MouseScroll feature addition

Adds the feature of mouse scroll in windows.

src/mouse.c

@@ -124,6 +124,38 @@ void clickMouse(MMMouseButton button)
 	toggleMouse(false, button);
 }
 
+/**
+ * Function used to scroll the screen in the required direction.
+ * This uses the magnitude to scroll the required amount in the direction. 
+ * TODO Requires further fine tuning based on the requirements.
+ */
+void scrollMouse(int scrollMagnitude, MMMouseWheelDirection scrollDirection)	
+{
+	/* Direction should only be considered based on the scrollDirection. This
+	 * Should not interfere. */
+	int cleanScrollMagnitude = abs(scrollMagnitude);
+	if (!(scrollDirection == DIRECTION_UP || scrollDirection == DIRECTION_DOWN))
+	{
+		return;
+	}
+
+	/* Set up the OS specific solution */
+	#if defined(__APPLE__)
+		/* TODO Add Code for this platform */
+	#elif defined(USE_X11)
+		/* TODO Add Code for this platform */
+	#elif defined(IS_WINDOWS)
+		INPUT mouseScrollInput;
+		mouseScrollInput.type = INPUT_MOUSE;
+		mouseScrollInput.mi.dx = 0;
+		mouseScrollInput.mi.dy = 0;
+		mouseScrollInput.mi.dwFlags = MOUSEEVENTF_WHEEL;
+		mouseScrollInput.mi.time = 0;
+		mouseScrollInput.mi.dwExtraInfo = 0;
+		mouseScrollInput.mi.mouseData = WHEEL_DELTA * scrollDirection * cleanScrollMagnitude;
+		SendInput(1, &mouseScrollInput, sizeof(mouseScrollInput));
+	#endif
+}
 /*
  * A crude, fast hypot() approximation to get around the fact that hypot() is
  * not a standard ANSI C function.

src/mouse.h

@@ -42,6 +42,12 @@ extern "C"
 		RIGHT_BUTTON = 3
 	};
 	typedef unsigned int MMMouseButton;
+
+	enum __MMMouseWheelDirection	{
+		DIRECTION_DOWN = -1,
+		DIRECTION_UP 	 = 1
+	};
+	typedef unsigned int MMMouseWheelDirection;
 
 #else
 	#error "No mouse button constants set for platform"
@@ -73,6 +79,10 @@ void toggleMouse(bool down, MMMouseButton button);
 /* Clicks the mouse with the given button in the current position. */
 void clickMouse(MMMouseButton button);
 
+/* Scrolls the mouse in the stated direction. 
+ * TODO: Add a smoothly scroll mouse next. */
+void scrollMouse(int scrollMagnitude, MMMouseWheelDirection scrollDirection);
+
 #endif /* MOUSE_H */
 
 #ifdef __cplusplus

src/robotjs.cc

@@ -166,6 +166,25 @@ NAN_METHOD(mouseToggle)
 	NanReturnValue(NanNew("1"));
 }
 
+NAN_METHOD(scrollMouse) 
+{
+	NanScope();
+
+	//Get the values of magnitude and direction from the arguments list
+	if(args.Length() == 2)	
+	{
+		int scrollMagnitude = args[0]->Int32Value();
+		int scrollDirection = args[1]->Int32Value();
+
+		scrollMouse(scrollMagnitude, scrollDirection);
+
+		NanReturnValue(NanNew("1"));
+	} 
+	else 
+	{
+		return NanThrowError("Invalid number of arguments.");
+	}
+}
 /*
  _  __          _                         _ 
 | |/ /___ _   _| |__   ___   __ _ _ __ __| |
@@ -489,6 +508,9 @@ void init(Handle<Object> target)
 
 	target->Set(NanNew<String>("mouseToggle"),
 		NanNew<FunctionTemplate>(mouseToggle)->GetFunction());
+
+	target->Set(NanNew<String>("scrollMouse"),
+		NanNew<FunctionTemplate>(scrollMouse)->GetFunction());
 
 	target->Set(NanNew<String>("keyTap"),
 		NanNew<FunctionTemplate>(keyTap)->GetFunction());