Added debug menu option for resetting key mappings to default. Added sanity checking requirement to ScreenMapControllers.

src/InputMapper.cpp

@@ -661,6 +661,67 @@ void InputMapper::ResetMappingsToDefault()
 	AddDefaultMappingsForCurrentGameIfUnmapped();
 }
 
+void InputMapper::CheckButtonAndAddToReason(GameButton menu, vector<RString>& full_reason, RString const& sub_reason)
+{
+	vector<GameInput> inputs;
+	bool exists= false;
+	// Only player 1 is checked because the player 2 buttons are rarely
+	// unmapped and do not exist on some keyboard models. -Kyz
+	GetInputScheme()->MenuButtonToGameInputs(menu, PLAYER_1, inputs);
+	if(!inputs.empty())
+	{
+		vector<DeviceInput> device_inputs;
+		FOREACH(GameInput, inputs, inp)
+		{
+			for(int slot= 0; slot < NUM_GAME_TO_DEVICE_SLOTS; ++slot)
+			{
+				device_inputs.push_back(m_mappings.m_GItoDI[inp->controller][inp->button][slot]);
+			}
+		}
+		FOREACH(DeviceInput, device_inputs, inp)
+		{
+			if(!inp->IsValid())
+			{
+				continue;
+			}
+			int use_count= 0;
+			FOREACH_ENUM(GameController,  cont)
+			{
+				FOREACH_GameButtonInScheme(GetInputScheme(), gb)
+				{
+					for(int slot= 0; slot < NUM_GAME_TO_DEVICE_SLOTS; ++slot)
+					{
+						use_count+= ((*inp) == m_mappings.m_GItoDI[cont][gb][slot]);
+					}
+				}
+			}
+			// If the device input is used more than once, it's a case where a
+			// default mapped key was remapped to some other game button. -Kyz
+			if(use_count == 1)
+			{
+				exists= true;
+			}
+		}
+	}
+	if(!exists)
+	{
+		full_reason.push_back(sub_reason);
+	}
+}
+
+void InputMapper::SanityCheckMappings(vector<RString>& reason)
+{
+	// This is just to check whether the current mapping has the minimum
+	// necessary to navigate the menus so the user can reach the config screen.
+	// For this purpose, only the following keys are needed:
+	// MenuLeft, MenuRight, Start, Operator
+	// The InputScheme handles OnlyDedicatedMenuButtons logic. -Kyz
+	CheckButtonAndAddToReason(GAME_BUTTON_MENULEFT, reason, "MenuLeftMissing");
+	CheckButtonAndAddToReason(GAME_BUTTON_MENURIGHT, reason, "MenuRightMissing");
+	CheckButtonAndAddToReason(GAME_BUTTON_START, reason, "StartMissing");
+	CheckButtonAndAddToReason(GAME_BUTTON_OPERATOR, reason, "OperatorMissing");
+}
+
 static LocalizedString CONNECTED			( "InputMapper", "Connected" );
 static LocalizedString DISCONNECTED			( "InputMapper", "Disconnected" );
 static LocalizedString AUTOMAPPING_ALL_JOYSTICKS	( "InputMapper", "Auto-mapping all joysticks." );