Reduce duplication in JSI GUI objects implementation.

- Store the functions in an unordered_map. A no-container implementation
is doable but likely not worth the added code complexity, maybe with
C++20
- Move more things into the _impl.h
- Clear out the un-necessary friends declaration in the specific types
by moving the functions to the public interface, which makes sense.
- Fix a memory leak (JS::PersistentRootedObject weren't deleted).

This doesn't change what one needs to do to add a new type, but it does
reduce the actual code that's necessary, and makes it less error prone.

Differential Revision: https://code.wildfiregames.com/D3214
This was SVN commit r24384.

source/gui/CGUI.cpp

@@ -23,6 +23,7 @@
 #include "gui/ObjectTypes/CGUIDummyObject.h"
 #include "gui/ObjectTypes/CTooltip.h"
 #include "gui/Scripting/ScriptFunctions.h"
+#include "gui/Scripting/JSInterface_GUIProxy.h"
 #include "i18n/L10n.h"
 #include "lib/bits.h"
 #include "lib/input.h"

source/gui/CGUI.h

@@ -47,6 +47,7 @@ struct SGUIImageEffects;
 struct SGUIScrollBarStyle;
 
 namespace js { class BaseProxyHandler; }
+class GUIProxyProps;
 
 using map_pObjects = std::map<CStr, IGUIObject*>;
 
@@ -247,7 +248,7 @@ public:
 	 */
 	const CGUIColor& GetPreDefinedColor(const CStr& name) const { return m_PreDefinedColors.at(name); }
 
-	void* GetProxyData(const js::BaseProxyHandler* ptr) { return m_ProxyData.at(ptr); }
+	GUIProxyProps* GetProxyData(const js::BaseProxyHandler* ptr) { return m_ProxyData.at(ptr).get(); }
 
 	shared_ptr<ScriptInterface> GetScriptInterface() { return m_ScriptInterface; };
 
@@ -611,15 +612,16 @@ private:
 	std::map<CStr, ConstructObjectFunction> m_ObjectTypes;
 
 	/**
-	 * This is intended to store the JS Functions returned when accessing some object properties.
+	 * This is intended to store the JSFunction when accessing certain properties.
-	 * It's not a great solution, but I can't find a better one at the moment.
 	 * The problem is that these functions are per-scriptInterface, and proxy handlers aren't.
 	 * So we know what we want to store, but we don't really have anywhere to store it.
 	 * It would be simpler to recreate the functions on every JS call, but that is slower
 	 * (this may or may not matter now and in the future).
-	 * Another alternative would be to store them on each proxied object, but that wastes memory.
+	 * It's not a great solution, but I can't find a better one at the moment.
+	 * An alternative would be to store these on the proxy's prototype,
+	 * but that embarks a lot of un-necessary code.
 	 */
-	std::unordered_map<const js::BaseProxyHandler*, void*> m_ProxyData;
+	std::unordered_map<const js::BaseProxyHandler*, std::unique_ptr<GUIProxyProps>> m_ProxyData;
 
 	/**
 	 * Map from hotkey names to objects that listen to the hotkey.

source/gui/ObjectBases/IGUIObject.cpp

@@ -462,15 +462,8 @@ bool IGUIObject::ScriptEventWithReturn(const CStr& eventName, const JS::HandleVa
 void IGUIObject::CreateJSObject()
 {
 	ScriptRequest rq(m_pGUI.GetScriptInterface());
-
+	using ProxyHandler = JSI_GUIProxy<std::remove_pointer_t<decltype(this)>>;
-	js::ProxyOptions options;
+	ProxyHandler::CreateJSObject(rq, this, GetGUI().GetProxyData(&ProxyHandler::Singleton()), m_JSObject);
-	options.setClass(&JSI_GUIProxy<IGUIObject>::ClassDefinition());
-
-	JS::RootedValue cppObj(rq.cx), data(rq.cx);
-	cppObj.get().setPrivate(this);
-	data.get().setPrivate(GetGUI().GetProxyData(&JSI_GUIProxy<IGUIObject>::Singleton()));
-	m_JSObject.init(rq.cx, js::NewProxyObject(rq.cx, &JSI_GUIProxy<IGUIObject>::Singleton(), cppObj, nullptr, options));
-	js::SetProxyReservedSlot(m_JSObject, 0, data);
 }
 
