Add Lua script to collapse playlists

share/scripts/collapse_playlists.lua

@@ -0,0 +1,64 @@
+ardour { ["type"] = "EditorAction", name = "Collapse Playlists",
+	license     = "MIT",
+	author      = "Ardour Team",
+	description = [[Add regions of all playlists to the current playlist of each selected track]]
+}
+
+function factory (params) return function ()
+
+	-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:Selection
+	local sel = Editor:get_selection ()
+
+	-- prepare undo operation
+	-- see http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Session
+	Session:begin_reversible_command ("Collapse Playlists")
+	local add_undo = false -- keep track if something has changed
+
+	-- Track/Bus Selection -- iterate over all Editor-GUI selected tracks
+	-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:TrackSelection
+	for route in sel.tracks:routelist():iter() do
+
+		-- each of the items 'route' is-a
+		-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Route
+		local track = route:to_track() -- see if it's a track
+		if track:isnil() then
+			-- if not, skip it
+			goto continue
+		end
+
+		-- get track's current playlist
+		-- http://manual.ardour.org/lua-scripting/class_reference/#ARDOUR:Playlist
+		local playlist = track:playlist()
+
+		-- clear existing changes, prepare "diff" of state for undo
+		playlist:to_stateful():clear_changes()
+
+		-- get and iterate over all playlists for the current track
+		for p in Session:playlists():playlists_for_track (track):iter() do
+			-- skip current active playlist
+			if (p ~= playlist) then
+				-- for each region of the playlist
+				for r in p:region_list():iter() do
+					-- add it to the current playlist
+					playlist:add_region (r, r:position(), 1, false, 0, 0, false)
+				end
+			end
+		end
+
+		-- collect undo data
+		if not Session:add_stateful_diff_command (playlist:to_statefuldestructible()):empty() then
+			-- is something has changed, we need to save it at the end.
+			add_undo = true
+		end
+
+		::continue::
+	end
+
+	-- all done, commit the combined Undo Operation
+	if add_undo then
+		-- the 'nil' Command here mean to use the collected diffs added above
+		Session:commit_reversible_command (nil)
+	else
+		Session:abort_reversible_command ()
+	end
+end end