/src/lib/abilities/observable.e
http://github.com/tybor/Liberty · Specman e · 70 lines · 29 code · 7 blank · 34 comment · 0 complexity · fbc57d5ac489222caa6bc9fcfa60ebf4 MD5 · raw file
- -- This file is part of a Liberty Eiffel library.
- -- See the full copyright at the end.
- --
- deferred class OBSERVABLE
- --
- -- Part of the ''Observer'' Design Pattern. An object of this class should notify its observers whenever its
- -- state changes. Use the `notify' feature for that.
- --
- -- See also OBSERVER.
- --
- feature {ANY}
- add (o: OBSERVER[like Current])
- -- Add an observer that should be notified
- do
- observers.add_last(o)
- end
- remove (o: OBSERVER[like Current])
- -- Remove an observer that should not be notified anymore
- require
- has(o)
- local
- i: INTEGER
- do
- i := observers.first_index_of(o)
- observers.remove(i)
- end
- has (o: OBSERVER[like Current]): BOOLEAN
- -- True if the observer will be notified when the state of Current changes
- do
- Result := observers.has(o)
- end
- feature {}
- notify
- -- Notify all the observers that the state of Current changed
- do
- observers.for_each(agent {OBSERVER[like Current]}.update(Current))
- end
- feature {}
- observers: COLLECTION[OBSERVER[like Current]]
- -- The collection of observers
- invariant
- notifiable: observers /= Void
- end -- class OBSERVABLE
- --
- -- Copyright (C) 2009-2017: by all the people cited in the AUTHORS file.
- --
- -- Permission is hereby granted, free of charge, to any person obtaining a copy
- -- of this software and associated documentation files (the "Software"), to deal
- -- in the Software without restriction, including without limitation the rights
- -- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- -- copies of the Software, and to permit persons to whom the Software is
- -- furnished to do so, subject to the following conditions:
- --
- -- The above copyright notice and this permission notice shall be included in
- -- all copies or substantial portions of the Software.
- --
- -- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- -- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- -- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- -- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- -- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- -- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- -- THE SOFTWARE.