 JSObject* IGUIObject::GetJSObject()

source/gui/ObjectTypes/CButton.cpp

@@ -119,23 +119,16 @@ const CGUIColor& CButton::ChooseColor()
 	return m_TextColorOver || m_TextColor;
 }
 
-void CButton::CreateJSObject()
-{
-	ScriptRequest rq(m_pGUI.GetScriptInterface());
-
-	js::ProxyOptions options;
-	options.setClass(&JSI_GUIProxy<CButton>::ClassDefinition());
-
-	JS::RootedValue cppObj(rq.cx), data(rq.cx);
-	cppObj.get().setPrivate(this);
-	data.get().setPrivate(GetGUI().GetProxyData(&JSI_GUIProxy<CButton>::Singleton()));
-	m_JSObject.init(rq.cx, js::NewProxyObject(rq.cx, &JSI_GUIProxy<CButton>::Singleton(), cppObj, nullptr, options));
-	js::SetProxyReservedSlot(m_JSObject, 0, data);
-}
-
 void CButton::getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret)
 {
 	ScriptRequest rq(scriptInterface);
 	UpdateText();
 	ScriptInterface::ToJSVal(rq, ret, m_GeneratedTexts[0].GetSize());
 }
+
+void CButton::CreateJSObject()
+{
+	ScriptRequest rq(m_pGUI.GetScriptInterface());
+	using ProxyHandler = JSI_GUIProxy<std::remove_pointer_t<decltype(this)>>;
+	ProxyHandler::CreateJSObject(rq, this, GetGUI().GetProxyData(&ProxyHandler::Singleton()), m_JSObject);
+}

source/gui/ObjectTypes/CButton.h

@@ -27,9 +27,6 @@
 class CButton : public IGUIObject, public IGUITextOwner, public IGUIButtonBehavior
 {
 	GUI_OBJECT(CButton)
-
-	friend JSI_GUIProxy<CButton>;
-
 public:
 	CButton(CGUI& pGUI);
 	virtual ~CButton();
@@ -54,6 +51,11 @@ public:
 	 */
 	virtual void Draw();
 
+	/**
+	 * Populate @param ret with the object's text size.
+	 */
+	void getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret);
+
 protected:
 	/**
 	 * Sets up text, should be called every time changes has been
@@ -73,8 +75,6 @@ protected:
 
 	virtual void CreateJSObject();
 
-	void getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret);
-
 	// Settings
 	float m_BufferZone;
 	i32 m_CellID;

source/gui/ObjectTypes/CList.cpp

@@ -504,14 +504,7 @@ int CList::GetHoveredItem()
 void CList::CreateJSObject()
 {
 	ScriptRequest rq(m_pGUI.GetScriptInterface());
-
+	using ProxyHandler = JSI_GUIProxy<std::remove_pointer_t<decltype(this)>>;
-	js::ProxyOptions options;
+	ProxyHandler::CreateJSObject(rq, this, GetGUI().GetProxyData(&ProxyHandler::Singleton()), m_JSObject);
-	options.setClass(&JSI_GUIProxy<CList>::ClassDefinition());
-
-	JS::RootedValue cppObj(rq.cx), data(rq.cx);
-	cppObj.get().setPrivate(this);
-	data.get().setPrivate(GetGUI().GetProxyData(&JSI_GUIProxy<CList>::Singleton()));
-	m_JSObject.init(rq.cx, js::NewProxyObject(rq.cx, &JSI_GUIProxy<CList>::Singleton(), cppObj, nullptr, options));
-	js::SetProxyReservedSlot(m_JSObject, 0, data);
 }
 

