diff --git a/README.md b/README.md
index d7d5229..370336e 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,6 @@ This is the repository of a Nintendo Entertainment System (NES) emulator in acti
 currently complete but can run and partially display a ROM. Note that the project may support Windows and MacOS, but was 
 only tested on Linux. Here is how to run the project:
  - Change the ```rom_path``` at line 26 of ```main.c```
- - Optionally, change ```gui.debug_enabled``` to ```true``` at line 33 of ```gui.c``` to enable debugging
  - Generate the Makefile with CMake: ```cmake .```
  - Build the project with Make: ```make```
  - Run the emulator: ```./nes_emulator```
@@ -21,6 +20,7 @@ only tested on Linux. Here is how to run the project:
  - SDL
 
 ## Development Roadmap
+- Basic component based GUI: Done
 - CPU
    - RAM: Done
    - ROM: Done (iNes 1.0 format only)
@@ -42,7 +42,7 @@ only tested on Linux. Here is how to run the project:
    - MMC5: To Do
    - ...
 - Debug
-   - Frame Delay: Done
+   - Frame Delay: Broken, removed
    - Pattern Table Viewer: Done
    - Nametable Viewer: Done
    - CPU Debugger: To Do
diff --git a/gui/CMakeLists.txt b/gui/CMakeLists.txt
index d93b2e4..aed2422 100644
--- a/gui/CMakeLists.txt
+++ b/gui/CMakeLists.txt
@@ -1,10 +1,5 @@
-set(HEADERS gui.h main_window.h)
-set(SOURCE gui.c main_window.c)
-
-if (NES_DEBUG)
-    list(APPEND HEADERS char_map.h pattern_window.h nametable_window.h dbg_pattern_table.h dbg_nametable.h dbg_palette.h)
-    list(APPEND SOURCE char_map.c pattern_window.c nametable_window.c dbg_pattern_table.c dbg_nametable.c dbg_palette.c)
-endif (NES_DEBUG)
+set(HEADERS actions.h gui.h main_window.h char_map.h pattern_window.h nametable_window.h dbg_pattern_table.h dbg_nametable.h dbg_palette.h)
+set(SOURCE actions.c gui.c main_window.c char_map.c pattern_window.c nametable_window.c dbg_pattern_table.c dbg_nametable.c dbg_palette.c)
 
 add_library(nes_gui ${SOURCE} ${HEADERS})
 
diff --git a/gui/actions.c b/gui/actions.c
new file mode 100644
index 0000000..4a3d4c5
--- /dev/null
+++ b/gui/actions.c
@@ -0,0 +1,17 @@
+//
+// Created by william on 9/2/24.
+//
+
+#include "actions.h"
+#include "gui.h"
+
+void process_action(ActionType type) {
+    switch (type) {
+        case ACTION_TYPE_OPEN_WINDOW_NAMETABLE:
+            gui_window_create(WINDOW_TYPE_NAMETABLE);
+            break;
+        case ACTION_TYPE_OPEN_WINDOW_PATTERN_TABLE:
+            gui_window_create(WINDOW_TYPE_PATTERN_TABLE);
+            break;
+    }
+}
diff --git a/gui/actions.h b/gui/actions.h
new file mode 100644
index 0000000..7fba24f
--- /dev/null
+++ b/gui/actions.h
@@ -0,0 +1,15 @@
+//
+// Created by william on 9/2/24.
+//
+
+#ifndef NES_EMULATOR_ACTIONS_H
+#define NES_EMULATOR_ACTIONS_H
+
+typedef enum {
+    ACTION_TYPE_OPEN_WINDOW_NAMETABLE = 1,
+    ACTION_TYPE_OPEN_WINDOW_PATTERN_TABLE = 2
+} ActionType;
+
+void process_action(ActionType type);
+
+#endif //NES_EMULATOR_ACTIONS_H
diff --git a/gui/components/window.c b/gui/components/window.c
index a2d86ad..8cb248c 100644
--- a/gui/components/window.c
+++ b/gui/components/window.c
@@ -7,6 +7,9 @@
 #include "log.h"
 #include "component.h"
 
+// A sequential window ID
+static int next_window_id = 1;
+
 /**
  * Easy declaration of commonly used component loop. The current component is in the 'component' variable.
  * Put the loop's body between FOR_EACH_COMPONENT and END_FOR_EACH_COMPONENT.
@@ -68,6 +71,7 @@ Window window_create(char *title, int width, int height, int scale) {
     }
 
     Window window;
+    window.id = next_window_id++;
     window.width = width;
     window.height = height;
     window.scale = scale;
diff --git a/gui/components/window.h b/gui/components/window.h
index 78be6aa..2817b08 100644
--- a/gui/components/window.h
+++ b/gui/components/window.h
@@ -15,6 +15,7 @@ typedef struct window_sdl_context {
 } WindowSdlContext;
 
 typedef struct window {
+    int id;
     int width;
     int height;
     int scale;
diff --git a/gui/components/window_menu.c b/gui/components/window_menu.c
index cbe2b95..50833a9 100644
--- a/gui/components/window_menu.c
+++ b/gui/components/window_menu.c
@@ -49,12 +49,13 @@ static inline MenuItemComponent *menu_get_next_item(LinkedListCursor *cursor) {
     return next_node->data;
 }
 
