lib/dijit/a11y.js.uncompressed.js

   1 define("dijit/a11y", [
   2         "dojo/_base/array", // array.forEach array.map
   3         "dojo/_base/config", // defaultDuration
   4         "dojo/_base/declare", // declare
   5         "dojo/dom",                     // dom.byId
   6         "dojo/dom-attr", // domAttr.attr domAttr.has
   7         "dojo/dom-style", // style.style
   8         "dojo/sniff", // has("ie")
   9         "./main"        // for exporting methods to dijit namespace
  10 ], function(array, config, declare, dom, domAttr, domStyle, has, dijit){
  11
  12         // module:
  13         //              dijit/a11y
  14
  15         var shown = (dijit._isElementShown = function(/*Element*/ elem){
  16                 var s = domStyle.get(elem);
  17                 return (s.visibility != "hidden")
  18                         && (s.visibility != "collapsed")
  19                         && (s.display != "none")
  20                         && (domAttr.get(elem, "type") != "hidden");
  21         });
  22
  23         dijit.hasDefaultTabStop = function(/*Element*/ elem){
  24                 // summary:
  25                 //              Tests if element is tab-navigable even without an explicit tabIndex setting
  26
  27                 // No explicit tabIndex setting, need to investigate node type
  28                 switch(elem.nodeName.toLowerCase()){
  29                         case "a":
  30                                 // An <a> w/out a tabindex is only navigable if it has an href
  31                                 return domAttr.has(elem, "href");
  32                         case "area":
  33                         case "button":
  34                         case "input":
  35                         case "object":
  36                         case "select":
  37                         case "textarea":
  38                                 // These are navigable by default
  39                                 return true;
  40                         case "iframe":
  41                                 // If it's an editor <iframe> then it's tab navigable.
  42                                 var body;
  43                                 try{
  44                                         // non-IE
  45                                         var contentDocument = elem.contentDocument;
  46                                         if("designMode" in contentDocument && contentDocument.designMode == "on"){
  47                                                 return true;
  48                                         }
  49                                         body = contentDocument.body;
  50                                 }catch(e1){
  51                                         // contentWindow.document isn't accessible within IE7/8
  52                                         // if the iframe.src points to a foreign url and this
  53                                         // page contains an element, that could get focus
  54                                         try{
  55                                                 body = elem.contentWindow.document.body;
  56                                         }catch(e2){
  57                                                 return false;
  58                                         }
  59                                 }
  60                                 return body && (body.contentEditable == 'true' ||
  61                                         (body.firstChild && body.firstChild.contentEditable == 'true'));
  62                         default:
  63                                 return elem.contentEditable == 'true';
  64                 }
  65         };
  66
  67         var isTabNavigable = (dijit.isTabNavigable = function(/*Element*/ elem){
  68                 // summary:
  69                 //              Tests if an element is tab-navigable
  70
  71                 // TODO: convert (and rename method) to return effective tabIndex; will save time in _getTabNavigable()
  72                 if(domAttr.get(elem, "disabled")){
  73                         return false;
  74                 }else if(domAttr.has(elem, "tabIndex")){
  75                         // Explicit tab index setting
  76                         return domAttr.get(elem, "tabIndex") >= 0; // boolean
  77                 }else{
  78                         // No explicit tabIndex setting, so depends on node type
  79                         return dijit.hasDefaultTabStop(elem);
  80                 }
  81         });
  82
  83         dijit._getTabNavigable = function(/*DOMNode*/ root){
  84                 // summary:
  85                 //              Finds descendants of the specified root node.
