C++ Value::toObject方法代码示例

void
nsGeolocationService::HandleMozsettingChanged(const PRUnichar* aData)
{
    // The string that we're interested in will be a JSON string that looks like:
    //  {"key":"gelocation.enabled","value":true}

    SafeAutoJSContext cx;

    nsDependentString dataStr(aData);
    JS::Value val;
    if (!JS_ParseJSON(cx, dataStr.get(), dataStr.Length(), &val) || !val.isObject()) {
      return;
    }

    JSObject &obj(val.toObject());
    JS::Value key;
    if (!JS_GetProperty(cx, &obj, "key", &key) || !key.isString()) {
      return;
    }

    JSBool match;
    if (!JS_StringEqualsAscii(cx, key.toString(), GEO_SETINGS_ENABLED, &match) || (match != JS_TRUE)) {
      return;
    }

    JS::Value value;
    if (!JS_GetProperty(cx, &obj, "value", &value) || !value.isBoolean()) {
      return;
    }

    HandleMozsettingValue(value.toBoolean());
}

NS_IMETHODIMP
TCPSocketChild::Send(const JS::Value& aData,
                     uint32_t aByteOffset,
                     uint32_t aByteLength,
                     JSContext* aCx)
{
  if (aData.isString()) {
    JSString* jsstr = aData.toString();
    nsDependentJSString str;
    bool ok = str.init(aCx, jsstr);
    NS_ENSURE_TRUE(ok, NS_ERROR_FAILURE);
    SendData(str);

  } else {
    NS_ENSURE_TRUE(aData.isObject(), NS_ERROR_FAILURE);
    JS::Rooted<JSObject*> obj(aCx, &aData.toObject());
    NS_ENSURE_TRUE(JS_IsArrayBufferObject(obj), NS_ERROR_FAILURE);
    uint32_t buflen = JS_GetArrayBufferByteLength(obj);
    aByteOffset = std::min(buflen, aByteOffset);
    uint32_t nbytes = std::min(buflen - aByteOffset, aByteLength);
    uint8_t* data = JS_GetArrayBufferData(obj);
    if (!data) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
    FallibleTArray<uint8_t> fallibleArr;
    if (!fallibleArr.InsertElementsAt(0, data, nbytes)) {
      return NS_ERROR_OUT_OF_MEMORY;
    }
    InfallibleTArray<uint8_t> arr;
    arr.SwapElements(fallibleArr);
    SendData(arr);
  }
  return NS_OK;
}

NS_IMETHODIMP
TCPSocketParent::InitJS(const JS::Value& aIntermediary, JSContext* aCx)
{
  MOZ_ASSERT(aIntermediary.isObject());
  mIntermediaryObj = &aIntermediary.toObject();
  return NS_OK;
}

// Helper for weighted regions.
nsresult
CameraControlImpl::Set(JSContext* aCx, uint32_t aKey, const JS::Value& aValue, uint32_t aLimit)
{
  if (aLimit == 0) {
    DOM_CAMERA_LOGI("%s:%d : aLimit = 0, nothing to do\n", __func__, __LINE__);
    return NS_OK;
  }

  if (!aValue.isObject()) {
    return NS_ERROR_INVALID_ARG;
  }

  uint32_t length = 0;

  JSObject* regions = &aValue.toObject();
  if (!JS_GetArrayLength(aCx, regions, &length)) {
    return NS_ERROR_FAILURE;
  }

  DOM_CAMERA_LOGI("%s:%d : got %d regions (limited to %d)\n", __func__, __LINE__, length, aLimit);
  if (length > aLimit) {
    length = aLimit;
  }

  nsTArray<CameraRegion> regionArray;
  regionArray.SetCapacity(length);

  for (uint32_t i = 0; i < length; ++i) {
    JS::Value v;

    if (!JS_GetElement(aCx, regions, i, &v)) {
      return NS_ERROR_FAILURE;
    }

    CameraRegion* r = regionArray.AppendElement();
    /**
     * These are the default values.  We can remove these when the xpidl
     * dictionary parser gains the ability to grok default values.
     */
    r->top = -1000;
    r->left = -1000;
    r->bottom = 1000;
    r->right = 1000;
    r->weight = 1000;

    nsresult rv = r->Init(aCx, &v);
    NS_ENSURE_SUCCESS(rv, rv);

    DOM_CAMERA_LOGI("region %d: top=%d, left=%d, bottom=%d, right=%d, weight=%d\n",
      i,
      r->top,
      r->left,
      r->bottom,
      r->right,
      r->weight
    );
  }
  SetParameter(aKey, regionArray);
  return NS_OK;
}