-MenuComponent *menu_create(Window *window, TTF_Font *font) {
+MenuComponent *menu_create(Window *window, TTF_Font *font, menu_action_processor action_processor) {
     MenuComponent *menu = malloc(sizeof(MenuComponent));
 
     menu->window_width = window->width * window->scale;
     menu->visible = false;
 
+    menu->action_processor = action_processor;
     menu->items = linked_list_create(false);
     menu->highlight_item = NULL;
 
@@ -66,11 +67,11 @@ MenuComponent *menu_create(Window *window, TTF_Font *font) {
     return menu;
 }
 
-MenuItemComponent *menu_item_create(char *label, on_click_callback on_click) {
+MenuItemComponent *menu_item_create(char *label, int click_action_type) {
     MenuItemComponent *menu_item = malloc(sizeof(MenuItemComponent));
 
     menu_item->label = label;
-    menu_item->on_click = on_click;
+    menu_item->click_action_type = click_action_type;
     menu_item->sub_items = linked_list_create(false);
     menu_item->is_highlighted = false;
 
@@ -234,7 +235,9 @@ bool menu_mouse_click(MenuComponent *menu) {
         return false;
     }
 
-    log_info("%s", menu->highlight_item->label);
+    int action_type = menu->highlight_item->click_action_type;
+    menu->action_processor(action_type);
+
     return true;
 }
 
diff --git a/gui/components/window_menu.h b/gui/components/window_menu.h
index 1b33715..5fb2fa3 100644
--- a/gui/components/window_menu.h
+++ b/gui/components/window_menu.h
@@ -17,11 +17,9 @@
 #define MENU_ITEM_MARGIN_X 20
 #define MENU_ITEM_MARGIN_Y 4
 
-typedef void (*on_click_callback)();
-
 typedef struct menu_item_component {
     char *label;
-    on_click_callback on_click;
+    int click_action_type;
 
     bool is_highlighted;
 
@@ -31,10 +29,13 @@ typedef struct menu_item_component {
     SDL_Rect collision_rect;
 } MenuItemComponent;
 
+typedef void (*menu_action_processor)(int);
+
 typedef struct menu_component {
     int window_width;
     bool visible;
 
+    menu_action_processor action_processor;
     LinkedList items;
     MenuItemComponent *highlight_item;
 
@@ -48,9 +49,10 @@ typedef struct menu_component {
  * Creates a menu fow a window.
  * @param window A reference to the window
  * @param font A reference to the TTF font to use to render text
+ * @param action_processor A reference to a function that will processes actions
  * @return A reference to the menu component
  */
-MenuComponent *menu_create(Window *window, TTF_Font *font);
+MenuComponent *menu_create(Window *window, TTF_Font *font, menu_action_processor action_processor);
 
 /**
  * Creates a menu item. Can be configured with a callback function which will be called when the menu item is clicked.
@@ -59,7 +61,7 @@ MenuComponent *menu_create(Window *window, TTF_Font *font);
  * @param on_click The callback function to call when clicked
  * @return A reference to the menu item
  */
-MenuItemComponent *menu_item_create(char *label, on_click_callback on_click);
+MenuItemComponent *menu_item_create(char *label, int click_action_type);
 
 /**
  * Adds an item to a menu.
diff --git a/gui/dbg_nametable.c b/gui/dbg_nametable.c
index 6fe3c70..7c9fc03 100644
--- a/gui/dbg_nametable.c
+++ b/gui/dbg_nametable.c
@@ -12,7 +12,15 @@
 DebugNameTable dbg_nametable;
 
 void dbg_nametable_init() {
+    if (dbg_nametable.initialized) {
+        // Already initialized
+        return;
+    }
+
+    dbg_pattern_table_init();
+
     dbg_nametable.vertical_mirroring = rom_get()->nametable_mirrored;
+    dbg_nametable.initialized = true;
 }
 
 void dbg_nametable_build_bank(byte *nametable, DebugTile *bank) {
diff --git a/gui/dbg_nametable.h b/gui/dbg_nametable.h
index 4d14d36..4a7cb8e 100644
--- a/gui/dbg_nametable.h
+++ b/gui/dbg_nametable.h
@@ -22,6 +22,7 @@ typedef struct dbg_nametable {
     DebugTile bank_0[NAMETABLE_BANK_SIZE];
     DebugTile bank_1[NAMETABLE_BANK_SIZE];
     bool vertical_mirroring;
+    bool initialized;
 } DebugNameTable;
 
 /**
diff --git a/gui/dbg_palette.c b/gui/dbg_palette.c
index 7f40aaf..b82f480 100644
--- a/gui/dbg_palette.c
+++ b/gui/dbg_palette.c
@@ -18,7 +18,7 @@ pixel dbg_color_list[0x40] = COLOR_LIST;
     COPY_PALETTE((memory)[(base_addr) + 0xd], (dest)[3]) \
 
 
-void dbg_palette_init() {
+void dbg_palette_update() {
     byte *memory = ppu_get_state()->memory.palette;
 
     palette_memory.universal_background_color = memory[0];
diff --git a/gui/dbg_palette.h b/gui/dbg_palette.h
index 38566e2..7c95a89 100644
--- a/gui/dbg_palette.h
+++ b/gui/dbg_palette.h
@@ -19,7 +19,7 @@ typedef struct dbg_palette_memory {
     DebugPalette sprite_palettes[PALETTE_COUNT];
 } DebugPaletteMemory;
 
