| 1 | /*
 | 
|---|
| 2 |  * Project: MoleCuilder
 | 
|---|
| 3 |  * Description: creates and alters molecular systems
 | 
|---|
| 4 |  * Copyright (C)  2010 University of Bonn. All rights reserved.
 | 
|---|
| 5 |  * Please see the LICENSE file or "Copyright notice" in builder.cpp for details.
 | 
|---|
| 6 |  */
 | 
|---|
| 7 | 
 | 
|---|
| 8 | /**
 | 
|---|
| 9 |  * \file actions.dox
 | 
|---|
| 10 |  *
 | 
|---|
| 11 |  * Created on: Oct 28, 2011
 | 
|---|
| 12 |  *    Author: heber
 | 
|---|
| 13 |  */
 | 
|---|
| 14 | 
 | 
|---|
| 15 | /** \page actions Actions
 | 
|---|
| 16 |  *
 | 
|---|
| 17 |  *  \link MoleCuilder::Action Actions \endlink are Command patterns
 | 
|---|
| 18 |  *  (http://en.wikipedia.org/wiki/Command_pattern)
 | 
|---|
| 19 |  *  to allow for undoing and redoing. Each specific Action derives from this
 | 
|---|
| 20 |  *  class to implement a certain functionality. There is a lot of preprocessor
 | 
|---|
| 21 |  *  magic implemented for making this as easy as possible. In effect you only
 | 
|---|
| 22 |  *  have to create three files of which only one actually contains more than a
 | 
|---|
| 23 |  *  few lines, namely the code of the Action itself.
 | 
|---|
| 24 |  *
 | 
|---|
| 25 |  *  Each Action has thus three types of functionalty: do, undo, and redo.
 | 
|---|
| 26 |  *
 | 
|---|
| 27 |  *  The ActionRegistry contains a prototype of each Action under its token
 | 
|---|
| 28 |  *  such that an instance can be retrieved by knowing this token.
 | 
|---|
| 29 |  *
 | 
|---|
| 30 |  *  Each Action obtains its options from a central ValueStorage such that
 | 
|---|
| 31 |  *  they are independent of where the option originated from: a command line
 | 
|---|
| 32 |  *  parameter, a value entered in a graphical dialog or given via the keyboard
 | 
|---|
| 33 |  *  in a terminal. That's why each begins with a function call to
 | 
|---|
| 34 |  *  getParametersfromValueStorage() to fill its internal Action::params
 | 
|---|
| 35 |  *  structure.
 | 
|---|
| 36 |  *
 | 
|---|
| 37 |  *  Also there is a regression test (\ref regression-test) for each Action to
 | 
|---|
| 38 |  *  check that it always behaves the same no matter how much the code
 | 
|---|
| 39 |  *  implementing actually has changed.
 | 
|---|
| 40 |  *
 | 
|---|
| 41 |  * \section actions-add To add a new action ...
 | 
|---|
| 42 |  *
 | 
|---|
| 43 |  *  The following steps have to be done for adding a new action:
 | 
|---|
| 44 |  *  -# Create three new files .cpp, .def, and .hpp
 | 
|---|
| 45 |  *  -# Add the files to \b src/Actions/Makefile.am.
 | 
|---|
| 46 |  *  -# Add the name of the Action to \b src/Actions/GlobalListOfActions.hpp
 | 
|---|
| 47 |  *    such that the ActionRegistry knows about it and can instantiate a
 | 
|---|
| 48 |  *    prototype.
 | 
|---|
| 49 |  *
 | 
|---|
| 50 |  * \section actions-undo-redo Undoing and Redoing actions ...
 | 
|---|
| 51 |  *
 | 
|---|
| 52 |  * The central points of Actions is that they can be undone and redone. This
 | 
|---|
| 53 |  * has to be implemented in two more functions beside the "do".
 | 
|---|
| 54 |  *
 | 
|---|
| 55 |  * Note that undoing means to get every back to its original state and by whatever
 | 
|---|
| 56 |  * means seem appropriate, e.g. just remvoing all inserted atoms.
 | 
|---|
| 57 |  * To make this more elaborate it is usually very useful to store extra information
 | 
|---|
| 58 |  * in the Action's state such that undo and redo can be accomplished more quickly.
 | 
|---|
| 59 |  * E.g. if your Action creates some new atoms, store their info as \ref AtomicInfo.
 | 
|---|
| 60 |  * Then, undo can simply delete the newly created atoms and redo can quickly re-
 | 
|---|
| 61 |  * create them in the state they have been before.
 | 
|---|
| 62 |  *
 | 
|---|
| 63 |  * Have a look at \ref UndoRedoHelpers.hpp for some helper functions on this.
 | 
|---|
| 64 |  *
 | 
|---|
| 65 |  * \section actions-further Further information
 | 
|---|
| 66 |  *
 | 
|---|
| 67 |  * If you want know:
 | 
|---|
| 68 |  * -# how the code knows about the valid tokens for actions and options and how
 | 
|---|
| 69 |  *    they are constructed, see \ref MoleCuilder::Action .
 | 
|---|
| 70 |  *
 | 
|---|
| 71 |  *
 | 
|---|
| 72 |  *  \date 2012-04-05
 | 
|---|
| 73 |  *
 | 
|---|
| 74 |  */
 | 
|---|