src/callbacks.js

   1 define([
   2         "./core",
   3         "./var/rnotwhite"
   4 ], function( jQuery, rnotwhite ) {
   5
   6 // Convert String-formatted options into Object-formatted ones
   7 function createOptions( options ) {
   8         var object = {};
   9         jQuery.each( options.match( rnotwhite ) || [], function( _, flag ) {
  10                 object[ flag ] = true;
  11         });
  12         return object;
  13 }
  14
  15 /*
  16  * Create a callback list using the following parameters:
  17  *
  18  *      options: an optional list of space-separated options that will change how
  19  *                      the callback list behaves or a more traditional option object
  20  *
  21  * By default a callback list will act like an event callback list and can be
  22  * "fired" multiple times.
  23  *
  24  * Possible options:
  25  *
  26  *      once:                   will ensure the callback list can only be fired once (like a Deferred)
  27  *
  28  *      memory:                 will keep track of previous values and will call any callback added
  29  *                                      after the list has been fired right away with the latest "memorized"
  30  *                                      values (like a Deferred)
  31  *
  32  *      unique:                 will ensure a callback can only be added once (no duplicate in the list)
  33  *
  34  *      stopOnFalse:    interrupt callings when a callback returns false
  35  *
  36  */
  37 jQuery.Callbacks = function( options ) {
  38
  39         // Convert options from String-formatted to Object-formatted if needed
  40         // (we check in cache first)
  41         options = typeof options === "string" ?
  42                 createOptions( options ) :
  43                 jQuery.extend( {}, options );
  44
  45         var // Flag to know if list is currently firing
  46                 firing,
  47                 // Last fire value for non-forgettable lists
  48                 memory,
  49                 // Flag to know if list was already fired
  50                 fired,
  51                 // Flag to prevent firing
  52                 locked,
  53                 // Actual callback list
  54                 list = [],
  55                 // Queue of execution data for repeatable lists
  56                 queue = [],
  57                 // Index of currently firing callback (modified by add/remove as needed)
  58                 firingIndex = -1,
  59                 // Fire callbacks
  60                 fire = function() {
  61
  62                         // Enforce single-firing
  63                         locked = options.once;
  64
  65                         // Execute callbacks for all pending executions,
  66                         // respecting firingIndex overrides and runtime changes
  67                         fired = firing = true;
  68                         for ( ; queue.length; firingIndex = -1 ) {
  69                                 memory = queue.shift();
  70                                 while ( ++firingIndex < list.length ) {
  71
  72                                         // Run callback and check for early termination
  73                                         if ( list[ firingIndex ].apply( memory[ 0 ], memory[ 1 ] ) === false &&
  74                                                 options.stopOnFalse ) {
  75
  76                                                 // Jump to end and forget the data so .add doesn't re-fire
  77                                                 firingIndex = list.length;
  78                                                 memory = false;
  79                                         }
  80                                 }
  81                         }
  82
  83                         // Forget the data if we're done with it
  84                         if ( !options.memory ) {
  85                                 memory = false;
  86                         }
  87
  88                         firing = false;
  89
  90                         // Clean up if we're done firing for good
  91                         if ( locked ) {
  92
  93                                 // Keep an empty list if we have data for future add calls
  94                                 if ( memory ) {
  95                                         list = [];
  96
  97                                 // Otherwise, this object is spent
  98                                 } else {
  99                                         list = "";
 100                                 }
 101                         }
 102                 },
 103
 104                 // Actual Callbacks object
 105                 self = {
 106
 107                         // Add a callback or a collection of callbacks to the list
 108                         add: function() {
 109                                 if ( list ) {
 110
 111                                         // If we have memory from a past run, we should fire after adding
 112                                         if ( memory && !firing ) {
 113                                                 firingIndex = list.length - 1;
 114                                                 queue.push( memory );
 115                                         }
 116
 117                                         (function add( args ) {
 118                                                 jQuery.each( args, function( _, arg ) {
 119                                                         if ( jQuery.isFunction( arg ) ) {
 120                                                                 if ( !options.unique || !self.has( arg ) ) {
 121                                                                         list.push( arg );
 122                                                                 }
 123                                                         } else if ( arg && arg.length && jQuery.type( arg ) !== "string" ) {
 124                                                                 // Inspect recursively
 125                                                                 add( arg );
 126                                                         }
 127                                                 });
 128                                         })( arguments );
 129
 130                                         if ( memory && !firing ) {
 131                                                 fire();
 132                                         }
 133                                 }
 134                                 return this;
 135                         },
 136
 137                         // Remove a callback from the list
 138                         remove: function() {
 139                                 jQuery.each( arguments, function( _, arg ) {
 140                                         var index;
 141                                         while ( ( index = jQuery.inArray( arg, list, index ) ) > -1 ) {
 142                                                 list.splice( index, 1 );
 143
 144                                                 // Handle firing indexes
 145                                                 if ( index <= firingIndex ) {
 146                                                         firingIndex--;
 147                                                 }
 148                                         }
 149                                 });
 150                                 return this;
 151                         },
 152
 153                         // Check if a given callback is in the list.
 154                         // If no argument is given, return whether or not list has callbacks attached.
 155                         has: function( fn ) {
 156                                 return fn ?
 157                                         jQuery.inArray( fn, list ) > -1 :
 158                                         list.length > 0;
 159                         },
 160
 161                         // Remove all callbacks from the list
 162                         empty: function() {
 163                                 if ( list ) {
 164                                         list = [];
 165                                 }
 166                                 return this;
 167                         },
 168
 169                         // Disable .fire and .add
 170                         // Abort any current/pending executions
 171                         // Clear all callbacks and values
 172                         disable: function() {
 173                                 locked = queue = [];
 174                                 list = memory = "";
 175                                 return this;
 176                         },
 177                         disabled: function() {
 178                                 return !list;
 179                         },
 180
 181                         // Disable .fire
 182                         // Also disable .add unless we have memory (since it would have no effect)
 183                         // Abort any pending executions
 184                         lock: function() {
 185                                 locked = queue = [];
 186                                 if ( !memory && !firing ) {
 187                                         list = memory = "";
 188                                 }
 189                                 return this;
 190                         },
 191                         locked: function() {
 192                                 return !!locked;
 193                         },
 194
 195                         // Call all callbacks with the given context and arguments
 196                         fireWith: function( context, args ) {
 197                                 if ( !locked ) {
 198                                         args = args || [];
 199                                         args = [ context, args.slice ? args.slice() : args ];
 200                                         queue.push( args );
 201                                         if ( !firing ) {
 202                                                 fire();
 203                                         }
 204                                 }
 205                                 return this;
 206                         },
 207
 208                         // Call all the callbacks with the given arguments
 209                         fire: function() {
 210                                 self.fireWith( this, arguments );
 211                                 return this;
 212                         },
 213
 214                         // To know if the callbacks have already been called at least once
 215                         fired: function() {
 216                                 return !!fired;
 217                         }
 218                 };
 219
 220         return self;
 221 };
 222
 223 return jQuery;
 224 });