PyQT: adding to QAbstractItemModel using a button - pyqt

Question

I'm trying to implement a TreeView using QAbstractItemModel. I want to set up an empty model and then add an item to the model using a button.
This appears to be a lot more complex than I'd realised! I've modified a custom instance of the QAbstractItemModel example found in the Lib\site-packages\PyQt4\examples\itemviews\simpletreemodel\simpletreemodel.pyw.
Rather than setting up the model all at once, I want o build it incrementally.
When I click the button, I get the message showing that the process method is executing, but the model isn't updated.
Any pointers as to why it's not working would be greatly appreciated!
from PyQt4 import QtGui, QtCore
import sys
class myWindow(QtGui.QWidget):
def __init__(self):
QtGui.QWidget.__init__(self)
self.resize(500, 400)
#Tree Widget
self.treeView = QtGui.QTreeView(self)
#Model
self.model = TreeModel()
self.treeView.setModel(self.model)
# Button
self.button = QtGui.QPushButton(self)
self.button.setText('Add Item')
self.button.clicked.connect(self.process)
# Add to Layout
self.gridLayout = QtGui.QGridLayout(self)
self.gridLayout.addWidget(self.button,0,0)
self.gridLayout.addWidget(self.treeView,1,0)
def process(self):
print "here"
newItem = TreeItem(["bob","bob","bob"],self.model.rootItem)
self.model.rootItem.appendChild(newItem)
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(QtCore.QAbstractItemModel):
def __init__(self, parent=None):
super(TreeModel, self).__init__(parent)
self.rootItem = TreeItem(("Model", "Status","Location"))
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 != QtCore.Qt.DisplayRole:
return None
item = index.internalPointer()
return item.data(index.column())
def flags(self, index):
if not index.isValid():
return QtCore.Qt.NoItemFlags
return QtCore.Qt.ItemIsEnabled | QtCore.Qt.ItemIsSelectable
def headerData(self, section, orientation, role):
if orientation == QtCore.Qt.Horizontal and role == QtCore.Qt.DisplayRole:
return self.rootItem.data(section)
return None
def index(self, row, column, parent):
if not self.hasIndex(row, column, parent):
return QtCore.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 QtCore.QModelIndex()
def parent(self, index):
if not index.isValid():
return QtCore.QModelIndex()
childItem = index.internalPointer()
parentItem = childItem.parent()
if parentItem == self.rootItem:
return QtCore.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()
if __name__ == "__main__":
app = QtGui.QApplication.instance() # checks if QApplication already exists
if not app: # create QApplication if it doesnt exist
app = QtGui.QApplication(sys.argv)
# Window
window = myWindow()
window.show()
sys.exit(app.exec_())

Answer 1

Using a QStandardItemModel has worked a treat!
import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
class Window(QWidget):
def __init__(self):
QWidget.__init__(self)
self.resize(500, 400)
#Tree Widget
self.treeView = QTreeView()
#Model
self.model = QStandardItemModel()
self.treeView.setModel(self.model)
# Button
self.button = QPushButton()
self.button.setText('Add Item')
self.button.clicked.connect(self.addChildClick)
# Add to Layout
self.gridLayout = QGridLayout(self)
self.gridLayout.addWidget(self.button,0,0)
self.gridLayout.addWidget(self.treeView,1,0)
def addChildClick(self):
selection = self.treeView.selectedIndexes()
text = "bob"
item = QStandardItem(text)
# if nothing selected parent is model
if selection == []:
parent = self.model
else: # Otherwise parent is what is selected
s = selection[0] # Handling multiple selectons
parent = self.model.itemFromIndex(s)
parent.appendRow(item)
#cleanup
self.treeView.expandAll()
self.treeView.clearSelection()
if __name__ == "__main__":
app = QApplication.instance() # checks if QApplication already exists
if not app: # create QApplication if it doesnt exist
app = QApplication(sys.argv)
# Window
window = Window()
window.show()
app.exec_()