-void dbg_palette_init();
+void dbg_palette_update();
 
 pixel dbg_get_background_color(byte palette, byte data);
 
diff --git a/gui/dbg_pattern_table.c b/gui/dbg_pattern_table.c
index ac49fb1..e64ab64 100644
--- a/gui/dbg_pattern_table.c
+++ b/gui/dbg_pattern_table.c
@@ -23,10 +23,16 @@ void dbg_pattern_table_build_bank(DebugPattern *bank, byte *pattern_memory) {
 }
 
 void dbg_pattern_table_init() {
+    if (pattern_table.initialized) {
+        // Already initialized
+        return;
+    }
+
     byte *pattern_memory = system_get_mapper()->ppu_read(0);
 
     dbg_pattern_table_build_bank(pattern_table.bank_0, pattern_memory);
     dbg_pattern_table_build_bank(pattern_table.bank_1, &pattern_memory[PATTERN_BANK_SIZE]);
+    pattern_table.initialized = true;
 }
 
 DebugPattern dbg_pattern_get(int pattern_id, int bank) {
diff --git a/gui/dbg_pattern_table.h b/gui/dbg_pattern_table.h
index 337fbbb..1a0b5c2 100644
--- a/gui/dbg_pattern_table.h
+++ b/gui/dbg_pattern_table.h
@@ -5,6 +5,7 @@
 #ifndef NES_EMULATOR_DBG_PATTERN_TABLE_H
 #define NES_EMULATOR_DBG_PATTERN_TABLE_H
 
+#include <stdbool.h>
 #include "../include/types.h"
 
 #define PATTERN_BANK_SIZE 0x1000
@@ -29,6 +30,7 @@ typedef struct dbg_pattern {
 typedef struct dbg_pattern_table {
     DebugPattern bank_0[PATTERN_TABLE_SIZE];
     DebugPattern bank_1[PATTERN_TABLE_SIZE];
+    bool initialized;
 } DebugPatternTable;
 
 /**
diff --git a/gui/gui.c b/gui/gui.c
index 49b3a9c..a494eb2 100644
--- a/gui/gui.c
+++ b/gui/gui.c
@@ -3,6 +3,7 @@
 //
 
 #include <SDL_ttf.h>
+#include <assert.h>
 #include "log.h"
 #include "gui.h"
 #include "main_window.h"
@@ -14,29 +15,95 @@
 #include "char_map.h"
 #include "dbg_palette.h"
 
-#if DEBUG
-#define WINDOW_ID_MAIN 3
-#else
-#define WINDOW_ID_MAIN 1
-#endif
-
 typedef struct nes_gui {
-    NesMainWindow main_window;
-    NesPatternWindow pattern_window;
-    NesNametableWindow nametable_window;
+    bool window_types_open[WINDOW_TYPE_MAX + 1];
+    void *window_types_ref[WINDOW_TYPE_MAX + 1];
+    int window_types_ids[WINDOW_TYPE_MAX + 1];
 
     TTF_Font *font;
 
     Uint32 last_frame_tick;
     Uint32 frame_delay;
 
-#if DEBUG
     unsigned long tick;
-#endif
 } NesGui;
 NesGui gui;
 
+#define GUI_WINDOW_OPEN_(window_type) gui.window_types_open[window_type]
+#define GUI_WINDOW_REF_(window_type) gui.window_types_ref[window_type]
+#define GUI_WINDOW_ACTION_BASE(window_type, call) \
+    if (GUI_WINDOW_OPEN_(window_type)) {          \
+        call(GUI_WINDOW_REF_(window_type));       \
+    }
+
+void gui_window_create(WindowType type) {
+    void **ref = &gui.window_types_ref[type];
+    if (gui.window_types_open[type]) {
+        return;
+    }
+    gui.window_types_open[type] = true;
+    int window_id = -1;
+
+    switch (type) {
+        case WINDOW_TYPE_MAIN:
+            *ref = main_window_create(&window_id);
+            break;
+        case WINDOW_TYPE_NAMETABLE:
+            *ref = nametable_window_create(&window_id);
+            break;
+        case WINDOW_TYPE_PATTERN_TABLE:
+            *ref = pattern_window_create(&window_id);
+            break;
+    }
+
+    gui.window_types_ids[type] = window_id;
+}
+
+void gui_window_destroy(WindowType type) {
+    bool *open = &gui.window_types_open[type];
+    if (*open == false) {
+        // The window doesn't exist
+        return;
+    }
+
+    void *ref = gui.window_types_ref[type];
+    switch (type) {
+        case WINDOW_TYPE_MAIN:
+            main_window_destroy(ref);
+            break;
+        case WINDOW_TYPE_NAMETABLE:
+            nametable_window_destroy(ref);
+            break;
+        case WINDOW_TYPE_PATTERN_TABLE:
+            pattern_window_destroy(ref);
+            break;
+    }
+
+    gui.window_types_ids[type] = -1;
+    *open = false;
+}
+
+void gui_window_destroy_by_id(int window_id) {
+    WindowType type = -1;
+    for (int i = 0; i <= WINDOW_TYPE_MAX; i++) {
+        if (gui.window_types_ids[i] == window_id) {
+            type = i;
+        }
+    }
+
+    if (type == -1) {
+        // Close event is sent twice?
+        log_error("Couldn't find window with ID %d", window_id);
+        return;
+    }
+
+    gui_window_destroy(type);
+}
+
 bool gui_init() {
+    memset(gui.window_types_open, false, sizeof(bool) * WINDOW_TYPE_MAX);
+    memset(gui.window_types_ref, 0, sizeof(void *) * WINDOW_TYPE_MAX);
+
     TTF_Init();
     gui.font = TTF_OpenFont("./nintendo-nes-font.ttf", 16);
     if (gui.font == NULL) {
@@ -44,56 +111,40 @@ bool gui_init() {
         return false;
     }
 
