ecomp-portal-FE/client/bower_components/jqTree/lib/scroll_handler.js

   1 var $, ScrollHandler;
   2
   3 $ = jQuery;
   4
   5 ScrollHandler = (function() {
   6   function ScrollHandler(tree_widget) {
   7     this.tree_widget = tree_widget;
   8     this.previous_top = -1;
   9     this.is_initialized = false;
  10   }
  11
  12   ScrollHandler.prototype._initScrollParent = function() {
  13     var $scroll_parent, getParentWithOverflow, setDocumentAsScrollParent;
  14     getParentWithOverflow = (function(_this) {
  15       return function() {
  16         var css_values, el, hasOverFlow, i, len, ref;
  17         css_values = ['overflow', 'overflow-y'];
  18         hasOverFlow = function(el) {
  19           var css_value, i, len, ref;
  20           for (i = 0, len = css_values.length; i < len; i++) {
  21             css_value = css_values[i];
  22             if ((ref = $.css(el, css_value)) === 'auto' || ref === 'scroll') {
  23               return true;
  24             }
  25           }
  26           return false;
  27         };
  28         if (hasOverFlow(_this.tree_widget.$el[0])) {
  29           return _this.tree_widget.$el;
  30         }
  31         ref = _this.tree_widget.$el.parents();
  32         for (i = 0, len = ref.length; i < len; i++) {
  33           el = ref[i];
  34           if (hasOverFlow(el)) {
  35             return $(el);
  36           }
  37         }
  38         return null;
  39       };
  40     })(this);
  41     setDocumentAsScrollParent = (function(_this) {
  42       return function() {
  43         _this.scroll_parent_top = 0;
  44         return _this.$scroll_parent = null;
  45       };
  46     })(this);
  47     if (this.tree_widget.$el.css('position') === 'fixed') {
  48       setDocumentAsScrollParent();
  49     }
  50     $scroll_parent = getParentWithOverflow();
  51     if ($scroll_parent && $scroll_parent.length && $scroll_parent[0].tagName !== 'HTML') {
  52       this.$scroll_parent = $scroll_parent;
  53       this.scroll_parent_top = this.$scroll_parent.offset().top;
  54     } else {
  55       setDocumentAsScrollParent();
  56     }
  57     return this.is_initialized = true;
  58   };
  59
  60   ScrollHandler.prototype._ensureInit = function() {
  61     if (!this.is_initialized) {
  62       return this._initScrollParent();
  63     }
  64   };
  65
  66   ScrollHandler.prototype.checkScrolling = function() {
  67     var hovered_area;
  68     this._ensureInit();
  69     hovered_area = this.tree_widget.dnd_handler.hovered_area;
  70     if (hovered_area && hovered_area.top !== this.previous_top) {
  71       this.previous_top = hovered_area.top;
  72       if (this.$scroll_parent) {
  73         return this._handleScrollingWithScrollParent(hovered_area);
  74       } else {
  75         return this._handleScrollingWithDocument(hovered_area);
  76       }
  77     }
  78   };
  79
  80   ScrollHandler.prototype._handleScrollingWithScrollParent = function(area) {
  81     var distance_bottom;
  82     distance_bottom = this.scroll_parent_top + this.$scroll_parent[0].offsetHeight - area.bottom;
  83     if (distance_bottom < 20) {
  84       this.$scroll_parent[0].scrollTop += 20;
  85       this.tree_widget.refreshHitAreas();
  86       return this.previous_top = -1;
  87     } else if ((area.top - this.scroll_parent_top) < 20) {
  88       this.$scroll_parent[0].scrollTop -= 20;
  89       this.tree_widget.refreshHitAreas();
  90       return this.previous_top = -1;
  91     }
  92   };
  93
  94   ScrollHandler.prototype._handleScrollingWithDocument = function(area) {
  95     var distance_top;
  96     distance_top = area.top - $(document).scrollTop();
  97     if (distance_top < 20) {
  98       return $(document).scrollTop($(document).scrollTop() - 20);
  99     } else if ($(window).height() - (area.bottom - $(document).scrollTop()) < 20) {
 100       return $(document).scrollTop($(document).scrollTop() + 20);
 101     }
 102   };
 103
 104   ScrollHandler.prototype.scrollTo = function(top) {
 105     var tree_top;
 106     this._ensureInit();
 107     if (this.$scroll_parent) {
 108       return this.$scroll_parent[0].scrollTop = top;
 109     } else {
 110       tree_top = this.tree_widget.$el.offset().top;
 111       return $(document).scrollTop(top + tree_top);
 112     }
 113   };
 114
 115   ScrollHandler.prototype.isScrolledIntoView = function(element) {
 116     var $element, element_bottom, element_top, view_bottom, view_top;
 117     this._ensureInit();
 118     $element = $(element);
 119     if (this.$scroll_parent) {
 120       view_top = 0;
 121       view_bottom = this.$scroll_parent.height();
 122       element_top = $element.offset().top - this.scroll_parent_top;
 123       element_bottom = element_top + $element.height();
 124     } else {
 125       view_top = $(window).scrollTop();
 126       view_bottom = view_top + $(window).height();
 127       element_top = $element.offset().top;
 128       element_bottom = element_top + $element.height();
 129     }
 130     return (element_bottom <= view_bottom) && (element_top >= view_top);
 131   };
 132
 133   return ScrollHandler;
 134
 135 })();
 136
 137 module.exports = ScrollHandler;