[KevinH]

@Binchen,

I think what you want already exists in a slightly different form.
I noticed the following code in the Sigil 1.7 and earlier in the Select Special Character dialog:

void SelectCharacter::SetSelectedCharacter(const QString &text)
{
    bool isCtrl = QApplication::keyboardModifiers() & Qt::ControlModifier;
    emit SelectedCharacter(text);

    if (isCtrl) {
        accept();
    }

    // Return focus to last window to allow typing to continue
    QApplication::setActiveWindow(parentWidget());
}

So try Control single clicking on a character you want. It should insert that char and then close the dialog.

If that doesn't work, file a bug report and I will try and fix it.

ps: Remember on macOS that Ctrl-Click is actually Command-Click via how Qt operates on macOS to make things cross-platform.

Works just fine on my macOS machine.