-#if DEBUG
-    gui.tick = 0;
-    pattern_window_init(&gui.pattern_window);
-    nametable_window_init(&gui.nametable_window);
-
-    char_map_init(gui.main_window.window.sdl_context.renderer, gui.font);
-#endif
-
-    main_window_init(&gui.main_window);
+    memset(gui.window_types_ids, -1, (WINDOW_TYPE_MAX + 1) * sizeof(*gui.window_types_ids));
+    gui_window_create(WINDOW_TYPE_MAIN);
 
     return true;
 }
 
-void gui_uninit() {
-    main_window_uninit(&gui.main_window);
-
-#if DEBUG
-    char_map_uninit();
-
-    pattern_window_uninit(&gui.pattern_window);
-    nametable_window_uninit(&gui.nametable_window);
-#endif
+void gui_free() {
+    for (int i = 0; i < WINDOW_TYPE_MAX; i++) {
+        gui_window_destroy(i);
+    }
 
     TTF_CloseFont(gui.font);
 }
 
-void gui_post_sysinit() {
-#if DEBUG
-    dbg_palette_init();
-    dbg_pattern_table_init();
-    dbg_nametable_init();
-
-    // TODO: The background_texture is rendered before the palette data is in the PPU memory, so the only color is grey
-    pattern_window_build_table(&gui.pattern_window);
-    nametable_window_update(&gui.nametable_window);
-#endif
-}
-
 bool lctrl = false;
 
 int gui_input() {
+    assert(gui.window_types_open[WINDOW_TYPE_MAIN]);
     SDL_Event event;
 
-#if DEBUG
     PPUDebugFlags *ppu_debug = &ppu_get_state()->debug;
-#endif
 
     while (SDL_PollEvent(&event)) {
         if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE) {
-            return -1;
+            Uint32 window_id = event.window.windowID;
+            for (int type = 0; type <= WINDOW_TYPE_MAX; type++) {
+                bool is_main_window = gui.window_types_ids[WINDOW_TYPE_MAIN] == window_id;
+
+                gui_window_destroy_by_id(window_id);
+
+                if (is_main_window) {
+                    return -1;
+                }
+            }
         }
 
         if (event.type == SDL_KEYDOWN && event.key.keysym.sym == SDLK_LCTRL) {
@@ -108,59 +159,53 @@ int gui_input() {
                 case SDLK_p:
                     system_toggle_pause(lctrl);
                     break;
-#if DEBUG
-                    case SDLK_t:
-                        ppu_debug->flags.tile_debugger = !ppu_debug->flags.tile_debugger;
-                        break;
-                    case SDLK_n:
-                        ppu_debug->flags.tile_debugger_pattern_half = (ppu_debug->flags.tile_debugger_pattern_half + 1) % 3;
-                        break;
-                    default:
-                        pattern_window_key_up(&gui.pattern_window, event.key.keysym.sym);
-                        break;
-#else
-                default:
+                case SDLK_t:
+                    ppu_debug->flags.tile_debugger = !ppu_debug->flags.tile_debugger;
+                    break;
+                case SDLK_n:
+                    ppu_debug->flags.tile_debugger_pattern_half = (ppu_debug->flags.tile_debugger_pattern_half + 1) % 3;
+                    break;
+                default:
+                    if (gui.window_types_open[WINDOW_TYPE_PATTERN_TABLE]) {
+                        pattern_window_key_up(gui.window_types_ref[WINDOW_TYPE_PATTERN_TABLE], event.key.keysym.sym);
+                    }
                     break;
-#endif
             }
         }
 
+        void *main_window_ref = gui.window_types_ref[WINDOW_TYPE_MAIN];
         if (event.type == SDL_MOUSEMOTION) {
             int x = event.motion.x;
             int y = event.motion.y;
 
-            if (event.window.windowID == WINDOW_ID_MAIN) {
-                main_window_mouse_motion(&gui.main_window, x, y);
+            if (gui.window_types_ids[WINDOW_TYPE_MAIN] == event.window.windowID) {
+                main_window_mouse_motion(main_window_ref, x, y);
             }
         }
 
