/**
* This class is the abstracted version of a cross-browser StringBuffer, as in Java(tm).
* It may be used with StringBuffer independently of any other JavaScript code.
* The dominant versions of Firefox and Opera (versions 1.x and up) have fixed the string concatenation
* problem with the + and += operator that
* has plagued Internet Explorer v6 and less (and perhaps v7), and Mozilla web browsers
* (including Netscape 7 and below). The string concatenation problem is very severe on these browsers.
*
* This StringBuffer class provides string concatenation on Firefox and Opera that comes very close to their
* native performance, while giving a performance boost of about six-fold to Internet Explorer, plus
* more gains in overall JavaScript application speed by avoiding unnecessary memory allocation on browsers
* that have the problem with string concatentation using the += operator.
*
* Testing results show that this class strikes an optimal balance, in a single class, between optimizing String
* concatenation for Internet Explorer/some other web browsers and delivering the extra-fast performance
* offered by Firefox and Opera.
*
* Please note that this class is highly optimized for execution speed. Take great care before altering its code.
* For example, the StringBuffer methods that use the += operator are in fact set
* in the concrete class, since they are more easily accessed there and since they need to be in order to
* avoid impacting the performance on Firefox and other browsers that do not have a problem with string
* concatenation using the += operator. Both sets of methods (using Array and using
* +=) cannot be set in the concrete class, since a single method identifier must point to them to
* maintain compliance with a proper StringBuffer interface.
*
* Ellen Hudson-Snyder,
* Elvin Vedar,
* Christopher M. Balz.
*
CVS Version Info:
* $Id: AbstractStringBuffer.js,v 1.4 2005/12/27 01:05:54 cbalz Exp $
*
* @boolean-prop this.booIsFixed Whether or not we are running on a browser with the problem with
* += described above.
* @author Team GigaToasted (Fall-2005-CMU-NASA/Google-Practicum Subteam)
* @version 1.0
*
*/
/**
* Create an AbstractStringBuffer class. This constructor is only
* called once during the operation of the application -- at initialization.
*/
function AbstractStringBuffer() {
var agt = navigator.userAgent.toLowerCase();
this.booIsFixed = ( agt.indexOf('firefox') != -1 || agt.indexOf('opera') != -1 );
this.append = AbstractStringBuffer_appendArray;
this.toString = AbstractStringBuffer_toStringFromArray;
}
/**
* This method appends to the string with the push method of
* an object of type Array.
* @param pArrStrings Array An array containing the string or strings to append.
*/
function AbstractStringBuffer_appendArray( pArrStrings ) {
this.arrStrings.push( pArrStrings.join( "" ) );
}
/**
* This method returns a string that was
* concatenated by means of an object of type Array.
* @return string The concatenated string.
*/
function AbstractStringBuffer_toStringFromArray() {
return this.arrStrings.join( "" );
}