Source code for napari.utils.notifications

from __future__ import annotations

import os
import sys
import threading
import warnings
from datetime import datetime
from enum import auto
from types import TracebackType
from typing import Callable, List, Optional, Sequence, Tuple, Type, Union

from .events import Event, EventEmitter
from .misc import StringEnum

    from napari_error_reporter import capture_exception, install_error_reporter
except ImportError:

    def _noop(*_, **__):

    install_error_reporter = _noop
    capture_exception = _noop

name2num = {
    'error': 40,
    'warning': 30,
    'info': 20,
    'debug': 10,
    'none': 0,

__all__ = [

[docs]class NotificationSeverity(StringEnum): """Severity levels for the notification dialog. Along with icons for each.""" ERROR = auto() WARNING = auto() INFO = auto() DEBUG = auto() NONE = auto() def as_icon(self): return { self.ERROR: "ⓧ", self.WARNING: "⚠️", self.INFO: "ⓘ", self.DEBUG: "🐛", self.NONE: "", }[self] def __lt__(self, other): return name2num[str(self)] < name2num[str(other)] def __le__(self, other): return name2num[str(self)] <= name2num[str(other)] def __gt__(self, other): return name2num[str(self)] > name2num[str(other)] def __ge__(self, other): return name2num[str(self)] >= name2num[str(other)] def __eq__(self, other): return str(self) == str(other) def __hash__(self): return hash(self.value)
ActionSequence = Sequence[Tuple[str, Callable[[], None]]]
[docs]class Notification(Event): """A Notifcation event. Usually created by :class:`NotificationManager`. Parameters ---------- message : str The main message/payload of the notification. severity : str or NotificationSeverity, optional The severity of the notification, by default `NotificationSeverity.WARNING`. actions : sequence of tuple, optional Where each tuple is a `(str, callable)` 2-tuple where the first item is a name for the action (which may, for example, be put on a button), and the callable is a callback to perform when the action is triggered. (for example, one might show a traceback dialog). by default () """ def __init__( self, message: str, severity: Union[ str, NotificationSeverity ] = NotificationSeverity.WARNING, actions: ActionSequence = (), **kwargs, ): self.severity = NotificationSeverity(severity) super().__init__(type=str(self.severity).lower(), **kwargs) self._message = message self.actions = actions # let's store when the object was created; = @property def message(self): return self._message @message.setter def message(self, value): self._message = value @classmethod def from_exception(cls, exc: BaseException, **kwargs) -> Notification: return ErrorNotification(exc, **kwargs) @classmethod def from_warning(cls, warning: Warning, **kwargs) -> Notification: return WarningNotification(warning, **kwargs) def __str__(self): return f'{str(self.severity).upper()}: {self.message}'
[docs]class ErrorNotification(Notification): """ Notification at an Error severity level. """ exception: BaseException def __init__(self, exception: BaseException, *args, **kwargs): msg = getattr(exception, 'message', str(exception)) actions = getattr(exception, 'actions', ()) super().__init__(msg, NotificationSeverity.ERROR, actions) self.exception = exception def as_html(self): from ._tracebacks import get_tb_formatter fmt = get_tb_formatter() exc_info = ( self.exception.__class__, self.exception, self.exception.__traceback__, ) return fmt(exc_info, as_html=True) def as_text(self): from ._tracebacks import get_tb_formatter fmt = get_tb_formatter() exc_info = ( self.exception.__class__, self.exception, self.exception.__traceback__, ) return fmt(exc_info, as_html=False, color="NoColor") def __str__(self): from ._tracebacks import get_tb_formatter fmt = get_tb_formatter() exc_info = ( self.exception.__class__, self.exception, self.exception.__traceback__, ) return fmt(exc_info, as_html=False)
[docs]class WarningNotification(Notification): """ Notification at a Warning severity level. """ warning: Warning def __init__( self, warning: Warning, filename=None, lineno=None, *args, **kwargs ): msg = getattr(warning, 'message', str(warning)) actions = getattr(warning, 'actions', ()) super().__init__(msg, NotificationSeverity.WARNING, actions) self.warning = warning self.filename = filename self.lineno = lineno def __str__(self): category = type(self.warning).__name__ return f'{self.filename}:{self.lineno}: {category}: {self.warning}!'
