dom/base/nsJSUtils.h

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  37
  38 #ifndef nsJSUtils_h__
  39 #define nsJSUtils_h__
  40
  41 /**
  42  * This is not a generated file. It contains common utility functions
  43  * invoked from the JavaScript code generated from IDL interfaces.
  44  * The goal of the utility functions is to cut down on the size of
  45  * the generated code itself.
  46  */
  47
  48 #include "nsISupports.h"
  49 #include "jsapi.h"
  50 #include "nsString.h"
  51
  52 class nsIDOMEventListener;
  53 class nsIScriptContext;
  54 class nsIScriptGlobalObject;
  55 class nsIPrincipal;
  56
  57 class nsJSUtils
  58 {
  59 public:
  60   static JSBool GetCallingLocation(JSContext* aContext, const char* *aFilename,
  61                                    PRUint32* aLineno, nsIPrincipal* aPrincipal);
  62
  63   static nsIScriptGlobalObject *GetStaticScriptGlobal(JSContext* aContext,
  64                                                       JSObject* aObj);
  65
  66   static nsIScriptContext *GetStaticScriptContext(JSContext* aContext,
  67                                                   JSObject* aObj);
  68
  69   static nsIScriptGlobalObject *GetDynamicScriptGlobal(JSContext *aContext);
  70
  71   static nsIScriptContext *GetDynamicScriptContext(JSContext *aContext);
  72
  73   /**
  74    * Retrieve the outer window ID based on the given JSContext.
  75    *
  76    * @param JSContext aContext
  77    *        The JSContext from which you want to find the outer window ID.
  78    *
  79    * @returns PRUint64 the outer window ID.
  80    */
  81   static PRUint64 GetCurrentlyRunningCodeWindowID(JSContext *aContext);
  82 };
  83
  84
  85 class nsDependentJSString : public nsDependentString
  86 {
  87 public:
  88   /**
  89    * In the case of string ids, getting the string's chars is infallible, so
  90    * the dependent string can be constructed directly.
  91    */
  92   explicit nsDependentJSString(jsid id)
  93     : nsDependentString(JS_GetInternedStringChars(JSID_TO_STRING(id)),
  94                         JS_GetStringLength(JSID_TO_STRING(id)))
  95   {
  96   }
  97
  98   /**
  99    * For all other strings, the nsDependentJSString object should be default
 100    * constructed, which leaves it empty (this->IsEmpty()), and initialized with
 101    * one of the fallible init() methods below.
 102    */
 103
 104   nsDependentJSString()
 105   {
 106   }
 107
 108   JSBool init(JSContext* aContext, JSString* str)
 109   {
 110       size_t length;
 111       const jschar* chars = JS_GetStringCharsZAndLength(aContext, str, &length);
 112       if (!chars)
 113           return JS_FALSE;
 114
 115       NS_ASSERTION(IsEmpty(), "init() on initialized string");
 116       nsDependentString* base = this;
 117       new(base) nsDependentString(chars, length);
 118       return JS_TRUE;
 119   }
 120
 121   JSBool init(JSContext* aContext, const jsval &v)
 122   {
 123       return init(aContext, JSVAL_TO_STRING(v));
 124   }
 125
 126   ~nsDependentJSString()
 127   {
 128   }
 129 };
 130
 131 #endif /* nsJSUtils_h__ */