Horizontal movement detection in context menus

[humdinger]

Here's an idea that may improve usability when using the navigational context menus to drill down the filesystem hierarchy. Especially when using a touchpad and dealing with wide context menus (because of long filenames in a folder), I tend to lose my way on the horizontal mouse pointer journey towards a subfolder. I sometimes stray vertically and accidentally lose my destination just to pop up another subfolder above or below it.
Actually, the following enhancement would be interesting for any menu.

Is it possible to teach the system to recognize horizontal movement (a relatively much higher horizontal than vertical velocity) and restrict vertical movement in that case?
It would be like a slightly magnetic horizontal guide as they are known from some graphics editors. Maybe some code from Haiku's "magnetic screen edge" can be re-used?

[stippi]

It's impossible to solve the problem the way you describe, since it does not work with absolute input devices like tablets or touch screens. However, the menu code should solve this issue by introducing a delay or via other means. IIRC it even contains such code already, it may not yet work optimally.

[humdinger]

Any other solution to the problem would be appreciated as well. :)
I'm not sure why absolute input devices should spoil the fun, however. Surely there has to be a way to distinguish if the user has pointed to some point or if she dragging the finger/pen. Dragging horizontally produces many increasing x-coordinates in a certain time frame, pointing does not.

There actually is a delay when straying vertically while moving horizontally that prevents closing the submenu immediately. You still have to correct your mouse-navigation quickly however, which isn't as nice by far than the suggested magnetic guide. Also, it looks like the delay depends on the number of items in the subfolder: if there are only 2 or 3, there's almost no delay, while crowded subfolders show a much longer delay. Compare e.g. ~/people and ~/mail.

[waddlesplash]

Moving Tracker enhancement tickets out of R1 milestone -- Tracker's source code comes from BeOS R5, so it already has all the features it did on R5.