how to mark current item text in QComboBox?

问题

I'm using a combo box as a simple command line with a history.

Here's the signal-slot definition:

QtWidgets.QShortcut(QtGui.QKeySequence(QtCore.Qt.Key_Return),
                    self.comboBox_cmd,
                    activated=self.queryLine)

...and the slot:

@QtCore.pyqtSlot()
def queryLine(self):
    '''
    Read cmd string from widget and write to device.
    '''
    ## comboBox can be enhanced with a history
    cmd = self.comboBox_cmd.currentText()
    cmds = [self.comboBox_cmd.itemText(i) for i in range(self.comboBox_cmd.count())]
    if not cmds or cmds[-1] != cmd:
    self.comboBox_cmd.addItem(cmd)
    self.query(cmd)

This works really well. Now, how can I mark the entire text of the current item after pressing Enter, so that I can replace the whole line if I so wish?

回答1:

You can automatically select the text of the line edit by catching the return/enter key press:

class SelectCombo(QtWidgets.QComboBox):
    def keyPressEvent(self, event):
        # call the base class implementation
        super().keyPressEvent(event)
        # if return/enter is pressed, select the text afterwards
        if event.key() in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
            self.lineEdit().selectAll()

回答2:

Ok, I've got it all assembled :) Problem was, I previously needed to define a shortcut since QComboBox does not have a returnPressed attribute. With the custom widget, I can change that easily, of course:

class SelectCombo(QtWidgets.QComboBox):
'''
https://stackoverflow.com/questions/62594748/how-to-mark-current-item-text-in-qcombobox/62598381
Modified QComboBox which selects the current text after Enter/Return.
'''
returnPressed = QtCore.pyqtSignal(str)

def keyPressEvent(self, event):
    ## call the base class implementation
    super().keyPressEvent(event)
    ## if return/enter is pressed, select the text afterwards
    if event.key() in (QtCore.Qt.Key_Return, QtCore.Qt.Key_Enter):
        self.lineEdit().selectAll()
        self.returnPressed.emit("Enter pressed!")

And in my GUI app, I simply need the following signal-slot definition to make it work:

    ## 1) QLineEdit has "returnPressed" but no history
    #self.lineEdit_cmd.returnPressed.connect(self.queryLine)
    ## 2) QComboBox has history, but no "returnPressed" attritbute==> need to define a shortcut
    #QtCore.QShortcut(QtGui.QKeySequence(QtCore.Qt.Key_Return),
    #QtWidgets.QShortcut(QtGui.QKeySequence(QtCore.Qt.Key_Return),
    #                    self.comboBox_cmd,
    #                    activated=self.queryLine)
    ## 3) custom SelectCombo widget has QComboBox's history plus "returnPressed"
    self.comboBox_cmd.returnPressed.connect(self.queryLine)

Thanks a lot for helping me!

来源：https://stackoverflow.com/questions/62594748/how-to-mark-current-item-text-in-qcombobox

标签

python

pyqt

pyqt5

qcombobox