src/gromacs/onlinehelp/helptopic.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares helper classes for implementing gmx::IHelpTopic.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_onlinehelp
  42  */
  43 #ifndef GMX_ONLINEHELP_HELPTOPIC_H
  44 #define GMX_ONLINEHELP_HELPTOPIC_H
  45
  46 #include <memory>
  47
  48 #include "gromacs/onlinehelp/ihelptopic.h"
  49 #include "gromacs/utility/classhelpers.h"
  50 #include "gromacs/utility/stringutil.h"
  51
  52 namespace gmx
  53 {
  54
  55 /*! \libinternal \brief
  56  * Abstract base class for help topics that have simple text and no subtopics.
  57  *
  58  * This class implements subtopic-related methods from IHelpTopic such
  59  * that there are no subtopics.  writeHelp() is also implemented such that it
  60  * uses HelpTopicContext::writeTextBlock() to write out the text returned by a
  61  * new virtual method helpText().
  62  *
  63  * \see SimpleHelpTopic
  64  *
  65  * \inlibraryapi
  66  * \ingroup module_onlinehelp
  67  */
  68 class AbstractSimpleHelpTopic : public IHelpTopic
  69 {
  70     public:
  71         const char *name() const  override = 0;
  72         const char *title() const override = 0;
  73
  74         bool hasSubTopics() const override;
  75         const IHelpTopic *findSubTopic(const char *name) const override;
  76
  77         void writeHelp(const HelpWriterContext &context) const override;
  78
  79     protected:
  80         /*! \brief
  81          * Returns the help text for this topic.
  82          *
  83          * writeHelp() calls this method to obtain the actual text to format
  84          * for the topic.  Markup substitution etc. is done automatically by
  85          * writeHelp().
  86          */
  87         virtual std::string helpText() const = 0;
  88 };
  89
  90 /*! \libinternal \brief
  91  * Abstract base class for help topics that have simple text and subtopics.
  92  *
  93  * This class implements an internal container for subtopics and provides
  94  * public methods for adding subtopics (as IHelpTopic objects).
  95  * Subtopic-related methods from IHelpTopic are implemented to access
  96  * the internal container.  writeHelp() is also implemented such that it
  97  * uses HelpTopicContext::writeTextBlock() to write out the text returned by a
  98  * new virtual method helpText(), and a list of subtopics is written after the
  99  * actual text.
 100  *
 101  * \see CompositeHelpTopic
 102  *
 103  * \inlibraryapi
 104  * \ingroup module_onlinehelp
 105  */
 106 class AbstractCompositeHelpTopic : public IHelpTopic
 107 {
 108     public:
 109         AbstractCompositeHelpTopic();
 110         ~AbstractCompositeHelpTopic() override;
 111
 112         const char *name() const  override = 0;
 113         const char *title() const override = 0;
 114
 115         bool hasSubTopics() const override;
 116         const IHelpTopic *findSubTopic(const char *name) const override;
 117
 118         void writeHelp(const HelpWriterContext &context) const override;
 119
 120         /*! \brief
 121          * Adds a given topic as a subtopic of this topic.
 122          *
 123          * \param   topic  Topis to add.
 124          * \throws  std::bad_alloc if out of memory.
 125          *
 126          * This topic takes ownership of the object.
 127          *
 128          * \see registerSubTopic()
 129          */
 130         void addSubTopic(HelpTopicPointer topic);
 131         /*! \brief
 132          * Registers a subtopic of a certain type to this topic.
 133          *
 134          * \tparam  Topic  Type of topic to register.
 135          * \throws  std::bad_alloc if out of memory.
 136          *
 137          * \p Topic must be default-constructible and implement
 138          * IHelpTopic.
 139          *
 140          * This method is provided as a convenient alternative to addSubTopic()
 141          * for cases where each topic is implemented by a different type
 142          * (which is a common case outside unit tests).
 143          */
 144         template <class Topic>
 145         void registerSubTopic()
 146         {
 147             addSubTopic(HelpTopicPointer(new Topic));
 148         }
 149
 150     protected:
 151         //! \copydoc gmx::AbstractSimpleHelpTopic::helpText()
 152         virtual std::string helpText() const = 0;
 153
 154         /*! \brief
 155          * Writes the list of subtopics.
