src/ibex/lib/redirect.t

   1 <!-- Copyleft 2004 - see COPYING for details [LGPL] -->
   2
   3 <ibex>
   4     <meta:doc>
   5         See xwt.theme.redirect for details
   6     </meta:doc>
   7
   8     <ui:box>
   9
  10         var locks = {};
  11         var redirects = {};
  12
  13         thisbox.redirectTo = function(v) {
  14             if (v == null) {
  15                 ibex.log.warn("Attempted to redirect properties to a null value");
  16                 return false;
  17             }
  18
  19             for (var i=1; arguments.length > i; i++) {
  20                 // get property from arguments
  21                 var p = arguments[i];
  22
  23                 // remove the trap if it already exists
  24                 if (redirects[p]) dropRedirect(v, p);
  25
  26                 // create and store redirecting functions
  27                 redirects[p] = [v,
  28                                 function(w) {
  29                                     if (!locks[p]) { locks[p] = true; cascade = w; thisbox[p] = w; locks[p] = null; }
  30                                 },
  31                                 function(w) {
  32                                     if (!locks[p]) { locks[p] = true; v[p] = w; locks[p] = null; }
  33                                     return true;
  34                                 },
  35                                 function() { return v[p]; }];
  36
  37                 // assign redirecting traps
  38                 try { // try/catch for properties that can't have write traps
  39                     thisbox[p] ++= redirects[p][2];
  40                     v[p] ++= redirects[p][1];
  41                 } catch(e) {
  42                     redirects[p][1] = null;
  43                     redirects[p][2] = null;
  44                 }
  45                 // try/catch for properties that can't have read traps
  46                 try { thisbox[p] ++= redirects[p][3]; }
  47                 catch(e) { redirects[p][3] = null; }
  48             }
  49
  50             // report success
  51             return true;
  52         }
  53
  54         thisbox.dropRedirect = function(v) {
  55             for (var i=1; arguments.length > i; i++) {
  56                 // get property from arguments
  57                 var p = arguments[i];
  58
  59                 // remove redirect traps and reference
  60                 if (redirects[p]) {
  61                     if (redirects[p][1]) redirects[p][0] --= redirects[p][1];
  62                     if (redirects[p][2]) thisbox[p] --= redirects[p][2];
  63                     if (redirects[p][3]) thisbox[p] --= redirects[p][3];
  64                     redirects[p] = null;
  65                 }
  66             }
  67
  68             return true;
  69         }
  70
  71     </ui:box>
  72 </ibex>