datamodel.py

   1 ##
   2 ## This file is part of the sigrok-meter project.
   3 ##
   4 ## Copyright (C) 2014 Jens Steinhauser <jens.steinhauser@gmail.com>
   5 ##
   6 ## This program is free software; you can redistribute it and/or modify
   7 ## it under the terms of the GNU General Public License as published by
   8 ## the Free Software Foundation; either version 2 of the License, or
   9 ## (at your option) any later version.
  10 ##
  11 ## This program is distributed in the hope that it will be useful,
  12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ## GNU General Public License for more details.
  15 ##
  16 ## You should have received a copy of the GNU General Public License
  17 ## along with this program; if not, write to the Free Software
  18 ## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19 ##
  20
  21 import collections
  22 import itertools
  23 import math
  24 import qtcompat
  25 import sigrok.core as sr
  26 import util
  27
  28 try:
  29     from itertools import izip
  30 except ImportError:
  31     izip = zip
  32
  33 QtCore = qtcompat.QtCore
  34 QtGui = qtcompat.QtGui
  35
  36 class Trace(object):
  37     '''Class to hold the measured samples.'''
  38
  39     def __init__(self):
  40         self.samples = []
  41         self.new = False
  42
  43     def append(self, sample):
  44         self.samples.append(sample)
  45         self.new = True
  46
  47 class MeasurementDataModel(QtGui.QStandardItemModel):
  48     '''Model to hold the measured values.'''
  49
  50     '''Role used to identify and find the item.'''
  51     idRole = QtCore.Qt.UserRole + 1
  52
  53     '''Role used to store the device vendor and model.'''
  54     descRole = QtCore.Qt.UserRole + 2
  55
  56     '''Role used to store a dictionary with the traces'''
  57     tracesRole = QtCore.Qt.UserRole + 3
  58
  59     '''Role used to store the color to draw the graph of the channel.'''
  60     colorRole = QtCore.Qt.UserRole + 4
  61
  62     def __init__(self, parent):
  63         super(self.__class__, self).__init__(parent)
  64
  65         # Use the description text to sort the items for now, because the
  66         # idRole holds tuples, and using them to sort doesn't work.
  67         self.setSortRole(MeasurementDataModel.descRole)
  68
  69         # A generator for the colors of the channels.
  70         self._colorgen = self._make_colorgen()
  71
  72     def _make_colorgen(self):
  73         cols = [
  74             QtGui.QColor(0x8F, 0x52, 0x02), # brown
  75             QtGui.QColor(0x73, 0xD2, 0x16), # green
  76             QtGui.QColor(0xCC, 0x00, 0x00), # red
  77             QtGui.QColor(0x34, 0x65, 0xA4), # blue
  78             QtGui.QColor(0xF5, 0x79, 0x00), # orange
  79             QtGui.QColor(0xED, 0xD4, 0x00), # yellow
  80             QtGui.QColor(0x75, 0x50, 0x7B)  # violet
  81         ]
  82
  83         def myrepeat(g, n):
  84             '''Repeats every element from 'g' 'n' times'.'''
  85             for e in g:
  86                 for f in itertools.repeat(e, n):
  87                     yield f
  88
  89         colorcycle = itertools.cycle(cols)
  90         darkness = myrepeat(itertools.count(100, 10), len(cols))
  91
  92         for c, d in izip(colorcycle, darkness):
  93             yield QtGui.QColor(c).darker(d)
  94
  95     def format_mqflags(self, mqflags):
  96         if sr.QuantityFlag.AC in mqflags:
  97             return 'AC'
  98         elif sr.QuantityFlag.DC in mqflags:
  99             return 'DC'
 100         else:
 101             return ''
 102
 103     def format_value(self, mag):
 104         if math.isinf(mag):
 105             return u'\u221E'
 106         return '{:f}'.format(mag)
 107
 108     def getItem(self, device, channel):
 109         '''Return the item for the device + channel combination from the
 110         model, or create a new item if no existing one matches.'''
 111
 112         # Unique identifier for the device + channel.
 113         # TODO: Isn't there something better?
 114         uid = (
 115             device.vendor,
 116             device.model,
 117             device.serial_number(),
 118             device.connection_id(),
 119             channel.index
 120         )
 121
 122         # Find the correct item in the model.
 123         for row in range(self.rowCount()):
 124             item = self.item(row)
 125             rid = item.data(MeasurementDataModel.idRole)
 126             rid = tuple(rid) # PySide returns a list.
