Much like the edit-tool and grid-types, clock-modes are UI state.
Saving the UI state separately allows them to be used
consistently for new sessions. Previously clock-modes were set
initially (at application start) and when loading sessions.
The clock modes of newly created sessions was different
depending on loading another session prior to creating the
session. This is now no longer the case.
Re-assigning a sigc::connection does not disconnect
any previously connected signals.
WindowProxy::setup may be called multiple times. Notably plugin
windows can change the managed _window (generic/custom), which
requires a call to setup.
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.
audio time nominally uses superclocks as its canonical unit. However
many things at a higher level only understand samples. If we
increment or decrement a superclock value by 1, the vast majority of
the time we will still get the same sample value after
conversion. Thus to correctly alter an audio time by an amount
that will manifest as 1 sample's difference, we have to use
samples_to_superclock(1)
Various operations, notably time-stretch and other filters, directly
added the generated whole-file region to the playlist.
The editor has not listed the generated Region in the RegionList.
This is required when adding locked regions to a playlist.
e.g. after a split or partition operation. It is only supposed
to be used from Playlist::add_region_internal() and
Playlist::partition_internal().
This allows to copy a property list and then selectively
replace various properties. e.g.
```
PropertyList plist (region->properties ());
plist.add (Properties::length, len);
plist.remove (Properties::start);
```
See also 8b0ab38675
and 97f0fac7d5
This also fixes the issue referenced in
8c83149c4c