source/gui/ObjectTypes/CList.h

@@ -38,9 +38,6 @@
 class CList : public IGUIObject, public IGUIScrollBarOwner, public IGUITextOwner
 {
 	GUI_OBJECT(CList)
-
-	friend JSI_GUIProxy<CList>;
-
 public:
 	CList(CGUI& pGUI);
 	virtual ~CList();

source/gui/ObjectTypes/CText.cpp

@@ -257,15 +257,8 @@ bool CText::MouseOverIcon()
 void CText::CreateJSObject()
 {
 	ScriptRequest rq(m_pGUI.GetScriptInterface());
-
+	using ProxyHandler = JSI_GUIProxy<std::remove_pointer_t<decltype(this)>>;
-	js::ProxyOptions options;
+	ProxyHandler::CreateJSObject(rq, this, GetGUI().GetProxyData(&ProxyHandler::Singleton()), m_JSObject);
-	options.setClass(&JSI_GUIProxy<CText>::ClassDefinition());
-
-	JS::RootedValue cppObj(rq.cx), data(rq.cx);
-	cppObj.get().setPrivate(this);
-	data.get().setPrivate(GetGUI().GetProxyData(&JSI_GUIProxy<CText>::Singleton()));
-	m_JSObject.init(rq.cx, js::NewProxyObject(rq.cx, &JSI_GUIProxy<CText>::Singleton(), cppObj, nullptr, options));
-	js::SetProxyReservedSlot(m_JSObject, 0, data);
 }
 
 void CText::getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret)

source/gui/ObjectTypes/CText.h

@@ -30,9 +30,6 @@
 class CText : public IGUIObject, public IGUIScrollBarOwner, public IGUITextOwner
 {
 	GUI_OBJECT(CText)
-
-	friend JSI_GUIProxy<CText>;
-
 public:
 	CText(CGUI& pGUI);
 	virtual ~CText();
@@ -52,6 +49,10 @@ public:
 	 */
 	virtual bool MouseOverIcon();
 
+	/**
+	 * Populate @param ret with the object's text size.
+	 */
+	void getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret);
 protected:
 	/**
 	 * Sets up text, should be called every time changes has been
@@ -71,8 +72,6 @@ protected:
 
 	virtual void CreateJSObject();
 
-	void getTextSize(ScriptInterface& scriptInterface, JS::MutableHandleValue ret);
-
 	/**
 	 * Placement of text. Ignored when scrollbars are active.
 	 */

source/gui/Scripting/JSInterface_CButton.cpp

@@ -17,65 +17,22 @@
 
 #include "precompiled.h"
 
-#include "JSInterface_GUIProxy.h"
-
-#include "gui/CGUI.h"
-#include "gui/CGUISetting.h"
-#include "gui/ObjectBases/IGUIObject.h"
-#include "gui/ObjectTypes/CButton.h"
-#include "ps/CLogger.h"
-#include "scriptinterface/ScriptExtraHeaders.h"
-#include "scriptinterface/ScriptInterface.h"
-
-#include <string>
-
-// Include the definition of the generic templates.
 #include "JSInterface_GUIProxy_impl.h"
 
-namespace
+#include "gui/ObjectTypes/CButton.h"
-{
-struct SData
-{
-	JS::PersistentRootedObject m_ToString;
-	JS::PersistentRootedObject m_Focus;
-	JS::PersistentRootedObject m_Blur;
-	JS::PersistentRootedObject m_GetComputedSize;
-	JS::PersistentRootedObject m_GetTextSize;
-};
-}
 
-template <>
+using GUIObjectType = CButton;
-bool JSI_GUIProxy<CButton>::FuncGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const
-{
-	const SData& data = *static_cast<const SData*>(js::GetProxyReservedSlot(proxy, 0).toPrivate());
-	if (propName == "toString")
-		return vp.setObjectOrNull(data.m_ToString), true;
-	if (propName == "focus")
-		return vp.setObjectOrNull(data.m_Focus), true;
-	if (propName == "blur")
-		return vp.setObjectOrNull(data.m_Blur), true;
-	if (propName == "getComputedSize")
-		return vp.setObjectOrNull(data.m_GetComputedSize), true;
-	if (propName == "getTextSize")
-		return vp.setObjectOrNull(data.m_GetTextSize), true;
-	return false;
-}
 
