Programming and Problem Solving with Java

CASE STUDY

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Now that we’ve identified these responsibilities, the user interface card can be low-

ered. As part of this process, however, we’ve determined that the input and the event

handling are part of the Stationclass. The user interface is not directly involved in the

data entry scenario. We should also note that each Stationrepresents a separate event

loop. What initializes and terminates these loops? Each loop is initialized by the user

interface instantiating a station, getting its user interface elements, and placing them

in the content pane. The loops are all terminated by closing the window. All of this

activity is handled in the initialization of the user interface, which occurs in the appli-

cation class. Let’s call it Rainfall.

Responsibility Algorithms:The Stationconstructor should take the name of the station

as a string and use it to form the first label, concatenating it with “Station” and “:”. This

label never changes again, so we can instantiate it anonymously. Our constructor needs

to create the rest of the user interface components described previously. They include

Class Name: Rainfall Superclass: Subclasses:

Responsibilities Collaborations

Initialize user interface

.

.

.

Station, JFrame, Container

Class Name: Station Superclass: Subclasses:

Responsibilities Collaborations

Create self

Get user interface elements

Handle button events

.

.

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JButton, JLabel, JTextField

None

ActionHandler, JTextField, JLabel