Improve speed of mass timeline updates (moving hundreds of clips), by disabling ZoomSlider, VideoCaching, certain log outputs, and adding a Wait cursor. This is easily a 10X improvement for many large timelines.

Author: jonoomph

src/windows/main_window.py

@@ -2630,7 +2630,6 @@ def SetWindowTitle(self, profile=None):
 
     # Update undo and redo buttons enabled/disabled to available changes
     def updateStatusChanged(self, undo_status, redo_status):
-        log.info('updateStatusChanged')
         self.actionUndo.setEnabled(undo_status)
         self.actionRedo.setEnabled(redo_status)
         self.actionClearHistory.setEnabled(undo_status | redo_status)

src/windows/views/timeline.py

@@ -195,6 +195,20 @@ def update_clip_data(self, clip_json, only_basic_props=True,
             log.warning('Failed to parse clip JSON data', exc_info=1)
             return
 
+        if not ignore_refresh:
+            # Refresh ZoomSlider and Enable video caching
+            get_app().restoreOverrideCursor()
+            self.window.sliderZoomWidget.ignore_updates = False
+            openshot.Settings.Instance().ENABLE_PLAYBACK_CACHING = True
+        else:
+            # Ignore certain updates for now (no ZoomSlider drawing, or video caching)
+            if not self.window.sliderZoomWidget.ignore_updates:
+                get_app().setOverrideCursor(QCursor(Qt.WaitCursor))
+                self.window.sliderZoomWidget.ignore_updates = True
+                openshot.Settings.Instance().ENABLE_PLAYBACK_CACHING = False
+            # Keep UI from freezing during mass timeline updates
+            get_app().processEvents()
+
         # Search for matching clip in project data (if any)
         existing_clip = Clip.get(id=clip_data.get("id"))
         if not existing_clip:

src/windows/views/zoom_slider.py

@@ -46,6 +46,9 @@ class ZoomSlider(QWidget, updates.UpdateInterface):
 
     # This method is invoked by the UpdateManager each time a change happens (i.e UpdateInterface)
     def changed(self, action):
+        if self.ignore_updates:
+            return
+
         # Ignore changes that don't affect this
         if action and len(action.key) >= 1 and action.key[0].lower() in ["files", "history", "profile"]:
             return
@@ -515,6 +518,7 @@ def __init__(self, *args):
         self.current_frame = 0
         self.is_auto_center = True
         self.min_distance = 0.02
+        self.ignore_updates = False
 
         # Load icon (using display DPI)
         self.cursors = {}
@@ -537,7 +541,6 @@ def __init__(self, *args):
 
         # Connect zoom functionality
         self.win.TimelineScrolled.connect(self.update_scrollbars)
-
         self.win.TimelineResize.connect(self.delayed_resize_callback)
 
         # Connect Selection signals