11 files changed, 11 insertions, 11 deletions
diff --git a/src/gui/sdlinput.cpp b/src/gui/sdlinput.cpp
index 2c4e8cbea..ce59f47fd 100644
--- a/src/gui/sdlinput.cpp
+++ b/src/gui/sdlinput.cpp
@@ -236,7 +236,7 @@ int SDLInput::convertMouseButton(const int button)
     }
 }
 
-int SDLInput::convertKeyCharacter(const SDL_Event event)
+int SDLInput::convertKeyCharacter(const SDL_Event &event)
 {
     const SDL_keysym keysym = event.key.keysym;
 
diff --git a/src/gui/sdlinput.h b/src/gui/sdlinput.h
index db082ef2a..534f0573e 100644
--- a/src/gui/sdlinput.h
+++ b/src/gui/sdlinput.h
@@ -182,7 +182,7 @@ protected:
      * @return a key value.
      * @see Key
      */
-    static int convertKeyCharacter(SDL_Event event);
+    static int convertKeyCharacter(const SDL_Event &event);
 
     std::queue<KeyInput> mKeyInputQueue;
     std::queue<gcn::MouseInput> mMouseInputQueue;
diff --git a/src/gui/theme.cpp b/src/gui/theme.cpp
index 679b975e0..26f250c4c 100644
--- a/src/gui/theme.cpp
+++ b/src/gui/theme.cpp
@@ -60,7 +60,7 @@ static void initDefaultThemePath()
         defaultThemePath = "themes/";
 }
 
-Skin::Skin(const ImageRect skin, const ImageRect images,
+Skin::Skin(const ImageRect &skin, const ImageRect &images,
            const std::string &filePath, const std::string &name,
            const int padding, const int titlePadding,
            std::map<std::string, int> *const options):
diff --git a/src/gui/theme.h b/src/gui/theme.h
index 5498996dd..de027523d 100644
--- a/src/gui/theme.h
+++ b/src/gui/theme.h
@@ -42,7 +42,7 @@ class ProgressBar;
 class Skin
 {
     public:
-        Skin(const ImageRect skin, const ImageRect images,
+        Skin(const ImageRect &skin, const ImageRect &images,
              const std::string &filePath, const std::string &name = "",
              const int padding = 3, const int titlePadding = 4,
              std::map<std::string, int> *const options = nullptr);
diff --git a/src/gui/userpalette.h b/src/gui/userpalette.h
index a808e865b..0ce3a6b85 100644
--- a/src/gui/userpalette.h
+++ b/src/gui/userpalette.h
@@ -117,7 +117,7 @@ class UserPalette : public Palette, public gcn::ListModel
          * @param type the color type requested
          * @param color the color that should be tested
          */
-        inline void setTestColor(const int type, const gcn::Color color)
+        inline void setTestColor(const int type, const gcn::Color &color)
         { mColors[type].testColor = color; }
 
         /**
diff --git a/src/gui/viewport.cpp b/src/gui/viewport.cpp
index 77bc7bb16..f521fde8c 100644
--- a/src/gui/viewport.cpp
+++ b/src/gui/viewport.cpp
@@ -348,7 +348,7 @@ void Viewport::_drawDebugPath(Graphics *const graphics)
 }
 
 void Viewport::_drawPath(Graphics *const graphics, const Path &path,
-                         const gcn::Color color) const
+                         const gcn::Color &color) const
 {
     graphics->setColor(color);
 
diff --git a/src/gui/viewport.h b/src/gui/viewport.h
index c83e83173..ec35ef3d6 100644
--- a/src/gui/viewport.h
+++ b/src/gui/viewport.h
@@ -292,7 +292,7 @@ class Viewport : public WindowContainer, public gcn::MouseListener,
          * Draws the given path.
          */
         void _drawPath(Graphics *const graphics, const Path &path,
-                       const gcn::Color color = gcn::Color(255, 0, 0)) const;
+                       const gcn::Color &color = gcn::Color(255, 0, 0)) const;
 
         /**
          * Make the player go to the mouse position.
diff --git a/src/gui/widgets/extendednamesmodel.cpp b/src/gui/widgets/extendednamesmodel.cpp
index 11c594321..083ce938e 100644
--- a/src/gui/widgets/extendednamesmodel.cpp
+++ b/src/gui/widgets/extendednamesmodel.cpp
@@ -51,7 +51,7 @@ std::string ExtendedNamesModel::getElementAt(int i)
     return mNames[i];
 }
 
-Image *ExtendedNamesModel::getImageAt(int i)
+const Image *ExtendedNamesModel::getImageAt(int i)
 {
     if (i >= static_cast<int>(mImages.size()) || i < 0)
         return nullptr;
diff --git a/src/gui/widgets/extendednamesmodel.h b/src/gui/widgets/extendednamesmodel.h
index 5a15949a9..be59c7e20 100644
--- a/src/gui/widgets/extendednamesmodel.h
+++ b/src/gui/widgets/extendednamesmodel.h
@@ -38,7 +38,7 @@ class ExtendedNamesModel : public ExtendedListModel
 
         virtual std::string getElementAt(int i);
 
-        virtual Image *getImageAt(int i);
+        virtual const Image *getImageAt(int i);
 
         StringVect &getNames()
         { return mNames; }
diff --git a/src/gui/widgets/slider.cpp b/src/gui/widgets/slider.cpp
index da6cb31f6..edc215b07 100644
--- a/src/gui/widgets/slider.cpp
+++ b/src/gui/widgets/slider.cpp
@@ -177,7 +177,7 @@ void Slider::draw(gcn::Graphics *graphics)
     drawMarker(graphics);
 }
 
-void Slider::drawMarker(gcn::Graphics *const graphics)
+void Slider::drawMarker(gcn::Graphics *const graphics) const
 {
     const Image *const img = (mHasMouse ? buttons[1].grid[HGRIP]
         : buttons[0].grid[HGRIP]);
diff --git a/src/gui/widgets/slider.h b/src/gui/widgets/slider.h
index 7ef121346..95d23f83e 100644
--- a/src/gui/widgets/slider.h
+++ b/src/gui/widgets/slider.h
@@ -64,7 +64,7 @@ class Slider : public gcn::Slider
         /**
          * Draws the marker.
          */
-        void drawMarker(gcn::Graphics *const graphics);
+        void drawMarker(gcn::Graphics *const graphics) const;
 
         /**
          * Called when the mouse enteres the widget area.