qutebrowser/qutebrowser/mainwindow/statusbar/prompter.py
2015-06-29 17:49:19 +02:00

348 lines
14 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2014-2015 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/>.
"""Manager for questions to be shown in the statusbar."""
import sip
import collections
from PyQt5.QtCore import pyqtSlot, pyqtSignal, QTimer, QObject
from PyQt5.QtWidgets import QLineEdit
from qutebrowser.keyinput import modeman
from qutebrowser.commands import cmdutils
from qutebrowser.utils import usertypes, log, qtutils, objreg, utils
PromptContext = collections.namedtuple('PromptContext',
['question', 'text', 'input_text',
'echo_mode', 'input_visible'])
AuthTuple = collections.namedtuple('AuthTuple', ['user', 'password'])
class Prompter(QObject):
"""Manager for questions to be shown in the statusbar.
The way in which multiple questions are handled deserves some explanation.
If a question is blocking, we *need* to ask it immediately, and can't wait
for previous questions to finish. We could theoretically ask a blocking
question inside of another blocking one, so in ask_question we simply save
the current prompt state on the stack, let the user answer the *most
recent* question, and then restore the previous state.
With a non-blocking question, things are a bit easier. We simply add it to
self._queue if we're still busy handling another question, since it can be
answered at any time.
In either case, as soon as we finished handling a question, we call
_pop_later() which schedules a _pop to ask the next question in _queue. We
schedule it rather than doing it immediately because then the order of how
things happen is clear, e.g. on_mode_left can't happen after we already set
up the *new* question.
Class Attributes:
KEY_MODES: A mapping of PromptModes to KeyModes.
Attributes:
_shutting_down: Whether we're currently shutting down the prompter and
should ignore future questions to avoid segfaults.
_question: A Question object with the question to be asked to the user.
_loops: A list of local EventLoops to spin in when blocking.
_queue: A deque of waiting questions.
_busy: If we're currently busy with asking a question.
_win_id: The window ID this object is associated with.
Signals:
show_prompt: Emitted when the prompt widget should be shown.
hide_prompt: Emitted when the prompt widget should be hidden.
"""
KEY_MODES = {
usertypes.PromptMode.yesno: usertypes.KeyMode.yesno,
usertypes.PromptMode.text: usertypes.KeyMode.prompt,
usertypes.PromptMode.user_pwd: usertypes.KeyMode.prompt,
usertypes.PromptMode.alert: usertypes.KeyMode.prompt,
}
show_prompt = pyqtSignal()
hide_prompt = pyqtSignal()
def __init__(self, win_id, parent=None):
super().__init__(parent)
self._shutting_down = False
self._question = None
self._loops = []
self._queue = collections.deque()
self._busy = False
self._win_id = win_id
def __repr__(self):
return utils.get_repr(self, loops=len(self._loops),
question=self._question, queue=len(self._queue),
busy=self._busy)
def _pop_later(self):
"""Helper to call self._pop as soon as everything else is done."""
QTimer.singleShot(0, self._pop)
def _pop(self):
"""Pop a question from the queue and ask it, if there are any."""
log.statusbar.debug("Popping from queue {}".format(self._queue))
if self._queue:
question = self._queue.popleft()
if not sip.isdeleted(question):
# the question could already be deleted, e.g. by a cancelled
# download. See
# https://github.com/The-Compiler/qutebrowser/issues/415
self.ask_question(question, blocking=False)
def _get_ctx(self):
"""Get a PromptContext based on the current state."""
if not self._busy:
return None
prompt = objreg.get('prompt', scope='window', window=self._win_id)
ctx = PromptContext(question=self._question,
text=prompt.txt.text(),
input_text=prompt.lineedit.text(),
echo_mode=prompt.lineedit.echoMode(),
input_visible=prompt.lineedit.isVisible())
return ctx
def _restore_ctx(self, ctx):
"""Restore state from a PromptContext.
Args:
ctx: A PromptContext previously saved by _get_ctx, or None.
Return: True if a context was restored, False otherwise.
"""
log.statusbar.debug("Restoring context {}".format(ctx))
if ctx is None:
self.hide_prompt.emit()
self._busy = False
return False
self._question = ctx.question
prompt = objreg.get('prompt', scope='window', window=self._win_id)
prompt.txt.setText(ctx.text)
prompt.lineedit.setText(ctx.input_text)
prompt.lineedit.setEchoMode(ctx.echo_mode)
prompt.lineedit.setVisible(ctx.input_visible)
self.show_prompt.emit()
mode = self.KEY_MODES[ctx.question.mode]
ctx.question.aborted.connect(
lambda: modeman.maybe_leave(self._win_id, mode, 'aborted'))
modeman.enter(self._win_id, mode, 'question asked')
return True
def _display_question(self):
"""Display the question saved in self._question."""
prompt = objreg.get('prompt', scope='window', window=self._win_id)
if self._question.mode == usertypes.PromptMode.yesno:
if self._question.default is None:
suffix = ""
elif self._question.default:
suffix = " (yes)"
else:
suffix = " (no)"
prompt.txt.setText(self._question.text + suffix)
prompt.lineedit.hide()
elif self._question.mode == usertypes.PromptMode.text:
prompt.txt.setText(self._question.text)
if self._question.default:
prompt.lineedit.setText(self._question.default)
prompt.lineedit.show()
elif self._question.mode == usertypes.PromptMode.user_pwd:
prompt.txt.setText(self._question.text)
if self._question.default:
prompt.lineedit.setText(self._question.default)
prompt.lineedit.show()
elif self._question.mode == usertypes.PromptMode.alert:
prompt.txt.setText(self._question.text + ' (ok)')
prompt.lineedit.hide()
else:
raise ValueError("Invalid prompt mode!")
log.modes.debug("Question asked, focusing {!r}".format(
prompt.lineedit))
prompt.lineedit.setFocus()
self.show_prompt.emit()
self._busy = True
def shutdown(self):
"""Cancel all blocking questions.
