Differential D2768 Diff 14088 source/gui/Scripting/JSInterface_GUIProxy.h

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source/gui/Scripting/JSInterface_GUIProxy.h

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				/* Copyright (C) 2019 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/>.
				*/

				#ifndef INCLUDED_JSI_GUIPROXY
				#define INCLUDED_JSI_GUIPROXY

				StanUnsubmitted Done Inline Actions Shouldn't that match the file name? Stan: Shouldn't that match the file name?
				#include "scriptinterface/ScriptExtraHeaders.h"

				StanUnsubmitted Not Done Inline Actions Typo. Stan: Typo.
				#include <utility>

				class ScriptInterface;

				/**
				* Handles the js interface with C++ GUI objects.
				* Proxy handlers must live for at least as long as the JS runtime
				* where a proxy object with that handler was created. The reason is that
				* proxy handlers are called during GC, such as on runtime destruction.
				* In practical terms, this means "just keep them static and store no data".
				*
				* GUI Objects only exist in C++ and have no JS-only properties.
				* As such, there is no "target" JS object that this proxy could point to,
				* and thus we should inherit from BaseProxyHandler and not js::Wrapper.
				*/
				template<typename GUIObjectType>
				class JSI_GUIProxy : public js::BaseProxyHandler
				{
				public:
				// Access the js::Class of the Proxy.
				static js::Class& ClassDefinition();

				// For convenience, this is the single instantiated JSI_GUIProxy.
				static JSI_GUIProxy& Singleton();

				StanUnsubmitted Done Inline Actions #include <utility> Stan: ```lang=cpp #include <utility> ```
				static std::pair<const js::BaseProxyHandler, void> CreateData(ScriptInterface& scriptInterface);
				protected:
				// @param family can't be nullptr because that's used for some DOM object and it crashes.
				JSI_GUIProxy() : BaseProxyHandler(this, false, false) {};
				// Note: SM provides no virtual destructor for baseProxyHandler.
				// This also enforces making proxy handlers dataless static variables.
				~JSI_GUIProxy() {};

				// This handles returning function properties.
				// Specialize this.
				bool funcGetter(GUIObjectType* elem, const std::string& propName, JS::MutableHandleValue vp) const;
				protected:
				// BaseProxyHandler interface below

				// Handler for `object.x`
				virtual bool get(JSContext* cx, JS::HandleObject proxy, JS::HandleValue receiver, JS::HandleId id, JS::MutableHandleValue vp) const override final;
				// Handler for `object.x = y;`
				virtual bool set(JSContext* cx, JS::HandleObject proxy, JS::HandleId id, JS::HandleValue vp,
				JS::HandleValue receiver, JS::ObjectOpResult& result) const final;
				// Handler for `delete object.x;`
				virtual bool delete_(JSContext* cx, JS::HandleObject proxy, JS::HandleId id, JS::ObjectOpResult& result) const override final;

				// The following methods are not provided by BaseProxyHandler.
				// We provide defaults that do nothing (some raise JS exceptions).

				// The JS code will see undefined when querying a property descriptor.
				virtual bool getOwnPropertyDescriptor(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), JS::HandleId UNUSED(id),
				JS::MutableHandle<JS::PropertyDescriptor> UNUSED(desc)) const override
				{
				return true;
				}
				// Throw an exception is JS code attempts defining a property.
				virtual bool defineProperty(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), JS::HandleId UNUSED(id),
				JS::Handle<JS::PropertyDescriptor> UNUSED(desc), JS::ObjectOpResult& UNUSED(result)) const override
				{
				return false;
				}
				// Return nothing.
				virtual bool ownPropertyKeys(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), JS::AutoIdVector& UNUSED(props)) const override
				{
				return true;
				}
				// Return nothing.
				virtual bool enumerate(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), JS::MutableHandleObject UNUSED(objp)) const override
				{
				return true;
				}
				// Throw an exception is JS attempts to query the prototype.
				virtual bool getPrototypeIfOrdinary(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), bool* UNUSED(isOrdinary), JS::MutableHandleObject UNUSED(protop)) const override
				{
				return false;
				}
				// Throw an exception - no prototype to set.
				virtual bool setImmutablePrototype(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), bool* UNUSED(succeeded)) const override
				{
				return false;
				}
				// We are not extensible.
				virtual bool preventExtensions(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), JS::ObjectOpResult& UNUSED(result)) const override
				{
				return true;
				}
				virtual bool isExtensible(JSContext* UNUSED(cx), JS::HandleObject UNUSED(proxy), bool* extensible) const override
				{
				*extensible = false;
				return true;
				}
				};

				#endif // INCLUDED_JSI_GUIPROXY