-        if (event.type == SDL_MOUSEBUTTONUP && event.window.windowID == WINDOW_ID_MAIN) {
-            main_window_mouse_click(&gui.main_window);
+        if (event.type == SDL_MOUSEBUTTONUP && gui.window_types_ids[WINDOW_TYPE_MAIN] == event.window.windowID) {
+            main_window_mouse_click(main_window_ref);
         }
     }
 
     return 1;
 }
 
+#define GUI_WINDOW_RENDER(window_type, prefix) GUI_WINDOW_ACTION_BASE(window_type, prefix ## _window_render)
+
 void gui_render() {
-    main_window_render(&gui.main_window, ppu_get_state()->pixels);
+    assert(gui.window_types_open[WINDOW_TYPE_MAIN]);
+    main_window_render(gui.window_types_ref[WINDOW_TYPE_MAIN], ppu_get_state()->pixels);
 
-#if DEBUG
-    dbg_palette_init();
-    pattern_window_render(&gui.pattern_window);
+    // Update the nametable
+    GUI_WINDOW_ACTION_BASE(WINDOW_TYPE_NAMETABLE, nametable_window_update);
+    GUI_WINDOW_RENDER(WINDOW_TYPE_NAMETABLE, nametable);
 
-    nametable_window_update(&gui.nametable_window);
-    nametable_window_render(&gui.nametable_window);
+    // Update the pattern table
+    GUI_WINDOW_ACTION_BASE(WINDOW_TYPE_PATTERN_TABLE, pattern_window_update);
+    GUI_WINDOW_RENDER(WINDOW_TYPE_PATTERN_TABLE, pattern)
 
     gui.tick++;
-#endif
-}
-
-void gui_present() {
-#if DEBUG
-    pattern_window_present(&gui.pattern_window);
-    nametable_window_present(&gui.nametable_window);
-#endif
 }
 
 void gui_delay() {
@@ -178,8 +223,4 @@ void gui_delay() {
 
 TTF_Font *gui_get_font() {
     return gui.font;
-}
-
-unsigned int gui_get_frame_delay() {
-    return gui.frame_delay;
 }
\ No newline at end of file
diff --git a/gui/gui.h b/gui/gui.h
index 6c0a96b..eaaa351 100644
--- a/gui/gui.h
+++ b/gui/gui.h
@@ -8,17 +8,50 @@
 #include <stdbool.h>
 #include <SDL_ttf.h>
 
+typedef enum {
+    WINDOW_TYPE_MAIN = 0,
+    WINDOW_TYPE_NAMETABLE = 1,
+    WINDOW_TYPE_PATTERN_TABLE = 2,
+} WindowType;
+#define WINDOW_TYPE_MAX WINDOW_TYPE_PATTERN_TABLE
+
+/**
+ * Initializes the graphical user interface of the emulator.
+ * @return A boolean indicating if the GUI was successfully initialized.
+ */
 bool gui_init();
-void gui_uninit();
 
-void gui_post_sysinit();
+/**
+ * Free the resources used by the graphical user interface.
+ */
+void gui_free();
 
+/**
+ * Creates and open a window. If a window of the given type already exists, focus it.
+ * @param type The type of window to open.
+ */
+void gui_window_create(WindowType type);
+
+/**
+ * Process user input events received since the last call to gui_input.
+ * @return An integer indicating if the user closed the main window (-1).
+ */
 int gui_input();
+
+/**
+ * Renders the graphical user interface to the screen.
+ */
 void gui_render();
-void gui_present();
+
+/**
+ * Blocks until the next frame should be drawn, making the frame rate 60 hertz.
+ */
 void gui_delay();
 
+/**
+ * Gets the font used for the graphical user interface.
+ * @return A reference to the TTF font.
+ */
 TTF_Font* gui_get_font();
-unsigned int gui_get_frame_delay();
 
 #endif //NES_EMULATOR_GUI_H
diff --git a/gui/main_window.c b/gui/main_window.c
index 2b824c7..239fe13 100644
--- a/gui/main_window.c
+++ b/gui/main_window.c
@@ -8,52 +8,46 @@
 #include "char_map.h"
 #include "gui.h"
 #include "components/window_menu.h"
+#include "actions.h"
 
-void main_window_init(NesMainWindow *window) {
+void main_window_menu_process_action(int action_type) {
+    process_action(action_type);
+}
+
+MainWindow *main_window_create(int* window_id) {
+    MainWindow *window = malloc(sizeof(MainWindow));
     window->window = window_create("NES Emulator", MAIN_WINDOW_WIDTH, MAIN_WINDOW_HEIGHT, MAIN_WINDOW_SCALE);
     window->texture = window_create_texture(&window->window, SDL_TEXTUREACCESS_STREAMING);
 
-    MenuComponent *menu = menu_create(&window->window, gui_get_font());
+    MenuComponent *menu = menu_create(&window->window, gui_get_font(), &main_window_menu_process_action);
 
-    MenuItemComponent *mi_file = menu_item_create("FILE", NULL);
-    menu_append(menu, mi_file);
-    MenuItemComponent *mi_file_open = menu_item_create("OPEN ROM...", NULL);
-    menu_item_append(mi_file, mi_file_open);
+//    MenuItemComponent *mi_file = menu_item_create("FILE", ACTION_TYPE_OPEN_);
+//    menu_append(menu, mi_file);
+//    MenuItemComponent *mi_file_open = menu_item_create("OPEN ROM...", NULL);
+//    menu_item_append(mi_file, mi_file_open);
 
