This is mostly a simple lexical search+replace but the absence of operator< for
std::weak_ptr<T> leads to some complications, particularly with Evoral::Sequence
and ExportPortChannel.
There already is a shaded coverage frame indicating
if a layer is audible. This leads to a more consistent view.
In addition changing layered mode now has to update the
colors (set_frame_color).
The region itself has no time_domain property, changing the time-domain
is done by changing the domain of the region length. undo/redo hence
emite a Length PropertyChange signal.
In the presence of tempo-changes distinguishing between offsets and
absolute positions is signficant. It is only valid to convert absolute
times using the tempo-map
Furthermore since GUI zoom-factor is time-invariant (samples per pixel),
all GUI operations must explictly use samples (or timecnt). It is not
valid (and problematic) to use use a location dependent timepos.
The class now has two separate methods for setting a duration or a point
value. They MUST be used appropriately, because their behavior is different.
When ::set_duration() is used in timecode mode, an extent (inclusive-end
length) is shown rather than a length.
Some objects, such as the TimeInfoBox, now deliberately shown an inclusive end
for their "end" clock, but this not universally followed, pending more feedback
from users and investigating of conventions in other DAWs.
Before nutempo, ::find_next_region_boundary() used to return -1
when no boundary was found (now timepos_t::max is returned).
timepos_t::increment() returns the incremented value, not increments
the variable itself.
RegionView::make_name already adds the prefix, AudioRegionView
does not need to add it again.
Also the font used on macOS (Lucia Grande) has a rather limited
UTF-8 charset and does not support:
\u20F0 (COMBINING ENCLOSING CIRCLE BACKSLASH)
\U0001F507 (SPEAKER WITH CANCELLATION STROKE)
so for now we keep using "!" on macOS.
::model_changed() is used when the model has changed (eg. new notes or some
notes deleted); ::view_changed() is used when only some view parameter (e.g.
zoom, scroll, track height etc) has been altered.
Not fully functional yet (::view_chanted() ignores scroll)
