dom/base/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 inline nsIScriptContextPrincipal*
  27 GetScriptContextPrincipalFromJSContext(JSContext *cx)
  28 {
  29   if (!(::JS_GetOptions(cx) & JSOPTION_PRIVATE_IS_NSISUPPORTS)) {
  30     return nsnull;
  31   }
  32
  33   nsCOMPtr<nsIScriptContextPrincipal> scx =
  34     do_QueryInterface(static_cast<nsISupports *>
  35                                  (::JS_GetContextPrivate(cx)));
  36
  37   // This will return a pointer to something that's about to be
  38   // released, but that's ok here.
  39   return scx;
  40 }
  41
  42 // A factory function for turning a jsval argv into an nsIArray
  43 // but also supports an effecient way of extracting the original argv.
  44 // Bug 312003 describes why this must be "void *", but argv will be cast to
  45 // jsval* and the args are found at:
  46 //    ((jsval*)aArgv)[0], ..., ((jsval*)aArgv)[aArgc - 1]
  47 // The resulting object will take a copy of the array, and ensure each
  48 // element is rooted.
  49 // Optionally, aArgv may be NULL, in which case the array is allocated and
  50 // rooted, but all items remain NULL.  This presumably means the caller will
  51 // then QI us for nsIJSArgArray, and set our array elements.
  52 nsresult NS_CreateJSArgv(JSContext *aContext, PRUint32 aArgc, void *aArgv,
  53                          nsIArray **aArray);
  54
  55 #endif // nsDOMJSUtils_h__