-    MenuItemComponent *mi_debug = menu_item_create("DEBUG", NULL);
+    MenuItemComponent *mi_debug = menu_item_create("DEBUG", -1);
     menu_append(menu, mi_debug);
-    MenuItemComponent *mi_debug_nametable = menu_item_create("NAMETABLE", NULL);
+    MenuItemComponent *mi_debug_nametable = menu_item_create("NAMETABLE", ACTION_TYPE_OPEN_WINDOW_NAMETABLE);
     menu_item_append(mi_debug, mi_debug_nametable);
-    MenuItemComponent *mi_debug_pattern = menu_item_create("PATTERN TABLE", NULL);
+    MenuItemComponent *mi_debug_pattern = menu_item_create("PATTERN TABLE", ACTION_TYPE_OPEN_WINDOW_PATTERN_TABLE);
     menu_item_append(mi_debug, mi_debug_pattern);
 
     menu_build(menu);
     window_add_component(&window->window, menu_as_component(menu));
+
+    *window_id = window->window.id;
+    return window;
 }
 
-void main_window_uninit(NesMainWindow *window) {
+void main_window_destroy(MainWindow *window) {
     SDL_DestroyTexture(window->texture);
     window_destroy(&window->window);
+
+    free(window);
 }
 
-#if DEBUG
-
-void main_window_render_delay(SDL_Renderer *renderer) {
-    Uint32 delay = gui_get_frame_delay();
-
-    char buffer[5];
-    buffer[0] = (char) ((delay / 10) + 48);
-    buffer[1] = (char) ((delay % 10) + 48);
-    buffer[2] = ' ';
-    buffer[3] = 'm';
-    buffer[4] = 's';
-
-    char_map_render(renderer, buffer);
-}
-
-#endif
-
-void main_window_render(NesMainWindow *window, pixel *pixels) {
+void main_window_render(MainWindow *window, pixel *pixels) {
     SDL_UpdateTexture(window->texture, NULL, pixels, 256 * sizeof(pixel));
 
     window_render_texture(&window->window, window->texture);
@@ -62,10 +56,10 @@ void main_window_render(NesMainWindow *window, pixel *pixels) {
     window_present(&window->window);
 }
 
-void main_window_mouse_motion(NesMainWindow *window, int x, int y) {
+void main_window_mouse_motion(MainWindow *window, int x, int y) {
     window_mouse_motion(&window->window, x, y);
 }
 
-void main_window_mouse_click(NesMainWindow *window) {
+void main_window_mouse_click(MainWindow *window) {
     window_mouse_click(&window->window);
 }
\ No newline at end of file
diff --git a/gui/main_window.h b/gui/main_window.h
index 60a08be..828fe78 100644
--- a/gui/main_window.h
+++ b/gui/main_window.h
@@ -17,13 +17,24 @@ typedef struct nes_main_window {
     Window window;
 
     SDL_Texture *texture;
-} NesMainWindow;
+} MainWindow;
 
-void main_window_init(NesMainWindow *window);
-void main_window_uninit(NesMainWindow *window);
+/**
+ * Creates an instance of the main window.
+ * @return A reference to the created main window instance
+ */
+MainWindow *main_window_create(int *window_id);
 
-void main_window_render(NesMainWindow *window, pixel* pixels);
-void main_window_mouse_motion(NesMainWindow *window, int x, int y);
-void main_window_mouse_click(NesMainWindow *window);
+/**
+ * Destroys an instance of the main window.
+ * @param window A reference to the window to destroy
+ */
+void main_window_destroy(MainWindow *window);
+
+void main_window_render(MainWindow *window, pixel *pixels);
+
+void main_window_mouse_motion(MainWindow *window, int x, int y);
+
+void main_window_mouse_click(MainWindow *window);
 
 #endif //NES_EMULATOR_MAIN_WINDOW_H
diff --git a/gui/nametable_window.c b/gui/nametable_window.c
index 1d3189e..544aedf 100644
--- a/gui/nametable_window.c
+++ b/gui/nametable_window.c
@@ -4,22 +4,32 @@
 
 #include "nametable_window.h"
 #include "dbg_nametable.h"
+#include "dbg_palette.h"
 
 #define NW_WIDTH (NW_ROW_TILE_COUNT * PATTERN_DRAW_SIZE)
 #define NW_HEIGHT (NW_ROW_COUNT * PATTERN_DRAW_SIZE)
 #define NW_BUFFER_SIZE (NAMETABLE_ROW_WIDTH * NAMETABLE_COL_HEIGHT * PATTERN_DRAW_SIZE * PATTERN_DRAW_SIZE)
 
-void nametable_window_init(NesNametableWindow *window) {
+NametableWindow *nametable_window_create(int *window_id) {
+    NametableWindow *window = malloc(sizeof(NametableWindow));
+
     window->window = window_create("Nametable", NW_WIDTH, NW_HEIGHT, NW_SCALE);
     window->texture = window_create_texture(&window->window, SDL_TEXTUREACCESS_STREAMING);
+
+    dbg_nametable_init();
+
+    *window_id = window->window.id;
+    return window;
 }
 
-void nametable_window_uninit(NesNametableWindow *window) {
+void nametable_window_destroy(NametableWindow *window) {
     SDL_DestroyTexture(window->texture);
     window_destroy(&window->window);
+
+    free(window);
 }
 