-template <>
+template<>
-std::pair<const js::BaseProxyHandler*, void*> JSI_GUIProxy<CButton>::CreateData(ScriptInterface& scriptInterface)
+void JSI_GUIProxy<GUIObjectType>::CreateFunctions(const ScriptRequest& rq, GUIProxyProps* cache)
 {
-	SData* data = new SData();
+#define func(class, func) &JSInterface_GUIProxy::apply_to<GUIObjectType, class, &class::func>
-	ScriptRequest rq(scriptInterface);
+	cache->setFunction(rq, "toString", func(IGUIObject, toString), 0);
-
+	cache->setFunction(rq, "focus", func(IGUIObject, focus), 0);
-#define func(class, func) &apply_to<CButton, class, &class::func>
+	cache->setFunction(rq, "blur", func(IGUIObject, blur), 0);
-	data->m_ToString.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, toString), 0, 0, "toString")));
+	cache->setFunction(rq, "getComputedSize", func(IGUIObject, getComputedSize), 0);
-	data->m_Focus.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, focus), 0, 0, "focus")));
+	cache->setFunction(rq, "getTextSize", func(GUIObjectType, getTextSize), 0);
-	data->m_Blur.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, blur), 0, 0, "blur")));
-	data->m_GetComputedSize.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, getComputedSize), 0, 0, "getComputedSize")));
-	data->m_GetTextSize.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(CButton, getTextSize), 0, 0, "getTextSize")));
 #undef func
-
-	return { &Singleton(), data };
 }
 
-template class JSI_GUIProxy<CButton>;
+template class JSI_GUIProxy<GUIObjectType>;

source/gui/Scripting/JSInterface_CList.cpp

@@ -17,31 +17,9 @@
 
 #include "precompiled.h"
 
-#include "JSInterface_GUIProxy.h"
-
-#include "gui/CGUI.h"
-#include "gui/CGUISetting.h"
-#include "gui/ObjectBases/IGUIObject.h"
-#include "gui/ObjectTypes/CList.h"
-#include "ps/CLogger.h"
-#include "scriptinterface/ScriptExtraHeaders.h"
-#include "scriptinterface/ScriptInterface.h"
-
-#include <string>
-
-// Include the definition of the generic templates.
 #include "JSInterface_GUIProxy_impl.h"
 
-namespace
+#include "gui/ObjectTypes/CList.h"
-{
-struct SData
-{
-	JS::PersistentRootedObject m_ToString;
-	JS::PersistentRootedObject m_Focus;
-	JS::PersistentRootedObject m_Blur;
-	JS::PersistentRootedObject m_GetComputedSize;
-	JS::PersistentRootedObject m_AddItem;
-};
 
 bool CList_AddItem(JSContext* cx, uint argc, JS::Value* vp)
 {
@@ -58,40 +36,19 @@ bool CList_AddItem(JSContext* cx, uint argc, JS::Value* vp)
 	e->AddItem(text, text);
 	return true;
 }
-}
 
