qutebrowser/qutebrowser/commands/command.py
2014-10-06 19:53:50 +02:00

447 lines
18 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2014 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser. If not, see <http://www.gnu.org/licenses/>.
"""Contains the Command class, a skeleton for a command."""
import inspect
import collections
from PyQt5.QtWebKit import QWebSettings
from qutebrowser.commands import cmdexc, argparser
from qutebrowser.utils import (log, utils, message, debug, usertypes, docutils,
objreg)
class Command:
"""Base skeleton for a command.
Attributes:
name: The main name of the command.
split: Whether to split the arguments.
hide: Whether to hide the arguments or not.
desc: The description of the command.
handler: The handler function to call.
completion: Completions to use for arguments, as a list of strings.
debug: Whether this is a debugging command (only shown with --debug).
parser: The ArgumentParser to use to parse this command.
_type_conv: A mapping of conversion functions for arguments.
_name_conv: A mapping of argument names to parameter names.
_needs_js: Whether the command needs javascript enabled
_modes: The modes the command can be executed in.
_not_modes: The modes the command can not be executed in.
_count: Whether the command supports a count, or not.
_instance: The object to bind 'self' to.
_scope: The scope to get _instance for in the object registry.
Class attributes:
AnnotationInfo: Named tuple for info from an annotation.
ParamType: Enum for an argparse parameter type.
"""
AnnotationInfo = collections.namedtuple('AnnotationInfo',
['kwargs', 'typ', 'name', 'flag'])
ParamType = usertypes.enum('ParamType', ['flag', 'positional'])
def __init__(self, name, split, hide, instance, completion, modes,
not_modes, needs_js, is_debug, ignore_args,
handler, scope):
# I really don't know how to solve this in a better way, I tried.
# pylint: disable=too-many-arguments,too-many-locals
self.name = name
self.split = split
self.hide = hide
self._instance = instance
self.completion = completion
self._modes = modes
self._not_modes = not_modes
self._scope = scope
self._needs_js = needs_js
self.debug = is_debug
self.ignore_args = ignore_args
self.handler = handler
self.docparser = docutils.DocstringParser(handler)
self.parser = argparser.ArgumentParser(
name, description=self.docparser.short_desc,
epilog=self.docparser.long_desc)
self.parser.add_argument('-h', '--help', action=argparser.HelpAction,
default=argparser.SUPPRESS, nargs=0,
help=argparser.SUPPRESS)
self._check_func()
self.opt_args = collections.OrderedDict()
self.namespace = None
self._count = None
self.pos_args = []
has_count, desc, type_conv, name_conv = self._inspect_func()
self.has_count = has_count
self.desc = desc
self._type_conv = type_conv
self._name_conv = name_conv
def _check_prerequisites(self, win_id):
"""Check if the command is permitted to run currently.
Args:
win_id: The window ID the command is run in.
Raise:
PrerequisitesError if the command can't be called currently.
"""
mode_manager = objreg.get('mode-manager', scope='window',
window=win_id)
curmode = mode_manager.mode()
if self._modes is not None and curmode not in self._modes:
mode_names = '/'.join(mode.name for mode in self._modes)
raise cmdexc.PrerequisitesError(
"{}: This command is only allowed in {} mode.".format(
self.name, mode_names))
elif self._not_modes is not None and curmode in self._not_modes:
mode_names = '/'.join(mode.name for mode in self._not_modes)
raise cmdexc.PrerequisitesError(
"{}: This command is not allowed in {} mode.".format(
self.name, mode_names))
if self._needs_js and not QWebSettings.globalSettings().testAttribute(
QWebSettings.JavascriptEnabled):
raise cmdexc.PrerequisitesError(
"{}: This command needs javascript enabled.".format(self.name))
def _check_func(self):
"""Make sure the function parameters don't violate any rules."""
signature = inspect.signature(self.handler)
if 'self' in signature.parameters and self._instance is None:
raise TypeError("{} is a class method, but instance was not "
"given!".format(self.name[0]))
elif 'self' not in signature.parameters and self._instance is not None:
raise TypeError("{} is not a class method, but instance was "
"given!".format(self.name[0]))
elif inspect.getfullargspec(self.handler).varkw is not None:
raise TypeError("{}: functions with varkw arguments are not "
"supported!".format(self.name[0]))
def _get_typeconv(self, param, typ):
"""Get a dict with a type conversion for the parameter.
Args:
param: The inspect.Parameter to handle.
typ: The type of the parameter.
