summaryrefslogtreecommitdiff
path: root/qutebrowser/misc/guiprocess.py
blob: 95bfac79e85a5361e768e1107c39893e10ac74e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:

# Copyright 2015-2017 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/>.

"""A QProcess which shows notifications in the GUI."""

import shlex

from PyQt5.QtCore import (pyqtSlot, pyqtSignal, QObject, QProcess,
                          QProcessEnvironment)

from qutebrowser.utils import message, log

# A mapping of QProcess::ErrorCode's to human-readable strings.

ERROR_STRINGS = {
    QProcess.FailedToStart: "The process failed to start.",
    QProcess.Crashed: "The process crashed.",
    QProcess.Timedout: "The last waitFor...() function timed out.",
    QProcess.WriteError: ("An error occurred when attempting to write to the "
                          "process."),
    QProcess.ReadError: ("An error occurred when attempting to read from the "
                         "process."),
    QProcess.UnknownError: "An unknown error occurred.",
}


class GUIProcess(QObject):

    """An external process which shows notifications in the GUI.

    Args:
        cmd: The command which was started.
        args: A list of arguments which gets passed.
        verbose: Whether to show more messages.
        _started: Whether the underlying process is started.
        _proc: The underlying QProcess.
        _what: What kind of thing is spawned (process/editor/userscript/...).
               Used in messages.

    Signals:
        error/finished/started signals proxied from QProcess.
    """

    error = pyqtSignal(QProcess.ProcessError)
    finished = pyqtSignal(int, QProcess.ExitStatus)
    started = pyqtSignal()

    def __init__(self, what, *, verbose=False, additional_env=None,
                 parent=None):
        super().__init__(parent)
        self._what = what
        self.verbose = verbose
        self._started = False
        self.cmd = None
        self.args = None

        self._proc = QProcess(self)
        self._proc.error.connect(self.on_error)
        self._proc.error.connect(self.error)
        self._proc.finished.connect(self.on_finished)
        self._proc.finished.connect(self.finished)
        self._proc.started.connect(self.on_started)
        self._proc.started.connect(self.started)

        if additional_env is not None:
            procenv = QProcessEnvironment.systemEnvironment()
            for k, v in additional_env.items():
                procenv.insert(k, v)
            self._proc.setProcessEnvironment(procenv)

    @pyqtSlot(QProcess.ProcessError)
    def on_error(self, error):
        """Show a message if there was an error while spawning."""
        msg = ERROR_STRINGS[error]
        message.error("Error while spawning {}: {}".format(self._what, msg))

    @pyqtSlot(int, QProcess.ExitStatus)
    def on_finished(self, code, status):
        """Show a message when the process finished."""
        self._started = False
        log.procs.debug("Process finished with code {}, status {}.".format(
            code, status))
        if status == QProcess.CrashExit:
            message.error("{} crashed!".format(self._what.capitalize()))
        elif status == QProcess.NormalExit and code == 0:
            if self.verbose:
                message.info("{} exited successfully.".format(
                    self._what.capitalize()))
        else:
            assert status == QProcess.NormalExit
            # We call this 'status' here as it makes more sense to the user -
            # it's actually 'code'.
            message.error("{} exited with status {}.".format(
                self._what.capitalize(), code))

            stderr = bytes(self._proc.readAllStandardError()).decode('utf-8')
            stdout = bytes(self._proc.readAllStandardOutput()).decode('utf-8')
            if stdout:
                log.procs.error("Process stdout:\n" + stdout.strip())
            if stderr:
                log.procs.error("Process stderr:\n" + stderr.strip())

    @pyqtSlot()
    def on_started(self):
        """Called when the process started successfully."""
        log.procs.debug("Process started.")
        assert not self._started
        self._started = True

    def _pre_start(self, cmd, args):
        """Prepare starting of a QProcess."""
        if self._started:
            raise ValueError("Trying to start a running QProcess!")
        self.cmd = cmd
        self.args = args
        fake_cmdline = ' '.join(shlex.quote(e) for e in [cmd] + list(args))
        log.procs.debug("Executing: {}".format(fake_cmdline))
        if self.verbose:
            message.info('Executing: ' + fake_cmdline)

    def start(self, cmd, args, mode=None):
        """Convenience wrapper around QProcess::start."""
        log.procs.debug("Starting process.")
        self._pre_start(cmd, args)
        if mode is None:
            self._proc.start(cmd, args)
        else:
            self._proc.start(cmd, args, mode)
        self._proc.closeWriteChannel()

    def start_detached(self, cmd, args, cwd=None):
        """Convenience wrapper around QProcess::startDetached."""
        log.procs.debug("Starting detached.")
        self._pre_start(cmd, args)
        ok, _pid = self._proc.startDetached(cmd, args, cwd)

        if ok:
            log.procs.debug("Process started.")
            self._started = True
        else:
            message.error("Error while spawning {}: {}".format(
                self._what, ERROR_STRINGS[self._proc.error()]))

    def exit_status(self):
        return self._proc.exitStatus()