Created a UIStack component that handles multiple screens.

Makefile

@@ -65,7 +65,7 @@ debug: build
 	gdb --nx -x .gdbinit --ex run --args builddir/runtests
 
 debug_run: build
-	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args builddir/under_the_dome
+	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args builddir/multiscreen
 
 debug_walk: build test
 	gdb --nx -x .gdbinit --batch --ex run --ex bt --ex q --args builddir/under_the_dome t

meson.build

@@ -140,3 +140,11 @@ executable('fragviewer',
   include_directories: inc_dirs,
   override_options: exe_defaults,
   dependencies: dependencies)
+
+executable('multiscreen',
+  [ 'tools/multiscreen.cpp' ],
+  cpp_args: cpp_args,
+  link_args: link_args,
+  include_directories: inc_dirs,
+  override_options: exe_defaults,
+  dependencies: dependencies)

src/graphics/scene.cpp

@@ -58,8 +58,6 @@ namespace scene {
   }
 
   void Engine::init() {
-    dbc::log($F("initialized scene with background {}", $scene.background));
-
     $gui.position(SCENE_VIEW_X, SCENE_VIEW_Y, SCENE_VIEW_WIDTH, SCENE_VIEW_HEIGHT);
     $gui.set<guecs::Background>($gui.MAIN, {$gui.$parser, guecs::THEME.TRANSPARENT});
     auto& background = $gui.get<guecs::Background>($gui.MAIN);

src/gui/fsm.cpp

@@ -49,8 +49,8 @@ namespace gui {
     $main_ui.init();
     $loot_ui.init();
 
-    for(auto& [name, scene] : $scenes) {
+    for(auto& name : $screens.screens.keys()) {
-      scene->init();
+      $screens.screens[name]->init();
     }
 
     // BUG: maybe this is a function on main_ui?
@@ -326,8 +326,8 @@ namespace gui {
   void FSM::mouse_action(guecs::Modifiers mods) {
     sf::Vector2f pos = mouse_position();
 
-    if($cur_scene != nullptr) {
+    if($screens.is_visible()) {
-      $cur_scene->mouse(pos.x, pos.y, mods);
+      $screens.mouse(pos.x, pos.y, mods);
       return;
     }
 
@@ -415,8 +415,8 @@ namespace gui {
   }
 
   void FSM::draw_gui() {
-    if($cur_scene != nullptr) {
+    if($screens.is_visible()) {
-      $cur_scene->render($window);
+      $screens.render($window);
     } else if($story != nullptr) {
       $story->render($window);
     } else {
@@ -432,8 +432,8 @@ namespace gui {
   }
 
   void FSM::update() {
-    if($cur_scene != nullptr) {
+    if($screens.is_visible()) {
-      $cur_scene->update();
+      $screens.update();
     } else if($story != nullptr) {
       $story->update();
     }
@@ -564,12 +564,12 @@ namespace gui {
   }
 
   void FSM::show_scene(const std::string& name) {
-    dbc::check($scenes.contains(name), $F("$scenes does not contain {}", name));
+    $screens.set_active(name);
-    $cur_scene = $scenes[name];
+    $screens.set_visible(true);
   }
 
   void FSM::close_scene() {
-    $cur_scene = nullptr;
+    $screens.set_visible(false);
   }
 
   void FSM::player_died() {
@@ -584,7 +584,7 @@ namespace gui {
 
     if(level.index < levels_to_win) {
       show_scene("NEXT_LEVEL");
-      $cur_scene->set_text(fmt::format("ENTERING\nLEVEL\n{}", level.index+2));
+      $screens.current_ui()->set_text(fmt::format("ENTERING\nLEVEL\n{}", level.index+2));
       state(State::NEXT_LEVEL_SCENE);
     } else {
       show_scene("WIN");

