Group all 'add to timeline' updates in a single undo/redo transaction (#5145)

Author: jonoomph

src/windows/add_to_timeline.py

@@ -27,6 +27,7 @@
  """
 
 import os
+import uuid
 from operator import itemgetter
 from random import shuffle, randint, uniform
 
@@ -152,6 +153,10 @@ def accept(self):
         """ Ok button clicked """
         log.info('accept')
 
+        # Transaction id to group all updates together
+        tid = str(uuid.uuid4())
+        get_app().updates.transaction_id = tid
+
         # Get settings from form
         start_position = self.txtStartTime.value()
         track_num = self.cmbTrack.currentData()
@@ -376,6 +381,9 @@ def accept(self):
             # Increment position by length of clip
             position += (end_time - start_time)
 
+        # Clear transaction
+        get_app().updates.transaction_id = None
+
         # Accept dialog
         super(AddToTimeline, self).accept()