 156          *
 157          * \param[in] context Context for writing the help.
 158          * \param[in] title  Title for the written list.
 159          * \returns   true if anything was printed.
 160          * \throws    std::bad_alloc if out of memory.
 161          * \throws    FileIOError on any I/O error.
 162          *
 163          * Subtopics with empty titles are skipped from the list.
 164          * If there would be no subtopics in the list, \p title is not printed
 165          * either.
 166          *
 167          * This method is provided for cases where helpText() does not provide
 168          * the needed flexibility and the derived class needs to override
 169          * writeHelp().  This method can then be called to print the same
 170          * subtopic list that is printed by the default writeHelp()
 171          * implementation.
 172          */
 173         bool writeSubTopicList(const HelpWriterContext &context,
 174                                const std::string       &title) const;
 175
 176     private:
 177         class Impl;
 178
 179         PrivateImplPointer<Impl> impl_;
 180 };
 181
 182 /*! \cond libapi */
 183 /*! \libinternal \brief
 184  * Smart pointer type to manage a AbstractCompositeHelpTopic object.
 185  *
 186  * \inlibraryapi
 187  */
 188 typedef std::unique_ptr<AbstractCompositeHelpTopic>
 189     CompositeHelpTopicPointer;
 190 //! \endcond
 191
 192 /*! \libinternal \brief
 193  * Template for simple implementation of AbstractSimpleHelpTopic.
 194  *
 195  * \tparam HelpText Struct that defines the data for the topic.
 196  *
 197  * \p HelpText should have public static members \c "const char name[]",
 198  * \c "const char title[]" and \c "const char *const text[]".
 199  *
 200  * Typical use:
 201  * \code
 202    struct ExampleHelpText
 203    {
 204        static const char name[];
 205        static const char title[];
 206        static const char *const text[];
 207    };
 208
 209    const char ExampleHelpText::name[] = "example";
 210    const char ExampleHelpText::title[] =
 211        "Example title";
 212    const char *const ExampleHelpText::text[] = {
 213        "Text for the topic.",
 214        "More text for the topic."
 215    };
 216
 217    typedef SimpleHelpTopic<ExampleHelpText> ExampleHelpTopic;
 218  * \endcode
 219  *
 220  * \inlibraryapi
 221  * \ingroup module_onlinehelp
 222  */
 223 template <class HelpText>
 224 class SimpleHelpTopic : public AbstractSimpleHelpTopic
 225 {
 226     public:
 227         const char *name() const override
 228         {
 229             return HelpText::name;
 230         }
 231         const char *title() const override
 232         {
 233             return HelpText::title;
 234         }
 235
 236     protected:
 237         std::string helpText() const override
 238         {
 239             return joinStrings(HelpText::text, "\n");
 240         }
 241 };
 242
 243 /*! \libinternal \brief
 244  * Template for simple implementation of AbstractCompositeHelpTopic.
 245  *
 246  * \tparam HelpText Struct that defines the data for the topic.
 247  *
 248  * Used similarly to SimpleHelpTopic.
 249  * \p HelpText should satisfy the same criteria as for SimpleHelpTopic.
 250  *
 251  * \see SimpleHelpTopic
 252  *
 253  * \inlibraryapi
 254  * \ingroup module_onlinehelp
 255  */
 256 template <class HelpText>
 257 class CompositeHelpTopic : public AbstractCompositeHelpTopic
 258 {
 259     public:
 260         // copydocs are needed with Doxygen 1.8.10, but not 1.8.5...
 261         //! \copydoc gmx::AbstractCompositeHelpTopic::name()
 262         const char *name() const override
 263         {
 264             return HelpText::name;
 265         }
 266         //! \copydoc gmx::AbstractCompositeHelpTopic::title()
 267         const char *title() const override
 268         {
 269             return HelpText::title;
 270         }
 271
 272     protected:
 273         //! \copydoc gmx::AbstractCompositeHelpTopic::helpText()
 274         std::string helpText() const override
 275         {
 276             return joinStrings(HelpText::text, "\n");
 277         }
 278 };
 279
 280 } // namespace gmx
 281
 282 #endif