JavaScript Example 2-2
Opening a "Webtop" Window

The "Webtop Widget" is part of Netscape's collection of sample code. It's by Gary Smith. See their original web page at http://developer.netscape.com/docs/examples/javascript/webwidget/doc.html

Unfortunately this code does not work with Microsoft IE5 because it uses Netscape-specific extensions, including the "netscape" object. I haven't yet tried to make an IE version of this.

Open Webtop

Using the form below, you specify the URL which you want opened on the "Webtop" and then submit.

Below is the code for the form. It simply calls the JavaScript function myWebtop(), passing it the URL that you supply.

      <form name="myForm" onsubmit="myWebtop(this); return false;">
        <input value="http://www.chipchapin.com/JavaScript/index.html"> 
        <input type="SUBMIT" value="Open Webtop!">
      </form>

The myWebtop() function is defined as follows:

var path = 
"http://developer.netscape.com/docs/examples/javascript/webwidget/";

function myWebtop(form) {
  if (location.replace && document.layers) {
    location.replace(path + 'webtop.html?' + form.elements[0].value);
  }
}

myWebtopsimply navigates to the Netscape webtop web page, passing the URL that you supplied as a "?" argument. For example, if you don't change the default URL, myWebtop will navigate to

http://developer.netscape.com/docs/examples/javascript/webwidget/webtop.html?http://www.chipchapin.com/JavaScript/index.html

So far this doesn't illustrate much, except that it is possible to do this (at least with Netscape).

How it Works

function openWebtopX(url) {
  netscape.security.PrivilegeManager.enablePrivilege('CanvasAccess'); 
  window.webtopWin = window.open(url || "http://developer.netscape.com", 
    'webtop', 
    'alwaysLowered=yes,outerWidth='+ screen.availWidth +',outerHeight='+ screen.availHeight +',left='+ screen.availLeft +',top='+ screen.availTop +',titlebar=no');
}

Note first of all the need to request 'CanvasAccess' from the netscape.security object. IE will fail at this point because, not surprisingly, it has no netscape object.

Next it simply opens a new window, window.open() takes three arguments: the URL to open, the window name ('webtop'), and an options string. The options string is where all the interesting stuff is.

• alwaysLowered causes the window to float below all other windows, in effect becoming part of the desktop. It is a secure feature, hence the preceding 'CanvasAccess' privilege request.
• outerWidth and outerHeight specify the dimensions of the outside boundary of the new window. Since we want it to cover the entire desktop, we read the properties from the screen object.
• The next two options force the position of the window. I'm not sure under what circumstances these would make any difference.
• The last option, titlebar=no, removes the window titlebar. This also is a secure feature.

Note that windows are created by default without scrollbars.

Resources

Netscape's JavaScript Reference Manual

See the section on window.open().

Netscape "Webtop Widget" page

The "Webtop Widget", by Gary Smith, is part of Netscape's collection of sample code.