From a8ba10d07417816967bf6174e782ee0d6beac6c0 Mon Sep 17 00:00:00 2001
From: Sebastian <sebastian.e.gross@gmail.com>
Date: Sun, 25 Nov 2018 21:26:06 +0000
Subject: [PATCH] Added code that moves module properties to hot-reloaded
 modules.

---
 Source/ImGui/Private/ImGuiModule.cpp | 19 ++++++++++++++++++-
 Source/ImGui/Public/ImGuiModule.h    |  1 +
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/Source/ImGui/Private/ImGuiModule.cpp b/Source/ImGui/Private/ImGuiModule.cpp
index 63bb1ab..c1cba99 100644
--- a/Source/ImGui/Private/ImGuiModule.cpp
+++ b/Source/ImGui/Private/ImGuiModule.cpp
@@ -130,6 +130,12 @@ void FImGuiModule::StartupModule()
 
 void FImGuiModule::ShutdownModule()
 {
+	// In editor store data that we want to move to hot-reloaded module.
+
+#if WITH_EDITOR
+	TOptional<FImGuiModuleProperties> PropertiesToMove = ImGuiModuleManager->GetProperties();
+#endif
+
 	// Before we shutdown we need to delete managers that will do all the necessary cleanup.
 
 #if WITH_EDITOR
@@ -147,7 +153,7 @@ void FImGuiModule::ShutdownModule()
 	// deleted. This can cause troubles after hot-reload when code in other modules calls ImGui interface functions
 	// which are statically bound to the obsolete module. To keep ImGui code functional we can redirect context handle
 	// to point to the new module.
-	FModuleManager::Get().OnModulesChanged().AddLambda([this](FName Name, EModuleChangeReason Reason)
+	FModuleManager::Get().OnModulesChanged().AddLambda([this, PropertiesToMove] (FName Name, EModuleChangeReason Reason) mutable
 	{
 		if (Reason == EModuleChangeReason::ModuleLoaded && Name == "ImGui")
 		{
@@ -155,6 +161,12 @@ void FImGuiModule::ShutdownModule()
 			if (&LoadedModule != this)
 			{
 				ImGuiImplementation::SetImGuiContextHandle(LoadedModule.GetImGuiContextHandle());
+
+				if (PropertiesToMove.IsSet())
+				{
+					LoadedModule.SetProperties(PropertiesToMove.GetValue());
+					PropertiesToMove.Reset();
+				}
 			}
 		}
 	});
@@ -162,6 +174,11 @@ void FImGuiModule::ShutdownModule()
 }
 
 #if WITH_EDITOR
+void FImGuiModule::SetProperties(const FImGuiModuleProperties& Properties)
+{
+	ImGuiModuleManager->GetProperties() = Properties;
+}
+
 ImGuiContext** FImGuiModule::GetImGuiContextHandle()
 {
 	return ImGuiImplementation::GetImGuiContextHandle();
diff --git a/Source/ImGui/Public/ImGuiModule.h b/Source/ImGui/Public/ImGuiModule.h
index 1a261ca..10b8adb 100644
--- a/Source/ImGui/Public/ImGuiModule.h
+++ b/Source/ImGui/Public/ImGuiModule.h
@@ -148,6 +148,7 @@ public:
 	private:
 
 #if WITH_EDITOR
+	virtual void SetProperties(const class FImGuiModuleProperties& Properties);
 	virtual struct ImGuiContext** GetImGuiContextHandle();
 #endif
 };