-template <>
+using GUIObjectType = CList;
-bool JSI_GUIProxy<CList>::FuncGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const
+
+template<>
+void JSI_GUIProxy<GUIObjectType>::CreateFunctions(const ScriptRequest& rq, GUIProxyProps* cache)
 {
-	const SData& data = *static_cast<const SData*>(js::GetProxyReservedSlot(proxy, 0).toPrivate());
+#define func(class, func) &JSInterface_GUIProxy::apply_to<GUIObjectType, class, &class::func>
-	if (propName == "toString")
+	cache->setFunction(rq, "toString", func(IGUIObject, toString), 0);
-		return vp.setObjectOrNull(data.m_ToString), true;
+	cache->setFunction(rq, "focus", func(IGUIObject, focus), 0);
-	if (propName == "focus")
+	cache->setFunction(rq, "blur", func(IGUIObject, blur), 0);
-		return vp.setObjectOrNull(data.m_Focus), true;
+	cache->setFunction(rq, "getComputedSize", func(IGUIObject, getComputedSize), 0);
-	if (propName == "blur")
-		return vp.setObjectOrNull(data.m_Blur), true;
-	if (propName == "getComputedSize")
-		return vp.setObjectOrNull(data.m_GetComputedSize), true;
-	if (propName == "addItem")
-		return vp.setObjectOrNull(data.m_AddItem), true;
-	return false;
-}
-
-template <>
-std::pair<const js::BaseProxyHandler*, void*> JSI_GUIProxy<CList>::CreateData(ScriptInterface& scriptInterface)
-{
-	SData* data = new SData();
-	ScriptRequest rq(scriptInterface);
-
-#define func(class, func) &apply_to<CList, class, &class::func>
-	data->m_ToString.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, toString), 0, 0, "toString")));
-	data->m_Focus.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, focus), 0, 0, "focus")));
-	data->m_Blur.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, blur), 0, 0, "blur")));
-	data->m_GetComputedSize.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, getComputedSize), 0, 0, "getComputedSize")));
 #undef func
-	data->m_AddItem.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, CList_AddItem, 1, 0, "addItem")));
+	cache->setFunction(rq, "addItem", CList_AddItem, 1);
-
-	return { &Singleton(), data };
 }
 
-template class JSI_GUIProxy<CList>;
+template class JSI_GUIProxy<GUIObjectType>;

source/gui/Scripting/JSInterface_CText.cpp

@@ -17,65 +17,22 @@
 
 #include "precompiled.h"
 
-#include "JSInterface_GUIProxy.h"
-
-#include "gui/CGUI.h"
-#include "gui/CGUISetting.h"
-#include "gui/ObjectBases/IGUIObject.h"
-#include "gui/ObjectTypes/CText.h"
-#include "ps/CLogger.h"
-#include "scriptinterface/ScriptExtraHeaders.h"
-#include "scriptinterface/ScriptInterface.h"
-
-#include <string>
-
-// Include the definition of the generic templates.
 #include "JSInterface_GUIProxy_impl.h"
 
-namespace
+#include "gui/ObjectTypes/CText.h"
-{
-struct SData
-{
-	JS::PersistentRootedObject m_ToString;
-	JS::PersistentRootedObject m_Focus;
-	JS::PersistentRootedObject m_Blur;
-	JS::PersistentRootedObject m_GetComputedSize;
-	JS::PersistentRootedObject m_GetTextSize;
-};
-}
 
-template <>
+using GUIObjectType = CText;
-bool JSI_GUIProxy<CText>::FuncGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const
-{
-	const SData& data = *static_cast<const SData*>(js::GetProxyReservedSlot(proxy, 0).toPrivate());
-	if (propName == "toString")
-		return vp.setObjectOrNull(data.m_ToString), true;
-	if (propName == "focus")
-		return vp.setObjectOrNull(data.m_Focus), true;
-	if (propName == "blur")
-		return vp.setObjectOrNull(data.m_Blur), true;
-	if (propName == "getComputedSize")
-		return vp.setObjectOrNull(data.m_GetComputedSize), true;
-	if (propName == "getTextSize")
-		return vp.setObjectOrNull(data.m_GetTextSize), true;
-	return false;
-}
 
