gecko-dev/dom/bindings/ToJSValue.h

347 lines
9.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* vim: set ts=2 sw=2 et tw=79: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_dom_ToJSValue_h
#define mozilla_dom_ToJSValue_h
#include "mozilla/TypeTraits.h"
#include "mozilla/Assertions.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/dom/TypedArray.h"
#include "jsapi.h"
#include "nsISupports.h"
#include "nsTArray.h"
#include "nsWrapperCache.h"
namespace mozilla {
namespace dom {
// If ToJSValue returns false, it must set an exception on the
// JSContext.
// Accept strings.
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
const nsAString& aArgument,
JS::MutableHandle<JS::Value> aValue);
// Accept booleans.
MOZ_WARN_UNUSED_RESULT inline bool
ToJSValue(JSContext* aCx,
bool aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setBoolean(aArgument);
return true;
}
// Accept integer types
inline bool
ToJSValue(JSContext* aCx,
int32_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setInt32(aArgument);
return true;
}
// The uint32_t version is disabled for now because on the super-old b2g
// compiler nsresult and uint32_t are the same type. If someone needs this at
// some point we'll need to figure out how to make it work (e.g. by switching to
// traits structs and using the trick IPC's ParamTraits uses, where a traits
// struct templated on the type inherits from a base traits struct of some sort,
// templated on the same type, or something). Maybe b2g will update to a modern
// compiler before that happens....
#if 0
inline bool
ToJSValue(JSContext* aCx,
uint32_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(aArgument);
return true;
}
#endif
inline bool
ToJSValue(JSContext* aCx,
int64_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(double(aArgument));
return true;
}
inline bool
ToJSValue(JSContext* aCx,
uint64_t aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(double(aArgument));
return true;
}
// accept floating point types
inline bool
ToJSValue(JSContext* aCx,
float aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(aArgument);
return true;
}
inline bool
ToJSValue(JSContext* aCx,
double aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setNumber(aArgument);
return true;
}
// Accept CallbackObjects
MOZ_WARN_UNUSED_RESULT inline bool
ToJSValue(JSContext* aCx,
CallbackObject& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
aValue.setObject(*aArgument.Callback());
return MaybeWrapValue(aCx, aValue);
}
// Accept objects that inherit from nsWrapperCache (e.g. most
// DOM objects).
template <class T>
MOZ_WARN_UNUSED_RESULT
typename EnableIf<IsBaseOf<nsWrapperCache, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
T& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
// Make sure non-webidl objects don't sneak in here
MOZ_ASSERT(aArgument.IsDOMBinding());
return GetOrCreateDOMReflector(aCx, aArgument, aValue);
}
// Accept typed arrays built from appropriate nsTArray values
template<typename T>
MOZ_WARN_UNUSED_RESULT
typename EnableIf<IsBaseOf<AllTypedArraysBase, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
const TypedArrayCreator<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
JSObject* obj = aArgument.Create(aCx);
if (!obj) {
return false;
}
aValue.setObject(*obj);
return true;
}
// We don't want to include nsContentUtils here, so use a helper
// function for the nsISupports case.
namespace tojsvalue_detail {
bool
ISupportsToJSValue(JSContext* aCx,
nsISupports* aArgument,
JS::MutableHandle<JS::Value> aValue);
} // namespace tojsvalue_detail
// Accept objects that inherit from nsISupports but not nsWrapperCache (e.g.
// nsIDOMFile).
template <class T>
MOZ_WARN_UNUSED_RESULT
typename EnableIf<!IsBaseOf<nsWrapperCache, T>::value &&
!IsBaseOf<CallbackObject, T>::value &&
IsBaseOf<nsISupports, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
T& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
return tojsvalue_detail::ISupportsToJSValue(aCx, &aArgument, aValue);
}
// Accept nsRefPtr/nsCOMPtr
template <typename T>
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
const nsCOMPtr<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, *aArgument.get(), aValue);
}
template <typename T>
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
const nsRefPtr<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, *aArgument.get(), aValue);
}
// Accept WebIDL dictionaries
template <class T>
MOZ_WARN_UNUSED_RESULT
typename EnableIf<IsBaseOf<DictionaryBase, T>::value, bool>::Type
ToJSValue(JSContext* aCx,
const T& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return aArgument.ToObjectInternal(aCx, aValue);
}
// Accept existing JS values (which may not be same-compartment with us
MOZ_WARN_UNUSED_RESULT inline bool
ToJSValue(JSContext* aCx, JS::Handle<JS::Value> aArgument,
JS::MutableHandle<JS::Value> aValue)
{
aValue.set(aArgument);
return MaybeWrapValue(aCx, aValue);
}
// Accept existing JS values on the Heap (which may not be same-compartment with us
MOZ_WARN_UNUSED_RESULT inline bool
ToJSValue(JSContext* aCx, const JS::Heap<JS::Value>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
aValue.set(aArgument);
return MaybeWrapValue(aCx, aValue);
}
// Accept existing rooted JS values (which may not be same-compartment with us
MOZ_WARN_UNUSED_RESULT inline bool
ToJSValue(JSContext* aCx, const JS::Rooted<JS::Value>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
aValue.set(aArgument);
return MaybeWrapValue(aCx, aValue);
}
// Accept nsresult, for use in rejections, and create an XPCOM
// exception object representing that nsresult.
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
nsresult aArgument,
JS::MutableHandle<JS::Value> aValue);
// Accept ErrorResult, for use in rejections, and create an exception
// representing the failure. Note, the ErrorResult must indicate a failure
// with aArgument.Failure() returning true.
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
ErrorResult& aArgument,
JS::MutableHandle<JS::Value> aValue);
// Accept pointers to other things we accept
template <typename T>
MOZ_WARN_UNUSED_RESULT
typename EnableIf<IsPointer<T>::value, bool>::Type
ToJSValue(JSContext* aCx,
T aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, *aArgument, aValue);
}
// Accept arrays of other things we accept
template <typename T>
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
T* aArguments,
size_t aLength,
JS::MutableHandle<JS::Value> aValue)
{
// Make sure we're called in a compartment
MOZ_ASSERT(JS::CurrentGlobalOrNull(aCx));
JS::AutoValueVector v(aCx);
if (!v.resize(aLength)) {
return false;
}
for (size_t i = 0; i < aLength; ++i) {
if (!ToJSValue(aCx, aArguments[i], v[i])) {
return false;
}
}
JSObject* arrayObj = JS_NewArrayObject(aCx, v);
if (!arrayObj) {
return false;
}
aValue.setObject(*arrayObj);
return true;
}
template <typename T>
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
const nsTArray<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, aArgument.Elements(),
aArgument.Length(), aValue);
}
template <typename T>
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
const FallibleTArray<T>& aArgument,
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, aArgument.Elements(),
aArgument.Length(), aValue);
}
template <typename T, int N>
MOZ_WARN_UNUSED_RESULT bool
ToJSValue(JSContext* aCx,
const T(&aArgument)[N],
JS::MutableHandle<JS::Value> aValue)
{
return ToJSValue(aCx, aArgument, N, aValue);
}
} // namespace dom
} // namespace mozilla
#endif /* mozilla_dom_ToJSValue_h */