How to resize rows in a QTreeView and a QStandardItemModel? - resize

Question

I'd like to set my rows to a fixed height. I've found an example using QAbstractItemModel, but I'm using QStandardItemModel. When I run the app, the QTreeView is blank. Any thoughts on how I could get this working for a QStandardItemModel?
import sys
from PySide import QtCore, QtGui
class TreeItem(object):
def __init__(self, data, parent=None):
self.parentItem = parent
self.data = data
self.childItems = []
def appendChild(self, item):
self.childItems.append(item)
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(None)
for i, c in enumerate("abcdefg"):
child = TreeItem([i, c], self.rootItem)
self.rootItem.appendChild(child)
parent = self.rootItem.childItems[1]
child = TreeItem(["down", "down"], parent)
parent.appendChild(child)
def columnCount(self, parent):
return 2
def data(self, index, role):
if not index.isValid():
return None
if role == QtCore.Qt.DisplayRole:
item = index.internalPointer()
return item.data[index.column()]
elif role == QtCore.Qt.SizeHintRole:
print "giving size hint"
return QtCore.QSize(10, 10)
return None
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 ["A", "B"][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.childItems[row]
if childItem:
return self.createIndex(row, column, childItem)
else:
return QtCore.QModelIndex()
def parent(self, index):
if not index.isValid():
return QtCore.QModelIndex()
parentItem = index.internalPointer().parentItem
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 len(parentItem.childItems)
if __name__ == '__main__':
app = QtGui.QApplication(sys.argv)
model = TreeModel()
view = QtGui.QTreeView()
view.setModel(model)
view.setWindowTitle("Simple Tree Model")
view.show()
sys.exit(app.exec_())
Also, I've been looking around for the meaning of the term delegate in Qt, but the concept still isn't clicking in my head yet. Any insight into that would be appreciated as well!

Answer 1

You generally do this using QItemDelegates (or QStyledItemDelegate if you want stylesheet styling to work) by overriding the sizeHint method and always returning a size of a fixed height.
class MyDelegate(QtGui.QStyledItemDelegate):
def sizeHint(self, option, index):
my_fixed_height = 30
size = super(MyDelegate, self).sizeHint(option, index)
size.setHeight(my_fixed_height)
return size
view = QtGui.QTreeView()
delegate = MyDelegate()
view.setItemDelegate(delegate)