-template <>
+template<>
-std::pair<const js::BaseProxyHandler*, void*> JSI_GUIProxy<CText>::CreateData(ScriptInterface& scriptInterface)
+void JSI_GUIProxy<GUIObjectType>::CreateFunctions(const ScriptRequest& rq, GUIProxyProps* cache)
 {
-	SData* data = new SData();
+#define func(class, func) &JSInterface_GUIProxy::apply_to<GUIObjectType, class, &class::func>
-	ScriptRequest rq(scriptInterface);
+	cache->setFunction(rq, "toString", func(IGUIObject, toString), 0);
-
+	cache->setFunction(rq, "focus", func(IGUIObject, focus), 0);
-#define func(class, func) &apply_to<CText, class, &class::func>
+	cache->setFunction(rq, "blur", func(IGUIObject, blur), 0);
-	data->m_ToString.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, toString), 0, 0, "toString")));
+	cache->setFunction(rq, "getComputedSize", func(IGUIObject, getComputedSize), 0);
-	data->m_Focus.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, focus), 0, 0, "focus")));
+	cache->setFunction(rq, "getTextSize", func(GUIObjectType, getTextSize), 0);
-	data->m_Blur.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, blur), 0, 0, "blur")));
-	data->m_GetComputedSize.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, getComputedSize), 0, 0, "getComputedSize")));
-	data->m_GetTextSize.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(CText, getTextSize), 0, 0, "getTextSize")));
 #undef func
-
-	return { &Singleton(), data };
 }
 
-template class JSI_GUIProxy<CText>;
+template class JSI_GUIProxy<GUIObjectType>;

source/gui/Scripting/JSInterface_GUIProxy.h

@@ -23,6 +23,7 @@
 #include <utility>
 
 class ScriptInterface;
+class ScriptRequest;
 
 // See JSI_GuiProxy below
 #if GCC_VERSION
@@ -33,6 +34,22 @@ class ScriptInterface;
 # pragma warning(disable: 4265)
 #endif
 
+/**
+ * Proxies need to store some data whose lifetime is tied to an interface.
+ * This is the virtual interface of that data.
+ */
+class GUIProxyProps
+{
+public:
+	virtual ~GUIProxyProps() {};
+
+	// @return true if @param name exists in this cache.
+	virtual bool has(const std::string& name) const = 0;
+	// @return the JSFunction matching @param name. Must call has() first as it can assume existence.
+	virtual JSObject* get(const std::string& name) const = 0;
+	virtual bool setFunction(const ScriptRequest& rq, const std::string& name, JSNative function, int nargs) = 0;
+};
+
 /**
  * Handles the js interface with C++ GUI objects.
  * Proxy handlers must live for at least as long as the JS runtime
@@ -43,6 +60,17 @@ class ScriptInterface;
  * 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.
+ *
+ * Proxies can be used with prototypes and almost treated like regular JS objects.
+ * However, the default implementation embarks a lot of code that we don't really need here,
+ * since the only fanciness is that we cache JSFunction* properties.
+ * As such, these GUI proxies don't have one and instead override get/set directly.
+ *
+ * To add a new JSI_GUIProxy, you'll need to:
+ *  - overload the GUI Object's CreateJSObject with the correct types and pointers
+ *  - change the CGUI::AddObjectTypes method
+ *  - explicitly instantiate the template.
+ *
  */
 template<typename GUIObjectType>
 class JSI_GUIProxy : public js::BaseProxyHandler
@@ -54,17 +82,27 @@ public:
 	// For convenience, this is the single instantiated JSI_GUIProxy.
 	static JSI_GUIProxy& Singleton();
 
-	static std::pair<const js::BaseProxyHandler*, void*> CreateData(ScriptInterface& scriptInterface);
+	// Call this in CGUI::AddObjectTypes.
+	static std::pair<const js::BaseProxyHandler*, GUIProxyProps*> CreateData(ScriptInterface& scriptInterface);
+
+	static void CreateJSObject(const ScriptRequest& rq, GUIObjectType* ptr, GUIProxyProps* data, JS::PersistentRootedObject& val);
 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.
+	// The default implementations need to know the type of the GUIProxyProps for this proxy type.
-	// Specialize this.
+	// This is done by specializing this struct's alias type.
-	bool FuncGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const;
+	struct PropCache;
+
+	// Specialize this to define the custom properties of this type.
+	static void CreateFunctions(const ScriptRequest& rq, GUIProxyProps* cache);
+
+	// This handles returning custom properties. Specialize this if needed.
+	bool PropGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const;
 protected:
 	// BaseProxyHandler interface below
 

source/gui/Scripting/JSInterface_GUIProxy_impl.h

@@ -17,6 +17,17 @@
 
 // This file is included directly into actual implementation files.
 
