power_sequencer/handlers.py

   1 # SPDX-License-Identifier: GPL-3.0-or-later
   2 # Copyright (C) 2016-2020 by Nathan Lovato, Daniel Oakey, Razvan Radulescu, and contributors
   3 import bpy
   4 from bpy.app.handlers import persistent
   5
   6
   7 @persistent
   8 def power_sequencer_playback_speed_post(scene):
   9     """
  10     Handler function for faster playback
  11     Skips keyframes after a frame change based on the playback_speed value
  12     It steps over frame rather than increase the playback speed smoothly,
  13     but it's still useful for faster editing
  14     """
  15
  16     # Calling this function triggers a callback to this function via the frame
  17     # changed handler, causing a stack overflow. We use a property to prevent
  18     # errors.
  19     if bpy.context.screen and not bpy.context.screen.is_animation_playing:
  20         return
  21
  22     playback_speed = scene.power_sequencer.playback_speed
  23
  24     target_frame = scene.frame_current
  25     if playback_speed == "DOUBLE":
  26         target_frame += 1
  27     elif playback_speed == "TRIPLE":
  28         target_frame += 2
  29
  30     if target_frame != scene.frame_current:
  31         bpy.ops.screen.frame_offset(delta=target_frame - scene.frame_current)
  32
  33
  34 def draw_playback_speed(self, context):
  35     layout = self.layout
  36     scene = context.scene
  37     layout.prop(scene.power_sequencer, "playback_speed")
  38
  39
  40 def draw_ui_menu(self, context):
  41     layout = self.layout
  42     layout.menu("POWER_SEQUENCER_MT_main")
  43
  44
  45 def register_handlers():
  46     # Menus
  47     bpy.types.SEQUENCER_HT_header.append(draw_ui_menu)
  48     bpy.types.SEQUENCER_HT_header.append(draw_playback_speed)
  49
  50     # Handlers
  51     bpy.app.handlers.frame_change_post.append(power_sequencer_playback_speed_post)
  52
  53
  54 def unregister_handlers():
  55     # Menus
  56     bpy.types.SEQUENCER_HT_header.remove(draw_ui_menu)
  57     bpy.types.SEQUENCER_HT_header.remove(draw_playback_speed)
  58
  59     # Handlers
  60     bpy.app.handlers.frame_change_post.remove(power_sequencer_playback_speed_post)