Package net.sf.cuf.state

The State/StateAdapter library eases the management and reaction of binary states.
It greatly reduces the code needed to keep the internal (logical) state of an application with its visual representation, e.g.

See: Description

Interface Summary

Interface	Description
MutableState	The MutableState interface describes a mutable (more-or-less) binary state.
State	The State interface describes a (more-or-less) binary state. Whenever the state changes from not initialized to true/false, from false to true or from true to false, all attached change listeners are notified. If a state changes from either true or false to uninitialized, its listeners are not notified. The source in the ChangeEvent can always be casted to State.
StateAdapter	The StateAdapter interface describes the observer of a State Object. A StateAdapter monitors one (or none) state object, and notifies its target objects whenever the monitored state changes. A implementation class of the StateAdapter interfaces defines the semantics of what really happens if the monitored state changes, the StateAdapter interface describes only the protocol to setup/tear down the connections.
StateExpression	The StateExpression interface allows to combine states to an arbitrary complex logical state expression.

Class Summary

Class	Description
AbstractState	This class holds common code of mutable and immutable states.
AbstractStateAdapter	This abstract implementation of StateAdapter handels all of the bookkeeping work and delegates the "real" work (adapting of a state change to a target object) to its subclasses.
SimpleState	This class implements a MutableState and holds the necessary state information inside the SimpleState object.
SimpleStateExpression	This class implements a StateExpression, see the interface for a description of what added value SimpleStateExpression provides.

Package net.sf.cuf.state Description

The State/StateAdapter library eases the management and reaction of binary states.
It greatly reduces the code needed to keep the internal (logical) state of an application with its visual representation, e.g. concerning the enabling/disabeling of buttons depending on the possible actions that can be taken.
The State/StateAdapter library is also great for expressing and acting on complex "if A then B" rules. Example: "If the actual user is jzeller and a record with number range 01 is loaded, than the record modification button should be enabled".

The state of the State/StateAdapter library is modeled in the State interface, the observing of a state is described in the StateAdapter interface.

The binary value of a state can be derived by a particular State implemention from widgets (e.g. the SwingListModelFillState watches the number of entries of a JList).
Also the adaption of a state via a particular StateAdapter can change widgets (e.g. the SwingEnabledAdapter adapts 0/1 of its state to enabling/disabling of Swing widgets).

A major goal of the State/StateAdapter library is the reduction of the LOC (lines of code) that are coded in callback methods and the shift from callback code to declarative code.