diff --git a/include/manager.hpp b/include/manager.hpp
index 40c1853..a833bea 100644
--- a/include/manager.hpp
+++ b/include/manager.hpp
@@ -25,6 +25,11 @@ private:
     bool running;
 
 public:
+    /**
+     * Énumération des modificateurs
+     */
+    enum class Modifier {CONTROL, ALT, SHIFT, SYSTEM};
+
     Manager();
 
     /**
@@ -82,6 +87,12 @@ public:
      * touche donnée ou non
      */
     bool isKeyPressed(sf::Keyboard::Key key) const;
+
+    /**
+     * Renvoie un booléen attestant de l'appui sur le
+     * modificateur
+     */
+    bool isKeyPressed(Modifier modifier) const;
 };
 
 #endif
diff --git a/include/state.hpp b/include/state.hpp
index 401517e..db25b59 100644
--- a/include/state.hpp
+++ b/include/state.hpp
@@ -4,8 +4,8 @@
 #include <SFML/Graphics.hpp>
 
 class ResourceManager;
-class Manager;
 class Object;
+class Manager;
 
 /**
  * Classe abstraite pour les états de jeu
@@ -38,20 +38,30 @@ public:
      */
     Manager& getManager();
 
+    /**
+     * Récupère le gestionnaire (version constante)
+     */
+    const Manager& getManager() const;
+
     /**
      * Récupère le gestionnaire de ressources
      */
     ResourceManager& getResourceManager();
 
+    /**
+     * Récupère le gestionnaire de ressources (version constante)
+     */
+    const ResourceManager& getResourceManager() const;
+
     /**
      * Récupère la fenêtre
      */
     sf::RenderWindow& getWindow();
 
     /**
-     * Récupère si une touche est pressée
+     * Récupère la fenêtre (version constante)
      */
-    bool isKeyPressed(sf::Keyboard::Key key) const;
+    const sf::RenderWindow& getWindow() const;
 };
 
 #endif
diff --git a/src/editor.cpp b/src/editor.cpp
index 6858f44..e67a413 100644
--- a/src/editor.cpp
+++ b/src/editor.cpp
@@ -65,7 +65,7 @@ void Editor::processEvent(const sf::Event& event) {
 
         if (event.mouseButton.button == sf::Mouse::Left) {
             // clic + shift : sélection par rectangle de sélection
-            if (isKeyPressed(sf::Keyboard::LShift)) {
+            if (getManager().isKeyPressed(Manager::Modifier::SHIFT)) {
                 drag_start = mouse_position;
                 drag_end = mouse_position;
                 drag_mode = DragMode::SELECT_RECT;
@@ -73,7 +73,7 @@ void Editor::processEvent(const sf::Event& event) {
 
             // clic sur un objet : démarrage de la sélection libre
             else if (pointed_object != nullptr) {
-                if (isKeyPressed(sf::Keyboard::LControl)) {
+                if (getManager().isKeyPressed(Manager::Modifier::CONTROL)) {
                     drag_start = mouse_position;
                     drag_end = mouse_position;
                     drag_mode = DragMode::SELECT_BULK;
diff --git a/src/manager.cpp b/src/manager.cpp
index 3cc65d3..5500ae5 100644
--- a/src/manager.cpp
+++ b/src/manager.cpp
@@ -98,3 +98,21 @@ void Manager::setTitle(sf::String set_title) {
 bool Manager::isKeyPressed(sf::Keyboard::Key key) const {
     return sf::Keyboard::isKeyPressed(key) && window.hasFocus();
 }
+
+bool Manager::isKeyPressed(Manager::Modifier modifier) const {
+    switch (modifier) {
+    case Manager::Modifier::CONTROL:
+        return isKeyPressed(sf::Keyboard::LControl) || isKeyPressed(sf::Keyboard::RControl);
+
+    case Manager::Modifier::ALT:
+        return isKeyPressed(sf::Keyboard::LAlt) || isKeyPressed(sf::Keyboard::RAlt);
+
+    case Manager::Modifier::SYSTEM:
+        return isKeyPressed(sf::Keyboard::LSystem) || isKeyPressed(sf::Keyboard::RSystem);
+
+    case Manager::Modifier::SHIFT:
+        return isKeyPressed(sf::Keyboard::LShift) || isKeyPressed(sf::Keyboard::RShift);
+    }
+
+    return false;
+}
diff --git a/src/player.cpp b/src/player.cpp
index 0640a0b..edda88a 100644
--- a/src/player.cpp
+++ b/src/player.cpp
@@ -41,21 +41,21 @@ sf::Vector2f Player::getForces(const Level& level) const {
 
     // déplacement de la balle après appui sur les touches de direction
     if (getPlayerNumber() == 0) {
-        if (level.isKeyPressed(sf::Keyboard::Left)) {
+        if (level.getManager().isKeyPressed(sf::Keyboard::Left)) {
             forces += level.getLeftDirection();
         }
 
-        if (level.isKeyPressed(sf::Keyboard::Right)) {
+        if (level.getManager().isKeyPressed(sf::Keyboard::Right)) {
             forces += level.getRightDirection();
         }
     }
 
     if (getPlayerNumber() == 1) {
-        if (level.isKeyPressed(sf::Keyboard::Q)) {
+        if (level.getManager().isKeyPressed(sf::Keyboard::Q)) {
             forces += level.getLeftDirection();
         }
 
-        if (level.isKeyPressed(sf::Keyboard::D)) {
+        if (level.getManager().isKeyPressed(sf::Keyboard::D)) {
             forces += level.getRightDirection();
         }
     }
diff --git a/src/state.cpp b/src/state.cpp
index b04cbcc..8b31fc3 100644
--- a/src/state.cpp
+++ b/src/state.cpp
@@ -8,14 +8,22 @@ Manager& State::getManager() {
     return manager;
 }
 
+const Manager& State::getManager() const {
+    return manager;
+}
+
 ResourceManager& State::getResourceManager() {
     return manager.getResourceManager();
 }
 
+const ResourceManager& State::getResourceManager() const {
+    return manager.getResourceManager();
+}
+
 sf::RenderWindow& State::getWindow() {
     return manager.getWindow();
 }
 
-bool State::isKeyPressed(sf::Keyboard::Key key) const {
-    return manager.isKeyPressed(key);
+const sf::RenderWindow& State::getWindow() const {
+    return manager.getWindow();
 }