediaTracker( this );
        // Load the images and put them in MediaTracker.
        for( int i = 0; i < egg.length; i++ )
        {
            egg[ i ] = getImage( getCodeBase(), "egg" + ( i + 1 ) + ".gif" );
            tracker.addImage( egg[ i ], 0 );
        }
        // Use MediaTracker to load all the images.
        try
        {
            tracker.waitForID( 0 );
        }
        catch( InterruptedException x )
        {
            System.err.println( "Error loading image with MediaTracker" );
        }
    }
    // Applet start.  When the page becomes visible.
    // Start the animationThread.
    public void start()
    {
        if( !animating )
        {
            animating = true;
            animationThread = new Thread( this );
            animationThread.start();
        }
    }
    // Applet stop.  When the user leaves the page.
    // Stop the applet.
    public void stop()
    {
        animating = false;
    }
    // Run method for the thread.
    // Runs while animating == true.
    // Simply waits for 100 ms then repaints the screen.
    public void run()
    {
        double time = System.currentTimeMillis();
        int delay = 100;
        while( animating )
        {
            time += delay;
            try
            {
                Thread.sleep( ( int ) Math.max( 0, time - System.currentTimeMillis() ) );
            }
            catch( InterruptedException x )
            {
            }
            repaint();
        }
    }
    // Paint method.
    // Initializes double buffering if needed.
    // Does all painting of images and drawing of strings to backbuffer,
    // then draws backbuffer to screen.  Results in smoother animation.
    public void paint( Graphics g )
    {
        if( backBuffer == null )
        {
            backBuffer = createImage( getWidth(), getHeight() );
            bg = backBuffer.getGraphics();
        }
        bg.setColor( Color.white );
        bg.fillRect( 0, 0, getWidth(), getHeight() );
        bg.setColor( Color.black );
        bg.drawImage(egg[ showingPic ], eggX, eggY, this);
        bg.drawString("Planning to Develop your WebSite!",100,50);
        bg.drawString("Give Usman Ahmad a crack at it.",100,300);
        g.drawImage( backBuffer, 0, 0, this );
    }
    // Update method.
    // Called by repaint().
    // Updates the egg position & image, then paints screen.
    public void update( Graphics g )
    {
        updateEgg();
        paint( g );
    }
    // Updates egg postion and image.
    public void updateEgg()
    {
        // Moving egg down by 10 pixels until it hits 150 pixels down.
        if( eggY < getHeight() - 150 )
        {
            eggY += 10;
            System.out.println( "Moving egg down." );
        }
        // If egg is at 150 pixels start animating cracking egg.
        // I set reset to 10 so that the user could see the cracked
        // egg for a little while.
        else if( reset < 15 )
        {
            reset++;
            // Can't let the array index go out of bounds!
            if( showingPic < egg.length - 1 )
            {
                showingPic++;
            }
            System.out.println( "Cracking egg." );
        }
        // Reset the animation loop.
        else
        {
            reset = 0;
            eggY = 0;
            showingPic = 0;
            System.out.println( "Resetting." );
        }
    }
}

You can see it run and grab the image files I ripped out of your animated gif at my crappy website ( http://members.fortunecity.com/nepruett/UsmanImage.html )
HTH,
-Nate

[Matt DeLacey]

Hmmm...strange Usman's works fine for me, but Nathan's does not.

[Nathan Pruett]

Matt,
Do you mean that it worked fine on your machine ( appletviewer or local web browser ), or on the actual website? When I look at the original applet on my local machine, it works great... but when I put it on the server the egg image disappeared... If you are trying to run my applet on your local machine you will also need the 6 images that I ripped out of the animated gif in the same directory as the applet... It should run from my website fine.
HTH,
-Nate

[Nathan Pruett]

Ooops!
I went to check my site and the images were not showing due to a bad HTML tag...
Sorry, they should be showing now!
-Nate

[usman ahmad]

Hi! I will be trying this soon.
Thanks
Regards,
Usman