Use const where possible

include/guisan/actionevent.hpp

@@ -98,7 +98,7 @@ namespace gcn
          * @param source The source widget of the event.
          * @param id An identifier of the event.
          */
-        ActionEvent(Widget* source, const std::string& id);
+        ActionEvent(Widget* source, std::string id);
 
         /**
          * Destructor.

include/guisan/exception.hpp

@@ -109,7 +109,7 @@ namespace gcn
          *
          * @param message The error message of the exception.
          */
-        Exception(const std::string& message);
+        Exception(std::string message);
 
         /**
          * Constructor.
@@ -124,9 +124,9 @@ namespace gcn
          * @param line The line number in the source code where the exception
          *             occured.
          */
-        Exception(const std::string& message,
-                  const std::string& function,
-                  const std::string& filename,
+        Exception(std::string message,
+                  std::string function,
+                  std::string filename,
                   unsigned int line);
 
         /**

include/guisan/imagefont.hpp

@@ -230,7 +230,7 @@ pqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"); @endcode
          *         with the font.
          * @throws Exception when no glyph is found.
          */
-        Rectangle scanForGlyph(unsigned char glyph, int x, int y, const Color& separator);
+        Rectangle scanForGlyph(unsigned char glyph, int x, int y, const Color& separator) const;
 
         /**
          * Holds the glyphs areas in the image.

include/guisan/widgets/button.hpp

@@ -93,7 +93,7 @@ namespace gcn
          *
          * @param caption the caption of the Button.
          */
-        Button(const std::string& caption);
+        Button(std::string caption);
 
         /**
          * Sets the Button caption.

include/guisan/widgets/dropdown.hpp

@@ -129,7 +129,7 @@ namespace gcn
          * @param selected the selected item as an index from the list model.
          * @see getSelected
          */
-        void setSelected(int selected);
+        void setSelected(int selected) const;
 
         /**
          * Sets the list model to use when displaying the list.

src/actionevent.cpp

@@ -62,9 +62,9 @@
 
 namespace gcn
 {
-    ActionEvent::ActionEvent(Widget* source, const std::string& id)
+    ActionEvent::ActionEvent(Widget* source, std::string id)
             :Event(source),
-             mId(id)
+             mId(std::move(id))
     {
 
     }

src/exception.cpp

@@ -71,22 +71,21 @@ namespace gcn
 
     }
 
-    Exception::Exception(const std::string& message)
+    Exception::Exception(std::string message)
         : mFunction("?"),
-          mMessage(message),
+          mMessage(std::move(message)),
           mFilename("?"),
           mLine(0)
     {
-
     }
 
-    Exception::Exception(const std::string& message,
-                         const std::string& function,
-                         const std::string& filename,
+    Exception::Exception(std::string message,
+                         std::string function,
+                         std::string filename,
                          unsigned int line)
-                         : mFunction(function),
-                           mMessage(message),
-                           mFilename(filename),
+                         : mFunction(std::move(function)),
+                           mMessage(std::move(message)),
+                           mFilename(std::move(filename)),
                            mLine(line)
     {
 

src/focushandler.cpp

@@ -221,13 +221,13 @@ namespace gcn
         {
             mFocusedWidget = mWidgets.at(focusedWidget);
 
-            Event focusEvent(mFocusedWidget);
+            const Event focusEvent(mFocusedWidget);
             distributeFocusGainedEvent(focusEvent);
         }
 
         if (focused >= 0)
         {
-            Event focusEvent(mWidgets.at(focused));
+            const Event focusEvent(mWidgets.at(focused));
             distributeFocusLostEvent(focusEvent);
         }
     }
@@ -249,7 +249,7 @@ namespace gcn
                 focusedWidget = i;
             }
         }
-        int focused = focusedWidget;
+        const int focused = focusedWidget;
 
         // i is a counter that ensures that the following loop
         // won't get stuck in an infinite loop
@@ -281,13 +281,13 @@ namespace gcn
         if (focusedWidget >= 0)
         {
             mFocusedWidget = mWidgets.at(focusedWidget);
-            Event focusEvent(mFocusedWidget);
+            const Event focusEvent(mFocusedWidget);
             distributeFocusGainedEvent(focusEvent);
         }
 
         if (focused >= 0)
         {
-            Event focusEvent(mWidgets.at(focused));
+            const Event focusEvent(mWidgets.at(focused));
             distributeFocusLostEvent(focusEvent);
         }
     }
@@ -388,7 +388,7 @@ namespace gcn
                 focusedWidget = i;
             }
         }
-        int focused = focusedWidget;
+        const int focused = focusedWidget;
         bool done = false;
 
