New change menu function

Move the most basic change menu to here

src/LiquidMenu.h

@@ -1186,6 +1186,12 @@ class LiquidSystem
   /// Switches to the next screen.
   void next_screen();
 
+  /**
+   * @brief Change to the next screen
+   * @return Whether we change the screen correctly or not
+   */
+  bool changeToNextScreen();
+
   /// Switches to the next screen.
   /**
   @note Prefix increment operator overloading.

src/LiquidSystem.cpp

@@ -116,6 +116,27 @@ void LiquidSystem::next_screen() {
 	_p_liquidMenu[_currentMenu]->next_screen();
 }
 
+bool LiquidSystem::changeToNextScreen()
+{
+	LiquidScreen *currentScreen = _p_liquidMenu[_currentMenu]->get_currentScreen();
+	if (currentScreen->get_next_screen() == NULL)
+	{
+		if (currentScreen->get_next_menu())
+		{
+			change_menu(*currentScreen->get_next_menu(), true);
+			return true;
+		}
+	}
+	else
+	{
+		change_menu(*currentScreen->get_next_menu(), false);
+		change_screen(currentScreen->get_next_screen());
+		return true;
+	}
+
+	return false;
+}
+
 void LiquidSystem::operator++() {
 	next_screen();
 }