0ad/source/gui/Scripting/JSInterface_GUIProxy_impl.h

/* Copyright (C) 2020 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

// This file is included directly into actual implementation files.

template <typename T>
js::Class& JSI_GUIProxy<T>::ClassDefinition()
{
	static js::Class c = PROXY_CLASS_DEF("GUIObjectProxy", JSCLASS_HAS_CACHED_PROTO(JSProto_Proxy) | JSCLASS_HAS_RESERVED_SLOTS(1));
	return c;
}

template <typename T>
JSI_GUIProxy<T>& JSI_GUIProxy<T>::Singleton()
{
	static JSI_GUIProxy<T> s;
	return s;
}

namespace
{
template<class OG, class R, void (R::*funcptr)(ScriptInterface&, JS::MutableHandleValue)>
inline bool apply_to(JSContext* cx, uint argc, JS::Value* vp)
{
	JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
	OG* e = static_cast<OG*>(js::GetProxyPrivate(args.thisv().toObjectOrNull()).toPrivate());
	if (!e)
		return false;

	(static_cast<R*>(e)->*(funcptr))(*(ScriptInterface::GetScriptInterfaceAndCBData(cx)->pScriptInterface), args.rval());

	return true;
}
}

template <typename T>
bool JSI_GUIProxy<T>::get(JSContext* cx, JS::HandleObject proxy, JS::HandleValue UNUSED(receiver), JS::HandleId id, JS::MutableHandleValue vp) const
{
	ScriptInterface* pScriptInterface = ScriptInterface::GetScriptInterfaceAndCBData(cx)->pScriptInterface;
	ScriptRequest rq(*pScriptInterface);

	T* e = static_cast<T*>(js::GetProxyPrivate(proxy.get()).toPrivate());
	if (!e)
		return false;

	JS::RootedValue idval(rq.cx);
	if (!JS_IdToValue(rq.cx, id, &idval))
		return false;

	std::string propName;
	if (!ScriptInterface::FromJSVal(rq, idval, propName))
		return false;

	// Return function properties. Specializable.
	if (funcGetter(proxy, propName, vp))
		return true;

	// Use onWhatever to access event handlers
	if (propName.substr(0, 2) == "on")
	{
		CStr eventName(propName.substr(2));
		std::map<CStr, JS::Heap<JSObject*>>::iterator it = e->m_ScriptHandlers.find(eventName);
		if (it == e->m_ScriptHandlers.end())
			vp.setNull();
		else
			vp.setObject(*it->second.get());
		return true;
	}

	if (propName == "parent")
	{
		IGUIObject* parent = e->GetParent();

		if (parent)
			vp.set(JS::ObjectValue(*parent->GetJSObject()));
		else
			vp.set(JS::NullValue());

		return true;
	}
	else if (propName == "children")
	{
		ScriptInterface::CreateArray(rq, vp);

		for (size_t i = 0; i < e->m_Children.size(); ++i)
			pScriptInterface->SetPropertyInt(vp, i, e->m_Children[i]);

		return true;
	}
	else if (propName == "name")
	{
		ScriptInterface::ToJSVal(rq, vp, e->GetName());
		return true;
	}
	else if (e->SettingExists(propName))
	{
		e->m_Settings[propName]->ToJSVal(rq, vp);
		return true;
	}

	LOGERROR("Property '%s' does not exist!", propName.c_str());
	return false;
}


template <typename T>
bool JSI_GUIProxy<T>::set(JSContext* cx, JS::HandleObject proxy, JS::HandleId id, JS::HandleValue vp,
							JS::HandleValue UNUSED(receiver), JS::ObjectOpResult& result) const
{
	T* e = static_cast<T*>(js::GetProxyPrivate(proxy.get()).toPrivate());
	if (!e)
		return result.fail(JSMSG_NOT_NONNULL_OBJECT);

	ScriptRequest rq(*ScriptInterface::GetScriptInterfaceAndCBData(cx)->pScriptInterface);

	JS::RootedValue idval(rq.cx);
	if (!JS_IdToValue(rq.cx, id, &idval))
		return result.fail(JSMSG_NOT_NONNULL_OBJECT);

	std::string propName;
	if (!ScriptInterface::FromJSVal(rq, idval, propName))
		return result.fail(JSMSG_UNDEFINED_PROP);

	if (propName == "name")
	{
		std::string value;
		if (!ScriptInterface::FromJSVal(rq, vp, value))
			return result.fail(JSMSG_UNDEFINED_PROP);
		e->SetName(value);
		return result.succeed();
	}

	JS::RootedObject vpObj(cx);
	if (vp.isObject())
		vpObj = &vp.toObject();

	// Use onWhatever to set event handlers
	if (propName.substr(0, 2) == "on")
	{
		if (vp.isPrimitive() || vp.isNull() || !JS_ObjectIsFunction(rq.cx, &vp.toObject()))
		{
			LOGERROR("on- event-handlers must be functions");
			return result.fail(JSMSG_NOT_FUNCTION);
		}

		CStr eventName(propName.substr(2));
		e->SetScriptHandler(eventName, vpObj);

		return result.succeed();
	}

	if (e->SettingExists(propName))
		return e->m_Settings[propName]->FromJSVal(rq, vp, true) ? result.succeed() : result.fail(JSMSG_USER_DEFINED_ERROR);

	LOGERROR("Property '%s' does not exist!", propName.c_str());
	return result.fail(JSMSG_UNDEFINED_PROP);
}

template<typename T>
bool JSI_GUIProxy<T>::delete_(JSContext* cx, JS::HandleObject proxy, JS::HandleId id, JS::ObjectOpResult& result) const
{
	T* e = static_cast<T*>(js::GetProxyPrivate(proxy.get()).toPrivate());
	if (!e)
		return result.fail(JSMSG_NOT_NONNULL_OBJECT);

	ScriptRequest rq(*ScriptInterface::GetScriptInterfaceAndCBData(cx)->pScriptInterface);

	JS::RootedValue idval(rq.cx);
	if (!JS_IdToValue(rq.cx, id, &idval))
		return result.fail(JSMSG_NOT_NONNULL_OBJECT);

	std::string propName;
	if (!ScriptInterface::FromJSVal(rq, idval, propName))
		return result.fail(JSMSG_UNDEFINED_PROP);

	// event handlers
	if (propName.substr(0, 2) == "on")
	{
		CStr eventName(propName.substr(2));
		e->UnsetScriptHandler(eventName);
		return result.succeed();
	}

	LOGERROR("Only event handlers can be deleted from GUI objects!");
	return result.fail(JSMSG_UNDEFINED_PROP);
}