fear

menu.ino

const char MENU_BACK[] PROGMEM = {0x1B, 0x20, 0x42, 0x61, 0x63, 0x6B}; // Says "<- Back"
... /*
Other strings.
Since they don't really matter, they'll be referred to as
MENU_OTHER
*/ ...

enum class MenuItemType : uint8_t {
	Button, InvertedButton, Checkbox, Info
};
// Buttons/InvButtons use ROM function pointers,
// Checkboxes use RAM variable pointers.

struct MenuItem {
	uint8_t x; // The display X
	uint8_t y; // The display Y
	MenuItemType type; // The type
	const char *textPointer; // Pointer to a ROM string
	void *actionPointer; // Can be either a ROM function pointer or a RAM variable pointer
};
struct MenuItemInfo {
	const MenuItem *items; // Pointer to the MenuItem array
	uint8_t length; // How long the MenuItem array is
};

const MenuItem MENU_ITEMS_MAIN[] PROGMEM {
	{14, 26, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{66, 26, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{14, 42, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{66, 42, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer}
};

const MenuItem MENU_ITEMS_MODE[] PROGMEM {
	{14, 10, MenuItemType::InvertedButton, MENU_BACK, menuItem_FuncPointer},
	{66, 10, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{14, 26, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{66, 26, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{14, 42, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{66, 42, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer}
};

const MenuItem MENU_ITEMS_MODE_A[] PROGMEM {
	{14, 18, MenuItemType::InvertedButton, MENU_BACK, menuItem_FuncPointer},
	{66, 18, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{14, 34, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{66, 34, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer}
};

const MenuItem MENU_ITEMS_MODE_B[] PROGMEM {
	{14, 18, MenuItemType::InvertedButton, MENU_BACK, menuItem_FuncPointer},
	{66, 18, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{14, 34, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer},
	{66, 34, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer}
};

const MenuItem MENU_ITEMS_OPTIONS[] PROGMEM {
	{14, 18, MenuItemType::InvertedButton, MENU_BACK, menuItem_FuncPointer},
	{66, 18, MenuItemType::Checkbox, MENU_OTHER, &boolPointer1},
	{14, 34, MenuItemType::Checkbox, MENU_OTHER, &boolPointer2},
	{66, 34, MenuItemType::Button, MENU_OTHER, menuItem_FuncPointer}
};

const MenuItemInfo *MENU_ITEMS_LOOKUP[] {
	{MENU_ITEMS_MAIN, 4},
	{MENU_ITEMS_MODE, 6},
	{MENU_ITEMS_MODE_A, 4},
	{MENU_ITEMS_MODE_B, 4},
	{MENU_ITEMS_OPTIONS, 4}
};

uint8_t menuCursor = 1;
uint8_t menuLength = 0;
MenuItem menuItems[6];

void updateMenu() {
	// TODO
}

void loadMenuItems(uint8_t index) {
	menuLength = pgm_read_byte(MENU_ITEMS_LOOKUP[index]->length);
	memcpy_P(menuItems, MENU_ITEMS_LOOKUP[index]->items, sizeof(MenuItem) * menuLength);
}

void drawAllMenuItems() {
	// TODO
}

void triggerItem(uint8_t index) {
	if (menuItems[index].type == MenuItemType::Button || menuItems[index].type == MenuItemType::InvertedButton) {
		// actionPointer is in ROM.
		// It's a function. Run it.
		
		(*(menuItems[index].actionPointer))();
	} else if (menuItems[index].type == MenuItemType::Checkbox) {
		// actionPointer is in RAM.
		// It's a bool. Toggle it.
		
		// [whatever actionPointer is pointing to in RAM.] = ![whatever actionPointer is pointing to in RAM, casted to a boolean.]
		*(menuItems[index].actionPointer) = !*TO_(bool*, menuItems[index].actionPointer);
	}
}

// cursor == buttonIndex ? (ab.buttonDown(B_BUTTON) ? ButtonsState::Pressed : ButtonState::Selected) : ButtonState::Unselected
void drawButton(const char *TEXT, uint8_t x, uint8_t y, uint8_t width, uint8_t height, ButtonState state, bool invert) {
	switch (state) {
		default: case ButtonState::Unselected:
			ab.drawRect(x, y, width, height);
		break;
		case ButtonState::Selected:
			y -= 2;
			
			ab.drawRect(x, y, width, height + 2);
			ab.drawFastHLine(x + 1, y + height - 1, width - 2);
		break;
		case ButtonState::Pressed:
			y++;
			
			ab.drawRect(x, y, width, height);
		break;
	}
	
	if (invert) {
		ab.setTextColor(BLACK);
		ab.setTextBackground(WHITE);
	} else {
		ab.setTextColor(WHITE);
		ab.setTextBackground(BLACK);
	}
	
	ab.setCursor(x + 2, y + 2);
	ab.print((__FlashStringHelper*)(TEXT));
}