Fiddled with scrolling to leave a bit of context on each side. 'scroll interval' is a single float, should make it a configuration variable some day
git-svn-id: svn://localhost/ardour2/branches/midi@796 d708f5d6-7413-0410-9779-e7cbd77b26cf
associated stuff are now separated (with common things in base classes).
Extremely dirty and in progress, but builds, runs, and audio/midi tracks/busses
all look (and really are) distinct in the GUI.
git-svn-id: svn://localhost/ardour2/branches/midi@691 d708f5d6-7413-0410-9779-e7cbd77b26cf
