C++ (Cpp) Handle::isNullOrUndefined示例

// static
nsresult
IDBKeyRange::FromJSVal(JSContext* aCx,
                       JS::Handle<JS::Value> aVal,
                       IDBKeyRange** aKeyRange)
{
  nsRefPtr<IDBKeyRange> keyRange;

  if (aVal.isNullOrUndefined()) {
    // undefined and null returns no IDBKeyRange.
    keyRange.forget(aKeyRange);
    return NS_OK;
  }

  JS::Rooted<JSObject*> obj(aCx, aVal.isObject() ? &aVal.toObject() : nullptr);
  if (aVal.isPrimitive() || JS_IsArrayObject(aCx, obj) ||
      JS_ObjectIsDate(aCx, obj)) {
    // A valid key returns an 'only' IDBKeyRange.
    keyRange = new IDBKeyRange(nullptr, false, false, true);

    nsresult rv = GetKeyFromJSVal(aCx, aVal, keyRange->Lower());
    if (NS_FAILED(rv)) {
      return rv;
    }
  }
  else {
    MOZ_ASSERT(aVal.isObject());
    // An object is not permitted unless it's another IDBKeyRange.
    if (NS_FAILED(UNWRAP_OBJECT(IDBKeyRange, obj, keyRange))) {
      return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
    }
  }

  keyRange.forget(aKeyRange);
  return NS_OK;
}

示例#2

显示文件

文件： IDBKeyRange.cpp 项目： bitwiseworks/mozilla-os2

// static
nsresult
IDBKeyRange::FromJSVal(JSContext* aCx,
                       JS::Handle<JS::Value> aVal,
                       IDBKeyRange** aKeyRange)
{
  MOZ_ASSERT_IF(!aCx, aVal.isUndefined());

  RefPtr<IDBKeyRange> keyRange;

  if (aVal.isNullOrUndefined()) {
    // undefined and null returns no IDBKeyRange.
    keyRange.forget(aKeyRange);
    return NS_OK;
  }

  JS::Rooted<JSObject*> obj(aCx, aVal.isObject() ? &aVal.toObject() : nullptr);
  bool isValidKey = aVal.isPrimitive();
  if (!isValidKey) {
    js::ESClass cls;
    if (!js::GetBuiltinClass(aCx, obj, &cls)) {
      return NS_ERROR_UNEXPECTED;
    }
    isValidKey = cls == js::ESClass::Array || cls == js::ESClass::Date;
  }
  if (isValidKey) {
    // A valid key returns an 'only' IDBKeyRange.
    keyRange = new IDBKeyRange(nullptr, false, false, true);

    nsresult rv = GetKeyFromJSVal(aCx, aVal, keyRange->Lower());
    if (NS_FAILED(rv)) {
      return rv;
    }
  }
  else {
    MOZ_ASSERT(aVal.isObject());
    // An object is not permitted unless it's another IDBKeyRange.
    if (NS_FAILED(UNWRAP_OBJECT(IDBKeyRange, obj, keyRange))) {
      return NS_ERROR_DOM_INDEXEDDB_DATA_ERR;
    }
  }

  keyRange.forget(aKeyRange);
  return NS_OK;
}

示例#3

显示文件

文件： WebGLContext.cpp 项目： Sleepwalker2014/gecko-dev

NS_IMETHODIMP
WebGLContext::SetContextOptions(JSContext* aCx, JS::Handle<JS::Value> aOptions)
{
    if (aOptions.isNullOrUndefined() && mOptionsFrozen) {
        return NS_OK;
    }

    WebGLContextAttributes attributes;
    NS_ENSURE_TRUE(attributes.Init(aCx, aOptions), NS_ERROR_UNEXPECTED);

    WebGLContextOptions newOpts;

    newOpts.stencil = attributes.mStencil;
    newOpts.depth = attributes.mDepth;
    newOpts.premultipliedAlpha = attributes.mPremultipliedAlpha;
    newOpts.antialias = attributes.mAntialias;
    newOpts.preserveDrawingBuffer = attributes.mPreserveDrawingBuffer;
    if (attributes.mAlpha.WasPassed()) {
      newOpts.alpha = attributes.mAlpha.Value();
    }

    // enforce that if stencil is specified, we also give back depth
    newOpts.depth |= newOpts.stencil;

#if 0
    GenerateWarning("aaHint: %d stencil: %d depth: %d alpha: %d premult: %d preserve: %d\n",
               newOpts.antialias ? 1 : 0,
               newOpts.stencil ? 1 : 0,
               newOpts.depth ? 1 : 0,
               newOpts.alpha ? 1 : 0,
               newOpts.premultipliedAlpha ? 1 : 0,
               newOpts.preserveDrawingBuffer ? 1 : 0);
#endif

    if (mOptionsFrozen && newOpts != mOptions) {
        // Error if the options are already frozen, and the ones that were asked for
        // aren't the same as what they were originally.
        return NS_ERROR_FAILURE;
    }

    mOptions = newOpts;
    return NS_OK;
}