JSScript *createScriptViaXDR(JSPrincipals *prin, JSPrincipals *orig, int testCase)
{
    const char src[] =
        "function f() { return 1; }\n"
        "f;\n";

    js::RootedObject global(cx, JS_GetGlobalObject(cx));
    JSScript *script = CompileScriptForPrincipalsVersionOrigin(cx, global, prin, orig,
                                                               src, strlen(src), "test", 1,
                                                               JSVERSION_DEFAULT);
    if (!script)
        return NULL;

    if (testCase == TEST_SCRIPT || testCase == TEST_SERIALIZED_FUNCTION) {
        script = FreezeThaw(cx, script);
        if (!script)
            return NULL;
        if (testCase == TEST_SCRIPT)
            return script;
    }

    JS::Value v;
    JSBool ok = JS_ExecuteScript(cx, global, script, &v);
    if (!ok || !v.isObject())
        return NULL;
    js::RootedObject funobj(cx, &v.toObject());
    if (testCase == TEST_FUNCTION) {
        funobj = FreezeThaw(cx, funobj);
        if (!funobj)
            return NULL;
    }
    return GetScript(cx, funobj);
}

// static
JSObject*
DOMProxyHandler::GetAndClearExpandoObject(JSObject* obj)
{
    MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
    JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
    if (v.isUndefined()) {
        return nullptr;
    }

    if (v.isObject()) {
        js::SetProxyExtra(obj, JSPROXYSLOT_EXPANDO, UndefinedValue());
        xpc::GetObjectScope(obj)->RemoveDOMExpandoObject(obj);
    } else {
        js::ExpandoAndGeneration* expandoAndGeneration =
            static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
        v = expandoAndGeneration->expando;
        if (v.isUndefined()) {
            return nullptr;
        }
        expandoAndGeneration->expando = UndefinedValue();
    }


    return &v.toObject();
}

nsresult xpcJSWeakReference::Init(JSContext* cx, const JS::Value& object)
{
    if (!object.isObject())
        return NS_OK;

    JS::RootedObject obj(cx, &object.toObject());

    XPCCallContext ccx(NATIVE_CALLER, cx);

    // See if the object is a wrapped native that supports weak references.
    nsISupports* supports =
        nsXPConnect::XPConnect()->GetNativeOfWrapper(cx, obj);
    nsCOMPtr<nsISupportsWeakReference> supportsWeakRef =
        do_QueryInterface(supports);
    if (supportsWeakRef) {
        supportsWeakRef->GetWeakReference(getter_AddRefs(mReferent));
        if (mReferent) {
            return NS_OK;
        }
    }
    // If it's not a wrapped native, or it is a wrapped native that does not
    // support weak references, fall back to getting a weak ref to the object.

    // See if object is a wrapped JSObject.
    nsRefPtr<nsXPCWrappedJS> wrapped;
    nsresult rv = nsXPCWrappedJS::GetNewOrUsed(obj,
                                               NS_GET_IID(nsISupports),
                                               getter_AddRefs(wrapped));
    if (!wrapped) {
        NS_ERROR("can't get nsISupportsWeakReference wrapper for obj");
        return rv;
    }

    return wrapped->GetWeakReference(getter_AddRefs(mReferent));
}

Promise*
WrapperPromiseCallback::GetDependentPromise()
{
  // Per spec, various algorithms like all() and race() are actually implemented
  // in terms of calling then() but passing it the resolve/reject functions that
  // are passed as arguments to function passed to the Promise constructor.
  // That will cause the promise in question to hold on to a
  // WrapperPromiseCallback, but the dependent promise should really be the one
  // whose constructor those functions came from, not the about-to-be-ignored
  // return value of "then".  So try to determine whether we're in that case and
  // if so go ahead and dig the dependent promise out of the function we have.
  JSObject* callable = mCallback->Callable();
  // Unwrap it, in case it's a cross-compartment wrapper.  Our caller here is
  // system, so it's really ok to just go and unwrap.
  callable = js::UncheckedUnwrap(callable);
  if (JS_IsNativeFunction(callable, Promise::JSCallback)) {
    JS::Value promiseVal =
      js::GetFunctionNativeReserved(callable, Promise::SLOT_PROMISE);
    Promise* promise;
    UNWRAP_OBJECT(Promise, &promiseVal.toObject(), promise);
    return promise;
  }

  if (mNextPromise) {
    return mNextPromise;
  }

  Promise* promise;
  if (NS_SUCCEEDED(UNWRAP_OBJECT(Promise, mNextPromiseObj, promise))) {
    return promise;
  }

