Learning Notes-state mode

State mode, which is mainly used for operations where there is a large number of case judgments, and the case depends on the state of the object, it is possible to encapsulate a large number of case judgments as separate classes.

Context:

-state the current state object.

Changestate (state), toggles the state object.

Operationinterface (), call State->operationinterface.

Operationchangestate (), call State->operationchangestate (Context).

State:

Changestate (context,state), called Context->changestate (state).

Operationinterface (), virtual, subclass implementation.

Operationchangestate (Context), virtual, sub-class implementation.

Statea:

Operationchangestate (context), called base->changestate (context, specified state).

Operationinterface (), subclass specific operation implementation.

In Statea, operationchangestate, if the extension, the individual think can be passed as a parameter, so that the context of state switching, you can do dynamic state changes, rather than the specific state changes as above, Only the code is written in a to B.

Learning Notes-state mode