src/gui/fsm.hpp

@@ -13,6 +13,7 @@
 #include "events.hpp"
 #include "gui/scene_ui.hpp"
 #include "gui/storyboard.hpp"
+#include "gui/uistack.hpp"
 
 namespace gui {
   enum class State {
@@ -43,14 +44,14 @@ namespace gui {
       gui::routing::Router $router;
       DNDLoot $dnd_loot;
       System::Registry $systems;
-      std::unordered_map<std::string, std::shared_ptr<gui::SceneUI>> $scenes{
+
+      gui::UIStack<gui::SceneUI> $screens{.screens={
         {"STARTING", std::make_shared<gui::SceneUI>("STARTING")},
         {"DEATH", std::make_shared<gui::SceneUI>("DEATH")},
         {"WIN", std::make_shared<gui::SceneUI>("WIN")},
         {"NEXT_LEVEL", std::make_shared<gui::SceneUI>("NEXT_LEVEL")},
-      };
+      }};
 
-      std::shared_ptr<gui::SceneUI> $cur_scene = nullptr;
       std::shared_ptr<storyboard::UI> $story = nullptr;
       bool $display_help = false;
 

src/gui/uistack.cpp

@@ -0,0 +1,6 @@
+#include "multiscreen.hpp"
+
+namespace gui {
+  using namespace std::chrono_literals;
+
+}

src/gui/uistack.hpp

@@ -0,0 +1,90 @@
+#include <guecs/ui.hpp>
+#include "dbc.hpp"
+#include "constants.hpp"
+#include <flat_map>
+
+namespace gui {
+  template<typename SCREEN_TYPE>
+    struct UIStack {
+      using UIStackMap = std::flat_map<std::string, std::shared_ptr<SCREEN_TYPE>>;
+
+      UIStackMap screens{};
+      bool visible = false;
+
+      UIStackMap::iterator $current{screens.begin()};
+      SCREEN_TYPE* $active = nullptr;
+
+      void add(const std::string& name, std::shared_ptr<SCREEN_TYPE> screen) {
+        screens.insert_or_assign(name, screen);
+        update_active(screens.begin());
+      }
+
+      void update_active(const UIStackMap::iterator& itr) {
+        $current = itr;
+        $active = (*$current).second.get();
+      }
+
+      void set_active(const std::string& name) {
+        dbc::check(screens.contains(name), $F("screen {} not in stack", name));
+        update_active(screens.find(name));
+      }
+
+      void set_visible(bool new_value) {
+        visible = new_value;
+      }
+
+      bool is_visible() {
+        return visible;
+      }
+
+      void render(sf::RenderTarget& target) {
+        dbc::check($active != nullptr, "you didn't set active");
+        $active->render(target);
+      }
+
+      void update() {
+        dbc::check($active != nullptr, "you didn't set active");
+        $active->update();
+      }
+
+      bool mouse(float x, float y, guecs::Modifiers mods = guecs::NO_MODS) {
+        dbc::check($active != nullptr, "you didn't set active");
+        return $active->mouse(x, y, mods);
+      }
+
+      bool move(const UIStackMap::iterator& itr, const UIStackMap::iterator& avoid, const UIStackMap::iterator& result) {
+        if(itr != avoid) {
+          update_active(result);
+          return true;
+        } else {
+          return false;
+        }
+      }
+
+      bool next() {
+        return move($current + 1, screens.end(), $current + 1);
+      }
+
+      bool prev() {
+        return move($current, screens.begin(), $current - 1);
+      }
+
+      void first() {
+        update_active(screens.begin());
+      }
+
+      void last() {
+        update_active(screens.end() - 1);
+      }
+
+      const std::string& current_name() {
+        dbc::check($active != nullptr, "you didn't set active");
+        return (*$current).first;
+      }
+
+      std::shared_ptr<SCREEN_TYPE> current_ui() {
+        dbc::check($active != nullptr, "you didn't set active");
+        return (*$current).second;
+      }
+    };
+}