JavaFX Code Recipes - JavaFX: Developing Rich Internet Applications - page 305

This provides the basic JavaFX code, but these instance values are still not con-
nected at all to the JSpinner object. To start connecting these instance variables
to JavaBeans properties, you assign a default value from the SpinnerModel and
then when the instance variable changes, you set that value in the JSpinner
object. Here is how value is now set.
public var value:Integer =
getModel().getNumber().intValue() on replace {
getModel().setValue(value);
};
There are a couple of things to point out with this. First, getModel() is a conve-
nience function that just gets the SpinnerNumberModel object from the JSpinner .
function getModel() : SpinnerNumberModel {
getJSpinner().getModel() as SpinnerNumberModel;
}
Second, it is necessary to narrow the model's getNumber() result. The getNumber()
method returns a java.lang.Number and this needs to be coerced to an integer
by calling its intValue() method. The rest of the variables work similarly; how-
ever, the variables minimum and maximum have a little twist.
In the SpinnerNumberModel , the minimum and maximum properties return an
object that may be null. When they are null, there is no minimum or maximum
integer, in effect they are infinite. The issue with this is that currently, Number
and Integer in JavaFX cannot be null, so we have to deal with this. There are sev-
eral options for handling this. One is to create a flag, one for each of the two
instance variables, to indicate that they are infinite. The other is to convert the
null to a very low minimum or a very high maximum, respectively. We decided
to do the latter. For the minimum variable, we created the getMinimum() function
as shown in the following listing.
function getMinimum() : Integer {
if(getModel().getMinimum() == null) {
java.lang.Integer.MIN_VALUE;
}else {
(getModel().getMinimum() as java.lang.Number).
intValue();
}
}
If the SpinnerNumberModel minimum property is null, this function returns
java.lang.Integer.MIN_VALUE . Next, we modify the minimum instance vari-
able to be initialized using this function.