git.maemo.org Git - ejpi/blob - src/qhistory.py

   1 #!/usr/bin/env python
   2
   3 """
   4 http://www.grigoriev.ru/svgmath/ (MathML->SVG in Python)
   5 http://helm.cs.unibo.it/mml-widget/ (MathML widget in C++)
   6 """
   7
   8 import logging
   9
  10 from PyQt4 import QtGui
  11 from PyQt4 import QtCore
  12
  13 import util.misc as misc_utils
  14 import history
  15 import operation
  16
  17
  18 _moduleLogger = logging.getLogger(__name__)
  19
  20
  21 class QCalcHistory(history.AbstractHistory):
  22
  23         _CLOSE_COLUMN = 0
  24         _EQ_COLUMN = 1
  25         _RESULT_COLUMN = 2
  26
  27         def __init__(self, errorReporter):
  28                 super(QCalcHistory, self).__init__()
  29                 self._prettyRenderer = operation.render_number()
  30                 self._errorReporter = errorReporter
  31
  32                 self._historyStore = QtGui.QStandardItemModel()
  33                 self._historyStore.setHorizontalHeaderLabels(["", "Equation", "Result"])
  34                 self._historyStore.itemChanged.connect(self._on_item_changed)
  35
  36                 self._historyView = QtGui.QTreeView()
  37                 self._historyView.setModel(self._historyStore)
  38                 self._historyView.setUniformRowHeights(True)
  39                 self._historyView.setHorizontalScrollBarPolicy(QtCore.Qt.ScrollBarAlwaysOff)
  40                 self._historyView.setSelectionBehavior(QtGui.QAbstractItemView.SelectRows)
  41                 self._historyView.setSelectionMode(QtGui.QAbstractItemView.SingleSelection)
  42                 self._historyView.setHeaderHidden(True)
  43
  44                 viewHeader = self._historyView.header()
  45                 viewHeader.setSortIndicatorShown(True)
  46                 viewHeader.setClickable(True)
  47
  48                 viewHeader.setResizeMode(self._CLOSE_COLUMN, QtGui.QHeaderView.ResizeToContents)
  49                 viewHeader.setResizeMode(self._EQ_COLUMN, QtGui.QHeaderView.Stretch)
  50                 viewHeader.setResizeMode(self._RESULT_COLUMN, QtGui.QHeaderView.ResizeToContents)
  51                 viewHeader.setStretchLastSection(False)
  52
  53                 self._rowCount = 0
  54                 self._programmaticUpdate = False
  55
  56         @property
  57         def toplevel(self):
  58                 return self._historyView
  59
  60         @property
  61         def errorReporter(self):
  62                 return self._errorReporter
  63
  64         def push(self, node):
  65                 simpleNode = node.simplify()
  66
  67                 icon = QtGui.QStandardItem(QtGui.QIcon.fromTheme("gtk-close"), "")
  68                 icon.setEditable(False)
  69                 equation = QtGui.QStandardItem(operation.render_operation(self._prettyRenderer, node))
  70                 equation.setData(node)
  71                 result = QtGui.QStandardItem(operation.render_operation(self._prettyRenderer, simpleNode))
  72                 result.setData(simpleNode)
  73
  74                 row = (icon, equation, result)
  75                 self._historyStore.appendRow(row)
  76
  77                 index = result.index()
  78                 self._historyView.scrollTo(index)
  79                 self._rowCount += 1
  80
  81         def pop(self):
  82                 if len(self) == 0:
  83                         raise IndexError("Not enough items in the history for the operation")
  84
  85                 icon, equation, result = self._historyStore.takeRow(self._rowCount - 1)
  86                 self._rowCount -= 1
  87                 return equation.data().toPyObject()
  88
  89         def peek(self):
  90                 if len(self) == 0:
  91                         raise IndexError("Not enough items in the history for the operation")
  92
  93                 icon, equation, result = self._historyStore.takeRow(self._rowCount - 1)
  94                 row = (icon, equation, result)
  95                 self._historyStore.appendRow(row)
  96
  97                 return equation.data().toPyObject()
  98
  99         def clear(self):
 100                 self._historyStore.clear()
 101                 self._rowCount = 0
 102
 103         @misc_utils.log_exception(_moduleLogger)
 104         def _on_item_changed(self, item):
 105                 if self._programmaticUpdate:
 106                         _moduleLogger.info("Blocking updating %r recursively" % item)
 107                         return
 108                 self._programmaticUpdate = True
 109                 try:
 110                         if item.column() in [self._EQ_COLUMN, self._RESULT_COLUMN]:
 111                                 self._update_input(item)
 112                         else:
 113                                 raise NotImplementedError("Unsupported column to edit %s" % item.column())
 114                 except StandardError, e:
 115                         self.errorReporter.push_exception()
 116                 finally:
 117                         self._programmaticUpdate = False
 118
 119         def _parse_value(self, value):
 120                 raise NotImplementedError("What?")
 121
 122         def _update_input(self, item):
 123                 node = item.data().toPyObject()
 124                 try:
 125                         eqNode = self._parse_value(str(item.text()))
 126                         newText = operation.render_operation(self._prettyRenderer, eqNode)
 127
 128                         eqItem = self._historyStore.item(item.row(), self._EQ_COLUMN)
 129                         eqItem.setData(eqNode)
 130                         eqItem.setText(newText)
 131
 132                         resultNode = eqNode.simplify()
 133                         resultText = operation.render_operation(self._prettyRenderer, resultNode)
 134                         resultItem = self._historyStore.item(item.row(), self._RESULT_COLUMN)
 135                         resultItem.setData(resultNode)
 136                         resultItem.setText(resultText)
 137                 except:
 138                         oldText = operation.render_operation(self._prettyRenderer, node)
 139                         item.setText(oldText)
 140                         raise
 141
 142         def __len__(self):
 143                 return self._rowCount
 144
 145         def __iter__(self):
 146                 for i in xrange(self._rowCount):
 147                         yield self._historyStore.item(i, 1).data().toPyObject()