Quits and removes all running event loops.
Return:
True if loops needed to be aborted,
False otherwise.
"""
self._shutting_down = True
if self._loops:
for loop in self._loops:
loop.quit()
loop.deleteLater()
return True
else:
return False
@pyqtSlot(usertypes.KeyMode)
def on_mode_left(self, mode):
"""Clear and reset input when the mode was left."""
prompt = objreg.get('prompt', scope='window', window=self._win_id)
if mode in (usertypes.KeyMode.prompt, usertypes.KeyMode.yesno):
prompt.txt.setText('')
prompt.lineedit.clear()
prompt.lineedit.setEchoMode(QLineEdit.Normal)
self.hide_prompt.emit()
self._busy = False
if self._question.answer is None and not self._question.is_aborted:
self._question.cancel()
@cmdutils.register(instance='prompter', hide=True, scope='window',
modes=[usertypes.KeyMode.prompt,
usertypes.KeyMode.yesno])
def prompt_accept(self):
"""Accept the current prompt.
//
This executes the next action depending on the question mode, e.g. asks
for the password or leaves the mode.
"""
prompt = objreg.get('prompt', scope='window', window=self._win_id)
if (self._question.mode == usertypes.PromptMode.user_pwd and
self._question.user is None):
# User just entered a username
self._question.user = prompt.lineedit.text()
prompt.txt.setText("Password:")
prompt.lineedit.clear()
prompt.lineedit.setEchoMode(QLineEdit.Password)
elif self._question.mode == usertypes.PromptMode.user_pwd:
# User just entered a password
password = prompt.lineedit.text()
self._question.answer = AuthTuple(self._question.user, password)
modeman.maybe_leave(self._win_id, usertypes.KeyMode.prompt,
'prompt accept')
self._question.done()
elif self._question.mode == usertypes.PromptMode.text:
# User just entered text.
self._question.answer = prompt.lineedit.text()
modeman.maybe_leave(self._win_id, usertypes.KeyMode.prompt,
'prompt accept')
self._question.done()
elif self._question.mode == usertypes.PromptMode.yesno:
# User wants to accept the default of a yes/no question.
self._question.answer = self._question.default
modeman.maybe_leave(self._win_id, usertypes.KeyMode.yesno,
'yesno accept')
self._question.done()
elif self._question.mode == usertypes.PromptMode.alert:
# User acknowledged an alert
self._question.answer = None
modeman.maybe_leave(self._win_id, usertypes.KeyMode.prompt,
'alert accept')
self._question.done()
else:
raise ValueError("Invalid question mode!")
@cmdutils.register(instance='prompter', hide=True, scope='window',
modes=[usertypes.KeyMode.yesno])
def prompt_yes(self):
"""Answer yes to a yes/no prompt."""
if self._question.mode != usertypes.PromptMode.yesno:
# We just ignore this if we don't have a yes/no question.
return
self._question.answer = True
modeman.maybe_leave(self._win_id, usertypes.KeyMode.yesno,
'yesno accept')
self._question.done()
@cmdutils.register(instance='prompter', hide=True, scope='window',
modes=[usertypes.KeyMode.yesno])
def prompt_no(self):
"""Answer no to a yes/no prompt."""
if self._question.mode != usertypes.PromptMode.yesno:
# We just ignore this if we don't have a yes/no question.
return
self._question.answer = False
modeman.maybe_leave(self._win_id, usertypes.KeyMode.yesno,
'prompt accept')
self._question.done()
@pyqtSlot(usertypes.Question, bool)
def ask_question(self, question, blocking):
"""Dispkay a question in the statusbar.
Args:
question: The Question object to ask.
blocking: If True, this function blocks and returns the result.
Return:
The answer of the user when blocking=True.
None if blocking=False.
"""
log.statusbar.debug("Asking question {}, blocking {}, loops {}, queue "
"{}".format(question, blocking, self._loops,
self._queue))
if self._shutting_down:
# If we're currently shutting down we have to ignore this question
# to avoid segfaults - see
# https://github.com/The-Compiler/qutebrowser/issues/95
log.statusbar.debug("Ignoring question because we're shutting "
"down.")
question.abort()
return None
if self._busy and not blocking:
# We got an async question, but we're already busy with one, so we
# just queue it up for later.
log.statusbar.debug("Adding {} to queue.".format(question))
self._queue.append(question)
return
if blocking:
# If we're blocking we save the old state on the stack, so we can
# restore it after exec, if exec gets called multiple times.
context = self._get_ctx()
self._question = question
self._display_question()
mode = self.KEY_MODES[self._question.mode]
question.aborted.connect(
lambda: modeman.maybe_leave(self._win_id, mode, 'aborted'))
modeman.enter(self._win_id, mode, 'question asked')
if blocking:
loop = qtutils.EventLoop()
self._loops.append(loop)
loop.destroyed.connect(lambda: self._loops.remove(loop))
question.completed.connect(loop.quit)
question.completed.connect(loop.deleteLater)
loop.exec_()
if not self._restore_ctx(context):
# Nothing left to restore, so we can go back to popping async
# questions.
if self._queue:
self._pop_later()
return self._question.answer
else:
question.completed.connect(self._pop_later)