# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et: # Copyright 2014-2016 Florian Bruhin (The Compiler) # # 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 . """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, usertypes.PromptMode.download: 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 in {usertypes.PromptMode.text, usertypes.PromptMode.user_pwd, usertypes.PromptMode.download}: 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.download: # User just entered a path for a download. target = usertypes.FileDownloadTarget(prompt.lineedit.text()) self._question.answer = target 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() @cmdutils.register(instance='prompter', hide=True, scope='window', modes=[usertypes.KeyMode.prompt]) def prompt_open_download(self): """Immediately open a download.""" if self._question.mode != usertypes.PromptMode.download: # We just ignore this if we don't have a download question. return self._question.answer = usertypes.OpenFileDownloadTarget() modeman.maybe_leave(self._win_id, usertypes.KeyMode.prompt, 'download open') self._question.done() @pyqtSlot(usertypes.Question, bool) def ask_question(self, question, blocking): """Display 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)