| [e2e035e] | 1 | /*
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 | 2 |  * Project: MoleCuilder
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 | 3 |  * Description: creates and alters molecular systems
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 | 4 |  * Copyright (C)  2010 University of Bonn. All rights reserved.
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 | 5 |  * Please see the LICENSE file or "Copyright notice" in builder.cpp for details.
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 | 6 |  */
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 | 7 | 
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 | 8 | /**
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 | 9 |  * \file observer.dox
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 | 10 |  *
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 | 11 |  * Created on: Dec 1, 2011
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 | 12 |  *    Author: heber
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 | 13 |  */
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 | 14 | 
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 | 15 | /** \page pattern-observer
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 | 16 |  *
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 | 17 |  * Basic structure for the observer pattern
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 | 18 |  *
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 | 19 |  * Observers register themselves with the observables to be notified when something changes.
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 | 20 |  * In the Observable code that changes, attributes should be started with OBSERVE;. This macro
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 | 21 |  * locks the observer mechanism while changes are done. At the end of the scope in which the
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 | 22 |  * macro was placed the lock is released. When the last lock is released all changes are
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 | 23 |  * propagated to the observers.
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 | 24 |  *
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 | 25 |  * Each observerable can have sub-observables. When one of these sub-observables changes and
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 | 26 |  * notifies its observers the observable that contains them will also notify its observers.
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 | 27 |  * This passing on of updates is blocked, when the main-observable is in the process of
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 | 28 |  * updating many of its internal sub-observables. This means the update is not passed, if
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 | 29 |  * it is produced while the main-observable itself is within any Observation block.
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| [b760ac5] | 30 |  *
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 | 31 |  * \section pattern-observer-howtos Howto
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 | 32 |  *
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 | 33 |  *  Below you find various howtos to guide you through how to use the various
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 | 34 |  *  observer patterns.
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 | 35 |  *
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 | 36 |  * \section pattern-observer-howtos-observer Observers
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 | 37 |  *
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 | 38 |  *  \todo write howto for using an Observer
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 | 39 |  *
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 | 40 |  * \section pattern-observer-howtos-observables Observables
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 | 41 |  *
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 | 42 |  *  \todo write howto for using an Observable
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 | 43 |  *
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 | 44 |  * \section pattern-observer-howtos-relay Relays
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 | 45 |  *
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 | 46 |  *  Lets us assume that you want to observe all instances of class "foo".
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 | 47 |  *  In order to create a Relay you have to do the following:
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 | 48 |  *  -# Create a new class "bar" that inherits the Relay pattern.
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 | 49 |  *  \code
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 | 50 |  *    #include "CodePatterns/Relay.hpp"
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 | 51 |  *    class bar : public Relay {
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 | 52 |  *    ...
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 | 53 |  *    };
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 | 54 |  *  \endcode
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 | 55 |  *  -# In the constructor bar::bar() create a Channels object for your Relay and
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 | 56 |  *     add a channel for each of foo's channels, use foo's enum for this:
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 | 57 |  *   \code
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 | 58 |  *     bar::bar() {
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 | 59 |  *      Channels *OurChannel = new Channels();
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 | 60 |  *      NotificationChannels.insert( std::make_pair(this, OurChannel) );
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 | 61 |  *      OurChannel->addChannel(foo::Notification1);
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 | 62 |  *      OurChannel->addChannel(foo::Notification2);
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 | 63 |  *      ...
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 | 64 |  *     }
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 | 65 |  *   \endcode
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 | 66 |  *   -# Someplace else you have add all Observers that need to check on all
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 | 67 |  *      instances of "foo" to be signed on.
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 | 68 |  *    \code
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 | 69 |  *    bar barInstance;
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 | 70 |  *    ... someObserverInstance;
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 | 71 |  *    barInstance.signOn(someObserverInstance);
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 | 72 |  *    \endcode
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 | 73 |  *   -# ... or maybe just for a specific channel of foo.
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 | 74 |  *    \code
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 | 75 |  *    bar barInstance;
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 | 76 |  *    ... someObserverInstance;
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 | 77 |  *    barInstance.signOn(someObserverInstance, foo::Notification1);
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 | 78 |  *    \endcode
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 | 79 |  *
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 | 80 |  *
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 | 81 |  * \date 2011-12-01
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| [e2e035e] | 82 |  */
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 | 83 | 
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