-void nametable_window_update_bank(NesNametableWindow *window, int bank, pixel *buffer) {
+void nametable_window_update_bank(NametableWindow *window, int bank, pixel *buffer) {
     dbg_nametable_render_bank(bank, buffer);
 
     SDL_Rect rect;
@@ -31,7 +41,8 @@ void nametable_window_update_bank(NesNametableWindow *window, int bank, pixel *b
     SDL_UpdateTexture(window->texture, &rect, buffer, (NW_WIDTH / 2) * sizeof(pixel));
 }
 
-void nametable_window_update(NesNametableWindow *window) {
+void nametable_window_update(NametableWindow *window) {
+    dbg_palette_update();
     dbg_nametable_update();
 
     pixel buffer[NW_BUFFER_SIZE * 4] = {0};
@@ -41,10 +52,7 @@ void nametable_window_update(NesNametableWindow *window) {
     nametable_window_update_bank(window, 3, buffer);
 }
 
-void nametable_window_render(NesNametableWindow *window) {
+void nametable_window_render(NametableWindow *window) {
     window_render_texture(&window->window, window->texture);
-}
-
-void nametable_window_present(NesNametableWindow *window) {
     window_present(&window->window);
-}
\ No newline at end of file
+}
diff --git a/gui/nametable_window.h b/gui/nametable_window.h
index 1233c22..d738ce9 100644
--- a/gui/nametable_window.h
+++ b/gui/nametable_window.h
@@ -15,16 +15,30 @@
 typedef struct nes_nametable_window {
     Window window;
     SDL_Texture *texture;
-} NesNametableWindow;
+} NametableWindow;
 
-void nametable_window_init(NesNametableWindow *window);
+/**
+ * Creates a nametable window instance.
+ * @return A reference to the created window
+ */
+NametableWindow *nametable_window_create(int *window_id);
 
-void nametable_window_uninit(NesNametableWindow *window);
+/**
+ * Destroys a nametable window instance.
+ * @param window A reference to the window to destroy
+ */
+void nametable_window_destroy(NametableWindow *window);
 
-void nametable_window_update(NesNametableWindow *window);
+/**
+ * Updates the content of a nametable window with the current data of the PPU.
+ * @param window A reference to the window to update
+ */
+void nametable_window_update(NametableWindow *window);
 
-void nametable_window_render(NesNametableWindow *window);
-
-void nametable_window_present(NesNametableWindow *window);
+/**
+ * Renders a nemtable window to the screen.
+ * @param window A reference to the window to render
+ */
+void nametable_window_render(NametableWindow *window);
 
 #endif //NES_EMULATOR_NAMETABLE_WINDOW_H
diff --git a/gui/pattern_window.c b/gui/pattern_window.c
index c1043fc..387e111 100644
--- a/gui/pattern_window.c
+++ b/gui/pattern_window.c
@@ -4,23 +4,35 @@
 
 #include "pattern_window.h"
 #include "dbg_pattern_table.h"
+#include "dbg_palette.h"
 
 #define PW_WIDTH (PW_ROW_TILE_COUNT * PATTERN_DRAW_SIZE)
 #define PW_HEIGHT (PW_WIDTH * 2)
 #define PW_BUFFER_SIZE (PW_WIDTH * PW_HEIGHT)
 
-void pattern_window_init(NesPatternWindow *window) {
+PatternWindow *pattern_window_create(int *window_id) {
+    PatternWindow *window = malloc(sizeof(PatternWindow));
+
     window->window = window_create("Pattern Table", PW_WIDTH, PW_HEIGHT, PW_SCALE);
     window->texture = window_create_texture(&window->window, SDL_TEXTUREACCESS_STATIC);
     window->palette = 0;
+
+    dbg_pattern_table_init();
+
+    *window_id = window->window.id;
+    return window;
 }
 
-void pattern_window_uninit(NesPatternWindow *window) {
+void pattern_window_destroy(PatternWindow *window) {
     SDL_DestroyTexture(window->texture);
     window_destroy(&window->window);
+
+    free(window);
 }
 
-void pattern_window_build_table(NesPatternWindow *window) {
+void pattern_window_update(PatternWindow *window) {
+    dbg_palette_update();
+
     pixel buffer[PW_BUFFER_SIZE] = {0};
     dbg_pattern_draw_bank(PATTERN_BANK_0, buffer, window->palette);
     dbg_pattern_draw_bank(PATTERN_BANK_1, &buffer[PW_WIDTH * (PW_HEIGHT / 2)], window->palette);
@@ -28,7 +40,7 @@ void pattern_window_build_table(NesPatternWindow *window) {
     SDL_UpdateTexture(window->texture, NULL, buffer, PW_WIDTH * sizeof(pixel));
 }
 
-void pattern_window_key_up(NesPatternWindow *window, SDL_KeyCode keycode) {
+void pattern_window_key_up(PatternWindow *window, SDL_KeyCode keycode) {
     if (keycode != SDLK_o) {
         return;
     }
@@ -38,13 +50,10 @@ void pattern_window_key_up(NesPatternWindow *window, SDL_KeyCode keycode) {
         window->palette = 0;
     }
 
