Support deleting GUI Object event handlers following af9c336b43, refs #5387.

Differential Revision: https://code.wildfiregames.com/D2395
Reported by: nani
Tested on: gcc 9.2.0, Jenkins/vs2015

This was SVN commit r23103.

binaries/data/mods/public/gui/pregame/MainMenuItemHandler.js

@@ -19,7 +19,6 @@ class MainMenuItemHandler
 		this.setupMenuButtons(this.mainMenuButtons.children, this.menuItems);
 		this.setupHotkeys(this.menuItems);
 
-		this.mainMenu.onTick = this.onTick.bind(this);
 		Engine.GetGUIObjectByName("closeMenuButton").onPress = this.closeSubmenu.bind(this);
 	}
 
@@ -93,6 +92,10 @@ class MainMenuItemHandler
 			size.top = this.submenu.size.bottom;
 			this.MainMenuPanelRightBorderBottom.size = size;
 		}
+
+		// Start animation
+		this.lastTickTime = Date.now();
+		this.mainMenu.onTick = this.onTick.bind(this);
 	}
 
 	closeSubmenu()
@@ -110,14 +113,19 @@ class MainMenuItemHandler
 	onTick()
 	{
 		let now = Date.now();
+		if (now == this.lastTickTime)
+			return;
 
 		let maxOffset = this.mainMenu.size.right - this.submenu.size.left;
 		let offset = Math.min(this.MenuSpeed * (now - this.lastTickTime), maxOffset);
 
 		this.lastTickTime = now;
 
-		if (this.submenu.hidden || offset <= 0)
+		if (this.submenu.hidden || !offset)
+		{
+			delete this.mainMenu.onTick;
 			return;
+		}
 
 		let size = this.submenu.size;
 		size.left += offset;

binaries/data/mods/public/gui/pregame/SplashscreenHandler.js

@@ -23,8 +23,7 @@ class SplashScreenHandler
 		if (this.showSplashScreen)
 			this.openPage();
 
-		// TODO: support actually deleting the handler
-		this.mainMenuPage.onTick = () => {};
+		delete this.mainMenuPage.onTick;
 	}
 
 	openPage()

binaries/data/mods/public/gui/session/Menu.js

@@ -101,8 +101,7 @@ class Menu
 
 		if (maxOffset <= 0)
 		{
-			// TODO: support actually deleting the handler
-			this.menuButtonPanel.onTick = () => {};
+			delete this.menuButtonPanel.onTick;
 			return;
 		}
 

source/gui/ObjectBases/IGUIObject.cpp

@@ -334,6 +334,19 @@ void IGUIObject::SetScriptHandler(const CStr& Action, JS::HandleObject Function)
 	m_ScriptHandlers[Action] = JS::Heap<JSObject*>(Function);
 }
 
+void IGUIObject::UnsetScriptHandler(const CStr& Action)
+{
+	std::map<CStr, JS::Heap<JSObject*> >::iterator it = m_ScriptHandlers.find(Action);
+
+	if (it == m_ScriptHandlers.end())
+		return;
+
+	m_ScriptHandlers.erase(it);
+
+	if (m_ScriptHandlers.empty())
+		JS_RemoveExtraGCRootsTracer(m_pGUI.GetScriptInterface()->GetJSRuntime(), Trace, this);
+}
+
 InReaction IGUIObject::SendEvent(EGUIMessageType type, const CStr& EventName)
 {
 	PROFILE2_EVENT("gui event");

source/gui/ObjectBases/IGUIObject.h

@@ -57,6 +57,7 @@ class IGUIObject
 	// Allow getProperty to access things like GetParent()
 	friend bool JSI_IGUIObject::getProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::MutableHandleValue vp);
 	friend bool JSI_IGUIObject::setProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::MutableHandleValue vp, JS::ObjectOpResult& result);
+	friend bool JSI_IGUIObject::deleteProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::ObjectOpResult& result);
 	friend bool JSI_IGUIObject::getComputedSize(JSContext* cx, uint argc, JS::Value* vp);
 
 public:
@@ -385,8 +386,16 @@ protected:
 	 */
 	void ScriptEvent(const CStr& Action, const JS::HandleValueArray& paramData);
 
+	/**
+	 * Assigns a JS function to the event name.
+	 */
 	void SetScriptHandler(const CStr& Action, JS::HandleObject Function);
 
+	/**
+	 * Deletes an event handler assigned to the given name, if such a handler exists.
+	 */
+	void UnsetScriptHandler(const CStr& Action);
+
 	/**
 	 * Inputes the object that is currently hovered, this function
 	 * updates this object accordingly (i.e. if it's the object

source/gui/Scripting/JSInterface_IGUIObject.cpp

@@ -27,8 +27,10 @@
 
 JSClass JSI_IGUIObject::JSI_class = {
 	"GUIObject", JSCLASS_HAS_PRIVATE,
-	nullptr, nullptr,
-	JSI_IGUIObject::getProperty, JSI_IGUIObject::setProperty,
+	nullptr,
+	JSI_IGUIObject::deleteProperty,
+	JSI_IGUIObject::getProperty,
+	JSI_IGUIObject::setProperty,
 	nullptr, nullptr, nullptr, nullptr,
 	nullptr, nullptr, nullptr, nullptr
 };
@@ -174,6 +176,33 @@ bool JSI_IGUIObject::setProperty(JSContext* cx, JS::HandleObject obj, JS::Handle
 	return result.fail(JSMSG_UNDEFINED_PROP);
 }
 
+bool JSI_IGUIObject::deleteProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::ObjectOpResult& result)
+{
+	IGUIObject* e = ScriptInterface::GetPrivate<IGUIObject>(cx, obj, &JSI_IGUIObject::JSI_class);
+	if (!e)
+		return result.fail(JSMSG_NOT_NONNULL_OBJECT);
+
+	JSAutoRequest rq(cx);
+	JS::RootedValue idval(cx);
+	if (!JS_IdToValue(cx, id, &idval))
+		return result.fail(JSMSG_NOT_NONNULL_OBJECT);
+
+	std::string propName;
+	if (!ScriptInterface::FromJSVal(cx, idval, propName))
+		return result.fail(JSMSG_UNDEFINED_PROP);
+
+	// event handlers
+	if (propName.substr(0, 2) == "on")
+	{
+		CStr eventName(CStr(propName.substr(2)).LowerCase());
+		e->UnsetScriptHandler(eventName);
+		return result.succeed();
+	}
+
+	JS_ReportError(cx, "Only event handlers can be deleted from GUI objects!");
+	return result.fail(JSMSG_UNDEFINED_PROP);
+}
+
 bool JSI_IGUIObject::toString(JSContext* cx, uint argc, JS::Value* vp)
 {
 	// No JSAutoRequest needed for these calls

source/gui/Scripting/JSInterface_IGUIObject.h

@@ -29,6 +29,7 @@ namespace JSI_IGUIObject
 
 	bool getProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::MutableHandleValue vp);
 	bool setProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::MutableHandleValue vp, JS::ObjectOpResult& result);
+	bool deleteProperty(JSContext* cx, JS::HandleObject obj, JS::HandleId id, JS::ObjectOpResult& result);
 	bool toString(JSContext* cx, uint argc, JS::Value* vp);
 	bool focus(JSContext* cx, uint argc, JS::Value* vp);
 	bool blur(JSContext* cx, uint argc, JS::Value* vp);