Article Outline
Python pyqt (gui) example 'simpletreemodel'
Modules used in program:
import simpletreemodel_rc
simpletreemodel
Python pyqt example: simpletreemodel
#!/usr/bin/env python
#############################################################################
##
## Copyright (C) 2013 Riverbank Computing Limited.
## Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
## All rights reserved.
##
## This file is part of the examples of PyQt.
##
## $QT_BEGIN_LICENSE:BSD$
## You may use this file under the terms of the BSD license as follows:
##
## "Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are
## met:
## * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## * Redistributions in binary form must reproduce the above copyright
## notice, this list of conditions and the following disclaimer in
## the documentation and/or other materials provided with the
## distribution.
## * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
## the names of its contributors may be used to endorse or promote
## products derived from this software without specific prior written
## permission.
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## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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## $QT_END_LICENSE$
##
#############################################################################
from PyQt5.QtCore import QAbstractItemModel, QFile, QIODevice, QModelIndex, Qt
from PyQt5.QtWidgets import QApplication, QTreeView
import simpletreemodel_rc
class TreeItem(object):
def __init__(self, data, parent=None):
self.parentItem = parent
self.itemData = data
self.childItems = []
def appendChild(self, item):
self.childItems.append(item)
def child(self, row):
return self.childItems[row]
def childCount(self):
return len(self.childItems)
def columnCount(self):
return len(self.itemData)
def data(self, column):
try:
return self.itemData[column]
except IndexError:
return None
def parent(self):
return self.parentItem
def row(self):
if self.parentItem:
return self.parentItem.childItems.index(self)
return 0
class TreeModel(QAbstractItemModel):
def __init__(self, data, parent=None):
super(TreeModel, self).__init__(parent)
self.rootItem = TreeItem(("Title", "Summary"))
self.setupModelData(data.split('\n'), self.rootItem)
def columnCount(self, parent):
if parent.isValid():
return parent.internalPointer().columnCount()
else:
return self.rootItem.columnCount()
def data(self, index, role):
if not index.isValid():
return None
if role != Qt.DisplayRole:
return None
item = index.internalPointer()
return item.data(index.column())
def flags(self, index):
if not index.isValid():
return Qt.NoItemFlags
return Qt.ItemIsEnabled | Qt.ItemIsSelectable
def headerData(self, section, orientation, role):
if orientation == Qt.Horizontal and role == Qt.DisplayRole:
return self.rootItem.data(section)
return None
def index(self, row, column, parent):
if not self.hasIndex(row, column, parent):
return QModelIndex()
if not parent.isValid():
parentItem = self.rootItem
else:
parentItem = parent.internalPointer()
childItem = parentItem.child(row)
if childItem:
return self.createIndex(row, column, childItem)
else:
return QModelIndex()
def parent(self, index):
if not index.isValid():
return QModelIndex()
childItem = index.internalPointer()
parentItem = childItem.parent()
if parentItem == self.rootItem:
return QModelIndex()
return self.createIndex(parentItem.row(), 0, parentItem)
def rowCount(self, parent):
if parent.column() > 0:
return 0
if not parent.isValid():
parentItem = self.rootItem
else:
parentItem = parent.internalPointer()
return parentItem.childCount()
def setupModelData(self, lines, parent):
parents = [parent]
indentations = [0]
number = 0
while number < len(lines):
position = 0
while position < len(lines[number]):
if lines[number][position] != ' ':
break
position += 1
lineData = lines[number][position:].trimmed()
if lineData:
# Read the column data from the rest of the line.
columnData = [s for s in lineData.split('\t') if s]
if position > indentations[-1]:
# The last child of the current parent is now the new
# parent unless the current parent has no children.
if parents[-1].childCount() > 0:
parents.append(parents[-1].child(parents[-1].childCount() - 1))
indentations.append(position)
else:
while position < indentations[-1] and len(parents) > 0:
parents.pop()
indentations.pop()
# Append a new item to the current parent's list of children.
parents[-1].appendChild(TreeItem(columnData, parents[-1]))
number += 1
if __name__ == '__main__':
import sys
app = QApplication(sys.argv)
f = QFile(':/default.txt')
f.open(QIODevice.ReadOnly)
model = TreeModel(f.readAll())
f.close()
view = QTreeView()
view.setModel(model)
view.setWindowTitle("Simple Tree Model")
view.show()
sys.exit(app.exec_())
Useful links
- Learn PyQt: https://pythonbasics.org/pyqt-hello-world/
- Install PyQt: https://pythonbasics.org/install-pyqt/