Return from sample callback if sigrok module is not available.

[sigrok-meter.git] / sigrok-meter

#!/usr/bin/env python

##
## This file is part of the sigrok-meter project.
##
## Copyright (C) 2013 Uwe Hermann <uwe@hermann-uwe.de>
## Copyright (C) 2014 Jens Steinhauser <jens.steinhauser@gmail.com>
##
## This program 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 2 of the License, or
## (at your option) any later version.
##
## This program 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 this program; if not, write to the Free Software
## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
##

import argparse
import datetime
import os.path
import re
import sigrok.core as sr
import sys
import textwrap

default_drivers = [('demo', {'analog_channels': 4})]
default_loglevel = sr.LogLevel.WARN

def parse_cli():
    parser = argparse.ArgumentParser(
        description='Simple sigrok GUI for multimeters and dataloggers.',
        epilog=textwrap.dedent('''\
            The DRIVER string is the same as for sigrok-cli(1).

            examples:

              %(prog)s --driver tecpel-dmm-8061-ser:conn=/dev/ttyUSB0

              %(prog)s --driver uni-t-ut61e:conn=1a86.e008
        '''),
        formatter_class=argparse.RawDescriptionHelpFormatter)

    parser.add_argument('-d', '--driver',
        action='append',
        help='The driver to use')
    parser.add_argument('-l', '--loglevel',
        type=int,
        help='Set loglevel (5 is most verbose)')
    parser.add_argument('--pyside',
        action='store_true',
        default=False,
        help='Force use of PySide (default is to use PyQt4)')
    args = parser.parse_args()

    result = {
        'drivers': default_drivers,
        'loglevel': default_loglevel,
        'pyside': args.pyside
    }

    if args.driver:
        result['drivers'] = []
        for d in args.driver:
            m = re.match('(?P<name>[^:]+)(?P<opts>(:[^:=]+=[^:=]+)*)', d)
            if not m:
                sys.exit('error parsing option "{}"'.format(d))

            opts = m.group('opts').split(':')[1:]
            opts = [tuple(kv.split('=')) for kv in opts]
            opts = dict(opts)

            result['drivers'].append((m.group('name'), opts))

    if args.loglevel != None:
        try:
            result['loglevel'] = sr.LogLevel.get(args.loglevel)
        except:
            sys.exit('error: invalid log level')

    return result

if __name__ == '__main__':
    # The command line parsing and import of the Qt modules is done here,
    # so that the modules are imported before the classes below derive
    # from classes therein. The rest of the main function is at the bottom.

    args = parse_cli()

    if args['pyside']:
        from PySide import QtCore, QtGui
    else:
        try:
            # Use version 2 API in all cases, because that's what PySide uses.
            import sip
            sip.setapi('QVariant', 2)
            sip.setapi('QDate', 2)
            sip.setapi('QDateTime', 2)
            sip.setapi('QString', 2)
            sip.setapi('QTextStream', 2)
            sip.setapi('QTime', 2)
            sip.setapi('QUrl', 2)
            sip.setapi('QVariant', 2)

            from PyQt4 import QtCore, QtGui

            # Add PySide compatible names.
            QtCore.Signal = QtCore.pyqtSignal
            QtCore.Slot = QtCore.pyqtSlot
        except:
            sys.stderr.write('import of PyQt4 failed, using PySide\n')
            from PySide import QtCore, QtGui

class SamplingThread(QtCore.QObject):
    '''A class that handles the reception of sigrok packets in the background.'''

    class Worker(QtCore.QObject):
        '''Helper class that does the actual work in another thread.'''

