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33 * Defines gmx::AbstractOption and a related template.
35 * This header defines base classes for option settings that are used with
36 * Options::addOption(). These classes implement the "named parameter"
37 * idiom for specifying option properties.
39 * These classes also take care of creating and setting up the actual option
42 * This header is needed directly only when implementing new option types,
43 * but methods of OptionTemplate are visible even to the normal user through
46 * \author Teemu Murtola <teemu.murtola@cbr.su.se>
48 * \ingroup module_options
50 #ifndef GMX_OPTIONS_ABSTRACTOPTION_H
51 #define GMX_OPTIONS_ABSTRACTOPTION_H
56 #include "../utility/uniqueptr.h"
58 #include "optionflags.h"
63 class AbstractOptionStorage;
64 template <typename T> class OptionStorageTemplate;
67 //! Smart pointer for managing an AbstractOptionStorage object.
68 typedef gmx_unique_ptr<AbstractOptionStorage>::type
69 AbstractOptionStoragePointer;
72 * Abstract base class for specifying option properties.
74 * Concrete classes should normally not derive directly from this class,
75 * but from OptionTemplate instead. Classes derived from this class
76 * are mainly designed to implement the "named parameter" idiom. For
77 * efficiency and clarity, these classes should only store values provided to
78 * them. All error checking and memory management should be postponed to the
79 * point when the actual option is created.
81 * Subclasses should override createStorage() to create the correct type
84 * \ingroup module_options
89 // Virtual only for completeness, in normal use should not be needed.
90 virtual ~AbstractOption() { }
94 //! Initializes the name and default values for an option.
95 explicit AbstractOption(const char *name)
96 : minValueCount_(1), maxValueCount_(1),
97 name_(name), descr_(NULL)
101 * Creates a default storage object for the option.
103 * \returns The created storage object.
104 * \throws APIError if invalid option settings have been provided.
106 * This method is called by Options::addOption() when initializing an
107 * option from the settings.
109 * Derived classes should implement the method to create an actual
110 * storage object and populate it with correct values.
111 * They should also throw APIError if they detect problems.
113 * Should only be called by Options::addOption().
115 virtual AbstractOptionStoragePointer createStorage() const = 0;
118 * Creates the description string for the option.
120 * \returns Description string for the option.
122 * This function is virtual to allow derived classes to customize the
123 * description programmatically, e.g., by adding the list of allowed
125 * The default implementation simply returns the user-provided
128 virtual std::string createDescription() const
129 { return descr_ ? descr_ : ""; }
131 //! Sets the description for the option.
132 void setDescription(const char *descr) { descr_ = descr; }
133 //! Sets a flag for the option.
134 void setFlag(OptionFlag flag) { flags_.set(flag); }
135 //! Clears a flag for the option.
136 void clearFlag(OptionFlag flag) { flags_.clear(flag); }
137 //! Sets or clears a flag for the option.
138 void setFlag(OptionFlag flag, bool bSet) { flags_.set(flag, bSet); }
139 //! Returns true if the option is vector-valued.
140 bool isVector() const { return hasFlag(efOption_Vector); }
142 * Sets the option to be vector-valued.
144 * This method is provided for convenience to make management of value
145 * counts easier. In order to implement a vector-valued option, the
146 * class derived from AbstractOption should expose a method that calls
147 * this method, and the storage object derived from
148 * AbstractOptionStorage should check isVector().
149 * If only a single value is provided, the storage object should fill
150 * the whole vector with that value.
152 * The length of the vector (the value of maxValueCount_) must be
153 * fixed. The default length is 3 elements.
157 setFlag(efOption_Vector);
159 if (maxValueCount_ == 1)
164 //! Sets the required number of values for the option.
165 void setValueCount(int count)
167 if (!hasFlag(efOption_Vector))
169 minValueCount_ = count;
171 maxValueCount_ = count;
174 //! Minimum number of values required for the option.
176 //! Maximum number of values allowed for the option.
181 //! Returns true if a flag has been set.
182 bool hasFlag(OptionFlag flag) const { return flags_.test(flag); }
185 //! Pointer to description of the option.
190 * Needed to initialize an AbstractOptionStorage object from this class
191 * without otherwise unnecessary accessors.
193 friend class AbstractOptionStorage;
195 * Needed to be able to call createStorage().
197 friend class Options;
201 * Templated base class for constructing concrete option settings classes.
203 * \tparam T Assignable type that stores a single option value.
204 * \tparam U Type of the derived class.
206 * This template is used as a base class like this:
208 class ConcreteOption : public OptionTemplate<int, ConcreteOption>
212 * All public functions in this class return \c *this casted to a reference to
213 * \p U. They do not throw.
