Java Reference
In-Depth Information
}
}
} );
}
Now whenever the JSpinner changes state, we are notified, and then we can
update the instance variables in JavaFX SwingNumberSpinner . Unfortunately,
the ChangeEvent does not tell us which value changed, so we have to update
them all. However, the JavaFX runtime knows if the value is actually changing
so any triggers or bind actions will only occur if there is a real change in value.
You may have noticed that we slipped in a Boolean variable, inChange , in the
preceding example. This is necessary, because if the change initiates from the
JavaFX code by changing one of the instance variables, the corresponding
JSpinner property will also be updated. This will cause the JSpinner object to
fire a change event, which in turn tries to change the instance variable. So we end up
in an unending loop. To avoid this, we introduce the Boolean variable, inChange .
When the change originates with a change to the JavaFX variable, inChange is
set to true so that the state changed handler will not then update the same
instance variable. The following listing shows how this is done with the JavaFX
instance variables.
var inChange = false;
public var value:Integer =
getModel().getNumber().intValue() on replace {
try {
inChange = true;
getModel().setValue(value);
} finally {
inChange = false;
}
};
Now we have full bidirectional coordination from the JavaFX object to the Java-
Beans component. Whenever the JavaFX object's state changes, the JavaBeans
object will immediately be updated to stay in synch. On the other side, whenever the
JavaBeans object changes state, the JavaFX object state will likewise be updated.
Server Call Back
Servers can asynchronously send messages to a JavaFX application using a vari-
ety of frameworks such as Message Oriented Middleware (MOM). To receive
 
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