-    pattern_window_build_table(window);
+    pattern_window_update(window);
 }
 
-void pattern_window_render(NesPatternWindow *window) {
+void pattern_window_render(PatternWindow *window) {
     window_render_texture(&window->window, window->texture);
-}
-
-void pattern_window_present(NesPatternWindow *window) {
     window_present(&window->window);
 }
\ No newline at end of file
diff --git a/gui/pattern_window.h b/gui/pattern_window.h
index caa8349..9a1161e 100644
--- a/gui/pattern_window.h
+++ b/gui/pattern_window.h
@@ -16,15 +16,37 @@ typedef struct nes_pattern_window {
     Window window;
     SDL_Texture *texture;
     byte palette;
-} NesPatternWindow;
+} PatternWindow;
 
-void pattern_window_init(NesPatternWindow *window);
-void pattern_window_uninit(NesPatternWindow *window);
+/**
+ * Creates a pattern window instance.
+ * @return A reference to the created window instance
+ */
+PatternWindow *pattern_window_create(int *window_id);
 
-void pattern_window_build_table(NesPatternWindow *window);
+/**
+ * Destroys a pattern window instance.
+ * @param window A reference to the window to destroy
+ */
+void pattern_window_destroy(PatternWindow *window);
 
-void pattern_window_key_up(NesPatternWindow *window, SDL_KeyCode keycode);
-void pattern_window_render(NesPatternWindow *window);
-void pattern_window_present(NesPatternWindow *window);
+/**
+ * Updates the content of a pattern window with the current data from the ROM mapper.
+ * @param window A reference to the window to update
+ */
+void pattern_window_update(PatternWindow *window);
+
+/**
+ * Renders a pattern window to the screen.
+ * @param window A reference to the window to render
+ */
+void pattern_window_render(PatternWindow *window);
+
+/**
+ * Sends a key up event to a pattern window.
+ * @param window A reference to the window to send the event to
+ * @param keycode The code of the key of the event
+ */
+void pattern_window_key_up(PatternWindow *window, SDL_KeyCode keycode);
 
 #endif //NES_EMULATOR_PATTERN_WINDOW_H
diff --git a/include/ppu.h b/include/ppu.h
index 4b2fda8..852dcd3 100644
--- a/include/ppu.h
+++ b/include/ppu.h
@@ -69,7 +69,6 @@ typedef struct ppu_tile_fetch {
     byte pattern_table_tile_high;
 } PPUTileFetch;
 
-#if DEBUG
 typedef union {
     struct {
         byte tile_debugger: 1;
@@ -77,7 +76,6 @@ typedef union {
     } flags;
     byte flags_byte;
 } PPUDebugFlags;
-#endif
 
 typedef struct ppu {
     PPUMemory memory;
@@ -103,9 +101,7 @@ typedef struct ppu {
     unsigned int scanline;
     unsigned int cycle;
 
-#if DEBUG
     PPUDebugFlags debug;
-#endif
 } PPU;
 
 PPU *ppu_get_state();
diff --git a/main.c b/main.c
index 125b706..2bb2647 100644
--- a/main.c
+++ b/main.c
@@ -101,30 +101,28 @@ int main() {
 
     if (!rom_load(rom_path)) {
         system_uninit();
-        gui_uninit();
+        gui_free();
         return EXIT_FAILURE;
     }
 
-    gui_post_sysinit();
     system_start();
 
-    bool stop = false;
-    while (!stop) {
+    while (true) {
         if (gui_input() < 0) {
-            stop = true;
+            // The main window has been closed, stop the emulation
+            break;
         }
 
         system_next_frame();
-
         gui_render();
 
-        gui_present();
+        // Delay the next frame to lock the emulation to 60hz
         gui_delay();
     }
 
     system_uninit();
     rom_unload();
-    gui_uninit();
+    gui_free();
 
     close_logging();
 
diff --git a/ppu/ppu.c b/ppu/ppu.c
index b03f086..08143a6 100644
--- a/ppu/ppu.c
+++ b/ppu/ppu.c
@@ -20,8 +20,8 @@
 #include "../cpu/cpu.h"
 #include "../include/rom.h"
 #include "colors.h"
-#include "tile_debugger.h"
 #include "log.h"
+#include "tile_debugger.h"
 
 #define PPU_SCANLINE_VISIBLE_MAX 240
 #define PPU_SCANLINE_POST_RENDER_MIN PPU_SCANLINE_VISIBLE_MAX
@@ -132,7 +132,6 @@ void ppu_draw_tile() {
 }
 
 byte ppu_get_pattern(byte tile_index, byte high) {
-#if DEBUG
     if (ppu_state.debug.flags.tile_debugger) {
         if ((ppu_state.debug.flags.tile_debugger_pattern_half == 1 && high) ||
             (ppu_state.debug.flags.tile_debugger_pattern_half == 2 && !high)) {
@@ -141,7 +140,6 @@ byte ppu_get_pattern(byte tile_index, byte high) {
 
         return tile_debugger_encode_number_as_pattern(tile_index, ppu_state.scanline % 8);
     }
-#endif
 
     byte tile_row_index = (ppu_state.scanline + ppu_state.y_scroll) % 8;
     address pattern_addr = ppu_state.bg_pattern_table_addr | tile_index << 4 | high << 3 | tile_row_index;