src/adapter.js

   1 +function ($) {
   2   'use strict';
   3
   4   var now = Date.now || function () { return new Date().getTime(); };
   5
   6   // Returns a function, that, as long as it continues to be invoked, will not
   7   // be triggered. The function will be called after it stops being called for
   8   // `wait` msec.
   9   //
  10   // This utility function was originally implemented at Underscore.js.
  11   var debounce = function (func, wait) {
  12     var timeout, args, context, timestamp, result;
  13     var later = function () {
  14       var last = now() - timestamp;
  15       if (last < wait) {
  16         timeout = setTimeout(later, wait - last);
  17       } else {
  18         timeout = null;
  19         result = func.apply(context, args);
  20         context = args = null;
  21       }
  22     };
  23
  24     return function () {
  25       context = this;
  26       args = arguments;
  27       timestamp = now();
  28       if (!timeout) {
  29         timeout = setTimeout(later, wait);
  30       }
  31       return result;
  32     };
  33   };
  34
  35   function Adapter () {}
  36
  37   $.extend(Adapter.prototype, {
  38     // Public properties
  39     // -----------------
  40
  41     id:        null, // Identity.
  42     completer: null, // Completer object which creates it.
  43     el:        null, // Textarea element.
  44     $el:       null, // jQuery object of the textarea.
  45     option:    null,
  46
  47     // Public methods
  48     // --------------
  49
  50     initialize: function (element, completer, option) {
  51       this.el        = element;
  52       this.$el       = $(element);
  53       this.id        = completer.id + this.constructor.name;
  54       this.completer = completer;
  55       this.option    = option;
  56
  57       if (this.option.debounce) {
  58         this._onKeyup = debounce(this._onKeyup, this.option.debounce);
  59       }
  60
  61       this._bindEvents();
  62     },
  63
  64     destroy: function () {
  65       this.$el.off('.' + this.id); // Remove all event handlers.
  66       this.$el = this.el = this.completer = null;
  67     },
  68
  69     // Update the element with the given value and strategy.
  70     //
  71     // value    - The selected object. It is one of the item of the array
  72     //            which was callbacked from the search function.
  73     // strategy - The Strategy associated with the selected value.
  74     select: function (/* value, strategy */) {
  75       throw new Error('Not implemented');
  76     },
  77
  78     // Returns the caret's relative coordinates from body's left top corner.
  79     getCaretPosition: function () {
  80       var position = this._getCaretRelativePosition();
  81       var offset = this.$el.offset();
  82
  83       // Calculate the left top corner of `this.option.appendTo` element.
  84       var $parent = this.option.appendTo;
  85       if ($parent) {
  86          if (!($parent instanceof $)) { $parent = $($parent); }
  87          var parentOffset = $parent.offsetParent().offset();
  88          offset.top -= parentOffset.top;
  89          offset.left -= parentOffset.left;
  90       }
  91
  92       position.top += offset.top;
  93       position.left += offset.left;
  94       return position;
  95     },
  96
  97     // Focus on the element.
  98     focus: function () {
  99       this.$el.focus();
 100     },
 101
 102     // Private methods
 103     // ---------------
 104
 105     _bindEvents: function () {
 106       this.$el.on('keyup.' + this.id, $.proxy(this._onKeyup, this));
 107     },
 108
 109     _onKeyup: function (e) {
 110       if (this._skipSearch(e)) { return; }
 111       this.completer.trigger(this.getTextFromHeadToCaret(), true);
 112     },
 113
 114     // Suppress searching if it returns true.
 115     _skipSearch: function (clickEvent) {
 116       switch (clickEvent.keyCode) {
 117         case 9:  // TAB
 118         case 13: // ENTER
 119         case 40: // DOWN
 120         case 38: // UP
 121         case 27: // ESC
 122           return true;
 123       }
 124       if (clickEvent.ctrlKey) switch (clickEvent.keyCode) {
 125         case 78: // Ctrl-N
 126         case 80: // Ctrl-P
 127           return true;
 128       }
 129     }
 130   });
 131
 132   $.fn.textcomplete.Adapter = Adapter;
 133 }(jQuery);