Handling Events - Beginning Java - page 923

}
// Set the value for the selection
public void setValue(int value) {
setText(Integer.toString(value)); // Set value as

the button label
this.value = value; // Save the value

}

// Check the value for the selection
boolean hasValue(int possible) {
return value==possible; // Return true if

equals current value
}

// Check the current choices
boolean isCurrentSelection(int possible) {
for(int i = 0 ; i < NUMBER_COUNT ; ++i) { // For each button

if(luckyNumbers[i].hasValue(possible)) { // check against

possible

return true; // Return true for

any =

}

}
return false; // Otherwise return false

}

private int value; // Value for the

selection button
}

Directory "Lottery 1"

How It Works
The constructor calls the base class constructor to set the initial label for the button. It also stores the
value of type int that is passed as an argument. The setValue() method just updates the value for
a selection button with the value passed as an argument and changes the button label by calling the
setText() method, which is inherited from the base class, JButton . The hasValue() method returns
true if the argument value passed to it is equal to the current value stored in the data member value and
returns false otherwise.
The actionPerformed() method has a little more meat to it, but the technique is similar to that in the
getNumbers() method. To change the selection, you must create a new random value for the button from
the numbers in the VALUES array, but excluding all the numbers currently assigned to the six buttons. To
do this you just check each candidate against the six existing selections by calling the isCurrentSelec-
tion() method and continue choosing a new candidate until you find one that's different.
In the isCurrentSelection() method, you just work through the array of Selection objects, luck-
yNumbers , comparing each value with the possible argument using the hasValue() method. If any but-
ton has the same value as possible , the method returns true ; otherwise, it returns false .