         // i is a counter that ensures that the following loop
@@ -429,13 +429,13 @@ namespace gcn
         if (focusedWidget >= 0)
         {
             mFocusedWidget = mWidgets.at(focusedWidget);
-            Event focusEvent(mFocusedWidget);
+            const Event focusEvent(mFocusedWidget);
             distributeFocusGainedEvent(focusEvent);
         }
 
         if (focused >= 0)
         {
-            Event focusEvent(mWidgets.at(focused));
+            const Event focusEvent(mWidgets.at(focused));
             distributeFocusLostEvent(focusEvent);
         }
     }
@@ -465,7 +465,7 @@ namespace gcn
                 focusedWidget = i;
             }
         }
-        int focused = focusedWidget;
+        const int focused = focusedWidget;
         bool done = false;
 
         // i is a counter that ensures that the following loop
@@ -506,13 +506,13 @@ namespace gcn
         if (focusedWidget >= 0)
         {
             mFocusedWidget = mWidgets.at(focusedWidget);
-            Event focusEvent(mFocusedWidget);
+            const Event focusEvent(mFocusedWidget);
             distributeFocusGainedEvent(focusEvent);
         }
 
         if (focused >= 0)
         {
-            Event focusEvent(mWidgets.at(focused));
+            const Event focusEvent(mWidgets.at(focused));
             distributeFocusLostEvent(focusEvent);
         }
     }

src/genericinput.cpp

@@ -138,14 +138,12 @@ namespace gcn
 
     KeyInput GenericInput::dequeueKeyInput()
     {
-        KeyInput keyInput;
-
         if (mKeyInputQueue.empty())
         {
             throw GCN_EXCEPTION("The queue is empty.");
         }
 
-        keyInput = mKeyInputQueue.front();
+        const KeyInput keyInput = mKeyInputQueue.front();
         mKeyInputQueue.pop();
 
         return keyInput;
@@ -158,17 +156,15 @@ namespace gcn
 
     MouseInput GenericInput::dequeueMouseInput()
     {
-        MouseInput mouseInput;
-
         if (mMouseInputQueue.empty())
         {
             throw GCN_EXCEPTION("The queue is empty.");
         }
 
-        mouseInput = mMouseInputQueue.front();
+        const MouseInput mouseInput = mMouseInputQueue.front();
         mMouseInputQueue.pop();
 
-        return mouseInput;        
+        return mouseInput;
     }
 
     void GenericInput::_pollInput()

src/imagefont.cpp

@@ -170,7 +170,7 @@ namespace gcn
         mFilename = filename;
         mImage = Image::load(filename, false);
 
-        Color separator = mImage->getPixel(0, 0);
+        const Color separator = mImage->getPixel(0, 0);
 
         int i = 0;
         for (i=0; separator == mImage->getPixel(i, 0)
@@ -284,7 +284,7 @@ namespace gcn
         return mGlyphSpacing;
     }
 
-    Rectangle ImageFont::scanForGlyph(unsigned char glyph, int x, int y, const Color& separator)
+    Rectangle ImageFont::scanForGlyph(unsigned char glyph, int x, int y, const Color& separator) const
     {
         Color color;
         do

src/sdl/sdl2graphics.cpp

@@ -225,10 +225,11 @@ namespace gcn
 
         if (mAlpha)
         {
-            int x1 = area.x > top.x ? area.x : top.x;
-            int y1 = area.y > top.y ? area.y : top.y;
-            int x2 = area.x + area.width < top.x + top.width ? area.x + area.width : top.x + top.width;
-            int y2 = area.y + area.height < top.y + top.height ? area.y + area.height : top.y + top.height;
+            const int x1 = area.x > top.x ? area.x : top.x;
+            const int y1 = area.y > top.y ? area.y : top.y;
+            const int x2 = area.x + area.width < top.x + top.width ? area.x + area.width : top.x + top.width;
+            const int y2 = area.y + area.height < top.y + top.height ? area.y + area.height : top.y + top.height;
+
             SDL_Rect rect;
             rect.x = x1;
             rect.y = y1;
@@ -381,10 +382,10 @@ namespace gcn
 
     void SDL2Graphics::drawRectangle(const Rectangle& rectangle)
     {
-        int x1 = rectangle.x;
-        int x2 = rectangle.x + rectangle.width - 1;
-        int y1 = rectangle.y;
-        int y2 = rectangle.y + rectangle.height - 1;
+        const int x1 = rectangle.x;
+        const int x2 = rectangle.x + rectangle.width - 1;
+        const int y1 = rectangle.y;
+        const int y2 = rectangle.y + rectangle.height - 1;
 
