... This makes it impossible to forget to include the EXPERIMENTAL definitions
(such as when cutting and pasting code) and so get unintended quiet changes of
behavior.
The EXPERIMENTAL flags are now specified instead in new file Experimental.cmake
... The setting of scale type now happens in the default constructor of
WaveformSettings, which calls LoadPrefs.
Since creation of WaveformSettings is always forced, we don't need the
distinction between WaveTrack::GetWaveformSettings and
WaveTrack::GetIndependentWaveformSettings.
That distinction was more analogy with the handling of SpectrogramSettings that
we don't need now.
... These do not require header files; they are tiny proto-plugins that work
by registration of AttachedVirtualFunction overrides at startup.
Dependency may go from them to TrackView subclasses but not back; so in
principle a reduced Audacity without time-shift could be linked that still uses
the TrackView subclasses.
But other work to make the hit test for the Time Shift tool registrable would
have to precede that.
... Because LabelTrack, unlike the others, will also need a mouse y coordinate.
The extra information is present when using the time-shift tool but not when
using the items in ClipMenus.
... for shifting of clips among tracks
But this (temporarily) breaks the behavior of dragging back to the original
clip without first releasing the mouse
... Preserving existing behavior, but maybe these cases should be reconsidered
and made more uniform. (e.g. should hit test on NoteTrack sometimes miss, as
with WaveTrack?)
Also made details of WaveTrack hit testing consistent with what ClipMenus does
... in TimeShiftHandle. They do nothing useful yet, but responsibilities
will shift into them.
TypeSwitch is avoided and the subclasses are defined in appropriate places
for dependency management, thanks to AttachedVirtualFunction.
... Implemented giving the Multi-view choice the special implementation that it
needs.
The "multi" choice is always last in the preference and in the command editing
drop-down menus, but that could be changed.
Multi-view should not be treated as another registered kind of sub-view on par
with others. This would complicate the implementation in worse ways.
... in Wave track context menu and SetTrackVisualsCommand
Instead, discover them through a registry.
This eliminates some duplication of string constants and prepares for
non-intrusive generalization to more kinds of sub-views.
This makes the command agnostic about which subview types are known, but the
context menu still has special case treatment for Spectrogram Settings and
Wave Colors.
... when you shrink a sub-view then toggle it, or toggle all views off then
exit multi-view
Fix it by making GetSubViews more robust to contents of mPlacements
