class SettingsDialog(QDialog, Ui_SettingsDialog):
    sumwarsDirChanged = QtCore.Signal(str)
    def __init__(self, parent=None):
        super(SettingsDialog, self).__init__(parent)
        self.setupUi(self)

        self.btnSumwarsDir.pressed.connect(self.slot_setSumwarsDir)
        self.btnNVAtlasDir.pressed.connect(self.slot_setNVAtlasDir)
        self.btnOgreToolsDir.pressed.connect(self.slot_setOgreToolsDir)
        self.btnMeshmagickDir.pressed.connect(self.slot_setMeshmagickDir)

    def slot_setSumwarsDir(self):
        dlg = QFileDialog(self)
        dlg.setFileMode(QFileDialog.DirectoryOnly)
        if dlg.exec_():
            dir = dlg.selectedFiles()
            self.sumwarsDirLineEdit.setText(dir[0])
            self.emit(self.sumwarsDirChanged(dir[0]))