         drawHLine(x1, y1, x2);
         drawHLine(x1, y2, x2);

src/sdl/sdlgraphics.cpp

@@ -108,7 +108,7 @@ namespace gcn
     bool SDLGraphics::pushClipArea(Rectangle area)
     {
         SDL_Rect rect;
-        bool result = Graphics::pushClipArea(area);
+        const bool result = Graphics::pushClipArea(area);
 
         const ClipRectangle& carea = mClipStack.top();
         rect.x = carea.x;
@@ -194,16 +194,15 @@ namespace gcn
 
         if (mAlpha)
         {
-            int x1 = area.x > top.x ? area.x : top.x;
-            int y1 = area.y > top.y ? area.y : top.y;
-            int x2 = area.x + area.width < top.x + top.width ? area.x + area.width : top.x + top.width;
-            int y2 = area.y + area.height < top.y + top.height ? area.y + area.height : top.y + top.height;
-            int x, y;
+            const int x1 = area.x > top.x ? area.x : top.x;
+            const int y1 = area.y > top.y ? area.y : top.y;
+            const int x2 = area.x + area.width < top.x + top.width ? area.x + area.width : top.x + top.width;
+            const int y2 = area.y + area.height < top.y + top.height ? area.y + area.height : top.y + top.height;
 
             SDL_LockSurface(mTarget);
-            for (y = y1; y < y2; y++)
+            for (int y = y1; y < y2; y++)
             {
-                for (x = x1; x < x2; x++)
+                for (int x = x1; x < x2; x++)
                 {
                     SDLputPixelAlpha(mTarget, x, y, mColor);
                 }
@@ -219,7 +218,7 @@ namespace gcn
             rect.w = area.width;
             rect.h = area.height;
 
-            Uint32 color = SDL_MapRGBA(mTarget->format, mColor.r, mColor.g, mColor.b, mColor.a);
+            const Uint32 color = SDL_MapRGBA(mTarget->format, mColor.r, mColor.g, mColor.b, mColor.a);
             SDL_FillRect(mTarget, &rect, color);
         }
     }
@@ -289,7 +288,7 @@ namespace gcn
             x2 = top.x + top.width -1;
         }
 
-        int bpp = mTarget->format->BytesPerPixel;
+        const int bpp = mTarget->format->BytesPerPixel;
 
         SDL_LockSurface(mTarget);
 
@@ -400,7 +399,7 @@ namespace gcn
             y2 = top.y + top.height - 1;
         }
 
-        int bpp = mTarget->format->BytesPerPixel;
+        const int bpp = mTarget->format->BytesPerPixel;
 
         SDL_LockSurface(mTarget);
 
@@ -472,10 +471,10 @@ namespace gcn
 
     void SDLGraphics::drawRectangle(const Rectangle& rectangle)
     {
-        int x1 = rectangle.x;
-        int x2 = rectangle.x + rectangle.width - 1;
-        int y1 = rectangle.y;
-        int y2 = rectangle.y + rectangle.height - 1;
+        const int x1 = rectangle.x;
+        const int x2 = rectangle.x + rectangle.width - 1;
+        const int y1 = rectangle.y;
+	const int y2 = rectangle.y + rectangle.height - 1;
 
         drawHLine(x1, y1, x2);
         drawHLine(x1, y2, x2);
@@ -510,8 +509,8 @@ namespace gcn
 
         // Draw a line with Bresenham
 
-        int dx = ABS(x2 - x1);
-        int dy = ABS(y2 - y1);
+        const int dx = ABS(x2 - x1);
+        const int dy = ABS(y2 - y1);
 
         if (dx > dy)
         {

src/widgets/button.cpp

@@ -85,8 +85,8 @@ namespace gcn
         addFocusListener(this);
     }
 
-    Button::Button(const std::string& caption)
-            : mCaption(caption),
+    Button::Button(std::string caption)
+            : mCaption(std::move(caption)),
               mHasMouse(false),
               mKeyPressed(false),
               mMousePressed(false),
@@ -264,7 +264,7 @@ namespace gcn
 
     void Button::keyPressed(KeyEvent& keyEvent)
     {
-        Key key = keyEvent.getKey();
+        const Key key = keyEvent.getKey();
 
         if (key.getValue() == Key::Enter
             || key.getValue() == Key::Space)
@@ -276,7 +276,7 @@ namespace gcn
 
     void Button::keyReleased(KeyEvent& keyEvent)
     {
-        Key key = keyEvent.getKey();
+        const Key key = keyEvent.getKey();
 
         if ((key.getValue() == Key::Enter
              || key.getValue() == Key::Space)