__init__.py

import bpy
import bpy_extras.io_utils
from bpy.types import Operator, AddonPreferences
from bpy.props import *
from bpy_extras.io_utils import ExportHelper, ImportHelper
from bpy.utils import register_class
from bpy.utils import unregister_class

import time

bl_info = {
    "name": "SEAnim Support",
    "author": "SE2Dev",
    "version": (0, 4, 1),
    "blender": (2, 80, 0),
    "location": "File > Import",
    "description": "Import SEAnim",
    "warning": "ADDITIVE animations are not currently supported",
    "wiki_url": "https://github.com/SE2Dev/io_anim_seanim",
    "tracker_url": "https://github.com/SE2Dev/io_anim_seanim/issues",
    "support": "COMMUNITY",
    "category": "Import-Export"
}

# To support reload properly, try to access a package var, if it's there,
# reload everything
if "bpy" in locals():
    import imp
    if "import_seanim" in locals():
        imp.reload(import_seanim)
else:
    from . import import_seanim


class ImportSEAnim(bpy.types.Operator, ImportHelper):
    bl_idname = "import_scene.seanim"
    bl_label = "Import SEAnim"
    bl_description = "Import one or more SEAnim files"
    bl_options = {'PRESET'}

    filename_ext = ".seanim"
    filter_glob: StringProperty(default="*.seanim", options={'HIDDEN'})

    files: CollectionProperty(type=bpy.types.PropertyGroup)

    def execute(self, context):
        # print("Selected: " + context.active_object.name)
        from . import import_seanim
        start_time = time.process_time()
        result = import_seanim.load(
            self, context, **self.as_keywords(ignore=("filter_glob", "files")))
        if not result:
            self.report({'INFO'}, "Import finished in %.4f sec." %
                        (time.process_time() - start_time))
            return {'FINISHED'}
        else:
            self.report({'ERROR'}, result)
            return {'CANCELLED'}

    @classmethod
    def poll(self, context):
        if context.active_object is not None:
            if context.active_object.type == 'ARMATURE':
                return True

            # Currently Disabled
            """
            elif context.active_object.parent is not None:
                return context.active_object.parent.type == 'ARMATURE'
            """

        return False


class ExportSEAnim(bpy.types.Operator, ExportHelper):
    bl_idname = "export_scene.seanim"
    bl_label = "Export SEAnim"
    bl_description = "Export an SEAnim"
    bl_options = {'PRESET'}

    filename_ext = ".seanim"
    filter_glob: StringProperty(default="*.seanim", options={'HIDDEN'})

    files: CollectionProperty(type=bpy.types.PropertyGroup)

    anim_type: EnumProperty(
        name="Anim Type",
        description="Choose between two items",
        items=(	('OPT_ABSOLUTE', "Absolute", "Used for viewmodel animations"),
                # ('OPT_ADDITIVE', "Additive", "Used for some idle animations"), # Currently Disabled  # nopep8
                ('OPT_RELATIVE', "Relative", "Used for most animations"),
                ('OPT_DELTA',    "Delta",    "Used for walk cycles")),
        default='OPT_RELATIVE',
    )

    key_types: EnumProperty(
        name="Keyframe Types",
        description="Export specific keyframe types",
        options={'ENUM_FLAG'},
        items=(('LOC', "Location", ""),
               ('ROT', "Rotation", ""),
               # ('SCALE', "Scale", ""), # Not Currently Supported  # nopep8
               ),
        default={'LOC', 'ROT'},  # , 'SCALE'},
    )

    every_frame: BoolProperty(
        name="Every Frame",
        description="Automatically generate keyframes for every single frame",
        default=False)

    high_precision: BoolProperty(
        name="High Precision",
        description=("Use double precision floating point values for "
                     "quaternions and vectors (Note: Increases file size)"),
        default=False)

    is_looped: BoolProperty(
        name="Looped",
        description="Mark the animation as a looping animation",
        default=False)

    use_actions: BoolProperty(
        name="Export All Actions",
        description="Export all actions to the target path",
        default=False)

    # PREFIX & SUFFIX Require "use_actions" to be true and are enabled /
    # disabled from __update_use_actions
    prefix: StringProperty(
        name="File Prefix",
        description=("The prefix string that is applied to the beginning "
                     "of the filename for each exported action"),
        default="")

    suffix: StringProperty(
        name="File Suffix",
        description=("The suffix string that is applied to the end "
                     "of the filename for each exported action"),
        default="")

    def draw(self, context):
        layout = self.layout
        layout.prop(self, "anim_type")

        row = layout.row()
        row.label(text="Include:")
        row.prop(self, "key_types")

        layout.prop(self, "high_precision")
        layout.prop(self, "is_looped")
        layout.prop(self, "every_frame")

        box = layout.box()
        box.prop(self, "use_actions")
        if(self.use_actions):
            box.prop(self, "prefix")
            box.prop(self, "suffix")

    def execute(self, context):
        # print("Selected: " + context.active_object.name)
        from . import export_seanim
        start_time = time.process_time()
        result = export_seanim.save(self, context)
        if not result:
            self.report({'INFO'}, "Export finished in %.4f sec." %
                        (time.process_time() - start_time))
            return {'FINISHED'}
        else:
            self.report({'ERROR'}, result)
            return {'CANCELLED'}

    @classmethod
    def poll(self, context):
        ob = context.active_object
        if ob is not None:
            if ob.type == 'ARMATURE' and ob.animation_data is not None:
                return True

            # Currently Disabled
            """
            elif context.active_object.parent is not None:
                return context.active_object.parent.type == 'ARMATURE'
            """

        return False


def get_operator(idname):
    op = bpy.ops
    for attr in idname.split("."):
        op = getattr(op, attr)
    return op


def menu_func_seanim_import(self, context):
    self.layout.operator(ImportSEAnim.bl_idname, text="SEAnim (.seanim)")


def menu_func_seanim_export(self, context):
    self.layout.operator(ExportSEAnim.bl_idname, text="SEAnim (.seanim)")


'''
    CLASS REGISTRATION
    SEE https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Python_API/Addons
'''

classes = (
    ImportSEAnim,
    ExportSEAnim
)


def register():
    for cls in classes:
        bpy.utils.register_class(cls)

    bpy.types.TOPBAR_MT_file_import.append(menu_func_seanim_import)
    bpy.types.TOPBAR_MT_file_export.append(menu_func_seanim_export)


def unregister():
    bpy.types.TOPBAR_MT_file_import.remove(menu_func_seanim_import)
    bpy.types.TOPBAR_MT_file_export.remove(menu_func_seanim_export)

    for cls in classes:
        bpy.utils.unregister_class(cls)



if __name__ == "__main__":
    register()