[Rosegarden-devel] Auto-scrolling tweaks patch

[William <ros...@or...>]

Here's a patch to tweak the behaviour of auto-scrolling.
Try it and see what you think.

1. Decelerate auto-scrolling when mouse starts moving in opposite direction.

2. Make rate of acceleration equal in opposite directions of mouse movement
   by using a float to int conversion of m_minDeltaScroll.

3. Increase maximum auto-scrolling speed by 50%.

4. Double the frequency of the auto-scrolling timer.

I haven't attempted to fix the zoom effect:
The speed of auto-scrolling is still too fast for zooms < 100% and
too slow for zooms > 100%.
Maybe the auto-scrolling speed should be multiplied by 1.0/(zoom/100.0).

William