From f5e5e8522b94a6b81a137d4bca7665ef15bcd2c6 Mon Sep 17 00:00:00 2001
From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Tue, 11 Aug 2015 10:06:11 +0200
Subject: [PATCH] enhanced application state control

---
 src/app/State.hpp       | 12 ++++++++++++
 src/app/UnloadState.cpp |  8 ++++++++
 src/app/UnloadState.hpp |  6 ++++--
 src/app/WorldState.cpp  | 13 +++++++++----
 src/app/WorldState.hpp  |  7 +++++++
 src/app/app.cpp         | 23 +++++++++++++++++++++++
 src/app/runtime.cpp     |  4 ----
 7 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/src/app/State.hpp b/src/app/State.hpp
index 2bdd41b..86ff0ad 100644
--- a/src/app/State.hpp
+++ b/src/app/State.hpp
@@ -6,16 +6,28 @@
 
 namespace blank {
 
+class Application;
 class Viewport;
 
 struct State {
 
+	friend class Application;
+
 	virtual void Handle(const SDL_Event &) = 0;
 
 	virtual void Update(int dt) = 0;
 
 	virtual void Render(Viewport &) = 0;
 
+
+private:
+	int ref_count = 0;
+
+	virtual void OnEnter() { }
+	virtual void OnResume() { }
+	virtual void OnPause() { }
+	virtual void OnExit() { }
+
 };
 
 };
diff --git a/src/app/UnloadState.cpp b/src/app/UnloadState.cpp
index 49801bf..9da6989 100644
--- a/src/app/UnloadState.cpp
+++ b/src/app/UnloadState.cpp
@@ -22,6 +22,14 @@ UnloadState::UnloadState(Environment &env, ChunkLoader &loader)
 }
 
 
+void UnloadState::OnResume() {
+	cur = loader.Loaded().begin();
+	end = loader.Loaded().end();
+	done = 0;
+	total = loader.Loaded().size();
+}
+
+
 void UnloadState::Handle(const SDL_Event &) {
 	// ignore everything
 }
diff --git a/src/app/UnloadState.hpp b/src/app/UnloadState.hpp
index 56394bb..6d5cea7 100644
--- a/src/app/UnloadState.hpp
+++ b/src/app/UnloadState.hpp
@@ -1,5 +1,5 @@
-#ifndef BLANK_APP_PRELOADSTATE_HPP_
-#define BLANK_APP_PRELOADSTATE_HPP_
+#ifndef BLANK_APP_UNLOADSTATE_HPP_
+#define BLANK_APP_UNLOADSTATE_HPP_
 
 #include "State.hpp"
 
@@ -22,6 +22,8 @@ class UnloadState
 public:
 	UnloadState(Environment &, ChunkLoader &);
 
+	void OnResume();
+
 	void Handle(const SDL_Event &) override;
 	void Update(int dt) override;
 	void Render(Viewport &) override;
diff --git a/src/app/WorldState.cpp b/src/app/WorldState.cpp
index 86e3eac..372b659 100644
--- a/src/app/WorldState.cpp
+++ b/src/app/WorldState.cpp
@@ -1,7 +1,6 @@
 #include "WorldState.hpp"
 
 #include "Environment.hpp"
-#include "UnloadState.hpp"
 
 #include <SDL.h>
 
@@ -17,11 +16,18 @@ WorldState::WorldState(
 : env(env)
 , world(env.assets, wc, save)
 , spawner(world)
-, interface(ic, env, world) {
+, interface(ic, env, world)
+, preload(env, world.Loader())
+, unload(env, world.Loader()) {
 
 }
 
 
+void WorldState::OnEnter() {
+	env.state.Push(&preload);
+}
+
+
 void WorldState::Handle(const SDL_Event &event) {
 	switch (event.type) {
 		case SDL_KEYDOWN:
@@ -43,8 +49,7 @@ void WorldState::Handle(const SDL_Event &event) {
 			interface.Handle(event.wheel);
 			break;
 		case SDL_QUIT:
-			// don't care about this leak just now
-			env.state.Switch(new UnloadState(env, world.Loader()));
+			env.state.Switch(&unload);
 			break;
 		default:
 			break;
diff --git a/src/app/WorldState.hpp b/src/app/WorldState.hpp
index 38f8944..6ab613f 100644
--- a/src/app/WorldState.hpp
+++ b/src/app/WorldState.hpp
@@ -1,7 +1,9 @@
 #ifndef BLANK_APP_WORLDSTATE_HPP_
 #define BLANK_APP_WORLDSTATE_HPP_
 
+#include "PreloadState.hpp"
 #include "State.hpp"
+#include "UnloadState.hpp"
 #include "../ai/Spawner.hpp"
 #include "../ui/Interface.hpp"
 #include "../world/World.hpp"
@@ -22,6 +24,8 @@ public:
 		const WorldSave &
 	);
 
+	void OnEnter() override;
+
 	void Handle(const SDL_Event &) override;
 	void Update(int dt) override;
 	void Render(Viewport &) override;
@@ -34,6 +38,9 @@ private:
 	Spawner spawner;
 	Interface interface;
 
+	PreloadState preload;
+	UnloadState unload;
+
 };
 
 }
diff --git a/src/app/app.cpp b/src/app/app.cpp
index 4a4769b..880dc71 100644
--- a/src/app/app.cpp
+++ b/src/app/app.cpp
@@ -145,18 +145,41 @@ void Application::Render() {
 
 
 void Application::PushState(State *s) {
+	if (!states.empty()) {
+		states.top()->OnPause();
+	}
 	states.emplace(s);
+	++s->ref_count;
+	if (s->ref_count == 1) {
+		s->OnEnter();
+	}
+	s->OnResume();
 }
 
 State *Application::PopState() {
 	State *s = states.top();
 	states.pop();
+	s->OnPause();
+	s->OnExit();
+	if (!states.empty()) {
+		states.top()->OnResume();
+	}
 	return s;
 }
 
 State *Application::SwitchState(State *s_new) {
 	State *s_old = states.top();
 	states.top() = s_new;
+	--s_old->ref_count;
+	++s_new->ref_count;
+	s_old->OnPause();
+	if (s_old->ref_count == 0) {
+		s_old->OnExit();
+	}
+	if (s_new->ref_count == 1) {
+		s_new->OnEnter();
+	}
+	s_new->OnResume();
 	return s_old;
 }
 
diff --git a/src/app/runtime.cpp b/src/app/runtime.cpp
index 32a4012..85d8280 100644
--- a/src/app/runtime.cpp
+++ b/src/app/runtime.cpp
@@ -1,6 +1,5 @@
 #include "Application.hpp"
 #include "Environment.hpp"
-#include "PreloadState.hpp"
 #include "Runtime.hpp"
 #include "WorldState.hpp"
 
@@ -244,9 +243,6 @@ int Runtime::Execute() {
 	WorldState world_state(env, config.interface, config.world, save);
 	app.PushState(&world_state);
 
-	PreloadState preloader(env, world_state.GetWorld().Loader());
-	app.PushState(&preloader);
-
 	switch (mode) {
 		default:
 		case NORMAL:
-- 
2.39.2