resources/jquery/jquery.autoEllipsis.js

   1 /**
   2  * Plugin that automatically truncates the plain text contents of an element and adds an ellipsis
   3  */
   4 ( function ( $ ) {
   5
   6 // Cache ellipsed substrings for every string-width-position combination
   7 var cache = { };
   8 // Use a separate cache when match highlighting is enabled
   9 var matchTextCache = { };
  10
  11 $.fn.autoEllipsis = function ( options ) {
  12         options = $.extend( {
  13                 position: 'center',
  14                 tooltip: false,
  15                 restoreText: false,
  16                 hasSpan: false,
  17                 matchText: null
  18         }, options );
  19         $(this).each( function () {
  20                 var $container, $trimmableText,
  21                         text, trimmableText, w, pw,
  22                         l, r, i, side,
  23                         $el = $(this);
  24                 if ( options.restoreText ) {
  25                         if ( !$el.data( 'autoEllipsis.originalText' ) ) {
  26                                 $el.data( 'autoEllipsis.originalText', $el.text() );
  27                         } else {
  28                                 $el.text( $el.data( 'autoEllipsis.originalText' ) );
  29                         }
  30                 }
  31
  32                 // container element - used for measuring against
  33                 $container = $el;
  34
  35                 // trimmable text element - only the text within this element will be trimmed
  36                 if ( options.hasSpan ) {
  37                         $trimmableText = $el.children( options.selector );
  38                 } else {
  39                         $trimmableText = $( '<span>' )
  40                                 .css( 'whiteSpace', 'nowrap' )
  41                                 .text( $el.text() );
  42                         $el
  43                                 .empty()
  44                                 .append( $trimmableText );
  45                 }
  46
  47                 text = $container.text();
  48                 trimmableText = $trimmableText.text();
  49                 w = $container.width();
  50                 pw = 0;
  51
  52                 // Try cache
  53                 if ( options.matchText ) {
  54                         if ( !( text in matchTextCache ) ) {
  55                                 matchTextCache[text] = {};
  56                         }
  57                         if ( !( options.matchText in matchTextCache[text] ) ) {
  58                                 matchTextCache[text][options.matchText] = {};
  59                         }
  60                         if ( !( w in matchTextCache[text][options.matchText] ) ) {
  61                                 matchTextCache[text][options.matchText][w] = {};
  62                         }
  63                         if ( options.position in matchTextCache[text][options.matchText][w] ) {
  64                                 $container.html( matchTextCache[text][options.matchText][w][options.position] );
  65                                 if ( options.tooltip ) {
  66                                         $container.attr( 'title', text );
  67                                 }
  68                                 return;
  69                         }
  70                 } else {
  71                         if ( !( text in cache ) ) {
  72                                 cache[text] = {};
  73                         }
  74                         if ( !( w in cache[text] ) ) {
  75                                 cache[text][w] = {};
  76                         }
  77                         if ( options.position in cache[text][w] ) {
  78                                 $container.html( cache[text][w][options.position] );
  79                                 if ( options.tooltip ) {
  80                                         $container.attr( 'title', text );
  81                                 }
  82                                 return;
  83                         }
  84                 }
  85
  86                 if ( $trimmableText.width() + pw > w ) {
  87                         switch ( options.position ) {
  88                                 case 'right':
  89                                         // Use binary search-like technique for efficiency
  90                                         l = 0;
  91                                         r = trimmableText.length;
  92                                         do {
  93                                                 var m = Math.ceil( ( l + r ) / 2 );
  94                                                 $trimmableText.text( trimmableText.substr( 0, m ) + '...' );
  95                                                 if ( $trimmableText.width() + pw > w ) {
  96                                                         // Text is too long
  97                                                         r = m - 1;
  98                                                 } else {
  99                                                         l = m;
 100                                                 }
 101                                         } while ( l < r );
 102                                         $trimmableText.text( trimmableText.substr( 0, l ) + '...' );
 103                                         break;
 104                                 case 'center':
 105                                         // TODO: Use binary search like for 'right'
 106                                         i = [Math.round( trimmableText.length / 2 ), Math.round( trimmableText.length / 2 )];
 107                                         // Begin with making the end shorter
 108                                         side = 1;
 109                                         while ( $trimmableText.outerWidth() + pw > w && i[0] > 0 ) {
 110                                                 $trimmableText.text( trimmableText.substr( 0, i[0] ) + '...' + trimmableText.substr( i[1] ) );
 111                                                 // Alternate between trimming the end and begining
 112                                                 if ( side === 0 ) {
 113                                                         // Make the begining shorter
 114                                                         i[0]--;
 115                                                         side = 1;
 116                                                 } else {
 117                                                         // Make the end shorter
 118                                                         i[1]++;
 119                                                         side = 0;
 120                                                 }
 121                                         }
 122                                         break;
 123                                 case 'left':
 124                                         // TODO: Use binary search like for 'right'
 125                                         r = 0;
 126                                         while ( $trimmableText.outerWidth() + pw > w && r < trimmableText.length ) {
 127                                                 $trimmableText.text( '...' + trimmableText.substr( r ) );
 128                                                 r++;
 129                                         }
 130                                         break;
 131                         }
 132                 }
 133                 if ( options.tooltip ) {
 134                         $container.attr( 'title', text );
 135                 }
 136                 if ( options.matchText ) {
 137                         $container.highlightText( options.matchText );
 138                         matchTextCache[text][options.matchText][w][options.position] = $container.html();
 139                 } else {
 140                         cache[text][w][options.position] = $container.html();
 141                 }
 142
 143         } );
 144 };
 145
 146 }( jQuery ) );