set maxVisibleItems property in Fusion Style for QtComboBox(dropdown box)

Qt_Python Learner

Hi all,

I am using Qt designer 5.11.1 and building a tool with Python (PyQt5). I saved my GUI in 'Fusion' style. In this, for combobox, there is a property 'maxVisibleItems'. Even though I set this property and limit the dropdown list so that only 5 elements are visible at a time and remaining needs to be scrolled, the combobox still displays all list of items present in the combo box.

I know the reason and this is the limitation that this property is ignored by non-editable styles as per documentation.

Note: This property is ignored for non-editable comboboxes in styles that returns true for QStyle::SH_ComboBox_Popup such as the Mac style or the Gtk+ Style.

With this property set, In Fusion style, the application shows all 20 items at once where as in other style, the application shows 5 items at a time . I do not want to change Fusion style. Could someone please help me if I can overcome.

Few users commented that using

"combo.setStyleSheet("QComboBox { combobox-popup: 0; }")"

helped them. But it did not work for me. Am I doing anything wrong or is there any different solution.

How I have tried:

self.comboBox_2.setStyleSheet("selection-color: rgb(255, 255, 255);\n"
"background-color: rgb(249, 255, 255);\n"
"selection-background-color: rgb(53, 107, 255);")
 self.comboBox_2.setObjectName("comboBox_2")
 self.comboBox_2.setStyleSheet("combobox-popup: 0;")
 self.comboBox_2.setMaxVisibleItems(5)

Thanks a lot in advance for sharing your knowledge with your valuable suggestions.

avilanova

Hi @Qt_Python-Learner,

I know this issue is quite old, but it might still help somebody. I managed to limit the number of visible items in a Fusion style dashboard using this class:

class ComboBox(QtWidgets.QComboBox):
    """ Modify default class of PyQT5 combobox. """

    def __init__(self, parent=None):

        super(ComboBox, self).__init__(parent)

        # setMaxVisibleItems only works if the box is editable
        # this creates a line edit that we need to overwrite
        self.setEditable(True)
        self.setMaxVisibleItems(15)

        # overwrite default line edit by an invisible one
        self.lineEdit().setFrame(False)
        self.lineEdit().setReadOnly(True)

    def showPopup(self):
        """ Show pop-up. """

        # set index of selected choice to highlight it
        text = self.lineEdit().text()
        index = self.findText(text, QtCore.Qt.MatchFixedString)
        self.setCurrentIndex(index)

        # show pop-up
        super().showPopup()

        # add vertical scroll bar
        self.view().setVerticalScrollBarPolicy(QtCore.Qt.ScrollBarAsNeeded)

        # increase the width of the elements on popup so they can be read
        self.view().setMinimumWidth(self.view().sizeHintForColumn(0))

I hope this can help you or others.
Cheers,
Alba