Thanks for contacting back. Here's the situation - I have anchors in my HTML which I link to with an a href, so there will be an anchor at the bottom of the page called <a name="Bottom"></a> and I will enable a link at the top to that with <a href="#Bottom">

The JavaScript I have (called jscrolls.js) will animate the scroll to the anchor, so instead of a single jutting motion, the screen gently scrolls down. You can see this working here by pressing the lower right button:

http://lovelago.googlepages.com/text_box7.html


What I need is to be able to click a java applet (the recursion one) and this link to an anchor on the same page, just like a normal a href image file would work, in the above example. The problem has been that links from the Java applets open in new windows or if in the same window it refreshes the page and the javascript that makes the page flow gently does not get a chance to work.

So, I  thought that passing a message from the java applet to a javascript hook inside the same page, to link to an anchor, would not refresh the page and then the javascript would then be able to scroll the page gently.

As I understand it what's happened now is that a message comes to the javascript in the html, form the java applet, and it produces a popup box. Instead of that message box, I need the javascript to go to an anchor on the same page. The javascript already there will then scroll the page nicely, hopefully.

I'm sorry to say but I just don't understand this anymore. Are you telling me I don't need the following because jscrolls is already on the page:

void mousePressed() {    
   JSObject win = (JSObject) JSObject.getWindow(this);
   String[] arguments = { "thispage.html", "Bottom" };
   win.call("ajaxpage", arguments);
}

and that I need this to jump to a link:

void mouseClicked()
{
 if (dist(mouseX, mouseY, width/2, height/2) < radius)
 {
   URL url = getDocumentBase();
//    System.err.println(url);
   try {
     URL anchor = new URL(url, "#2.5");
//      System.err.println(anchor);
     getAppletContext().showDocument(anchor);
   } catch (MalformedURLException e) {}
 }

I remember using that code dind't work for what I wanted, I've tried mashing them together and I don't understand enough about it to make it work. What I have is this and it doesn't work:

void mousePressed() {
 if (ms.isReady() && isMouseInDisk()) {
      JSObject win = (JSObject) JSObject.getWindow(this);
   String[] arguments = { "index.html", "Bottom" };
   win.call("ajaxpage", arguments);
}

in the html I still have the header code, which I probably don't need:

<script type="text/javascript" language="JavaScript">//<![CDATA[
function DumbTest(message)
{
 alert("This is a dumb test with a message:\n" + message);
}
//]]>
</script>


I don't need to call a JS routine do I? But then how to I link to an anchor without leaving the page and having it nicely scroll down. If it get complicated like this I just don't know what to do. Thanks.

Thanks for getting back to me, I reviewed the situation my end and realise what you were trying to do with the JavaScript call - to have it execute. When in fact the JavaScript intervenes when a normal anchor link is requested, so executing it would do nothing. I then went back to the earlier examples and decided to try again to get the Java applet linking:

Here's my code for the button:


private static final int WIDTH = 100;
private static final int HEIGHT = 100;
private static final int HWIDTH = (WIDTH / 2);
private static final int HHEIGHT = (HEIGHT / 2);
private static final float LENGTH = (HEIGHT * .6);
 
float theta = 0.0;
float angle = 0.0;

import netscape.javascript.*;
 
void setup() {
 size(WIDTH, HEIGHT);
 smooth();
}
 
void draw() {
 background(255);
 
 // move origin to centre
 translate(HWIDTH, 0);
   
 // theta will oscillate between -1 and 1
 // we want the angle to go from about -45 from vertical to +45 from vertical
 // except we're using radians so -(PI/4) to +(PI/4)
 // ALSO 0 is to the right so add PI/2 to rotate it to the bottom
 // made this .2 * PI
 angle = HALF_PI + (sin(theta) * PI * .1);
   
 // With each cycle, increment theta
 theta += 0.03;
   
 drawCircle(LENGTH, LENGTH - 1);
}

void mousePressed() {
//    URL url = getDocumentBase();
//    System.err.println(url);
//    try {
     link("http://projectmio.com/index.html#frontBottom","_self");    
//      URL anchor = new URL(url, "#frontBottom");
//      System.err.println(anchor);
//      getAppletContext().showDocument(anchor);
//    } catch (MalformedURLException e) {}
}

 
// Learning Processing
// Daniel Shiffman
// http://www.learningprocessing.com
 
// Example 13-8: Recursion (modified)
 
void drawCircle(float len, float radius) {
 noFill();
   
 float x = (len) * cos(angle);
 float y = (len) * sin(angle);
 ellipse(x, y, radius, radius);
 if(radius > 2) {
   // drawCircle() calls itself twice, creating a branching effect.
   drawCircle(len + radius / 7, radius / 2);
   drawCircle(len - radius / 1, radius / 2);  
 }
}



I tried two ways, but they both open a new page within the same page, hense you can click back in the browser history and the #frontBottom anchor shows at the end of the URL, which means the JS did not catch it.

void mousePressed() {
     URL url = getDocumentBase();
   System.err.println(url);
   try {
     URL anchor = new URL(url, "#frontBottom");
     System.err.println(anchor);
     getAppletContext().showDocument(anchor);
   } catch (MalformedURLException e) {}
}


AND

     link("http://projectmio.com/index.html#frontBottom","_self");


I am thinking now that maybe I need to create a piece of JS just for the flowing action to the #frontBottom anchor, so that the code you most recently posted will call it and the action will flow to the anchor. Unless there is a way of getting the JS to see the mouseclick when the Java applet is pressed like when the PNG image is pressed within the HTML.

My domain is up now so here is the site: http://www.projectmio.com/

What do you think?

Thank you!

Ah ha, it does work, great! But, always a but, any reason why the png (http://www.projectmio.com/buttonsettle1a.png), when clicked, does not scroll down with the JavScript as before? I find that when I click that button to go down it jumps down, but pressing the recursion Java applet to go back up scrolls (excellent!) and then when clicking the PNG to go back down it scrolls but not the first time?

The thing is the user clicking down will probably only happen once and up also, I doubt there's going to be a lot of up and down scrolling so its imperative that it work for those first times.

Strange how the PNG doesn't work first time isn't it? But I'm overwhealemd tht the Java applet does, well done, you did it!