Source code for events.hooks
# ../events/hooks.py
"""Provides event hooking functionality."""
# =============================================================================
# >> IMPORTS
# =============================================================================
# Python Imports
# Enum
from enum import IntEnum
# Source.Python Imports
# Core
from core import AutoUnload
# Events
from events import GameEvent
from events.manager import game_event_manager
# Hooks
from hooks.exceptions import except_hooks
# Memory
from memory import get_virtual_function
from memory import make_object
from memory.hooks import PreHook
# =============================================================================
# >> ALL DECLARATION
# =============================================================================
__all__ = ('EventAction',
'PreEvent',
'_PreEventManager',
'pre_event_manager',
)
# =============================================================================
# >> CLASSES
# =============================================================================
[docs]class EventAction(IntEnum):
"""Enum class used to know what to do with a pre-hooked event."""
CONTINUE = 0
STOP_BROADCAST = 1
BLOCK = 2
[docs]class PreEvent(AutoUnload):
"""Pre-Event decorator class."""
def __init__(self, *event_names):
"""Store the event names."""
self._event_names = event_names
self.callback = None
def __call__(self, callback):
"""Store the callback and register the pre-events."""
# Store the callback
self.callback = callback
# Loop through all pre-event names
for event_name in self._event_names:
# Register the pre-event
pre_event_manager.register_for_event(event_name, self.callback)
# Return the callback
return self.callback
def _unload_instance(self):
"""Unregister the pre-events."""
# Loop through all pre-event names
for event_name in self._event_names:
# Unregister the pre-event
pre_event_manager.unregister_for_event(event_name, self.callback)
class _PreEventManager(dict):
"""Dictionary class used to store pre-events with their callbacks."""
def __missing__(self, event_name):
"""Add the event to the dictionary and return its instance."""
# Add the event to the dictionary as a new list
value = self[event_name] = _PreEventList(event_name)
# Return the instance
return value
def register_for_event(self, event_name, callback):
"""Register the callback for the given event.
:param str event_name: The name of the event to register.
:param callback: The function to be called when the
event is fired on the server.
.. code-block:: python
from events.hooks import pre_event_manager
def function(game_event):
# Code...
pre_event_manager.register_for_event('player_death', function)
.. seealso:: :doc:`../events` for a list of supported events per game.
"""
# Is the callback callable?
if not callable(callback):
# Raise an error
raise TypeError(
"'" + type(callback).__name__ + "' object is not callable.")
# Add the callback to the pre-event's registered callback list
self[event_name].append(callback)
def unregister_for_event(self, event_name, callback):
"""Unregister the callback for the given event.
:param str event_name: The name of the event to unregister.
:param callback: The function to unregister from the event.
.. code-block:: python
from events.hooks import pre_event_manager
def function(game_event):
# Code...
pre_event_manager.unregister_for_event('player_death', function)
"""
# Is the event registered?
if event_name not in self:
# Raise an error
raise ValueError(
'Pre-Event "{0}" is not registered'.format(event_name))
# Remove the callback from the pre-event's list
self[event_name].remove(callback)
# Are there any callbacks remaining for the pre-event?
if not self[event_name]:
# Remove the pre-event from the dictionary
del self[event_name]
# The singleton object of the :class:`_PreEventManager` class
pre_event_manager = _PreEventManager()
class _PreEventList(list):
"""List class used to store callbacks for a given event."""
def __init__(self, event_name):
"""Initialize the list and store the event name."""
# Initialize the list
super().__init__()
# Store the event name
self.event_name = event_name
def append(self, callback):
"""Add the callback to the list."""
# Is the callback already in the list?
if callback in self:
# Raise an error
raise ValueError(
'Pre-Event callback "{0}" is already registered '
'for event "{1}"'.format(callback, self.event_name))
# Add the callback to the list
super().append(callback)
def remove(self, callback):
"""Remove the callback from the list."""
# Is the callback in the list?
if callback not in self:
# If not, raise an error
raise ValueError(
'Pre-Event callback "{0}" is not registered for '
'event "{1}"'.format(callback, self.event_name))
# Remove the callback from the list
super().remove(callback)
# =============================================================================
# >> PRE-HOOK FUNCTIONS
# =============================================================================
@PreHook(get_virtual_function(game_event_manager, 'FireEvent'))
def _pre_game_event(args):
"""Call pre-event functions if the event is registered."""
# Crashfix for CS:GO:
# https://github.com/Source-Python-Dev-Team/Source.Python/issues/230
game_event_ptr = args[1]
if not game_event_ptr:
return False
# Get the GameEvent object
game_event = make_object(GameEvent, game_event_ptr)
# Get the name of the event
event_name = game_event.name
# If the current event is not in the dictionary, return
if event_name not in pre_event_manager:
return
# Create a variable to know what to do after all pre-events are called
event_action = EventAction.CONTINUE
# Loop through all callbacks in the pre-event's list
for callback in pre_event_manager[event_name]:
# Use try/except in case an error occurs during in the callback
try:
# Call the callback and get its return value
current_action = callback(game_event)
# Is the return value invalid?
if (current_action is not None and
not isinstance(current_action, EventAction)):
# Raise an error to exit the try
raise ValueError(
'Invalid return value for pre-event "{0}".'.format(
current_action))
# Was an error encountered?
except:
# Print the exception to the console
except_hooks.print_exception()
# Was no error encountered?
else:
# Does the current action have a higher priority?
if current_action is not None and current_action > event_action:
# Change the event action
event_action = current_action
# Does the return value want to set the dontbroadcast value?
if event_action is EventAction.STOP_BROADCAST:
# Set the dontbroadcast value
args[2] = True
# Does the return value want to block the event?
elif event_action is EventAction.BLOCK:
# Free the event
game_event_manager.free_event(game_event)
# Block the event
return False
