resources/jquery/jquery.tabIndex.js

   1 /**
   2  * jQuery tabIndex
   3  */
   4 ( function ( $ ) {
   5
   6         /**
   7          * Finds the lowerst tabindex in use within a selection
   8          *
   9          * @return number Lowest tabindex on the page
  10          */
  11         $.fn.firstTabIndex = function () {
  12                 var minTabIndex = null;
  13                 $(this).find( '[tabindex]' ).each( function () {
  14                         var tabIndex = parseInt( $(this).prop( 'tabindex' ), 10 );
  15                         // In IE6/IE7 the above jQuery selector returns all elements,
  16                         // becuase it has a default value for tabIndex in IE6/IE7 of 0
  17                         // (rather than null/undefined). Therefore check "> 0" as well.
  18                         // Under IE7 under Windows NT 5.2 is also capable of returning NaN.
  19                         if ( tabIndex > 0 && !isNaN( tabIndex ) ) {
  20                                 // Initial value
  21                                 if ( minTabIndex === null ) {
  22                                         minTabIndex = tabIndex;
  23                                 } else if ( tabIndex < minTabIndex ) {
  24                                         minTabIndex = tabIndex;
  25                                 }
  26                         }
  27                 } );
  28                 return minTabIndex;
  29         };
  30
  31         /**
  32          * Finds the highest tabindex in use within a selection
  33          *
  34          * @return number Highest tabindex on the page
  35          */
  36         $.fn.lastTabIndex = function () {
  37                 var maxTabIndex = null;
  38                 $(this).find( '[tabindex]' ).each( function () {
  39                         var tabIndex = parseInt( $(this).prop( 'tabindex' ), 10 );
  40                         if ( tabIndex > 0 && !isNaN( tabIndex ) ) {
  41                                 // Initial value
  42                                 if ( maxTabIndex === null ) {
  43                                         maxTabIndex = tabIndex;
  44                                 } else if ( tabIndex > maxTabIndex ) {
  45                                         maxTabIndex = tabIndex;
  46                                 }
  47                         }
  48                 } );
  49                 return maxTabIndex;
  50         };
  51
  52 }( jQuery ) );