romannumeralsqt.pyw

#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.

#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.

#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import romannumerals

class Form(QDialog):
    def __init__(self, parent=None):
        super().__init__(parent)

        # Raw text labels. result_label is dynamic.
        self.DECIMAL_LABEL = QLabel("Decimal")
        self.NUMERAL_LABEL = QLabel("Numeral")
        self.result_label = QLabel("N/A")

        # Data insertion for users
        self.decimal_spinbox = QSpinBox()
        self.decimal_spinbox.setValue(1)
        self.decimal_spinbox.setMinimum(1)
        self.decimal_spinbox.setMaximum(3999)

        self.numeral_line_edit = QLineEdit()
        self.numeral_line_edit.setText("I")

        # Conversion push buttons
        self.dec_to_num_push_button = QPushButton("Convert decimal")
        self.num_to_dec_push_button = QPushButton("Convert numeral")

        grid = QGridLayout()

        # First row
        grid.addWidget(self.DECIMAL_LABEL, 0, 0)
        grid.addWidget(self.decimal_spinbox, 0, 1)
        grid.addWidget(self.dec_to_num_push_button, 0, 2)

        # Second row
        grid.addWidget(self.NUMERAL_LABEL, 1, 0)
        grid.addWidget(self.numeral_line_edit, 1, 1)
        grid.addWidget(self.num_to_dec_push_button, 1, 2)

        # Third row
        grid.addWidget(self.result_label, 2, 1)

        # Finalise the layout.
        self.setLayout(grid)

        self.setWindowTitle("Roman numeral converter")

        # Click events
        self.dec_to_num_push_button.clicked.connect(self.dec_to_num)
        self.num_to_dec_push_button.clicked.connect(self.num_to_dec)

    def dec_to_num(self):
        """Takes value from decimal_spinbox and converts it. Returns result
        to result_label.
        """

        dec = self.decimal_spinbox.value()
        self.result_label.setText(romannumerals.decimal_to_numeral(dec))

    def num_to_dec(self):
        """Takes value from numeral_line_edit and converts it. Returns result
        to result_label.
        """

        num = self.numeral_line_edit.text().upper()
        try:
            self.result_label.setNum(romannumerals.numeral_to_decimal(num))
        except:
            self.result_label.setText("Invalid input")

def main():
    app = QApplication(sys.argv)
    form = Form()
    form.show()
    app.exec_()

if __name__ == "__main__":
    main()