+#include "JSInterface_GUIProxy.h"
+
+#include "gui/CGUI.h"
+#include "gui/CGUISetting.h"
+#include "gui/ObjectBases/IGUIObject.h"
+#include "ps/CLogger.h"
+#include "scriptinterface/ScriptExtraHeaders.h"
+#include "scriptinterface/ScriptInterface.h"
+
+#include <string>
+
 template <typename T>
 JSClass& JSI_GUIProxy<T>::ClassDefinition()
 {
@@ -31,8 +42,12 @@ JSI_GUIProxy<T>& JSI_GUIProxy<T>::Singleton()
 	return s;
 }
 
-namespace
+// Use a common namespace to avoid duplicating the symbols un-necessarily.
+namespace JSInterface_GUIProxy
 {
+/**
+ * Conveniently wrap a simple C++ function to a JSNative.
+ */
 template<class OG, class R, void (R::*funcptr)(ScriptInterface&, JS::MutableHandleValue)>
 inline bool apply_to(JSContext* cx, uint argc, JS::Value* vp)
 {
@@ -45,6 +60,76 @@ inline bool apply_to(JSContext* cx, uint argc, JS::Value* vp)
 
 	return true;
 }
+
+// Default implementation of the cache via unordered_map
+class MapCache : public GUIProxyProps
+{
+public:
+	virtual ~MapCache() {};
+
+	virtual bool has(const std::string& name) const override
+	{
+		return m_Functions.find(name) != m_Functions.end();
+	}
+
+	virtual JSObject* get(const std::string& name) const override
+	{
+		return m_Functions.at(name).get();
+	}
+
+	virtual bool setFunction(const ScriptRequest& rq, const std::string& name, JSNative function, int nargs) override
+	{
+		m_Functions[name].init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, function, nargs, 0, name.c_str())));
+		return true;
+	}
+
+protected:
+	std::unordered_map<std::string, JS::PersistentRootedObject> m_Functions;
+};
+}
+
+// The default propcache is a MapCache.
+template<typename T>
+struct JSI_GUIProxy<T>::PropCache
+{
+	using type = JSInterface_GUIProxy::MapCache;
+};
+
+template <typename T>
+bool JSI_GUIProxy<T>::PropGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const
+{
+	using PropertyCache = typename PropCache::type;
+	// Since we know at compile time what the type actually is, avoid the virtual call.
+	const PropertyCache* data = static_cast<const PropertyCache*>(static_cast<const GUIProxyProps*>(js::GetProxyReservedSlot(proxy, 0).toPrivate()));
+	if (data->has(propName))
+	{
+		vp.setObjectOrNull(data->get(propName));
+		return true;
+	}
+	return false;
+}
+
+template <typename T>
+std::pair<const js::BaseProxyHandler*, GUIProxyProps*> JSI_GUIProxy<T>::CreateData(ScriptInterface& scriptInterface)
+{
+	using PropertyCache = typename PropCache::type;
+	PropertyCache* data = new PropertyCache();
+	ScriptRequest rq(scriptInterface);
+	CreateFunctions(rq, data);
+	return { &Singleton(), data };
+}
+
+template<typename T>
+void JSI_GUIProxy<T>::CreateJSObject(const ScriptRequest& rq, T* ptr, GUIProxyProps* dataPtr, JS::PersistentRootedObject& val)
+{
+	js::ProxyOptions options;
+	options.setClass(&ClassDefinition());
+
+	JS::RootedValue cppObj(rq.cx), data(rq.cx);
+	cppObj.get().setPrivate(ptr);
+	data.get().setPrivate(static_cast<void*>(dataPtr));
+	val.init(rq.cx, js::NewProxyObject(rq.cx, &Singleton(), cppObj, nullptr, options));
+	js::SetProxyReservedSlot(val, 0, data);
 }
 
 template <typename T>
@@ -66,7 +151,7 @@ bool JSI_GUIProxy<T>::get(JSContext* cx, JS::HandleObject proxy, JS::HandleValue
 		return false;
 
