power_sequencer/operators/crossfade_add.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
   7 from .utils.functions import find_sequences_after
   8 from .utils.functions import convert_duration_to_frames
   9 from .utils.global_settings import SequenceTypes
  10 from .utils.doc import doc_name, doc_idname, doc_brief, doc_description
  11
  12
  13 class POWER_SEQUENCER_OT_crossfade_add(bpy.types.Operator):
  14     """
  15     *brief* Adds cross fade between selected sequence and the closest sequence to its right
  16
  17     Based on the active strip, finds the closest next sequence of a similar type, moves it
  18     so it overlaps the active strip, and adds a gamma cross effect between them. Works with
  19     MOVIE, IMAGE and META strips
  20     """
  21
  22     doc = {
  23         "name": doc_name(__qualname__),
  24         "demo": "https://i.imgur.com/ZyEd0jD.gif",
  25         "description": doc_description(__doc__),
  26         "shortcuts": [
  27             ({"type": "C", "value": "PRESS", "ctrl": True, "alt": True}, {}, "Add Crossfade")
  28         ],
  29         "keymap": "Sequencer",
  30     }
  31     bl_idname = doc_idname(__qualname__)
  32     bl_label = doc["name"]
  33     bl_description = doc_brief(doc["description"])
  34     bl_options = {"REGISTER", "UNDO"}
  35
  36     crossfade_duration: bpy.props.FloatProperty(
  37         name="Crossfade Duration", description="The duration of the crossfade", default=0.5, min=0
  38     )
  39     auto_move_strip: bpy.props.BoolProperty(
  40         name="Auto Move Strip",
  41         description=(
  42             "When true, moves the second strip so the crossfade"
  43             " is of the length set in 'Crossfade Length'"
  44         ),
  45         default=True,
  46     )
  47
  48     @classmethod
  49     def poll(cls, context):
  50         return context.selected_sequences
  51
  52     def execute(self, context):
  53         sorted_selection = sorted(context.selected_sequences, key=lambda s: s.frame_final_start)
  54         for s in sorted_selection:
  55             s_next = self.get_next_sequence_after(context, s)
  56             s_to_offset = s_next.input_1 if hasattr(s_next, "input_1") else s_next
  57
  58             if self.auto_move_strip:
  59                 offset = s_to_offset.frame_final_start - s.frame_final_end
  60                 s_to_offset.frame_start -= offset
  61
  62             if s_to_offset.frame_final_start == s.frame_final_end:
  63                 self.offset_sequence_handles(context, s, s_to_offset)
  64
  65             self.apply_crossfade(context, s, s_next)
  66         return {"FINISHED"}
  67
  68     def get_next_sequence_after(self, context, sequence):
  69         """
  70         Returns the first sequence after `sequence` by frame_final_start
  71         """
  72         next_sequence = None
  73         next_in_channel = [
  74             s for s in find_sequences_after(context, sequence) if s.channel == sequence.channel
  75         ]
  76         next_transitionable = (s for s in next_in_channel if s.type in SequenceTypes.TRANSITIONABLE)
  77         try:
  78             next_sequence = min(next_transitionable, key=lambda s: s.frame_final_start)
  79         except ValueError:
  80             pass
  81         return next_sequence
  82
  83     def apply_crossfade(self, context, strip_from, strip_to):
  84         for s in bpy.context.selected_sequences:
  85             s.select = False
  86         strip_from.select = True
  87         strip_to.select = True
  88         context.scene.sequence_editor.active_strip = strip_to
  89         bpy.ops.sequencer.effect_strip_add(type="GAMMA_CROSS")
  90
  91     def offset_sequence_handles(self, context, sequence_1, sequence_2):
  92         """
  93         Moves the handles of the two sequences before adding the crossfade
  94         """
  95         fade_duration = convert_duration_to_frames(context, self.crossfade_duration)
  96         fade_offset = int(fade_duration / 2)
  97
  98         if hasattr(sequence_1, "input_1"):
  99             sequence_1.input_1.frame_final_end -= fade_offset
 100         else:
 101             sequence_1.frame_final_end -= fade_offset
 102
 103         if hasattr(sequence_2, "input_1"):
 104             sequence_2.input_1.frame_final_start += fade_offset
 105         else:
 106             sequence_2.frame_final_start += fade_offset