How to scroll in browser with Logitech Trackman Marble?

Question

I have a Logitech Trackman Marble and I really love it. I spend a lot of time on web browser and code editors. I was wondering if there could be a feature like when I press Option Key the trackball becomes a scroll wheel. So that I can use the trackball for both moving cursor and scrolling.

Answer 1

You can use KeyRemap4MacBook:

<autogen>__PointingRelativeToScroll__ PointingButton::NONE, ModifierFlag::FN | ModifierFlag::NONE</autogen>

Replace ModifierFlag::FN with VK_CONTROL for either control. Keys that aren't modifier keys can be mapped to EXTRA1:

<autogen>__KeyToKey__ KeyCode::F1, KeyCode::VK_MODIFIER_EXTRA1</autogen>
<autogen>__PointingRelativeToScroll__ PointingButton::NONE, ModifierFlag::EXTRA1</autogen>

Key Repeat > [Pointing Device] CursorMove to ScrollWheel Rate changes the scrolling speed.

See the source for the key code values and predefined settings.