resources/src/jquery/jquery.autoEllipsis.js

   1 /**
   2  * @class jQuery.plugin.autoEllipsis
   3  */
   4 ( function ( $ ) {
   5
   6 var
   7         // Cache ellipsed substrings for every string-width-position combination
   8         cache = {},
   9
  10         // Use a separate cache when match highlighting is enabled
  11         matchTextCache = {};
  12
  13 /**
  14  * Automatically truncate the plain text contents of an element and add an ellipsis
  15  *
  16  * @param {Object} options
  17  * @param {'center'|'left'|'right'} [options.position='center'] Where to remove text.
  18  * @param {boolean} [options.tooltip=false] Whether to show a tooltip with the remainder
  19  * of the text.
  20  * @param {boolean} [options.restoreText=false] Whether to save the text for restoring
  21  * later.
  22  * @param {boolean} [options.hasSpan=false] Whether the element is already a container,
  23  * or if the library should create a new container for it.
  24  * @param {string|null} [options.matchText=null] Text to highlight, e.g. search terms.
  25  * @return {jQuery}
  26  * @chainable
  27  */
  28 $.fn.autoEllipsis = function ( options ) {
  29         options = $.extend( {
  30                 position: 'center',
  31                 tooltip: false,
  32                 restoreText: false,
  33                 hasSpan: false,
  34                 matchText: null
  35         }, options );
  36
  37         return this.each( function () {
  38                 var $trimmableText,
  39                         text, trimmableText, w, pw,
  40                         l, r, i, side, m,
  41                         // container element - used for measuring against
  42                         $container = $( this );
  43
  44                 if ( options.restoreText ) {
  45                         if ( !$container.data( 'autoEllipsis.originalText' ) ) {
  46                                 $container.data( 'autoEllipsis.originalText', $container.text() );
  47                         } else {
  48                                 $container.text( $container.data( 'autoEllipsis.originalText' ) );
  49                         }
  50                 }
  51
  52                 // trimmable text element - only the text within this element will be trimmed
  53                 if ( options.hasSpan ) {
  54                         $trimmableText = $container.children( options.selector );
  55                 } else {
  56                         $trimmableText = $( '<span>' )
  57                                 .css( 'whiteSpace', 'nowrap' )
  58                                 .text( $container.text() );
  59                         $container
  60                                 .empty()
  61                                 .append( $trimmableText );
  62                 }
  63
  64                 text = $container.text();
  65                 trimmableText = $trimmableText.text();
  66                 w = $container.width();
  67                 pw = 0;
  68
  69                 // Try cache
  70                 if ( options.matchText ) {
  71                         if ( !( text in matchTextCache ) ) {
  72                                 matchTextCache[text] = {};
  73                         }
  74                         if ( !( options.matchText in matchTextCache[text] ) ) {
  75                                 matchTextCache[text][options.matchText] = {};
  76                         }
  77                         if ( !( w in matchTextCache[text][options.matchText] ) ) {
  78                                 matchTextCache[text][options.matchText][w] = {};
  79                         }
  80                         if ( options.position in matchTextCache[text][options.matchText][w] ) {
  81                                 $container.html( matchTextCache[text][options.matchText][w][options.position] );
  82                                 if ( options.tooltip ) {
  83                                         $container.attr( 'title', text );
  84                                 }
  85                                 return;
  86                         }
  87                 } else {
  88                         if ( !( text in cache ) ) {
  89                                 cache[text] = {};
  90                         }
  91                         if ( !( w in cache[text] ) ) {
  92                                 cache[text][w] = {};
  93                         }
  94                         if ( options.position in cache[text][w] ) {
  95                                 $container.html( cache[text][w][options.position] );
  96                                 if ( options.tooltip ) {
  97                                         $container.attr( 'title', text );
  98                                 }
  99                                 return;
 100                         }
 101                 }
 102
 103                 if ( $trimmableText.width() + pw > w ) {
 104                         switch ( options.position ) {
 105                                 case 'right':
 106                                         // Use binary search-like technique for efficiency
 107                                         l = 0;
 108                                         r = trimmableText.length;
 109                                         do {
 110                                                 m = Math.ceil( ( l + r ) / 2 );
 111                                                 $trimmableText.text( trimmableText.substr( 0, m ) + '...' );
 112                                                 if ( $trimmableText.width() + pw > w ) {
 113                                                         // Text is too long
 114                                                         r = m - 1;
 115                                                 } else {
 116                                                         l = m;
 117                                                 }
 118                                         } while ( l < r );
 119                                         $trimmableText.text( trimmableText.substr( 0, l ) + '...' );
 120                                         break;
 121                                 case 'center':
 122                                         // TODO: Use binary search like for 'right'
 123                                         i = [Math.round( trimmableText.length / 2 ), Math.round( trimmableText.length / 2 )];
 124                                         // Begin with making the end shorter
 125                                         side = 1;
 126                                         while ( $trimmableText.outerWidth() + pw > w && i[0] > 0 ) {
 127                                                 $trimmableText.text( trimmableText.substr( 0, i[0] ) + '...' + trimmableText.substr( i[1] ) );
 128                                                 // Alternate between trimming the end and begining
 129                                                 if ( side === 0 ) {
 130                                                         // Make the begining shorter
 131                                                         i[0]--;
 132                                                         side = 1;
 133                                                 } else {
 134                                                         // Make the end shorter
 135                                                         i[1]++;
 136                                                         side = 0;
 137                                                 }
 138                                         }
 139                                         break;
 140                                 case 'left':
 141                                         // TODO: Use binary search like for 'right'
 142                                         r = 0;
 143                                         while ( $trimmableText.outerWidth() + pw > w && r < trimmableText.length ) {
 144                                                 $trimmableText.text( '...' + trimmableText.substr( r ) );
 145                                                 r++;
 146                                         }
 147                                         break;
 148                         }
 149                 }
 150                 if ( options.tooltip ) {
 151                         $container.attr( 'title', text );
 152                 }
 153                 if ( options.matchText ) {
 154                         $container.highlightText( options.matchText );
 155                         matchTextCache[text][options.matchText][w][options.position] = $container.html();
 156                 } else {
 157                         cache[text][w][options.position] = $container.html();
 158                 }
 159
 160         } );
 161 };
 162
 163 /**
 164  * @class jQuery
 165  * @mixins jQuery.plugin.autoEllipsis
 166  */
 167
 168 }( jQuery ) );