        '''Signal emitted when new data arrived.'''
        measured = QtCore.Signal(object, object)

        '''Signal emmited in case of an error.'''
        error = QtCore.Signal(str)

        def __init__(self, drivers, loglevel):
            super(self.__class__, self).__init__()

            self.sampling = False
            self.drivers = drivers

            self.context = sr.Context_create()
            self.context.log_level = loglevel

            self.sr_pkg_version = self.context.package_version
            self.sr_lib_version = self.context.lib_version

        @QtCore.Slot()
        def start_sampling(self):
            devices = []
            for name, options in self.drivers:
                try:
                    dr = self.context.drivers[name]
                    devices.append(dr.scan(**options)[0])
                except:
                    self.error.emit(
                        'Unable to get device for driver "{}".'.format(name))
                    return

            self.session = self.context.create_session()
            for dev in devices:
                self.session.add_device(dev)
                dev.open()
            self.session.add_datafeed_callback(self.callback)
            self.session.start()
            self.sampling = True
            self.session.run()

            # If sampling is 'True' here, it means that 'stop_sampling()' was
            # not called, therefore 'session.run()' ended too early, indicating
            # an error.
            if self.sampling:
                self.error.emit('An error occured during the acquisition.')

        def stop_sampling(self):
            if self.sampling:
                self.sampling = False
                self.session.stop()

        def callback(self, device, packet):
            if not sr:
                # In rare cases it can happen that the callback fires while
                # the interpreter is shutting down. Then the sigrok module
                # is already set to 'None'.
                return

            if packet.type == sr.PacketType.ANALOG:
                self.measured.emit(device, packet.payload)

            # wait a short time so that in any case we don't flood the GUI
            # with new data (for example if the demo device is used)
            self.thread().msleep(100)

    # signal used to start the worker across threads
    _start_signal = QtCore.Signal()

    def __init__(self, drivers, loglevel):
        super(self.__class__, self).__init__()

        self.worker = self.Worker(drivers, loglevel)
        self.thread = QtCore.QThread()
        self.worker.moveToThread(self.thread)

        self._start_signal.connect(self.worker.start_sampling)

        # expose the signals of the worker
        self.measured = self.worker.measured
        self.error = self.worker.error

        self.thread.start()

    def start(self):
        '''Starts sampling'''
        self._start_signal.emit()

    def stop(self):
        '''Stops sampling and the background thread.'''
        self.worker.stop_sampling()
        self.thread.quit()
        # the timeout is needed when the demo device is used, because it
        # produces so much outstanding data that quitting takes a long time
        self.thread.wait(500)

    def sr_pkg_version(self):
        '''Returns the version number of the libsigrok package.'''
        return self.worker.sr_pkg_version

    def sr_lib_version(self):
        '''Returns the version number fo the libsigrok library.'''
        return self.worker.sr_lib_version

class MeasurementDataModel(QtGui.QStandardItemModel):
    '''Model to hold the measured values.'''

    '''Role used to identify and find the item.'''
    _idRole = QtCore.Qt.UserRole + 1

    '''Role used to store the device vendor and model.'''
    descRole = QtCore.Qt.UserRole + 2

    def __init__(self, parent):
        super(self.__class__, self).__init__(parent)

        # Use the description text to sort the items for now, because the
        # _idRole holds tuples, and using them to sort doesn't work.
        self.setSortRole(MeasurementDataModel.descRole)

        # Used in 'format_mag()' to check against.
        self.inf = float('inf')

    def format_unit(self, u):
        units = {
            sr.Unit.VOLT:                   'V',
            sr.Unit.AMPERE:                 'A',
            sr.Unit.OHM:                   u'\u03A9',
            sr.Unit.FARAD:                  'F',
            sr.Unit.KELVIN:                 'K',
            sr.Unit.CELSIUS:               u'\u00B0C',
            sr.Unit.FAHRENHEIT:            u'\u00B0F',
            sr.Unit.HERTZ:                  'Hz',
            sr.Unit.PERCENTAGE:             '%',
          # sr.Unit.BOOLEAN
            sr.Unit.SECOND:                 's',
            sr.Unit.SIEMENS:                'S',
            sr.Unit.DECIBEL_MW:             'dBu',
            sr.Unit.DECIBEL_VOLT:           'dBV',
          # sr.Unit.UNITLESS
            sr.Unit.DECIBEL_SPL:            'dB',
          # sr.Unit.CONCENTRATION
            sr.Unit.REVOLUTIONS_PER_MINUTE: 'rpm',
            sr.Unit.VOLT_AMPERE:            'VA',
            sr.Unit.WATT:                   'W',
            sr.Unit.WATT_HOUR:              'Wh',
            sr.Unit.METER_SECOND:           'm/s',
            sr.Unit.HECTOPASCAL:            'hPa',
            sr.Unit.HUMIDITY_293K:          '%rF',
            sr.Unit.DEGREE:                u'\u00B0',
            sr.Unit.HENRY:                  'H'
        }

