GdkScrollEvent reports raw scroll events from mouse wheels, 2-fingers touchpad motions, trackpoint scroll motions... Scroll events have different use cases. The most common one is to move content on screen. But they can also be used to switch weapon on a video-game, itterate values in a combo box or a number picker, zoom on a picture... Users ask for a way to configure the scroll speed. It only concerns the first most-common use case.
This MR adds 3 new
GtkSettings keys to control the scrolling speed on each scroll device:
trackpoint. It also implement these settings in
GtkScrolledWindow. To determine the device where the scroll event come from, we look at the
GdkScrollUnit of the event. We need a new unit to distinguish the trackpoint case. That's why I have added a new
GDK_SCROLL_UNIT_CONTINUOUS enum. I have modified the
GdkScrollUnit docs to precisely explain the meaning of each