modifiable mouse wheel scroll step

source/gui/basis.cpp

@@ -14,21 +14,33 @@
 
 #include <nana/gui/basis.hpp>
 
-namespace nana
+using namespace nana;
+using namespace nana::parameters;
+
+//struct appearance
+appearance::appearance()
+	:taskbar(true), floating(false), no_activate(false),
+	 minimize(true), maximize(true), sizable(true),
+	 decoration(true)
+{}
+
+appearance::appearance(bool has_decorate, bool taskbar, bool is_float, bool no_activate, bool min, bool max, bool sizable)
+	:	taskbar(taskbar), floating(is_float), no_activate(no_activate),
+		minimize(min), maximize(max), sizable(sizable),
+		decoration(has_decorate)
+{}
+//end struct appearance
+
+#if defined(NANA_WINDOWS)
+#	include <windows.h>
+#endif
+
+mouse_wheel::mouse_wheel()
+	: lines(3), characters(3)
 {
-	//struct appearance
-	//@brief: Window appearance structure
-		appearance::appearance()
-			:taskbar(true), floating(false), no_activate(false),
-			 minimize(true), maximize(true), sizable(true),
-			 decoration(true)
-		{}
-
-		appearance::appearance(bool has_decorate, bool taskbar, bool is_float, bool no_activate, bool min, bool max, bool sizable)
-			:	taskbar(taskbar), floating(is_float), no_activate(no_activate),
-				minimize(min), maximize(max), sizable(sizable),
-				decoration(has_decorate)
-		{}
-	//end struct appearance
-}//end namespace nana
+#if defined(NANA_WINDOWS)
+	::SystemParametersInfo(SPI_GETWHEELSCROLLLINES, 0, &lines, 0);
+	::SystemParametersInfo(SPI_GETWHEELSCROLLCHARS, 0, &characters, 0);
+#endif
+}