setStyleSheet or QStyledItemDelegate for a node in QTreeView - qt

Question

I am trying to change a icon for specific nodes in a QTreeView. Nodes will use QCheckbox, and based on app logic, some nodes will instead use other icons for node selected/unselected state.
An example below shows how I can set a stylesheet for the entire tree, but I don't think I can set a stylesheet for a single node in the tree.
#Based on http://stackoverflow.com/questions/5374168/unable-to-select-checkbox-inside-treeview
import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4 import QtGui, QtCore
class Window(QtGui.QWidget):
changeStyleTriggered = QtCore.pyqtSignal()
def __init__(self):
QtGui.QWidget.__init__(self)
self.createTree()
self.connectSlots()
def createTree(self):
data = ['A', 'B', 'C', 'D', 'E', 'F']
model = MyTreeView(data)
self.treeView = QTreeView()
self.treeView.setModel(model)
layout = QtGui.QVBoxLayout()
layout.addWidget(self.treeView)
self.changeIconPushButton = QtGui.QPushButton("Change a single icon")
layout.addWidget(self.changeIconPushButton)
self.setLayout(layout)
def fireChangeStyleSignal(self):
self.changeStyleTriggered.emit()
#pyqtSlot()
def changeStyleSignal(self):
print(">>changeStyleSignal()")
self.setStyleSheet("QTreeView::indicator:unchecked {image: url(:/icons/image.png);}")
def connectSlots(self):
self.changeStyleTriggered.connect(self.changeStyleSignal)
self.changeIconPushButton.clicked.connect(self.fireChangeStyleSignal)
class TestItem():
def __init__(self, name, checked):
self.checked = checked
self.name = name
class MyTreeView(QAbstractListModel):
def __init__(self, args, parent=None):
super(StbTreeView, self).__init__(parent)
self.args = []
for item_name in args:
self.args.append(TestItem(item_name, False))
for item in self.args:
print (item.name)
def rowCount(self, parent):
return len(self.args)
def headerData(self, section, orientation, role):
if role == Qt.DisplayRole:
if orientation == Qt.Horizontal:
return "Nodes"
def flags(self, index):
return Qt.ItemIsUserCheckable | Qt.ItemIsEditable | Qt.ItemIsSelectable | Qt.ItemIsEnabled
def data(self, index, role=Qt.DisplayRole):
if role == Qt.DisplayRole:
row = index.row()
print (self.args[row].name)
return self.args[row].name
if role == Qt.CheckStateRole:
row = index.row()
print (self.args[row].checked)
if self.args[row].checked == False:
return Qt.Unchecked
else:
return Qt.Checked
def setData(self, index, value, role):
if role == Qt.CheckStateRole:
row = index.row()
self.args[row].checked = not self.args[row].checked
return True
def main():
myapp = QApplication(sys.argv)
window = Window()
window.show()
myapp.exec_()
if __name__ == '__main__':
main()
The other option is to use QStyledItemDelegate. Below is a small class to change the font, but I haven't worked out how to change a single icon with delegate.
class BoldDelegate(QtGui.QStyledItemDelegate):
def paint(self, painter, option, index):
option.font.setWeight(QtGui.QFont.Bold)
QtGui.QStyledItemDelegate.paint(self, painter, option, index)
and to use it run this (eg in a #pyqtSlot() for the QTreeView):
self.setItemDelegate(BoldDelegate(self))
Any ideas?

Answer 1

A QCheckBox doesn't use an icon to display its state. You should first create a project where, through whatever means, you get a widget that acts like you wish, with correct checked/unchecked appearance.
Once you have that, you'll have your delegate create such items based on some property of the data item of the model. For example, you might have a custom role that indicates to your delegate that a non-default widget class should be used to edit the item.