oscillode/oscillode/registration.py

# oscillode
# Copyright (C) 2024 oscillode Project Contributors
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""Manages the registration of Blender classes, including delayed registrations that require access to Python dependencies.

Attributes:
	_ADDON_KEYMAP: Addon-specific keymap used to register operator hotkeys.
	REG__CLASSES: Currently registered Blender classes.
	_REGISTERED_HOTKEYS: Currently registered Blender keymap items.
"""

import bpy

from . import contracts as ct
from .utils import logger

log = logger.get(__name__)

####################
# - Globals
####################
_REGISTERED_CLASSES: list[ct.BLClass] = []

_ADDON_KEYMAP: bpy.types.KeyMap | None = None
_REGISTERED_HOTKEYS: list[ct.BLKeymapItem] = []

_REGISTERED_HANDLERS: ct.BLHandlers | None = None


####################
# - Class Registration
####################
def register_classes(bl_register: list[ct.BLClass]) -> None:
	"""Registers a list of Blender classes.

	Parameters:
		bl_register: List of Blender classes to register.
	"""
	log.info('Registering %s Classes', len(bl_register))
	for cls in bl_register:
		if cls.bl_idname in _REGISTERED_CLASSES:
			msg = f'Skipping register of {cls.bl_idname}'
			log.info(msg)
			continue

		log.debug(
			'Registering Class %s',
			repr(cls),
		)
		bpy.utils.register_class(cls)
		_REGISTERED_CLASSES.append(cls)


def unregister_classes() -> None:
	"""Unregisters all previously registered Blender classes."""
	log.info('Unregistering %s Classes', len(_REGISTERED_CLASSES))
	for cls in reversed(_REGISTERED_CLASSES):
		log.debug(
			'Unregistering Class %s',
			repr(cls),
		)
		bpy.utils.unregister_class(cls)

	_REGISTERED_CLASSES.clear()


####################
# - Handler Registration
####################
def register_handlers(bl_handlers: ct.BLHandlers) -> None:
	"""Register the given Blender handlers."""
	global _REGISTERED_HANDLERS  # noqa: PLW0603

	log.info('Registering BLHandlers')  ## TODO: More information
	if _REGISTERED_HANDLERS is None:
		bl_handlers.register()
		_REGISTERED_HANDLERS = bl_handlers

	msg = 'There are already BLHandlers registered; they must be unregistered before a new set can be registered.'
	raise ValueError(msg)


def unregister_handlers() -> None:
	"""Unregister this addon's registered Blender handlers."""
	global _REGISTERED_HANDLERS  # noqa: PLW0603

	log.info('Unregistering BLHandlers')  ## TODO: More information
	if _REGISTERED_HANDLERS is not None:
		_REGISTERED_HANDLERS.register()
		_REGISTERED_HANDLERS = None

	msg = 'There are no BLHandlers registered; therefore, there is nothing to register.'
	raise ValueError(msg)


####################
# - Keymap Registration
####################
def register_hotkeys(hotkey_defs: list[dict]) -> None:
	"""Registers a list of Blender hotkey definitions.

	Parameters:
		hotkey_defs: List of Blender hotkey definitions to register.
	"""
	# Lazy-Load BL_NODE_KEYMAP
	global _ADDON_KEYMAP  # noqa: PLW0603
	if _ADDON_KEYMAP is None:
		_ADDON_KEYMAP = bpy.context.window_manager.keyconfigs.addon.keymaps.new(
			name='Node Editor',
			space_type='NODE_EDITOR',
		)
		log.info(
			'Registered Addon Keymap (Base for Keymap Items): %s',
			str(_ADDON_KEYMAP),
		)

	# Register Keymaps
	log.info('Registering %s Keymap Items', len(hotkey_defs))
	for keymap_item_def in hotkey_defs:
		keymap_item = _ADDON_KEYMAP.keymap_items.new(
			*keymap_item_def['_'],
			ctrl=keymap_item_def['ctrl'],
			shift=keymap_item_def['shift'],
			alt=keymap_item_def['alt'],
		)
		log.debug(
			'Registered Keymap Item %s with spec %s',
			repr(keymap_item),
			keymap_item_def,
		)
		_REGISTERED_HOTKEYS.append(keymap_item)


def unregister_hotkeys() -> None:
	"""Unregisters all Blender hotkeys associated with the addon."""
	global _ADDON_KEYMAP  # noqa: PLW0603

	# Unregister Keymaps
	log.info('Unregistering %s Keymap Items', len(_REGISTERED_HOTKEYS))
	for keymap_item in reversed(_REGISTERED_HOTKEYS):
		log.debug(
			'Unregistered Keymap Item %s',
			repr(keymap_item),
		)
		_ADDON_KEYMAP.keymap_items.remove(keymap_item)

	# Lazy-Unload BL_NODE_KEYMAP
	if _ADDON_KEYMAP is not None:
		log.info(
			'Unregistered Keymap %s',
			repr(_ADDON_KEYMAP),
		)
		_REGISTERED_HOTKEYS.clear()
		_ADDON_KEYMAP = None