This concept from 2007 is no longer required Temporal::get_grid
already limits the number of grid-lines depending on the step
size (mod-bar, beat_div) and start/end positions.
We now generate a grid from the TempoMap of appropriate "density". Doing this
in the editor just gets things wrong (and partially duplicates the (complex)
logic already present in the TempoMap).
Found via `codespell -q 3 -S *.po,./.git,./share/patchfiles,./libs,./msvc_extra_headers,./share/web_surfaces,*.patch -L ba,buss,busses,discreet,doubleclick,hsi,ontop,ro,scrollin,seh,siz,sord,sur,te,trough,ue`
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.
Previously a triggerbox_ui.h change triggered a complete UI
rebuild. This follows the concept of other editor_selection
lists which use forward declarations.
We need to be able to construct Metrics after the ruler is constructed
in order to deal with Triggers which are potentially short-lived. We
stored the reference as a pointer anyway, so it's not as much of a change
as it appears.
