```
gtk2_ardour/ardour_ui.cc:2060: error: ISO C++ says that these are ambiguous, even though the worst conversion for the first is better than the worst conversion for the second:
/usr/include/architecture/i386/math.h:343: note: candidate 1: double pow(double, double)
/usr/include/c++/4.2.1/cmath:357: note: candidate 2: float std::pow(float, float)
```
Previously x-axis threshold was in samples. This is
useless unless zoomed in to the max. So in most cases
the first-move was always in x-direction, making constrained
y-axis drags near impossible.
Furthermore the threshold for copy-drags was increased
as per #8686
Region positions were updated in the GUI, before the playlist
was catching up.
The butler thread reads a region using the region's new position,
but the playlist's old range.
Thread 1 (GUI)
```
#22 ARDOUR::Playlist::notify_layering_changed()
#26 ARDOUR::AudioPlaylist::region_changed
#27 ARDOUR::Playlist::region_changed_proxy
#35 ARDOUR::Region::send_change
#36 ARDOUR::Region::set_position
#37 RegionRippleDrag::remove_unselected_from_views
#38 RegionRippleDrag::finished
```
LayeringChanged() also triggers DiskIOProcessor::playlist_modified
which schedules a pending-override and summons the butler.
Note that when moving only a few regions the butler starts after all
updates have been completed.
Butler thread:
```
#4 ARDOUR::AudioRegion::read_at
#5 ARDOUR::AudioPlaylist::read
#6 ARDOUR::DiskReader::audio_read
#7 ARDOUR::DiskReader::overwrite_existing_audio
#8 ARDOUR::DiskReader::overwrite_existing_buffers
#9 ARDOUR::Track::overwrite_existing_buffers
#10 ARDOUR::Session::non_realtime_overwrite
```
Region read fails:
```
libs/ardour/audioregion.cc:503 assert (position >= _position);
(gdb) p position
$1 = 1312000
(gdb) p _position
$2 = {<PBD::PropertyTemplate<long>> = {_have_old = true,
_current = 1336000, _old = 1312000} }
```
The DraggingView's time_axis_view (index) is set to the size of _time_axis_views
in ::motion() near line 1149. This makes it invalid as index into the vector.
see also 25c0bd9274
play, locate, play resulted in the video-monitor showing
the target frame shortly, and play a few frames from the old
location.
This was due to locate happening async. Click to locate
directly sends the new location:
```
VideoTimeLine::manual_seek_video_monitor
ARDOUR_UI::update_transport_clocks
CursorDrag::fake_locate
CursorDrag::start_grab
DragManager::start_grab
```
CursorDrag::finished unset _dragging_playhead before the
call to resuest_locate(). Meanwhile playback continues.
This is an initial work-around for signal emission with
Playlist:region_lock held:
Playlist::duplicate() takes RegionWriteLock() and then calls
RegionFactory::create(). The newly created region does NOT have
property-changes suspended, and the RegionFactory can change
region-properties which results in signal-emission.
This in turn can lead to a call Editor::session_gui_extents()
-> ARDOUR::Playlist::get_extent() -> Playlist::RegionReadLock
which deadlocks: https://pastebin.com/84rSbsA3
Eventually we need a mechanism to create regions with
->suspend_property_changes() and add it to the playlist's
thawlist (pass a thawlist to the region-factory).
Playlist changes do not include region-property changes.
When inserting a region, position(s) of other Regions may
change and those changes have to be recorded explicitly (for now).
see also RegionRippleDrag.
The undo command needs to be started before calling
playlist->add_region() because that may move automation
or include ripple changes. see the following backtrace:
```
UndoTransaction::add_command
ARDOUR::DiskReader::move_processor_automation
ARDOUR::Route::foreach_processor
ARDOUR::DiskReader::playlist_ranges_moved
ARDOUR::Playlist::flush_notifications
ARDOUR::Playlist::RegionWriteLock::~RegionWriteLock
ARDOUR::Playlist::add_region
Editor::bounce_range_selection
```
Except. it seems automation is moved incorrectly in this case..
Some plugin UIs, particularly those that cannot be resized
unset `autoresizesSubviews`. Since the plugin-view is re-parented,
the host has to directly set the view's size.
However some plugins have multiple child views, apparently
for off-screen pixmaps (e.g. UAD plugins). Those additional
should not be resized (or re-stacked).
e.g.
Reason-Rack
view 0x7fe27e44e570 @ 0, 33 834 x 804
view 0x7fe288aa3770 @ 278, 268 278 x 268
UAD Tube-tech
view 0x7fe270a9cbf0 @ 0, 33 1160 x 374
view 0x7fe28883d030 @ 0, 0 1160 x 374
view 0x7fe2888546e0 @ 0, 0 1160 x 24
see also aef366c156https://discourse.ardour.org/t/uad-plugin-will-not-load-shows-as-expired-when-its-not/105756/5?u=x42
Preferences is a tabbable, a leftover artifact of when it was, in fact, intended to be a tabbable. Rather than
re-engineer this right now, add a key event handler so that Primary-w works for this just like other dialogs
