power_sequencer/handlers.py

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