"""
type_conv = {}
if utils.is_enum(typ):
type_conv[param.name] = argparser.enum_getter(typ)
elif isinstance(typ, tuple):
if param.default is not inspect.Parameter.empty:
typ = typ + (type(param.default),)
type_conv[param.name] = argparser.multitype_conv(typ)
return type_conv
def _get_nameconv(self, param, annotation_info):
"""Get a dict with a name conversion for the paraeter.
Args:
param: The inspect.Parameter to handle.
annotation_info: The AnnotationInfo tuple for the parameter.
"""
d = {}
if annotation_info.name is not None:
d[param.name] = annotation_info.name
return d
def _inspect_func(self):
"""Inspect the function to get useful informations from it.
Return:
A (has_count, desc, parser, type_conv) tuple.
has_count: Whether the command supports a count.
desc: The description of the command.
type_conv: A mapping of args to type converter callables.
name_conv: A mapping of names to convert.
"""
type_conv = {}
name_conv = {}
signature = inspect.signature(self.handler)
has_count = 'count' in signature.parameters
doc = inspect.getdoc(self.handler)
if doc is not None:
desc = doc.splitlines()[0].strip()
else:
desc = ""
if not self.ignore_args:
for param in signature.parameters.values():
if param.name in ('self', 'count', 'win_id'):
continue
annotation_info = self._parse_annotation(param)
typ = self._get_type(param, annotation_info)
args, kwargs = self._param_to_argparse_args(
param, annotation_info)
type_conv.update(self._get_typeconv(param, typ))
name_conv.update(self._get_nameconv(param, annotation_info))
callsig = debug.format_call(
self.parser.add_argument, args, kwargs,
full=False)
log.commands.vdebug('Adding arg {} of type {} -> {}'.format(
param.name, typ, callsig))
self.parser.add_argument(*args, **kwargs)
return has_count, desc, type_conv, name_conv
def _param_to_argparse_args(self, param, annotation_info):
"""Get argparse arguments for a parameter.
Return:
An (args, kwargs) tuple.
Args:
param: The inspect.Parameter object to get the args for.
annotation_info: An AnnotationInfo tuple for the parameter.
"""
kwargs = {}
typ = self._get_type(param, annotation_info)
param_type = self.ParamType.positional
try:
kwargs['help'] = self.docparser.arg_descs[param.name]
except KeyError:
pass
if isinstance(typ, tuple):
pass
elif utils.is_enum(typ):
kwargs['choices'] = [e.name.replace('_', '-') for e in typ]
kwargs['metavar'] = param.name
elif typ is bool:
param_type = self.ParamType.flag
kwargs['action'] = 'store_true'
elif typ is not None:
kwargs['type'] = typ
if param.kind == inspect.Parameter.VAR_POSITIONAL:
kwargs['nargs'] = '+'
elif param.kind == inspect.Parameter.KEYWORD_ONLY:
param_type = self.ParamType.flag
kwargs['default'] = param.default
elif typ is not bool and param.default is not inspect.Parameter.empty:
kwargs['default'] = param.default
kwargs['nargs'] = '?'
args = []
name = annotation_info.name or param.name
shortname = annotation_info.flag or param.name[0]
if param_type == self.ParamType.flag:
long_flag = '--{}'.format(name)
short_flag = '-{}'.format(shortname)
args.append(long_flag)
args.append(short_flag)
self.opt_args[param.name] = long_flag, short_flag
elif param_type == self.ParamType.positional:
args.append(name)
self.pos_args.append((param.name, name))
else:
raise ValueError("Invalid ParamType {}!".format(param_type))
kwargs.update(annotation_info.kwargs)
return args, kwargs
def _parse_annotation(self, param):
"""Get argparse arguments and type from a parameter annotation.
Args:
param: A inspect.Parameter instance.
Return:
An AnnotationInfo namedtuple.
kwargs: A dict of keyword args to add to the
argparse.ArgumentParser.add_argument call.
typ: The type to use for this argument.
flag: The short name/flag if overridden.
name: The long name if overridden.
"""
info = {'kwargs': {}, 'typ': None, 'flag': None, 'name': None}
if param.annotation is not inspect.Parameter.empty:
log.commands.vdebug("Parsing annotation {}".format(
param.annotation))
if isinstance(param.annotation, dict):
for field in ('type', 'flag', 'name'):
if field in param.annotation:
info[field] = param.annotation[field]
del param.annotation[field]
info['kwargs'] = param.annotation
else:
info['typ'] = param.annotation
return self.AnnotationInfo(**info)
def _get_type(self, param, annotation_info):
"""Get the type of an argument from its default value or annotation.
