Remember pressed message box button longer

Remember which button was pressed until a new interactive message box is
displayed or until the pressed button number is read.

Before that, it was not possible to get the pressed button after the
message box was hidden/destroyed.

apps/openmw/mwgui/messagebox.cpp

@@ -14,6 +14,7 @@ namespace MWGui
         mMessageBoxSpeed = 0.1;
         mInterMessageBoxe = NULL;
         mStaticMessageBox = NULL;
+        mLastButtonPressed = -1;
     }
 
     void MessageBoxManager::onFrame (float frameDuration)
@@ -62,6 +63,7 @@ namespace MWGui
         }
 
         if(mInterMessageBoxe != NULL && mInterMessageBoxe->mMarkedToDelete) {
+            mLastButtonPressed = mInterMessageBoxe->readPressedButton();
             delete mInterMessageBoxe;
             mInterMessageBoxe = NULL;
             MWBase::Environment::get().getInputManager()->changeInputMode(
@@ -107,6 +109,7 @@ namespace MWGui
         }
 
         mInterMessageBoxe = new InteractiveMessageBox(*this, message, buttons);
+        mLastButtonPressed = -1;
 
         return true;
     }
@@ -154,11 +157,9 @@ namespace MWGui
 
     int MessageBoxManager::readPressedButton ()
     {
-        if(mInterMessageBoxe != NULL)
-        {
-            return mInterMessageBoxe->readPressedButton();
-        }
-        return -1;
+        int pressed = mLastButtonPressed;
+        mLastButtonPressed = -1;
+        return pressed;
     }
 
 
@@ -421,9 +422,7 @@ namespace MWGui
 
     int InteractiveMessageBox::readPressedButton ()
     {
-        int pressed = mButtonPressed;
-        mButtonPressed = -1;
-        return pressed;
+        return mButtonPressed;
     }
 
 }

apps/openmw/mwgui/messagebox.hpp

@@ -56,6 +56,7 @@ namespace MWGui
             MessageBox* mStaticMessageBox;
             std::vector<MessageBoxManagerTimer> mTimers;
             float mMessageBoxSpeed;
+            int mLastButtonPressed;
     };
 
     class MessageBox : public OEngine::GUI::Layout