        return units.get(u, '')

    def format_mqflags(self, mqflags):
        if sr.QuantityFlag.AC in mqflags:
            return 'AC'
        elif sr.QuantityFlag.DC in mqflags:
            return 'DC'
        else:
            return ''

    def format_mag(self, mag):
        if mag == self.inf:
            return u'\u221E'
        return '{:f}'.format(mag)

    def getItem(self, device, channel):
        '''Returns the item for the device + channel combination from the model,
        or creates a new item if no existing one matches.'''

        # unique identifier for the device + channel
        # TODO: isn't there something better?
        uid = (
            device.vendor,
            device.model,
            device.serial_number(),
            device.connection_id(),
            channel.index
        )

        # find the correct item in the model
        for row in range(self.rowCount()):
            item = self.item(row)
            rid = item.data(MeasurementDataModel._idRole)
            rid = tuple(rid) # PySide returns a list
            if uid == rid:
                return item

        # nothing found, create a new item
        desc = '{} {}, channel "{}"'.format(
                device.vendor, device.model, channel.name)

        item = QtGui.QStandardItem()
        item.setData(uid, MeasurementDataModel._idRole)
        item.setData(desc, MeasurementDataModel.descRole)
        self.appendRow(item)
        self.sort(0)
        return item

    @QtCore.Slot(object, object)
    def update(self, device, payload):
        '''Updates the data for the device (+channel) with the most recent
        measurement from the given payload.'''

        if not len(payload.channels):
            return

        # TODO: find a device with multiple channels in one packet
        channel = payload.channels[0]

        item = self.getItem(device, channel)

        # the most recent value
        mag = payload.data[0][-1]

        unit_str = self.format_unit(payload.unit)
        mqflags_str = self.format_mqflags(payload.mq_flags)
        mag_str = self.format_mag(mag)
        disp = ' '.join([mag_str, unit_str, mqflags_str])
        item.setData(disp, QtCore.Qt.DisplayRole)

class MultimeterDelegate(QtGui.QStyledItemDelegate):
    '''Delegate to show the data items from a MeasurementDataModel.'''

    def __init__(self, parent, font):
        '''Initializes the delegate.

        :param font: Font used for the description text, the value is drawn
                     with a slightly bigger and bold variant of the font.
        '''

        super(self.__class__, self).__init__(parent)

        self._nfont = font
        self._bfont = QtGui.QFont(self._nfont)

        self._bfont.setBold(True)
        if self._bfont.pixelSize() != -1:
            self._bfont.setPixelSize(self._bfont.pixelSize() * 1.8)
        else:
            self._bfont.setPointSizeF(self._bfont.pointSizeF() * 1.8)

        fi = QtGui.QFontInfo(self._nfont)
        self._nfontheight = fi.pixelSize()

        fm = QtGui.QFontMetrics(self._bfont)
        r = fm.boundingRect('-XX.XXXXXX X XX')
        self._size = QtCore.QSize(r.width() * 1.2, r.height() * 3.5)

    def sizeHint(self, option=None, index=None):
        return self._size

    def paint(self, painter, options, index):
        value = index.data(QtCore.Qt.DisplayRole)
        desc = index.data(MeasurementDataModel.descRole)

        # description in the top left corner
        painter.setFont(self._nfont)
        p = options.rect.topLeft()
        p += QtCore.QPoint(self._nfontheight, 2 * self._nfontheight)
        painter.drawText(p, desc)

        # value in the center
        painter.setFont(self._bfont)
        r = options.rect.adjusted(self._nfontheight, 2.5 * self._nfontheight,
                0, 0)
        painter.drawText(r, QtCore.Qt.AlignCenter, value)

class EmptyMessageListView(QtGui.QListView):
    '''List view that shows a message if the model im empty.'''