  // Oh, well.
  return nullptr;
}

NS_IMETHODIMP
SmsManager::Send(const JS::Value& aNumber, const nsAString& aMessage, JS::Value* aReturn)
{
  nsresult rv;
  nsIScriptContext* sc = GetContextForEventHandlers(&rv);
  NS_ENSURE_STATE(sc);
  AutoPushJSContext cx(sc->GetNativeContext());
  NS_ASSERTION(cx, "Failed to get a context!");

  if (!aNumber.isString() &&
      !(aNumber.isObject() && JS_IsArrayObject(cx, &aNumber.toObject()))) {
    return NS_ERROR_INVALID_ARG;
  }

  JSObject* global = sc->GetNativeGlobal();
  NS_ASSERTION(global, "Failed to get global object!");

  JSAutoRequest ar(cx);
  JSAutoCompartment ac(cx, global);

  if (aNumber.isString()) {
    return Send(cx, global, aNumber.toString(), aMessage, aReturn);
  }

  // Must be an array then.
  JSObject& numbers = aNumber.toObject();

  uint32_t size;
  JS_ALWAYS_TRUE(JS_GetArrayLength(cx, &numbers, &size));

  JS::Value* requests = new JS::Value[size];

  for (uint32_t i=0; i<size; ++i) {
    JS::Value number;
    if (!JS_GetElement(cx, &numbers, i, &number)) {
      return NS_ERROR_INVALID_ARG;
    }

    nsresult rv = Send(cx, global, number.toString(), aMessage, &requests[i]);
    NS_ENSURE_SUCCESS(rv, rv);
  }

  aReturn->setObjectOrNull(JS_NewArrayObject(cx, size, requests));
  NS_ENSURE_TRUE(aReturn->isObject(), NS_ERROR_FAILURE);

  return NS_OK;
}

NS_IMETHODIMP
TimeZoneSettingObserver::Observe(nsISupports *aSubject,
                     const char *aTopic,
                     const PRUnichar *aData)
{
  if (strcmp(aTopic, MOZSETTINGS_CHANGED) != 0) {
    return NS_OK;
  }

  // Note that this function gets called for any and all settings changes,
  // so we need to carefully check if we have the one we're interested in.
  //
  // The string that we're interested in will be a JSON string that looks like:
  // {"key":"time.timezone","value":"America/Chicago"}

  // Get the safe JS context.
  nsCOMPtr<nsIThreadJSContextStack> stack =
    do_GetService("@mozilla.org/js/xpc/ContextStack;1");
  if (!stack) {
    ERR("Failed to get JSContextStack");
    return NS_OK;
  }
  JSContext *cx = stack->GetSafeJSContext();
  if (!cx) {
    ERR("Failed to GetSafeJSContext");
    return NS_OK;
  }

  // Parse the JSON value.
  nsDependentString dataStr(aData);
  JS::Value val;
  if (!JS_ParseJSON(cx, dataStr.get(), dataStr.Length(), &val) ||
      !val.isObject()) {
    return NS_OK;
  }

  // Get the key, which should be the JS string "time.timezone".
  JSObject &obj(val.toObject());
  JS::Value key;
  if (!JS_GetProperty(cx, &obj, "key", &key) ||
      !key.isString()) {
    return NS_OK;
  }
  JSBool match;
  if (!JS_StringEqualsAscii(cx, key.toString(), TIME_TIMEZONE, &match) ||
      match != JS_TRUE) {
    return NS_OK;
  }

  // Get the value, which should be a JS string like "America/Chicago".
  JS::Value value;
  if (!JS_GetProperty(cx, &obj, "value", &value) ||
      !value.isString()) {
    return NS_OK;
  }

  // Set the system timezone.
  return SetTimeZone(value, cx);
}

bool
ValueHasISupportsPrivate(const JS::Value &v)
{
  if (!v.isObject()) {
    return false;
  }

  const DOMClass* domClass = GetDOMClass(&v.toObject());
  if (domClass) {
    return domClass->mDOMObjectIsISupports;
  }

  JSClass* clasp = ::JS_GetClass(&v.toObject());
  const uint32_t HAS_PRIVATE_NSISUPPORTS =
    JSCLASS_HAS_PRIVATE | JSCLASS_PRIVATE_IS_NSISUPPORTS;
  return (clasp->flags & HAS_PRIVATE_NSISUPPORTS) == HAS_PRIVATE_NSISUPPORTS;
}

nsresult
nsJSON::EncodeInternal(JSContext* cx, const JS::Value& aValue,
                       nsJSONWriter* writer)
{
  JSAutoRequest ar(cx);

  // Backward compatibility:
  // nsIJSON does not allow to serialize anything other than objects
  if (!aValue.isObject()) {
    return NS_ERROR_INVALID_ARG;
  }

  JSObject* obj = &aValue.toObject();

  JS::Value val = aValue;

