Make sure important data is synchronized between ImHex and plugins

plugins/libimhex/include/helpers/shared_data.hpp

@@ -0,0 +1,71 @@
+#pragma once
+
+#include <functional>
+#include <vector>
+
+#include <helpers/event.hpp>
+#include <imgui.h>
+
+namespace hex { class SharedData; }
+
+namespace hex::plugin::internal {
+    void initializePlugin(SharedData &sharedData);
+}
+
+namespace hex {
+
+    namespace prv { class Provider; }
+
+    class SharedData {
+        SharedData() = default;
+    public:
+        SharedData(const SharedData&) = delete;
+        SharedData(SharedData&&) = delete;
+
+        static auto& get() {
+            static SharedData instance;
+
+            return instance;
+        }
+
+        friend void hex::plugin::internal::initializePlugin(SharedData &sharedData);
+        friend class Window;
+
+    private:
+
+        void initializeData() {
+            static std::vector<EventHandler> eventHandlersStorage;
+            static std::vector<std::function<void()>> deferredCallsStorage;
+            static prv::Provider *currentProviderStorage;
+            static ImVec2 windowPosStorage, windowSizeStorage;
+
+            this->imguiContext      = ImGui::GetCurrentContext();
+            this->eventHandlers     = &eventHandlersStorage;
+            this->deferredCalls     = &deferredCallsStorage;
+            this->currentProvider   = &currentProviderStorage;
+
+            this->windowPos         = &windowPosStorage;
+            this->windowSize        = &windowSizeStorage;
+        }
+
+        void initializeData(const SharedData &other) {
+            this->imguiContext      = other.imguiContext;
+            this->eventHandlers     = other.eventHandlers;
+            this->deferredCalls     = other.deferredCalls;
+            this->currentProvider   = other.currentProvider;
+
+            this->windowPos         = other.windowPos;
+            this->windowSize        = other.windowSize;
+        }
+
+    public:
+        ImGuiContext *imguiContext;
+        std::vector<EventHandler> *eventHandlers;
+        std::vector<std::function<void()>> *deferredCalls;
+        prv::Provider **currentProvider;
+
+        ImVec2 *windowPos;
+        ImVec2 *windowSize;
+    };
+
+}