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 qtcompat
  24 import sigrok.core as sr
  25 import util
  26
  27 try:
  28     from itertools import izip
  29 except ImportError:
  30     izip = zip
  31
  32 QtCore = qtcompat.QtCore
  33 QtGui = qtcompat.QtGui
  34
  35 class Trace(object):
  36     '''Class to hold the measured samples.'''
  37
  38     def __init__(self):
  39         self.samples = []
  40         self.new = False
  41
  42     def append(self, sample):
  43         self.samples.append(sample)
  44         self.new = True
  45
  46 class MeasurementDataModel(QtGui.QStandardItemModel):
  47     '''Model to hold the measured values.'''
  48
  49     '''Role used to identify and find the item.'''
  50     idRole = QtCore.Qt.UserRole + 1
  51
  52     '''Role used to store the device vendor and model.'''
  53     descRole = QtCore.Qt.UserRole + 2
  54
  55     '''Role used to store a dictionary with the traces'''
  56     tracesRole = QtCore.Qt.UserRole + 3
  57
  58     '''Role used to store the color to draw the graph of the channel.'''
  59     colorRole = QtCore.Qt.UserRole + 4
  60
  61     def __init__(self, parent):
  62         super(self.__class__, self).__init__(parent)
  63
  64         # Use the description text to sort the items for now, because the
  65         # idRole holds tuples, and using them to sort doesn't work.
  66         self.setSortRole(MeasurementDataModel.descRole)
  67
  68         # Used in 'format_value()' to check against.
  69         self.inf = float('inf')
  70
  71         # A generator for the colors of the channels.
  72         self._colorgen = self._make_colorgen()
  73
  74     def _make_colorgen(self):
  75         cols = [
  76             QtGui.QColor(0x8F, 0x52, 0x02), # brown
  77             QtGui.QColor(0x73, 0xD2, 0x16), # green
  78             QtGui.QColor(0xCC, 0x00, 0x00), # red
  79             QtGui.QColor(0x34, 0x65, 0xA4), # blue
  80             QtGui.QColor(0xF5, 0x79, 0x00), # orange
  81             QtGui.QColor(0xED, 0xD4, 0x00), # yellow
  82             QtGui.QColor(0x75, 0x50, 0x7B)  # violet
  83         ]
  84
  85         def myrepeat(g, n):
  86             '''Repeats every element from 'g' 'n' times'.'''
  87             for e in g:
  88                 for f in itertools.repeat(e, n):
  89                     yield f
  90
  91         colorcycle = itertools.cycle(cols)
  92         darkness = myrepeat(itertools.count(100, 10), len(cols))
  93
  94         for c, d in izip(colorcycle, darkness):
  95             yield QtGui.QColor(c).darker(d)
  96
  97     def format_mqflags(self, mqflags):
  98         if sr.QuantityFlag.AC in mqflags:
  99             return 'AC'
 100         elif sr.QuantityFlag.DC in mqflags:
 101             return 'DC'
 102         else:
 103             return ''
 104
 105     def format_value(self, mag):
 106         if mag == self.inf:
 107             return u'\u221E'
 108         return '{:f}'.format(mag)
 109
 110     def getItem(self, device, channel):
 111         '''Return the item for the device + channel combination from the
 112         model, or create a new item if no existing one matches.'''
 113
 114         # Unique identifier for the device + channel.
 115         # TODO: Isn't there something better?
 116         uid = (
 117             device.vendor,
 118             device.model,
 119             device.serial_number(),
 120             device.connection_id(),
 121             channel.index
 122         )
 123
 124         # Find the correct item in the model.
 125         for row in range(self.rowCount()):
 126             item = self.item(row)
 127             rid = item.data(MeasurementDataModel.idRole)
 128             rid = tuple(rid) # PySide returns a list.
 129             if uid == rid:
 130                 return item
 131
 132         # Nothing found, create a new item.