215 * For examples of how to use classes derived from this class, see the class
216 * documentation for Options.
219 * \ingroup module_options
221 template <typename T, class U>
222 class OptionTemplate : public AbstractOption
225 //! Type that stores a single option value.
227 //! Alias for the derived class type.
231 * Sets a description for the option.
233 * \param[in] descr Description to set.
235 * String in \p descr is copied when the option is created.
237 MyClass &description(const char *descr)
238 { setDescription(descr); return me(); }
239 //! Hides the option from normal help output.
240 MyClass &hidden(bool bHidden = true)
241 { setFlag(efOption_Hidden, bHidden); return me(); }
242 //! Requires the option to be specified explicitly.
243 MyClass &required(bool bRequired = true)
244 { setFlag(efOption_Required, bRequired); return me(); }
245 //! Allows the option to be specified multiple times.
246 MyClass &allowMultiple(bool bMulti = true)
247 { setFlag(efOption_MultipleTimes, bMulti); return me(); }
248 //! Requires exactly \p count values for the option.
249 MyClass &valueCount(int count) { setValueCount(count); return me(); }
250 //! Allows any number of values for the option.
251 MyClass &multiValue() { maxValueCount_ = -1; return me(); }
254 * Sets a default value for the option.
256 * \param[in] defaultValue Default value.
258 * If the option is never set, the default value is copied to the
259 * assigned storage. Note that if the option is not set and there
260 * is no default value, the storage is not altered, which can also be
261 * used to provide a default value. The latter method has to be used
262 * if the option can take multiple values.
263 * If required() is specified, only affects the default value shown in
266 * \p defaultValue is copied when the option is created.
268 MyClass &defaultValue(const T &defaultValue)
269 { defaultValue_ = &defaultValue; return me(); }
271 * Sets a default value for the option when it is set.
273 * \param[in] defaultValue Default value.
275 * This value is used if the option is set, but no value is provided.
276 * If the option is never set, the value set with defaultValue() is
277 * used. Can only be used for options that accept a single value.
279 * \p defaultValue is copied when the option is created.
281 MyClass &defaultValueIfSet(const T &defaultValue)
282 { defaultValueIfSet_ = &defaultValue; return me(); }
284 * Stores value(s) in memory pointed by \p store.
286 * \param[in] store Storage for option value(s).
288 * The caller is responsible for allocating enough memory such that
289 * the any allowed number of values fits into the array pointed by
290 * \p store. If there is no maximum allowed number or if the maximum
291 * is inconveniently large, storeVector() should be used.
293 * For information on when values are available in the storage, see
296 * The pointer provided should remain valid as long as the associated
297 * Options object exists.
299 MyClass &store(T *store)
300 { store_ = store; return me(); }
302 * Stores number of values in the value pointed by \p countptr.
304 * \param[in] countptr Storage for the number of values.
306 * For information on when values are available in the storage, see
309 * The pointers provided should remain valid as long as the associated
310 * Options object exists.
312 MyClass &storeCount(int *countptr)
313 { countptr_ = countptr; return me(); }
315 * Stores option values in the provided vector.
317 * \param[in] store Vector to store option values in.
319 * Values are added to the vector after each successful set of values
320 * is parsed. Note that for some options, the value may be changed
321 * later, and is only guaranteed to be correct after Options::finish()
324 * The pointer provided should remain valid as long as the associated
325 * Options object exists.
327 MyClass &storeVector(std::vector<T> *store)
328 { storeVector_ = store; return me(); }
332 //! Alias for the template class for use in base classes.
333 typedef OptionTemplate<T, U> MyBase;
335 //! Initializes the name and default values for an option.
336 explicit OptionTemplate(const char *name)
337 : AbstractOption(name),
338 defaultValue_(NULL), defaultValueIfSet_(NULL), store_(NULL),
339 countptr_(NULL), storeVector_(NULL)
343 * Returns a pointer to user-specified default value, or NULL if there
346 const T *defaultValue() const { return defaultValue_; }
348 * Returns a pointer to user-specified default value, or NULL if there
351 const T *defaultValueIfSet() const { return defaultValueIfSet_; }
352 //! Returns \p *this casted into MyClass to reduce typing.
353 MyClass &me() { return static_cast<MyClass &>(*this); }
357 const T *defaultValue_;
358 const T *defaultValueIfSet_;
361 std::vector<T> *storeVector_;
364 * Needed to initialize storage from this class without otherwise
365 * unnecessary accessors.
367 friend class OptionStorageTemplate<T>;