48dde40b4f
This also uses the new API exposed by MidiViewBackground so that the header simply re-uses the same exact position & height values computed by the background for its note lines. PianoRollHeaderBase is the base class with the shared implementation. PianoRollHeader is the GTK widget derived class. ArdourCanvas::PianoRollHeader is the canvas item derived class. Both PianoRollHeader implementations have to implement various methods that gloss over the differences between drawing and event handling in a GTK widget context or in a canvas item context
Please see the Ardour web site at https://ardour.org/ for all documentation..
For information on building ardour:
https://ardour.org/development.html