| 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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| 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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| 82 | */ | 
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| 83 |  | 
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