CSCE 155
Homework
Assignment 3:
A
Measurement Unit Converter
Assigned:
Due: Start of Class,
Note: This assignment is to be
completed individually - collaboration is strictly prohibited.
Points: 100 points
Problem Description
The
Graphical User Interface (GUI) is an important component in software. It
provides a user-friendly communication media between the users and an
application. Users provide input to the application; the application processes
the input, performs some computations and provides some feedback to the users.
The role of the GUI is to provide the bridge between the user and the
application.
Java
provides a variety of tools to help us build a GUI easily.
·
The
Swing library provides a rich set of graphical components. For example, JFrame, JPanel, and JDialog are some of the classes that can help you put
graphical component into your interface. JButton, JTextfield, JRadioButton, and JCheckBox are graphical components you might use for your
GUI. Layout Managers help you organize your interface components in a natural
and user-friendly manner.
·
Java
also provides an event-handling mechanism that facilitates user centric
programming. Any action performed by the user is captured and notification is
send to the application. The application must respond to these actions
accordingly. You can write action listeners to process different actions that
you think are meaningful to your application.
For
Assignment 3, you are given a set of requirements to design a GUI for an
application called Converter:
1.
The
application should provide a window for a user to convert between different measures
of weight (kilograms—pounds), length (meter—feet) and temperature (centigrade—Fahrenheit).
For example, when the user enters the weight in kilograms, your application may
convert the weight to the corresponding value in pounds; or vice versa.
2.
For
your convenience, use Table 1 to implement your conversions.
|
Measurement |
Metric to
American |
American to
Metric |
|
Weight |
1
kg à 2.2 lbs |
1
lb à 0.45 kg |
|
Length |
1
m à 3.28 ft |
1
ft à 0.30 m |
|
Temperature |
F
à (9/5)*C + 32 |
C
à (5/9)*(F –
32) |
Table 1.
Conversion equations.
3.
You
are required to make the appearance of the interface similar to the snapshot
shown in Figure 1. Allow the window to be big enough to accommodate all of your
components.
Figure 1.
Snapshot of a Converter window.
4.
First,
use three JRadioButton objects as the options
for the user. Each JRadioButton object is for one measurement type: length,
weight, or temperature.
5.
Second,
for each measurement type, create two JTextField objects so that the
user can type into the JTextField objects.
6.
Third,
create three buttons: “Convert”, “Clear”, and “Quit”.
·
When
the “Quit” button is clicked, your application should terminate and the window
should disappear.
·
When
the “Clear” button is clicked, your application should remove all entered text
from the JTextField objects.
·
When
the “Convert” button is clicked, your application should check for the
following:
a.
Check
to see if one JRadioButton object has been
selected. If no, then send a warning.
Otherwise, move to the next check.
a.
Check
to see if only one JTextField object has been modified by the user. If none or two have been modified, then send
a warning. Otherwise, move to the next check.
b.
Check
to see if the entered text is a number.
If no, then send a warning. Otherwise, move to the next check.
c.
Use the conversion equations in Table 1 to perform the
conversion, echo the input number,
and output the conversion result.
7.
Sending a Warning: This is
shown in Figure 2. Use a dialog or
message box to do this. You must also be
specific in your warning, pointing out specifically what the user has done
incorrectly.
Figure 2.
Snapshot of a warning window.
8. Echoing the input number and Outputting the Conversion Result: This is shown in Figure 3. You must show what the user has entered and the conversion result.
Figure 3. Snapshot of an
echo and conversion result window.
9. Take the user input and store the information internally in your program. Your program should check whether a file called “CSE155.txt” exists in your current directory. If the file exists, open it and append each conversion to the file. You may use a space or comma delimited format to store this text file. Do 10 conversions at least. If the file does not exist, create the file from your program, open it and start appending new records. Submit your test results in hard copy too.
Supplied Solution Components
None.
Challenge - Extra Credit (10 points)
Change all the JRadioButton
objects to JCheckBox objects, so
that the user can convert more than one of the measurement types when clicking
the “Convert” button. For example,
check both weight and temperature, and do both conversions and
show the results in one message/dialog box.