QTreeView horizontal tab key navigation

[maranos]

Hi,

when the user presses TAB while editing an item in a QTreeView, the view closes the current editor and starts editing the item below. Is there a way to change this behavior so that the item on the right is edited? (similar to LibreOffice Calc and probably Excel)
I tried setting event filters and overwriting the event-function in the tree, the viewport and the editor (using a custom delegate), but I was not able to intercept this TAB event.

Below you will find a simple test script (in PyQt), without event filters.

Thanks

from PyQt5 import QtCore, QtWidgets
from PyQt5.QtCore import Qt
#from PyQt4 import QtCore, QtGui as QtWidgets
#from PyQt4.QtCore import Qt
 
class TreeView(QtWidgets.QTreeWidget):
    def __init__(self):
        super().__init__()
        self.setColumnCount(5)
        for i in range(3):
            item = QtWidgets.QTreeWidgetItem(["Some", "Test", "Strings"])
            item.setFlags(Qt.ItemIsSelectable | Qt.ItemIsEditable | Qt.ItemIsEnabled)
            self.addTopLevelItem(item)
 
 
app = QtWidgets.QApplication([])
tree = TreeView()
tree.show()
app.exec_()

from PyQt5 import QtCore, QtWidgets
from PyQt5.QtCore import Qt
#from PyQt4 import QtCore, QtGui as QtWidgets
#from PyQt4.QtCore import Qt

class TreeView(QtWidgets.QTreeWidget):
    def __init__(self):
        super().__init__()
        self.setColumnCount(5)
        for i in range(3):
            item = QtWidgets.QTreeWidgetItem(["Some", "Test", "Strings"])
            item.setFlags(Qt.ItemIsSelectable | Qt.ItemIsEditable | Qt.ItemIsEnabled)
            self.addTopLevelItem(item)
  

app = QtWidgets.QApplication([])
tree = TreeView()
tree.show()
app.exec_()

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[anda_skoa]

If it should behave more like a spreadsheet, maybe use QTableView?

Cheers,
_

[maranos]

The test script looks like a table, but in the real application I need a tree structure.

[ChrisW67]

I think the correct approach here is to provide override QTreeView::moveCursor(), do something different for MoveNext and MovePrevious, and fall back to the base behaviour for the other options.

[maranos]

Thank you, this solves the problem!

Here is a simple implementation (not covering the cases where the next/previous index has a different parent):

def moveCursor(self, cursorAction, modifiers):
        if cursorAction == QtWidgets.QAbstractItemView.MoveNext:
            index = self.currentIndex()
            if index.isValid():
                if index.column()+1 < self.model().columnCount():
                    return index.sibling(index.row(), index.column()+1)
                elif index.row()+1 < self.model().rowCount(index.parent()):
                    return index.sibling(index.row()+1, 0)
                else:
                    return QtCore.QModelIndex()
        elif cursorAction == QtWidgets.QAbstractItemView.MovePrevious:
            index = self.currentIndex()
            if index.isValid():
                if index.column() >= 1:
                    return index.sibling(index.row(), index.column()-1)
                elif index.row() >= 1:
                    return index.sibling(index.row()-1, self.model().columnCount()-1)
                else:
                    return QtCore.QModelIndex()
        super().moveCursor(cursorAction, modifiers)

def moveCursor(self, cursorAction, modifiers):
        if cursorAction == QtWidgets.QAbstractItemView.MoveNext:
            index = self.currentIndex()
            if index.isValid():
                if index.column()+1 < self.model().columnCount():
                    return index.sibling(index.row(), index.column()+1)
                elif index.row()+1 < self.model().rowCount(index.parent()):
                    return index.sibling(index.row()+1, 0)
                else:
                    return QtCore.QModelIndex()
        elif cursorAction == QtWidgets.QAbstractItemView.MovePrevious:
            index = self.currentIndex()
            if index.isValid():
                if index.column() >= 1:
                    return index.sibling(index.row(), index.column()-1)
                elif index.row() >= 1:
                    return index.sibling(index.row()-1, self.model().columnCount()-1)
                else:
                    return QtCore.QModelIndex()
        super().moveCursor(cursorAction, modifiers)

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