  86                 // description:
  87                 //              Finds the following descendants of the specified root node:
  88                 //
  89                 //              - the first tab-navigable element in document order
  90                 //                without a tabIndex or with tabIndex="0"
  91                 //              - the last tab-navigable element in document order
  92                 //                without a tabIndex or with tabIndex="0"
  93                 //              - the first element in document order with the lowest
  94                 //                positive tabIndex value
  95                 //              - the last element in document order with the highest
  96                 //                positive tabIndex value
  97                 var first, last, lowest, lowestTabindex, highest, highestTabindex, radioSelected = {};
  98
  99                 function radioName(node){
 100                         // If this element is part of a radio button group, return the name for that group.
 101                         return node && node.tagName.toLowerCase() == "input" &&
 102                                 node.type && node.type.toLowerCase() == "radio" &&
 103                                 node.name && node.name.toLowerCase();
 104                 }
 105
 106                 var walkTree = function(/*DOMNode*/ parent){
 107                         for(var child = parent.firstChild; child; child = child.nextSibling){
 108                                 // Skip text elements, hidden elements, and also non-HTML elements (those in custom namespaces) in IE,
 109                                 // since show() invokes getAttribute("type"), which crash on VML nodes in IE.
 110                                 if(child.nodeType != 1 || (has("ie") <= 9 && child.scopeName !== "HTML") || !shown(child)){
 111                                         continue;
 112                                 }
 113
 114                                 if(isTabNavigable(child)){
 115                                         var tabindex = +domAttr.get(child, "tabIndex"); // + to convert string --> number
 116                                         if(!domAttr.has(child, "tabIndex") || tabindex == 0){
 117                                                 if(!first){
 118                                                         first = child;
 119                                                 }
 120                                                 last = child;
 121                                         }else if(tabindex > 0){
 122                                                 if(!lowest || tabindex < lowestTabindex){
 123                                                         lowestTabindex = tabindex;
 124                                                         lowest = child;
 125                                                 }
 126                                                 if(!highest || tabindex >= highestTabindex){
 127                                                         highestTabindex = tabindex;
 128                                                         highest = child;
 129                                                 }
 130                                         }
 131                                         var rn = radioName(child);
 132                                         if(domAttr.get(child, "checked") && rn){
 133                                                 radioSelected[rn] = child;
 134                                         }
 135                                 }
 136                                 if(child.nodeName.toUpperCase() != 'SELECT'){
 137                                         walkTree(child);
 138                                 }
 139                         }
 140                 };
 141                 if(shown(root)){
 142                         walkTree(root);
 143                 }
 144                 function rs(node){
 145                         // substitute checked radio button for unchecked one, if there is a checked one with the same name.
 146                         return radioSelected[radioName(node)] || node;
 147                 }
 148
 149                 return { first: rs(first), last: rs(last), lowest: rs(lowest), highest: rs(highest) };
 150         };
 151         dijit.getFirstInTabbingOrder = function(/*String|DOMNode*/ root, /*Document?*/ doc){
 152                 // summary:
 153                 //              Finds the descendant of the specified root node
 154                 //              that is first in the tabbing order
 155                 var elems = dijit._getTabNavigable(dom.byId(root, doc));
 156                 return elems.lowest ? elems.lowest : elems.first; // DomNode
 157         };
 158
 159         dijit.getLastInTabbingOrder = function(/*String|DOMNode*/ root, /*Document?*/ doc){
 160                 // summary:
 161                 //              Finds the descendant of the specified root node
 162                 //              that is last in the tabbing order
 163                 var elems = dijit._getTabNavigable(dom.byId(root, doc));
 164                 return elems.last ? elems.last : elems.highest; // DomNode
 165         };
 166
 167         return {
 168                 // summary:
 169                 //              Accessibility utility functions (keyboard, tab stops, etc.)
 170
 171                 hasDefaultTabStop: dijit.hasDefaultTabStop,
 172                 isTabNavigable: dijit.isTabNavigable,
 173                 _getTabNavigable: dijit._getTabNavigable,
 174                 getFirstInTabbingOrder: dijit.getFirstInTabbingOrder,
 175                 getLastInTabbingOrder: dijit.getLastInTabbingOrder
 176         };
 177 });