  /* Backward compatibility:
   * Manually call toJSON if implemented by the object and check that
   * the result is still an object
   * Note: It is perfectly fine to not implement toJSON, so it is
   * perfectly fine for GetMethod to fail
   */
  JS::Value toJSON;
  if (JS_GetMethod(cx, obj, "toJSON", NULL, &toJSON) &&
      !JSVAL_IS_PRIMITIVE(toJSON) &&
      JS_ObjectIsCallable(cx, JSVAL_TO_OBJECT(toJSON))) {
    // If toJSON is implemented, it must not throw
    if (!JS_CallFunctionValue(cx, obj, toJSON, 0, NULL, &val)) {
      if (JS_IsExceptionPending(cx))
        // passing NS_OK will throw the pending exception
        return NS_OK;

      // No exception, but still failed
      return NS_ERROR_FAILURE;
    }

    // Backward compatibility:
    // nsIJSON does not allow to serialize anything other than objects
    if (JSVAL_IS_PRIMITIVE(val))
      return NS_ERROR_INVALID_ARG;
  }
  // GetMethod may have thrown
  else if (JS_IsExceptionPending(cx))
    // passing NS_OK will throw the pending exception
    return NS_OK;

  // Backward compatibility:
  // function shall not pass, just "plain" objects and arrays
  JSType type = JS_TypeOfValue(cx, val);
  if (type == JSTYPE_FUNCTION)
    return NS_ERROR_INVALID_ARG;

  // We're good now; try to stringify
  if (!JS_Stringify(cx, &val, NULL, JSVAL_NULL, WriteCallback, writer))
    return NS_ERROR_FAILURE;

  return NS_OK;
}

//static
JSObject *
DOMProxyHandler::GetExpandoObject(JSObject *obj)
{
  MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
  JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
  if (v.isObject()) {
    return &v.toObject();
  }

  if (v.isUndefined()) {
    return nullptr;
  }

  js::ExpandoAndGeneration* expandoAndGeneration =
    static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
  v = expandoAndGeneration->expando;
  return v.isUndefined() ? nullptr : &v.toObject();
}

// JS-to-native helpers
// Setter for weighted regions: { top, bottom, left, right, weight }
nsresult
nsDOMCameraControl::Set(JSContext* aCx, uint32_t aKey, const JS::Value& aValue, uint32_t aLimit)
{
  if (aLimit == 0) {
    DOM_CAMERA_LOGI("%s:%d : aLimit = 0, nothing to do\n", __func__, __LINE__);
    return NS_OK;
  }

  if (!aValue.isObject()) {
    return NS_ERROR_INVALID_ARG;
  }

  uint32_t length = 0;

  JS::Rooted<JSObject*> regions(aCx, &aValue.toObject());
  if (!JS_GetArrayLength(aCx, regions, &length)) {
    return NS_ERROR_FAILURE;
  }

  DOM_CAMERA_LOGI("%s:%d : got %d regions (limited to %d)\n", __func__, __LINE__, length, aLimit);
  if (length > aLimit) {
    length = aLimit;
  }

  nsTArray<ICameraControl::Region> regionArray;
  regionArray.SetCapacity(length);

  for (uint32_t i = 0; i < length; ++i) {
    JS::Rooted<JS::Value> v(aCx);

    if (!JS_GetElement(aCx, regions, i, &v)) {
      return NS_ERROR_FAILURE;
    }

    CameraRegion region;
    if (!region.Init(aCx, v)) {
      return NS_ERROR_FAILURE;
    }

    ICameraControl::Region* r = regionArray.AppendElement();
    r->top = region.mTop;
    r->left = region.mLeft;
    r->bottom = region.mBottom;
    r->right = region.mRight;
    r->weight = region.mWeight;

    DOM_CAMERA_LOGI("region %d: top=%d, left=%d, bottom=%d, right=%d, weight=%u\n",
      i,
      r->top,
      r->left,
      r->bottom,
      r->right,
      r->weight
    );
  }
  return mCameraControl->Set(aKey, regionArray);
}

nsresult
MobileMessageManager::GetMessageId(AutoPushJSContext &aCx,
                                   const JS::Value &aMessage, int32_t &aId)
{
  nsCOMPtr<nsIDOMMozSmsMessage> smsMessage =
    do_QueryInterface(nsContentUtils::XPConnect()->GetNativeOfWrapper(aCx, &aMessage.toObject()));
  if (smsMessage) {
    return smsMessage->GetId(&aId);
  }

  nsCOMPtr<nsIDOMMozMmsMessage> mmsMessage =
    do_QueryInterface(nsContentUtils::XPConnect()->GetNativeOfWrapper(aCx, &aMessage.toObject()));
  if (mmsMessage) {
    return mmsMessage->GetId(&aId);
  }

  return NS_ERROR_INVALID_ARG;
}