dom/public/nsDOMJSUtils.h

   1
   2 #ifndef nsDOMJSUtils_h__
   3 #define nsDOMJSUtils_h__
   4
   5 #include "jsapi.h"
   6 #include "nsIScriptContext.h"
   7
   8 // seems like overkill for just this 1 function - but let's see what else
   9 // falls out first.
  10 inline nsIScriptContext *
  11 GetScriptContextFromJSContext(JSContext *cx)
  12 {
  13   if (!(::JS_GetOptions(cx) & JSOPTION_PRIVATE_IS_NSISUPPORTS)) {
  14     return nsnull;
  15   }
  16
  17   nsCOMPtr<nsIScriptContext> scx =
  18     do_QueryInterface(static_cast<nsISupports *>
  19                                  (::JS_GetContextPrivate(cx)));
  20
  21   // This will return a pointer to something that's about to be
  22   // released, but that's ok here.
  23   return scx;
  24 }
  25
  26 // A factory function for turning a jsval argv into an nsIArray
  27 // but also supports an effecient way of extracting the original argv.
  28 // Bug 312003 describes why this must be "void *", but argv will be cast to
  29 // jsval* and the args are found at:
  30 //    ((jsval*)aArgv)[0], ..., ((jsval*)aArgv)[aArgc - 1]
  31 // The resulting object will take a copy of the array, and ensure each
  32 // element is rooted.
  33 // Optionally, aArgv may be NULL, in which case the array is allocated and
  34 // rooted, but all items remain NULL.  This presumably means the caller will
  35 // then QI us for nsIJSArgArray, and set our array elements.
  36 nsresult NS_CreateJSArgv(JSContext *aContext, PRUint32 aArgc, void *aArgv,
  37                          nsIArray **aArray);
  38
  39 #endif // nsDOMJSUtils_h__