[FIXED] Filter a supplier_combo_box as user types, if the typed text matches anything in the combo box values. I use PyQt5 and python 3.11

Issue

Sorry for the formatting, I am new in Python, but I know Cobol and Pascal. So some bad habits I picked up from there.

class FilterComboBox(QtWidgets.QComboBox):
    def __init__(self, parent=None):
        super(FilterComboBox, self).__init__(parent)
        self.setFocusPolicy(QtCore.Qt.StrongFocus)
        self.setEditable(True)

        # add a filter model to filter matching items
        self.pFilterModel = QtCore.QSortFilterProxyModel(self)
        self.pFilterModel.setFilterCaseSensitivity(QtCore.Qt.CaseInsensitive)

        # add a completer, which uses the filter model
        self.completer = QtWidgets.QCompleter(self.pFilterModel, self)
        # filter the completions
        self.completer.setCompletionMode(QtWidgets.QCompleter.PopupCompletion)
        self.setCompleter(self.completer)

        # connect signals
        self.lineEdit().textEdited.connect(self.on_lineEdit_textEdited)
        self.completer.activated.connect(self.on_completer_activated)

    def on_lineEdit_textEdited(self, text):
        regex = QtCore.QRegExp(".*" + text + ".*", QtCore.Qt.CaseInsensitive, QtCore.QRegExp.RegExp)
        self.pFilterModel.setFilterRegExp(regex)

    # on selection of an item from the completer, select the corresponding item from combobox 
    def on_completer_activated(self, text):
        if text:
            index = self.findText(text)
            self.setCurrentIndex(index)
            self.activated[str].emit(self.itemText(index))

    # on model change, update the models of the filter and the completer as well 
    def setModel(self, model):
        super(FilterComboBox, self).setModel(model)
        self.pFilterModel.setSourceModel(model)
        self.completer.setModel(self.pFilterModel)

    # on model column change, update the model column of the filter and completer as well
    def setModelColumn(self, column):
        self.completer.setCompletionColumn(column)
        self.pFilterModel.setFilterKeyColumn(column)
        super(FilterComboBox, self).setModelColumn(column)

Works if the typed text matches the beginning of the values in the list of combo box items. But doesn't filter if it matches anything inside the string.

Solution

This is how I modified my class to work with the combo box

class FilterComboBox(QtWidgets.QComboBox):
    def __init__(self, parent=None):
        super(FilterComboBox, self).__init__(parent)
        self.setEditable(True)

        # add a filter model to filter matching items
        self.pFilterModel = QtCore.QSortFilterProxyModel(self)
        self.pFilterModel.setSourceModel(self.model())
        self.pFilterModel.setFilterCaseSensitivity(QtCore.Qt.CaseInsensitive)

        # add a completer, which uses the filter model
        self.completer = QtWidgets.QCompleter(self.pFilterModel, self)
        # always show all (filtered) completions
        self.completer.setCompletionMode(QtWidgets.QCompleter.UnfilteredPopupCompletion)
        self.setCompleter(self.completer)

        # connect signals
        self.lineEdit().textEdited.connect(self.pFilterModel.setFilterFixedString)
        self.completer.activated.connect(self.on_completer_activated)

    def on_completer_activated(self, text):
        if text:
            index = self.findText(text)
            self.setCurrentIndex(index)
            self.activated[str].emit(self.itemText(index))

I create my combo box like this

        # Create a label and a combo box
        supplier_label = QtWidgets.QLabel("Supplier:")
        supplier_combo_box = FilterComboBox()
        supplier_combo_box.addItems(['John Doe', 'Jane Doe', 'John Smith', 'Jane Smith'])

Answered By - Bikitsos