Avoid rebuilding the dialogue topics pane unnecessarily

Also retaining key focus.

apps/openmw/mwgui/dialogue.cpp

@@ -241,6 +241,7 @@ namespace MWGui
 
     DialogueWindow::DialogueWindow()
         : WindowBase("openmw_dialogue_window.layout")
+        , mIsCompanion(false)
         , mGoodbye(false)
         , mPersuasionDialog()
     {
@@ -404,6 +405,9 @@ namespace MWGui
             for (std::vector<DialogueText*>::iterator it = mHistoryContents.begin(); it != mHistoryContents.end(); ++it)
                 delete (*it);
             mHistoryContents.clear();
+
+            mKeywords.clear();
+            updateTopicsPane();
         }
 
         for (std::vector<Link*>::iterator it = mLinks.begin(); it != mLinks.end(); ++it)
@@ -438,6 +442,16 @@ namespace MWGui
     }
 
     void DialogueWindow::setKeywords(std::list<std::string> keyWords)
+    {
+        if (mKeywords == keyWords && isCompanion() == mIsCompanion)
+            return;
+        mIsCompanion = isCompanion();
+        mKeywords = keyWords;
+
+        updateTopicsPane();
+    }
+
+    void DialogueWindow::updateTopicsPane()
     {
         mTopicsList->clear();
         for (std::map<std::string, Link*>::iterator it = mTopicLinks.begin(); it != mTopicLinks.end(); ++it)
@@ -484,7 +498,7 @@ namespace MWGui
             mTopicsList->addSeparator();
 
 
-        for(std::list<std::string>::iterator it = keyWords.begin(); it != keyWords.end(); ++it)
+        for(std::list<std::string>::iterator it = mKeywords.begin(); it != mKeywords.end(); ++it)
         {
             mTopicsList->addItem(*it);
 

apps/openmw/mwgui/dialogue.hpp

@@ -132,6 +132,7 @@ namespace MWGui
 
     protected:
         void updateTopics();
+        void updateTopicsPane();
         bool isCompanion();
 
         void onPersuadeResult(const std::string& title, const std::string& text);
@@ -156,6 +157,9 @@ namespace MWGui
 
         bool mEnabled;
 
+        bool mIsCompanion;
+        std::list<std::string> mKeywords;
+
         std::vector<DialogueText*> mHistoryContents;
         std::vector<std::pair<std::string, int> > mChoices;
         bool mGoodbye;