 	// Return function properties. Specializable.
-	if (FuncGetter(proxy, propName, vp))
+	if (PropGetter(proxy, propName, vp))
 		return true;
 
 	// Use onWhatever to access event handlers

source/gui/Scripting/JSInterface_IGUIObject.cpp

@@ -17,59 +17,19 @@
 
 #include "precompiled.h"
 
-#include "JSInterface_GUIProxy.h"
-
-#include "gui/CGUI.h"
-#include "gui/CGUISetting.h"
-#include "gui/ObjectBases/IGUIObject.h"
-#include "gui/ObjectTypes/CText.h"
-#include "ps/CLogger.h"
-#include "scriptinterface/ScriptExtraHeaders.h"
-#include "scriptinterface/ScriptInterface.h"
-
-#include <string>
-
-// Include the definition of the generic templates.
 #include "JSInterface_GUIProxy_impl.h"
 
-namespace
+using GUIObjectType = IGUIObject;
-{
-struct SData
-{
-	JS::PersistentRootedObject m_ToString;
-	JS::PersistentRootedObject m_Focus;
-	JS::PersistentRootedObject m_Blur;
-	JS::PersistentRootedObject m_GetComputedSize;
-};
-}
 
-template <>
+template<>
-bool JSI_GUIProxy<IGUIObject>::FuncGetter(JS::HandleObject proxy, const std::string& propName, JS::MutableHandleValue vp) const
+void JSI_GUIProxy<GUIObjectType>::CreateFunctions(const ScriptRequest& rq, GUIProxyProps* cache)
 {
-	const SData& data = *static_cast<const SData*>(js::GetProxyReservedSlot(proxy, 0).toPrivate());
+#define func(class, func) &JSInterface_GUIProxy::apply_to<GUIObjectType, class, &class::func>
-	if (propName == "toString")
+	cache->setFunction(rq, "toString", func(IGUIObject, toString), 0);
-		return vp.setObjectOrNull(data.m_ToString), true;
+	cache->setFunction(rq, "focus", func(IGUIObject, focus), 0);
-	if (propName == "focus")
+	cache->setFunction(rq, "blur", func(IGUIObject, blur), 0);
-		return vp.setObjectOrNull(data.m_Focus), true;
+	cache->setFunction(rq, "getComputedSize", func(IGUIObject, getComputedSize), 0);
-	if (propName == "blur")
-		return vp.setObjectOrNull(data.m_Blur), true;
-	if (propName == "getComputedSize")
-		return vp.setObjectOrNull(data.m_GetComputedSize), true;
-	return false;
-}
-
-template <>
-std::pair<const js::BaseProxyHandler*, void*> JSI_GUIProxy<IGUIObject>::CreateData(ScriptInterface& scriptInterface)
-{
-	SData* data = new SData();
-	ScriptRequest rq(scriptInterface);
-#define func(class, func) &apply_to<IGUIObject, class, &class::func>
-	data->m_ToString.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, toString), 0, 0, "toString")));
-	data->m_Focus.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, focus), 0, 0, "focus")));
-	data->m_Blur.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, blur), 0, 0, "blur")));
-	data->m_GetComputedSize.init(rq.cx, JS_GetFunctionObject(JS_NewFunction(rq.cx, func(IGUIObject, getComputedSize), 0, 0, "getComputedSize")));
 #undef func
-	return { &Singleton(), data };
 }
 
-template class JSI_GUIProxy<IGUIObject>;
+template class JSI_GUIProxy<GUIObjectType>;