 127             if uid == rid:
 128                 return item
 129
 130         # Nothing found, create a new item.
 131         desc = '{} {}, {}'.format(
 132                 device.vendor, device.model, channel.name)
 133
 134         item = QtGui.QStandardItem()
 135         item.setData(uid, MeasurementDataModel.idRole)
 136         item.setData(desc, MeasurementDataModel.descRole)
 137         item.setData(collections.defaultdict(Trace), MeasurementDataModel.tracesRole)
 138         item.setData(next(self._colorgen), MeasurementDataModel.colorRole)
 139         self.appendRow(item)
 140         self.sort(0)
 141         return item
 142
 143     @QtCore.Slot(float, sr.classes.Device, sr.classes.Channel, tuple)
 144     def update(self, timestamp, device, channel, data):
 145         '''Update the data for the device (+channel) with the most recent
 146         measurement from the given payload.'''
 147
 148         item = self.getItem(device, channel)
 149
 150         value, unit, mqflags = data
 151         value_str = self.format_value(value)
 152         unit_str = util.format_unit(unit)
 153         mqflags_str = self.format_mqflags(mqflags)
 154
 155         # The display role is a tuple containing the value and the unit/flags.
 156         disp = (value_str, ' '.join([unit_str, mqflags_str]))
 157         item.setData(disp, QtCore.Qt.DisplayRole)
 158
 159         # The samples role is a dictionary that contains the old samples for each unit.
 160         # Should be trimmed periodically, otherwise it grows larger and larger.
 161         if not math.isinf(value) and not math.isnan(value):
 162             sample = (timestamp, value)
 163             traces = item.data(MeasurementDataModel.tracesRole)
 164             traces[unit].append(sample)
 165
 166 class MultimeterDelegate(QtGui.QStyledItemDelegate):
 167     '''Delegate to show the data items from a MeasurementDataModel.'''
 168
 169     def __init__(self, parent, font):
 170         '''Initialize the delegate.
 171
 172         :param font: Font used for the text.
 173         '''
 174
 175         super(self.__class__, self).__init__(parent)
 176
 177         self._nfont = font
 178
 179         fi = QtGui.QFontInfo(self._nfont)
 180         self._nfontheight = fi.pixelSize()
 181
 182         fm = QtGui.QFontMetrics(self._nfont)
 183         r = fm.boundingRect('-XX.XXXXXX X XX')
 184
 185         w = 1.4 * r.width() + 2 * self._nfontheight
 186         h = 2.6 * self._nfontheight
 187         self._size = QtCore.QSize(w, h)
 188
 189     def sizeHint(self, option=None, index=None):
 190         return self._size
 191
 192     def _color_rect(self, outer):
 193         '''Returns the dimensions of the clickable rectangle.'''
 194         x1 = (outer.height() - self._nfontheight) / 2
 195         r = QtCore.QRect(x1, x1, self._nfontheight, self._nfontheight)
 196         r.translate(outer.topLeft())
 197         return r
 198
 199     def paint(self, painter, options, index):
 200         value, unit = index.data(QtCore.Qt.DisplayRole)
 201         desc = index.data(MeasurementDataModel.descRole)
 202         color = index.data(MeasurementDataModel.colorRole)
 203
 204         painter.setFont(self._nfont)
 205
 206         # Draw the clickable rectangle.
 207         painter.fillRect(self._color_rect(options.rect), color)
 208
 209         # Draw the text
 210         h = options.rect.height()
 211         p = options.rect.topLeft()
 212         p += QtCore.QPoint(h, (h + self._nfontheight) / 2 - 2)
 213         painter.drawText(p, desc + ': ' + value + ' ' + unit)
 214
 215     def editorEvent(self, event, model, options, index):
 216         if type(event) is QtGui.QMouseEvent:
 217             if event.type() == QtCore.QEvent.MouseButtonPress:
 218                 rect = self._color_rect(options.rect)
 219                 if rect.contains(event.x(), event.y()):
 220                     c = index.data(MeasurementDataModel.colorRole)
 221                     c = QtGui.QColorDialog.getColor(c, None,
 222                         'Choose new color for channel')
 223
 224                     item = model.itemFromIndex(index)
 225                     item.setData(c, MeasurementDataModel.colorRole)
 226
 227                     return True
 228
 229         return False