QSortFilterProxyModel: Update after insert columns

Knacktus

Hi guys,

I've got a problem with a QSortFilterProxyModel. After inserting a new column, the view doesn't update properly. I've called beginInsertColumns(QModelIndex(), old_row_count, old_row_count) before and self.model.endInsertColumns() after inserting the new column, but the view doesn't display the data and alternating row coloring properly.

All seems to be fine and dandy if I don't use the proxy model.

My understanding is that under "normal" circumstances I don't need to reimplement the usual methods (like, "index", "data", ...) when subclassing a QSortFilterProxyModel. The QSortFilterProxyModel's standard implementations call these methods after converting the indeces. Is that correct?

Any advice?

Cheers and many thanks in advance,

Jan

I've prepared a full working example, posted in two parts. Here Part 1 (custom tree_items, header, proxymodel and view), Part 2 (model and code to run the example) follows in the first answer to this question.

@
import collections

from PyQt4.QtGui import *
from PyQt4.QtCore import *

class ViewItem(object):

def __init__(self, data, parent):
    self.data = data
    self.parent = parent
    self.children = []

class ColumnHeader(QHeaderView):

colums_about_to_be_updated = pyqtSignal(int)
colums_updated = pyqtSignal()

def __init__(self, applicable_columns, initial_columns, parent=None):
    super(ColumnHeader, self).__init__(Qt.Horizontal, parent)
    self.applicable_columns = applicable_columns
    self.initial_columns = initial_columns
    self.all_columns = self.applicable_columns
    self.columns = initial_columns
    self.setMovable(True)
    self.setContextMenuPolicy(Qt.ActionsContextMenu)
    self.att_name_to_action = collections.OrderedDict()
    self._prepopulate_att_name_to_action()
    self._create_att_name_to_action()
    self._set_initial_colums()

def _prepopulate_att_name_to_action(self):
    for col in self.columns:
        self.att_name_to_action[col] = None

def _create_att_name_to_action(self):
    for col in self.all_columns:
        action = QAction(col, self)
        action.setCheckable(True)
        action.toggled.connect(self.set_columns)
        self.addAction(action)
        self.att_name_to_action[col] = action

def _set_initial_colums(self):
    for active_name in self.columns:
        self.att_name_to_action[active_name].toggle()

def set_columns(self):
    self.colums_about_to_be_updated.emit(len(self.columns))
    self.columns = []
    for att, action in self.att_name_to_action.items():
        if action.isChecked():
            self.columns.append(att)
    self.colums_updated.emit()

class SearchFilterProxyModel(QSortFilterProxyModel):

def __init__(self, source_model, parent=None):
    super(SearchFilterProxyModel, self).__init__(parent)
    self.source_model = source_model
    self.setSourceModel(self.source_model)

class TreeView(QTreeView):

def __init__(self, aux_root_view_item, all_applicable_attributes, initial_columns, parent=None):

    super(TreeView, self).__init__(parent)
    self.aux_root_view_item = aux_root_view_item
    self.setAlternatingRowColors(True)

    self.column_header = ColumnHeader(all_applicable_attributes, initial_columns)
    self.column_header.setStretchLastSection(True)
    self.setHeader(self.column_header)

    self.column_header.colums_about_to_be_updated.connect(self.header_about_to_be_changed)
    self.column_header.colums_updated.connect(self.header_changed)

    self.model = TreeModel(aux_root_view_item, self.column_header, self)
    self.proxy_model = SearchFilterProxyModel(self.model, self)

    #self.setModel(self.proxy_model)
    self.setModel(self.model)

    self.selection_model = self.selectionModel()

def header_about_to_be_changed(self, old_row_count):
    self.model.beginInsertColumns(QModelIndex(), old_row_count, old_row_count)

def header_changed(self):
    self.model.endInsertColumns()

@

Knacktus

Here Part 2:

@
class TreeModel(QAbstractItemModel):
def init(self, aux_root_view_item, header, parent):
super(TreeModel, self).init(parent)
self.tree_view = parent
self.aux_root_view_item = aux_root_view_item
self.header = header

def rowCount(self, parent_index=QModelIndex()):
    if parent_index.column() > 0:
        return 0
    parent_view_item = self.view_item_from_index(parent_index)
    if parent_view_item is None:
        return 0
    return len(parent_view_item.children)

def columnCount(self, parent_index=QModelIndex()):
    return len(self.header.columns)

def headerData(self, section, orientation, role):
    if (orientation == Qt.Horizontal and
        role == Qt.DisplayRole):
        assert 0 <= section <= len(self.header.columns)
        return self.header.columns[section]
    elif role == Qt.DisplayRole:
        return QVariant(int(section + 1))
    return QVariant()

def data(self, index, role):
    view_item = self.view_item_from_index(index)
    data = view_item.data
    if data is None:
        return None
    if role != Qt.DisplayRole and role != Qt.EditRole:
        return None
    column = index.column()
    value = data[column]
    return unicode(value)

def index(self, row, column, parent_index):
    if row < 0 or column < 0:
        return QModelIndex()
    view_item_parent = self.view_item_from_index(parent_index)
    if row > len(view_item_parent.children) - 1:
        return QModelIndex()
    child = view_item_parent.children[row]
    return self.createIndex(row, column, child)

def parent(self, child_index):
    child_view_item = self.view_item_from_index(child_index)
    if child_view_item is None:
        return QModelIndex()
    parent_view_item = child_view_item.parent
    if parent_view_item is None:
        return QModelIndex()
    grandparent_view_item = parent_view_item.parent
    if grandparent_view_item is None:
        return QModelIndex()
    row = grandparent_view_item.children.index(parent_view_item)
    assert row != -1
    return self.createIndex(row, 0, parent_view_item)

def view_item_from_index(self, index):
    if index.isValid():
        view_item = index.internalPointer()
        return view_item
    else:
        return self.aux_root_view_item

def create_test_data():

aux_root_view_item = ViewItem(None, None)
root_view_item = ViewItem(["1a", "1b", "1c"], aux_root_view_item)
child_11 = ViewItem(["11a", "11b", "11c"], root_view_item)
child_12 = ViewItem(["12a", "12b", "12c"], root_view_item)
child_111 = ViewItem(["111a", "111b", "111c"], child_11)
child_112 = ViewItem(["112a", "112b", "112c"], child_11)

aux_root_view_item.children = [root_view_item]
root_view_item.children = [child_11, child_12]
child_11.children = [child_111, child_112]

return aux_root_view_item

if name == "main":

import sys

app = QApplication(sys.argv)

aux_root_view_item = create_test_data()
tree_view = TreeView(aux_root_view_item,["a", "b", "c"], ["a", "b"])
tree_view.show()

app.exec_()

@

andre

Did you call setDynamicSortFilter(true) on your proxy model?

Knacktus

No, I didn't. And doing (toggle true / false) so does not have any effect on my issue.

LivTarg

Hi,
I know this thread is half a year old but i'm facing
the same problem right now.
Did you manage to solve it somehow?

Ben

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QSortFilterProxyModel: Update after insert columns