lib/dropdown.js

   1 /****
   2 Author: Jerome Mouneyrac
   3 Bug Reference: http://tracker.moodle.org/browse/MDL-14439
   4 IE and Opera fire the onchange when ever you move into a dropdwown list with the keyboard.
   5 These functions fix this problem.
   6 ****/
   7
   8 /*
   9 global variables
  10
  11 Note:
  12 if I didn't use global variables, we would need to pass them as parameter:
  13 => in initSelect():
  14    I would write "theSelect.onchange = selectChanged(...);"
  15    This code causes a javascript error on IE. (not firefox)
  16 so I had to write theSelect.onchange = selectChanged; It's why I use global variables .
  17 Because I use global variables, I didn't put this code in javascript-static.js.
  18 This file is loaded in javascript.php.
  19 */
  20 var select_formid;
  21 var select_targetwindow;
  22
  23 //we redefine all user actions on the dropdown list
  24 //onfocus, onchange, onkeydown, and onclick
  25 function initSelect(formId,targetWindow)
  26 {
  27     //initialise global variables
  28     select_formid=formId;
  29     select_targetwindow=targetWindow;
  30
  31     var theSelect = document.getElementById(select_formid+"_jump");
  32
  33     theSelect.changed = false;
  34
  35     selectFocussed();
  36
  37     theSelect.onchange = selectChanged;
  38     theSelect.onkeydown = selectKeyed;
  39     theSelect.onclick = selectClicked;
  40
  41     return true;
  42 }
  43
  44 function selectChanged(theElement)
  45 {
  46     var theSelect;
  47
  48     if (theElement && theElement.value)
  49     {
  50         theSelect = theElement;
  51     }
  52     else
  53     {
  54         theSelect = this;
  55     }
  56
  57     if (!theSelect.changed)
  58     {
  59         return false;
  60     }
  61
  62     //here is the onchange redirection
  63     select_targetwindow.location=document.getElementById(select_formid).jump.options[document.getElementById(select_formid).jump.selectedIndex].value;
  64
  65     return true;
  66 }
  67
  68 function selectClicked()
  69 {
  70     this.changed = true;
  71 }
  72
  73 function selectFocussed()
  74 {
  75     this.initValue = this.value;
  76
  77     return true;
  78 }
  79
  80 //we keep Firefox behaviors: onchange is fired when we press "Enter", "Esc", or "Tab"" keys.
  81 //note that is probably not working on Mac (keyCode could be different)
  82 function selectKeyed(e)
  83 {
  84     var theEvent;
  85     var keyCodeTab = "9";
  86     var keyCodeEnter = "13";
  87     var keyCodeEsc = "27";
  88
  89     if (e)
  90     {
  91         theEvent = e;
  92     }
  93     else
  94     {
  95         theEvent = event;
  96     }
  97
  98     if ((theEvent.keyCode == keyCodeEnter || theEvent.keyCode == keyCodeTab) && this.value != this.initValue)
  99     {
 100         this.changed = true;
 101         selectChanged(this);
 102     }
 103     else if (theEvent.keyCode == keyCodeEsc)
 104     {
 105         this.value = this.initValue;
 106     }
 107     else
 108     {
 109         this.changed = false;
 110     }
 111
 112     return true;
 113 }