"""
File: temperatureconverter.py
Project 8.4
Temperature conversion between Fahrenheit and Celsius.
Illustrates the use of numeric data fields.
Responds to a return key event in the entry fields.
"""

from breezypythongui import EasyFrame

class TemperatureConverter(EasyFrame):
    """A termperature conversion program."""

    def __init__(self):
        """Sets up the window and widgets."""
        EasyFrame.__init__(self, title = "Temperature Converter")

        # Label and field for Celsius
        self.addLabel(text = "Celsius",
                      row = 0, column = 0)
        self.celsiusField = self.addFloatField(value = 0.0,
                                               row = 1,
                                               column = 0,
                                               precision = 2)
        # Label and field for Fahrenheit
        self.addLabel(text = "Fahrenheit",
                      row = 0, column = 1)
        self.fahrField = self.addFloatField(value = 32.0,
                                            row = 1,
                                            column = 1,
                                            precision = 2)
        # Celsius to Fahrenheit button
        self.addButton(text = ">>>>",
                       row = 2, column = 0,
                       command = self.computeFahr)

        # Fahrenheit to Celsius button
        self.addButton(text = "<<<<",
                       row = 2, column = 1,
                       command = self.computeCelsius)

    # The controller methods
    def computeFahr(self):
        """Inputs the Celsius degrees
        and outputs the Fahrenheit degrees."""
        degrees = self.celsiusField.getNumber()
        degrees = degrees * 9 / 5 + 32
        self.fahrField.setNumber(degrees)

    def computeCelsius(self):
        """Inputs the Fahrenheit degrees
        and outputs the Celsius degrees."""
        degrees = self.fahrField.getNumber()
        degrees = (degrees - 32) * 5 / 9
        self.celsiusField.setNumber(degrees)

def main():
    """Instantiate and pop up the window."""
    TemperatureConverter().mainloop()

if __name__ == "__main__":
    main()