This is implemented on top of a Tree that represents the whole timeline.
SourceClips can not fully overlap anymore and the tests have been
updated to take that into account. Some new tests were added to verify
that behaviour in greater details
Auto transition when having 3 overlapping clips in a same point in the
timeline is not supported as we can't handle it in a nice way. Before we
to avoid creating 2 overlapping transitions (which is plain broken in
NLE) were completely disabling `auto-transition` and removing all
auto-transitions in the timeline but this is pretty weird for the end
user. This commit changes and now makes sure 2 transitions are not
created in the same place.
Also cleanup previous test case.
When removing an effect from a clip, first the notify::priority signals
were being emitted for the remaining effects which changed priority, and only
at the end the child-removed signal. Now the child-removed signal is emitted
first.
In the (now tested) scenario where we have a transition on the right
side of a clip we are splitting, auto transitions can't be created
because we resize the clip after adding the new one, meaning that
there are 3 elements in the "transition zone", we need to force
auto transition creation after the splitting.
Fixes https://gitlab.gnome.org/GNOME/pitivi/issues/2142
Had to separate timeline_emit_group_added from timeline_add_group
to avoid emitting group-added when the project is being loaded.
Reviewed-by: Thibault Saunier <thibault.saunier@collabora.com>
Differential Revision: https://phabricator.freedesktop.org/D1302
