Qt MVC concept example in a Jupyter Notebook

QtMVC.ipynb

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  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Example of  a simple QTableView and QAbstractTableModel \n",
    "\n",
    "awesome explained at http://doc.qt.io/qt-5/modelview.html"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "import sys\n",
    "import logging\n",
    "\n",
    "logger = logging.getLogger(__name__)\n",
    "handler = logging.StreamHandler(sys.stdout)\n",
    "formatter = logging.Formatter('%(asctime)s - %(name)s - %(funcName)s - %(levelname)s - %(message)s')\n",
    "handler.setFormatter(formatter)\n",
    "logger.addHandler(handler)\n",
    "logger.setLevel(logging.DEBUG)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2018-05-31 09:58:14,576 - __main__ - <module> - INFO - Test\n"
     ]
    }
   ],
   "source": [
    "logger.info('Test')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "%gui qt5"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 39,
   "metadata": {},
   "outputs": [],
   "source": [
    "from PyQt5.QtGui import QBrush\n",
    "from PyQt5.QtWidgets import QTableView\n",
    "from PyQt5.QtCore import QAbstractTableModel, Qt, QModelIndex"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 41,
   "metadata": {},
   "outputs": [],
   "source": [
    "class MyModel(QAbstractTableModel):\n",
    "    def __init__(self,data,parent=None):\n",
    "        super(MyModel,self).__init__(parent)\n",
    "        self._data = data\n",
    "        self._data_handlers = {\n",
    "            Qt.DisplayRole:self._handle_data_display_role,\n",
    "            Qt.BackgroundRole:self._handle_data_background_role,\n",
    "        }\n",
    "        \n",
    "    def rowCount(self,index):\n",
    "        logger.debug('index %s:%s',index.row(),index.column())\n",
    "        return len(self._data)\n",
    "    \n",
    "    def columnCount(self,index):\n",
    "        logger.debug('index %s:%s',index.row(),index.column())\n",
    "        try:\n",
    "            return len(self._data[0])\n",
    "        except: \n",
    "            return 0\n",
    "    \n",
    "    def data(self,index,role):\n",
    "        if role in self._data_handlers:\n",
    "            logger.debug('%s index %s:%s',role,index.row(),index.column())\n",
    "            return self._data_handlers[role](index)\n",
    "            \n",
    "    def _handle_data_display_role(self,index):\n",
    "        return self._data[index.row()][index.column()]\n",
    "    \n",
    "    def _handle_data_background_role(self,index):\n",
    "        if index.column() == 1:\n",
    "            return QBrush(Qt.red)\n",
    "        "
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 42,
   "metadata": {},
   "outputs": [],
   "source": [
    "data = [['hallo']]"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 43,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2018-05-31 10:16:46,052 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,054 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,055 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,055 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,056 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,058 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,083 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,084 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,084 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:46,085 - __main__ - data - DEBUG - 0 index 0:0\n",
      "2018-05-31 10:16:46,086 - __main__ - data - DEBUG - 8 index 0:0\n"
     ]
    }
   ],
   "source": [
    "tableview = QTableView()\n",
    "mymodel = MyModel(data)\n",
    "tableview.setModel(mymodel)\n",
    "tableview.show()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Update the contents of a Cell"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 44,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2018-05-31 10:16:48,146 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:48,147 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:48,147 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:48,148 - __main__ - data - DEBUG - 0 index 0:0\n",
      "2018-05-31 10:16:48,149 - __main__ - data - DEBUG - 8 index 0:0\n"
     ]
    }
   ],
   "source": [
    "mymodel._data[0][0] = 'Hallo'\n",
    "index = mymodel.createIndex(0,0)\n",
    "mymodel.dataChanged.emit(index,index,[Qt.DisplayRole])"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Insert an additional column in the first row"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 45,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2018-05-31 10:16:49,717 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:49,722 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:49,723 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:49,724 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:49,725 - __main__ - data - DEBUG - 0 index 0:0\n",
      "2018-05-31 10:16:49,725 - __main__ - data - DEBUG - 8 index 0:0\n",
      "2018-05-31 10:16:49,726 - __main__ - rowCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:49,727 - __main__ - columnCount - DEBUG - index -1:-1\n",
      "2018-05-31 10:16:49,728 - __main__ - data - DEBUG - 0 index 0:1\n",
      "2018-05-31 10:16:49,728 - __main__ - data - DEBUG - 8 index 0:1\n"
     ]
    }
   ],
   "source": [
    "i = len(mymodel._data)\n",
    "mymodel.beginInsertColumns(QModelIndex(), i, i)# a table has no childs so the parent must be an invalid index\n",
    "data[0].append('Martin')\n",
    "mymodel.endInsertColumns()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
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