获取当前选择的QTreeWidget单元格

Question

I'd like to modify QTreeWidget to make the selected cell editable when the enter key is hit, but keep the selection to full rows.

I've done a hacky implementation of figuring out where the last click was and saving the value, then sending those values to my edit_item function on the key press (also used for the itemDoubleClicked signal). It's not great though and I'm wondering if there's a much easier way to do it.

For the record, clicking on an item still selects the whole row. It's probably hidden behaviour by default, but in Maya there's a visible selection thing of the last cell that was moved over while the mouse button was held. If I could somehow get access to that, I could also add in behaviour to control it with the arrow keys.

This is an example of the selected cell:

This is my code so far:

class QTreeWidget(QtWidgets.QTreeWidget):

    returnPressed = QtCore.Signal(QTreeWidget, int)

    def __init__(self,  *args, **kwargs):
        QtWidgets.QTreeWidget.__init__(self, *args, **kwargs)

    def keyPressEvent(self, event):
        if event.key() == QtCore.Qt.Key_Return:
            self.returnPressed.emit(self._selected_item, self._selected_column)
        else:
            QtWidgets.QTreeWidget.keyPressEvent(self, event)

    def _mouse_pos_calculate(self, x_pos):
        """Find the currently selected column."""
        try:
            item = self.selectedItems()[0]
        except IndexError:
            item = None

        header = self.header()
        total_width = 0
        for i in range(self.columnCount()):
            total_width += header.sectionSize(i)
            if total_width > x_pos:
                return (item, i)

    def mousePressEvent(self, event):
        QtWidgets.QTreeWidget.mousePressEvent(self, event)
        self._selected_item, self._selected_column = self._mouse_pos_calculate(event.pos().x())

    def mouseReleaseEvent(self, event):
        QtWidgets.QTreeWidget.mouseReleaseEvent(self, event)
        self._selected_item, self._selected_column = self._mouse_pos_calculate(event.pos().x())

Edit: Improved function thanks to eyllanesc

class QTreeWidget(QtWidgets.QTreeWidget):
    """Add ability to edit cells when pressing return."""
    itemEdit = QtCore.Signal(QtWidgets.QTreeWidgetItem, int)

    def __init__(self,  *args, **kwargs):
        QtWidgets.QTreeWidget.__init__(self, *args, **kwargs)

        self._last_item = None
        self._last_column = 0
        self.itemDoubleClicked.connect(self._edit_item_intercept)

    def _edit_item_intercept(self, item=None, column=None):
        if item is None:
            item = self._last_item
        if column is None:
            column = self._last_column
        self.itemEdit.emit(item, column)

    def _store_last_cell(self, pos):
        selected_item = self.itemAt(pos)
        if selected_item is None:
            return
        self._last_item = selected_item
        self._last_column = self.header().logicalIndexAt(pos.x())

    def keyPressEvent(self, event):
        if event.key() == QtCore.Qt.Key_Return:
            return self._edit_item_intercept()
        QtWidgets.QTreeWidget.keyPressEvent(self, event)

    def mouseMoveEvent(self, event):
        QtWidgets.QTreeWidget.mouseMoveEvent(self, event)
        self._store_last_cell(event.pos())

Answer 1

You are doing a lot of calculation unnecessarily, in the next part I show a cleaner solution:

from PySide2 import QtCore, QtGui, QtWidgets


class QTreeWidget(QtWidgets.QTreeWidget):
    def __init__(self, *args, **kwargs):
        super(TreeWidget, self).__init__(*args, **kwargs)
        self.special_item = None
        self.special_col = 0

    def keyPressEvent(self, event):
        if event.key() == QtCore.Qt.Key_Return:
            self.editItem(self.special_item, self.special_col)
        QtWidgets.QTreeWidget.keyPressEvent(self, event)

    def editEnable(self, pos):
        press_item = self.itemAt(pos)
        if press_item is None:
            return
        if press_item is self.selectedItems()[0]:
            col = self.header().logicalIndexAt(pos.x())
            self.special_item = press_item
            self.special_col = col

    def mousePressEvent(self, event):
        QtWidgets.QTreeWidget.mousePressEvent(self, event)
        self.editEnable(event.pos())