    def __init__(self, message, parent=None):
        super(self.__class__, self).__init__(parent)

        self._message = message

    def paintEvent(self, event):
        m = self.model()
        if m and m.rowCount():
            super(self.__class__, self).paintEvent(event)
            return

        painter = QtGui.QPainter(self.viewport())
        painter.drawText(self.rect(), QtCore.Qt.AlignCenter, self._message)

class SigrokMeter(QtGui.QMainWindow):
    '''The main window of the application.'''

    def __init__(self, thread):
        super(SigrokMeter, self).__init__()

        self.delegate = MultimeterDelegate(self, self.font())
        self.model = MeasurementDataModel(self)
        self.model.rowsInserted.connect(self.modelRowsInserted)

        self.setup_ui()

        self.thread = thread
        self.thread.measured.connect(self.model.update)
        self.thread.error.connect(self.error)
        self.thread.start()

    def setup_ui(self):
        self.setWindowTitle('sigrok-meter')
        # resizing the listView below will increase this again
        self.resize(10, 10)

        p = os.path.abspath(os.path.dirname(__file__))
        p = os.path.join(p, 'sigrok-logo-notext.png')
        self.setWindowIcon(QtGui.QIcon(p))

        actionQuit = QtGui.QAction(self)
        actionQuit.setText('&Quit')
        actionQuit.setIcon(QtGui.QIcon.fromTheme('application-exit'))
        actionQuit.setShortcut('Ctrl+Q')
        actionQuit.triggered.connect(self.close)

        actionAbout = QtGui.QAction(self)
        actionAbout.setText('&About')
        actionAbout.setIcon(QtGui.QIcon.fromTheme('help-about'))
        actionAbout.triggered.connect(self.show_about)

        menubar = self.menuBar()
        menuFile = menubar.addMenu('&File')
        menuFile.addAction(actionQuit)
        menuHelp = menubar.addMenu('&Help')
        menuHelp.addAction(actionAbout)

        self.listView = EmptyMessageListView('waiting for data...')
        self.listView.setFrameShape(QtGui.QFrame.NoFrame)
        self.listView.viewport().setBackgroundRole(QtGui.QPalette.Window)
        self.listView.viewport().setAutoFillBackground(True)
        self.listView.setMinimumWidth(260)
        self.listView.setSelectionMode(QtGui.QAbstractItemView.NoSelection)
        self.listView.setEditTriggers(QtGui.QAbstractItemView.NoEditTriggers)
        self.listView.setVerticalScrollMode(QtGui.QAbstractItemView.ScrollPerPixel)
        self.listView.setItemDelegate(self.delegate)
        self.listView.setModel(self.model)
        self.listView.setUniformItemSizes(True)
        self.listView.setMinimumSize(self.delegate.sizeHint())

        self.setCentralWidget(self.listView)
        self.centralWidget().setContentsMargins(0, 0, 0, 0)

    @QtCore.Slot()
    def show_about(self):
        text = textwrap.dedent('''\
            <div align="center">
                <b>sigrok-meter</b><br/>
                0.1.0<br/>
                Using libsigrok {} (lib version {}).<br/>
                <a href='http://www.sigrok.org'>
                         http://www.sigrok.org</a><br/>
                <br/>
                This program comes with ABSOLUTELY NO WARRANTY;<br/>
                for details visit
                <a href='http://www.gnu.org/licenses/gpl.html'>
                         http://www.gnu.org/licenses/gpl.html</a>
            </div>
        '''.format(self.thread.sr_pkg_version(), self.thread.sr_lib_version()))

        QtGui.QMessageBox.about(self, 'About sigrok-meter', text)

    @QtCore.Slot(str)
    def error(self, msg):
        '''Error handler for the sampling thread.'''
        QtGui.QMessageBox.critical(self, 'Error', msg)
        self.close()

    @QtCore.Slot(object, int, int)
    def modelRowsInserted(self, parent, start, end):
        '''Resizes the list view to the size of the content.'''

        rows = self.model.rowCount()
        dh = self.delegate.sizeHint().height()
        self.listView.setMinimumHeight(dh * rows)

if __name__ == '__main__':
    thread = SamplingThread(args['drivers'], args['loglevel'])

    app = QtGui.QApplication([])
    s = SigrokMeter(thread)
    s.show()

    r = app.exec_()
    thread.stop()
    sys.exit(r)