Modify JumpToStart to use the GetMinFrame() method, and have it scrol…

…l to the new playhead position. This will select the first clip on the timeline and jump the scrollbar to it. Also updated the JumpToEnd to scroll to the playhead position.

src/windows/main_window.py

@@ -1119,13 +1119,18 @@ def actionJumpStart_trigger(self, checked=True):
         player = self.preview_thread.player
         current_speed = player.Speed()
 
+        min_frame = 1
+        if self.preview_thread and self.preview_thread.timeline:
+            min_frame = self.preview_thread.timeline.GetMinFrame()
+
         # Switch speed back to forward (and then pause)
         # This will allow video caching to start working in the forward direction
         self.SpeedSignal.emit(1)
         self.SpeedSignal.emit(0)
 
         # Seek to the 1st frame
-        self.SeekSignal.emit(1)
+        self.SeekSignal.emit(min_frame)
+        QTimer.singleShot(50, self.actionCenterOnPlayhead_trigger)
 
         # If playing, continue playing
         if current_speed >= 0:
@@ -1140,6 +1145,7 @@ def actionJumpEnd_trigger(self, checked=True):
         # Determine last frame (based on clips) & seek there
         max_frame = get_app().window.timeline_sync.timeline.GetMaxFrame()
         self.SeekSignal.emit(max_frame)
+        QTimer.singleShot(50, self.actionCenterOnPlayhead_trigger)
 
     def onPlayCallback(self):
         """Handle when playback is started"""