The suspend/resume routes code requires that there be a call to
Editor::redisplay_track_views() if anything is to happen on resume. This was
missing from the events triggered by a UI scale change.
Deleting _track_canvas_viewport automatically destroys
any child Items. The LocationMarker's group was already destroyed
when ~ArdourMarker() runs and calls `delete group`.
So first delete the marker, then the canvas
* in the 'fake_drag' case (dragging the playhead from the ruler), the
mouse events are delivered to the playhead during the drag so we need
to temporarily sensitize the playhead during that operation, then reset
the sensitivity via config
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.
Import via Drag/Drop previously worked by selecting a track,
and then importing to the selected track.
This approach fails when the selected track is in a track-group,
and selecting the track also selects other tracks of different type.
Now the track to drop onto is passed directly passed through to
::finish_bringing_in_material as existing_track.
The track-header (gtk) is packed with 1px box spacing. This
is added at the top of each box (best seen by looking at the
group-tab vs track-header alignment in the editor).
However the actual track separator line on the canvas is at the
bottom of each track, aligning with the top of the next track
or automation-lane.
The first track however lacks a separator at the top, which
needs to be provided by the ruler. Once the canvas is scrolled
this ruler/canvas separator overlaps with the bottom separator of
each TAV.
Using ruler Rectangle::set_outline had various issues.
The outline extends outside the rectangle. It bled into the
video-timeline instead of the canvas' top y-axis pixel.
Also the separator was above the video-timeline, not above the
canvas. Hence a dedicated separator Line is preferable.
It also provides a consistent separator if no rulers are visible.
The track-height change needs to be applied so that
vertical_adjustment max range is set correctly.
Otherwise vertical_adjustment.set_value() may fail
or scroll to the wrong position.
In 5b3eacd421 `redisplay_track_views()` was moved from
EditorRoutes to Editor. The call was delegated to the idle
thread, potentially collecting multiple calls before performing
the update.
This resulted in "Fit selection" to set the y-offset before the
height-change was applied.
When importing a multi-track MIDI files with identical track-names,
Ardour would create the same file for each track. Effectively
overwriting an existing file.
The following MIDI file would create the same file twice
in `interchange/`, once for each MTrk.
```
MFile 1 2 240
MTrk
0 Meta SeqName "Foo Bar"
0 TimeSig 4/4 24 8
0 Tempo 666667
0 Meta TrkEnd
TrkEnd
MTrk
0 Meta TrkName "Foo Bar"
0 On ch=10 n=36 v=95
...
```
