Apply Guichan's changes from 3acee30c0bb2540b2104ee2f803d8cd2844af0b9…

TODO

@@ -1,4 +1,4 @@
-* Continue rebasing from 3acee30c0bb2540b2104ee2f803d8cd2844af0b9
+* Continue rebasing from 1478f70095c523d7fcb95cc37cd770afb9cd4516
 * Add a focus listener interface.
 * Make focus apply synchronously.
 * Graphics and input objects for DirectX.

include/guisan/rectangle.hpp

@@ -119,6 +119,15 @@ namespace gcn
          */
         bool isPointInRect(int x, int y) const;
 
+        /**
+         * Checks whether the rectangle is empty or not. A rectangle
+         * is considered empty when it's width or height is either
+         * zero or negative.
+         *
+         * @return True if the rectangle is empty, false otherwise.
+         */
+        bool isEmpty() const;
+
         /**
          * Output operator for output.
          *

src/graphics.cpp

@@ -76,7 +76,7 @@ namespace gcn
     {
         // Ignore area with a negative width or height
         // by simple pushing an empty clip area to the stack.
-        if (area.width < 0 || area.height < 0)
+        if (area.isEmpty())
         {
             ClipRectangle carea;
             mClipStack.push(carea);

src/rectangle.cpp

@@ -131,6 +131,11 @@ namespace gcn
                 && y < (this->y + this->height));
     }
 
+    bool Rectangle::isEmpty() const
+    {
+        return width < 0 || height < 0;
+    }
+
     std::ostream& operator<<(std::ostream& out, const Rectangle& rectangle)
     {
         return out << "Rectangle [x = " << rectangle.x << ", y = " << rectangle.y

src/widgets/scrollarea.cpp

@@ -990,7 +990,7 @@ namespace gcn
                                    0,
                                    getWidth() - (mVBarVisible ? mScrollbarWidth : 0),
                                    getHeight() - (mHBarVisible ? mScrollbarWidth : 0));
-        if (area.width < 0 || area.height < 0)
+        if (area.isEmpty())
         {
             return Rectangle();
         }