[docs]class NotificationManager: """ A notification manager, to route all notifications through. Only one instance is in general available through napari; as we need notification to all flow to a single location that is registered with the sys.except_hook and showwarning hook. This can and should be used a context manager; the context manager will properly re-entered, and install/remove hooks and keep them in a stack to restore them. While it might seem unnecessary to make it re-entrant; or to make the re-entrancy no-op; one need to consider that this could be used inside another context manager that modify except_hook and showwarning. Currently the original except and show warnings hooks are not called; but this could be changed in the future; this poses some questions with the re-entrency of the hooks themselves. """ records: List[Notification] _instance: Optional[NotificationManager] = None def __init__(self) -> None: self.records: List[Notification] = [] self.exit_on_error = os.getenv('NAPARI_EXIT_ON_ERROR') in ('1', 'True') self.catch_error = os.getenv("NAPARI_CATCH_ERRORS") not in ( '0', 'False', ) self.notification_ready = self.changed = EventEmitter( source=self, event_class=Notification ) self._originals_except_hooks = [] self._original_showwarnings_hooks = [] self._originals_thread_except_hooks = [] def __enter__(self): self.install_hooks() return self def __exit__(self, *args, **kwargs): self.restore_hooks()
[docs] def install_hooks(self): """ Install a `sys.excepthook`, a `showwarning` hook and a threading.excepthook to display any message in the UI, storing the previous hooks to be restored if necessary. """ if getattr(threading, 'excepthook', None): # TODO: we might want to display the additional thread information self._originals_thread_except_hooks.append(threading.excepthook) threading.excepthook = self.receive_thread_error else: # Patch for Python < 3.8 _setup_thread_excepthook() install_error_reporter() self._originals_except_hooks.append(sys.excepthook) self._original_showwarnings_hooks.append(warnings.showwarning) sys.excepthook = self.receive_error warnings.showwarning = self.receive_warning
[docs] def restore_hooks(self): """ Remove hooks installed by `install_hooks` and restore previous hooks. """ if getattr(threading, 'excepthook', None): # `threading.excepthook` available only for Python >= 3.8 threading.excepthook = self._originals_thread_except_hooks.pop() sys.excepthook = self._originals_except_hooks.pop() warnings.showwarning = self._original_showwarnings_hooks.pop()
def dispatch(self, notification: Notification): self.records.append(notification) self.notification_ready(notification) def receive_thread_error(self, args: threading.ExceptHookArgs): self.receive_error(*args) def receive_error( self, exctype: Optional[Type[BaseException]] = None, value: Optional[BaseException] = None, traceback: Optional[TracebackType] = None, thread: Optional[threading.Thread] = None, ): if isinstance(value, KeyboardInterrupt): sys.exit("Closed by KeyboardInterrupt") capture_exception(value) if self.exit_on_error: sys.__excepthook__(exctype, value, traceback) sys.exit("Exit on error") if not self.catch_error: sys.__excepthook__(exctype, value, traceback) return try: self.dispatch(Notification.from_exception(value)) except Exception: pass def receive_warning( self, message: Warning, category: Type[Warning], filename: str, lineno: int, file=None, line=None, ): self.dispatch( Notification.from_warning( message, filename=filename, lineno=lineno ) ) def receive_info(self, message: str): self.dispatch(Notification(message, 'INFO'))
notification_manager = NotificationManager()
[docs]def show_info(message: str): """ Show an info message in the notification manager. """ notification_manager.dispatch( Notification(message, severity=NotificationSeverity.INFO) )
def show_warning(message: str): """ Show a warning in the notification manager. """ notification_manager.dispatch( Notification(message, severity=NotificationSeverity.WARNING) )
[docs]def show_error(message: str): """ Show an error in the notification manager. """ notification_manager.dispatch( Notification(message, severity=NotificationSeverity.ERROR) )
[docs]def show_console_notification(notification: Notification): """ Show a notification in the console. """ try: from ..settings import get_settings if ( notification.severity < get_settings().application.console_notification_level ): return print(notification) except Exception: print( "An error occurred while trying to format an error and show it in console.\n" "You can try to uninstall IPython to disable rich traceback formatting\n" "And/or report a bug to napari" ) # this will likely get silenced by QT. raise
def _setup_thread_excepthook(): """ Workaround for `sys.excepthook` thread bug from: """ _init = threading.Thread.__init__ def init(self, *args, **kwargs): _init(self, *args, **kwargs) _run = def run_with_except_hook(*args2, **kwargs2): try: _run(*args2, **kwargs2) except Exception: sys.excepthook(*sys.exc_info()) = run_with_except_hook threading.Thread.__init__ = init