1 files changed, 93 insertions, 0 deletions
diff --git a/src/states.h b/src/states.h
new file mode 100644
index 0000000..57898a6
--- /dev/null
+++ b/src/states.h
@@ -0,0 +1,93 @@
+#ifndef STATES_H
+#define STATES_H
+
+#include <SFML/Graphics.hpp>
+#include <functional>
+#include "states/ids.h"
+#include "resourceManager.h"
+#include "resourceIds.h"
+
+class StateStack;
+
+class State {
+    public:
+        using Ptr = std::unique_ptr<State>;
+
+        struct Context{
+            sf::RenderWindow *window;
+            TextureManager *textures;
+            // add IO controller
+        };
+        State(StateStack &stack, State::Context context);
+        virtual void update(sf::Time dt) =0;
+        virtual void render() =0;
+        virtual void handleEvent(const sf::Event &event) =0;
+
+    protected:
+        void requestPush(States::Id state_id);
+        void requestPop();
+        void requestClear();
+
+        Context context_;
+        StateStack *stack_;
+};
+
+class StateStack{
+    public:
+        enum class OpId{
+            Push,
+            Pop,
+            Clear
+        };
+
+        struct Op{
+            Op(OpId op_id, States::Id state_id = States::None)
+                : id(op_id)
+                , state(state_id){}
+            OpId id;
+            States::Id state;
+        };
+
+    private:
+        std::vector<Op> pendingOps_;
+        std::vector<State::Ptr> states_;
+        std::map<States::Id, std::function<State::Ptr()>> stateFactory_;
+
+        State::Context context_;
+
+    public:
+        StateStack(State::Context context);
+
+        void update(sf::Time dt);
+        void render();
+        void handleEvent(const sf::Event &event);
+
+        void requestOp(Op op);
+
+        void push(States::Id state_id);
+        void pop();
+        void clear();
+
+        void applyPending();
+
+        bool isEmpty() const;
+
+        template<typename T>
+        void registerState(States::Id id);
+
+
+        State::Ptr createState(States::Id id);
+};
+
+
+template<typename T>
+void StateStack::registerState(States::Id id){
+    static_assert(std::is_base_of<State, T>::value,
+      "StateStack: attempting to registerState something that is not a State");
+    stateFactory_[id] = [this] ()
+    {
+        return State::Ptr(new T(*this, context_));
+    };
+}
+
+#endif // STATES_H