Args:
param: The inspect.Parameter to look at.
annotation_info: An AnnotationInfo tuple which overrides the type.
"""
if annotation_info.typ is not None:
return annotation_info.typ
elif param.default is None or param.default is inspect.Parameter.empty:
return None
else:
return type(param.default)
def _get_self_arg(self, win_id, param, args):
"""Get the self argument for a function call.
Arguments:
win_id: The window id this command should be executed in.
param: The count parameter.
args: The positional argument list. Gets modified directly.
"""
assert param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD
if self._scope is not 'window':
win_id = None
obj = objreg.get(self._instance, scope=self._scope,
window=win_id)
args.append(obj)
def _get_count_arg(self, param, args, kwargs):
"""Add the count argument to a function call.
Arguments:
param: The count parameter.
args: The positional argument list. Gets modified directly.
kwargs: The keyword argument dict. Gets modified directly.
"""
if not self.has_count:
raise TypeError("{}: count argument given with a command which "
"does not support count!".format(self.name))
if param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
if self._count is not None:
args.append(self._count)
else:
args.append(param.default)
elif param.kind == inspect.Parameter.KEYWORD_ONLY:
if self._count is not None:
kwargs['count'] = self._count
else:
raise TypeError("{}: invalid parameter type {} for argument "
"'count'!".format(self.name, param.kind))
def _get_win_id_arg(self, win_id, param, args, kwargs):
"""Add the win_id argument to a function call.
Arguments:
win_id: The window ID to add.
param: The count parameter.
args: The positional argument list. Gets modified directly.
kwargs: The keyword argument dict. Gets modified directly.
"""
if param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
args.append(win_id)
elif param.kind == inspect.Parameter.KEYWORD_ONLY:
kwargs['win_id'] = win_id
else:
raise TypeError("{}: invalid parameter type {} for argument "
"'count'!".format(self.name, param.kind))
def _get_param_name_and_value(self, param):
"""Get the converted name and value for an inspect.Parameter."""
name = self._name_conv.get(param.name, param.name)
value = getattr(self.namespace, name)
if param.name in self._type_conv:
# We convert enum types after getting the values from
# argparse, because argparse's choices argument is
# processed after type conversation, which is not what we
# want.
value = self._type_conv[param.name](value)
return name, value
def _get_call_args(self, win_id): # noqa
"""Get arguments for a function call.
Args:
win_id: The window id this command should be executed in.
Return:
An (args, kwargs) tuple.
"""
args = []
kwargs = {}
signature = inspect.signature(self.handler)
if self.ignore_args:
if self._instance is not None:
param = list(signature.parameters.values())[0]
self._get_self_arg(win_id, param, args)
return args, kwargs
for i, param in enumerate(signature.parameters.values()):
if i == 0 and self._instance is not None:
# Special case for 'self'.
self._get_self_arg(win_id, param, args)
continue
elif param.name == 'count':
# Special case for 'count'.
self._get_count_arg(param, args, kwargs)
continue
elif param.name == 'win_id':
# Special case for 'win_id'.
self._get_win_id_arg(win_id, param, args, kwargs)
continue
name, value = self._get_param_name_and_value(param)
if param.kind == inspect.Parameter.POSITIONAL_OR_KEYWORD:
args.append(value)
elif param.kind == inspect.Parameter.VAR_POSITIONAL:
if value is not None:
args += value
elif param.kind == inspect.Parameter.KEYWORD_ONLY:
kwargs[name] = value
else:
raise TypeError("{}: Invalid parameter type {} for argument "
"'{}'!".format(
self.name, param.kind, param.name))
return args, kwargs
def run(self, win_id, args=None, count=None):
"""Run the command.
Note we don't catch CommandError here as it might happen async.
Args:
win_id: The window ID the command is run in.
args: Arguments to the command.
count: Command repetition count.
"""
dbgout = ["command called:", self.name]
if args:
dbgout.append(str(args))
if count is not None:
dbgout.append("(count={})".format(count))
log.commands.debug(' '.join(dbgout))
try:
self.namespace = self.parser.parse_args(args)
except argparser.ArgumentParserError as e:
message.error(win_id, '{}: {}'.format(self.name, e))
return
except argparser.ArgumentParserExit as e:
log.commands.debug("argparser exited with status {}: {}".format(
e.status, e))
return
self._count = count
posargs, kwargs = self._get_call_args(win_id)
self._check_prerequisites(win_id)
log.commands.debug('Calling {}'.format(
debug.format_call(self.handler, posargs, kwargs)))
self.handler(*posargs, **kwargs)