This is needed to be able to lock the application fully on OS X, where the global menu bar would still allow interaction
even when a modal dialog is displayed.
Deleting regions (or ranges, or anything) shouldn't affect the contents of
the clipboard - only CutCopyOp::Copy, CutCopyOp::Cut and CutCopyOp::Clear
should do that.
Add a value for Ripple to EditMode enum.
Add Ripple edit mode to edit mode dropdown, by adding it to the
Editor::build_edit_mode_menu() helper function, and remove the old code that
added items to the (now unused) Editor::edit_mode_strings.
Add the regions that should be affected by the drag to RegionDrag::_views so
that the drag carries them along automatically.
Use a copy of the RegionList in Playlist::core_ripple(), since bad things
happen when iterating over regions and they get moved around in the list.
Handle rippling in removal of regions from playlist.
When dragging in ripple mode, exclude all regions that lie before the
original start position of the selected regions being dragged from
rippling: this is what Mixbus does.
Make editor dragging respect snap-to settings, by using the existing
compute_x_delta() function, which did almost the right thing. Move setting
of _last_frame_position out of that function so all ripple-dragged regions
can move.
Ripple when dragging from region list: even though Mixbus doesn't do this, it
seems like a good idea.
Prevent multi-track selection being dragged across tracks, by making
RegionMotionDrag::y_movement_allowed() virtual, and overriding it in
RegionRippleDrag to forbid dragging of selections containing regions on more
than one track to dofferent tracks in ripple mode.
Remember which TimeAxisView a ripple-mode drag that's allowed cross-track
drags started from, so that the effect of rippling regions after any region
that's dragged off that track can be undone.
Existing code would cause data loss due to creation of two Source objects referring the same path, one with removable flags and one without. Careful code review suggested a variety of thinkos, function naming problems and other confusion that caused this. I have tried ot extensively comment what is going on with these operations, because it is one key area in which MIDI differs from audio: with audio, capture is the only way to add a new audio region, but for MIDI there are GUI input events that can add a new region.
Dragging regions vertically does the quantization BUT speed control is lacking and the region ends up on
a track that is still invisible ... to be fixed as the sun rises.