 133         desc = '{} {}, {}'.format(
 134                 device.vendor, device.model, channel.name)
 135
 136         item = QtGui.QStandardItem()
 137         item.setData(uid, MeasurementDataModel.idRole)
 138         item.setData(desc, MeasurementDataModel.descRole)
 139         item.setData(collections.defaultdict(Trace), MeasurementDataModel.tracesRole)
 140         item.setData(next(self._colorgen), MeasurementDataModel.colorRole)
 141         self.appendRow(item)
 142         self.sort(0)
 143         return item
 144
 145     @QtCore.Slot(float, sr.classes.Device, sr.classes.Channel, tuple)
 146     def update(self, timestamp, device, channel, data):
 147         '''Update the data for the device (+channel) with the most recent
 148         measurement from the given payload.'''
 149
 150         item = self.getItem(device, channel)
 151
 152         value, unit, mqflags = data
 153         value_str = self.format_value(value)
 154         unit_str = util.format_unit(unit)
 155         mqflags_str = self.format_mqflags(mqflags)
 156
 157         # The display role is a tuple containing the value and the unit/flags.
 158         disp = (value_str, ' '.join([unit_str, mqflags_str]))
 159         item.setData(disp, QtCore.Qt.DisplayRole)
 160
 161         # The samples role is a dictionary that contains the old samples for each unit.
 162         # Should be trimmed periodically, otherwise it grows larger and larger.
 163         sample = (timestamp, value)
 164         traces = item.data(MeasurementDataModel.tracesRole)
 165         traces[unit].append(sample)
 166
 167 class MultimeterDelegate(QtGui.QStyledItemDelegate):
 168     '''Delegate to show the data items from a MeasurementDataModel.'''
 169
 170     def __init__(self, parent, font):
 171         '''Initialize the delegate.
 172
 173         :param font: Font used for the text.
 174         '''
 175
 176         super(self.__class__, self).__init__(parent)
 177
 178         self._nfont = font
 179
 180         fi = QtGui.QFontInfo(self._nfont)
 181         self._nfontheight = fi.pixelSize()
 182
 183         fm = QtGui.QFontMetrics(self._nfont)
 184         r = fm.boundingRect('-XX.XXXXXX X XX')
 185
 186         w = 1.4 * r.width() + 2 * self._nfontheight
 187         h = 2.6 * self._nfontheight
 188         self._size = QtCore.QSize(w, h)
 189
 190     def sizeHint(self, option=None, index=None):
 191         return self._size
 192
 193     def _color_rect(self, outer):
 194         '''Returns the dimensions of the clickable rectangle.'''
 195         x1 = (outer.height() - self._nfontheight) / 2
 196         r = QtCore.QRect(x1, x1, self._nfontheight, self._nfontheight)
 197         r.translate(outer.topLeft())
 198         return r
 199
 200     def paint(self, painter, options, index):
 201         value, unit = index.data(QtCore.Qt.DisplayRole)
 202         desc = index.data(MeasurementDataModel.descRole)
 203         color = index.data(MeasurementDataModel.colorRole)
 204
 205         painter.setFont(self._nfont)
 206
 207         # Draw the clickable rectangle.
 208         painter.fillRect(self._color_rect(options.rect), color)
 209
 210         # Draw the text
 211         h = options.rect.height()
 212         p = options.rect.topLeft()
 213         p += QtCore.QPoint(h, (h + self._nfontheight) / 2 - 2)
 214         painter.drawText(p, desc + ': ' + value + ' ' + unit)
 215
 216     def editorEvent(self, event, model, options, index):
 217         if type(event) is QtGui.QMouseEvent:
 218             if event.type() == QtCore.QEvent.MouseButtonPress:
 219                 rect = self._color_rect(options.rect)
 220                 if rect.contains(event.x(), event.y()):
 221                     c = index.data(MeasurementDataModel.colorRole)
 222                     c = QtGui.QColorDialog.getColor(c, None,
 223                         'Choose new color for channel')
 224
 225                     item = model.itemFromIndex(index)
 226                     item.setData(c, MeasurementDataModel.colorRole)
 227
 228                     return True
 229
 230         return False