src/gromacs/onlinehelp/helpwritercontext.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares gmx::HelpWriterContext.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_onlinehelp
  42  */
  43 #ifndef GMX_ONLINEHELP_HELPWRITERCONTEXT_H
  44 #define GMX_ONLINEHELP_HELPWRITERCONTEXT_H
  45
  46 #include <string>
  47 #include <vector>
  48
  49 #include "gromacs/utility/classhelpers.h"
  50
  51 namespace gmx
  52 {
  53
  54 class TextLineWrapperSettings;
  55 class TextWriter;
  56
  57 /*! \cond libapi */
  58 //! \libinternal Output format for help writing.
  59 enum HelpOutputFormat
  60 {
  61     eHelpOutputFormat_Console,  //!< Plain text directly on the console.
  62     eHelpOutputFormat_Rst,      //!< reStructuredText for online manual and man pages.
  63     eHelpOutputFormat_Other,    //!< Used for extensions in other modules.
  64     eHelpOutputFormat_NR        //!< Used for the number of output formats.
  65 };
  66 //! \endcond
  67
  68 /*! \libinternal \brief
  69  * Hyperlink data for writing out help.
  70  *
  71  * This class is separate from HelpWriterContext to allow constructing the list
  72  * of links once and reusing them across multiple help writer contexts.
  73  * This is used when exporting all the help from the wrapper binary to avoid
  74  * repeatedly constructing the same data structure for each help item.
  75  *
  76  * While the links are in principle independent of the output format, the
  77  * constructor takes the output format to be able to preformat the links,
  78  * avoiding repeated processing during markup substitution.  Could be hidden
  79  * behind the scenes in HelpWriterContext, but that would complicate the
  80  * implementation.
  81  *
  82  * \ingroup module_onlinehelp
  83  */
  84 class HelpLinks
  85 {
  86     public:
  87         /*! \brief
  88          * Initializes an empty links collection for the given output format.
  89          */
  90         explicit HelpLinks(HelpOutputFormat format);
  91         ~HelpLinks();
  92
  93         /*! \brief
  94          * Adds a link.
  95          *
  96          * \param[in] linkName     Name of the link in input text.
  97          * \param[in] targetName   Hyperlink target.
  98          * \param[in] displayName  Text to show as the link.
  99          *
 100          * Any occurrence of \p linkName in the text passed to markup
 101          * substitution methods in HelpWriterContext is made into a hyperlink
 102          * to \p targetName if the markup format supports that.
 103          */
 104         void addLink(const std::string &linkName,
 105                      const std::string &targetName,
 106                      const std::string &displayName);
 107
 108     private:
 109         class Impl;
 110
 111         PrivateImplPointer<Impl> impl_;
 112
 113         //! Allows the context to use the links.
 114         friend class HelpWriterContext;
 115 };
 116
 117 /*! \libinternal \brief
 118  * Context information for writing out help.
 119  *
 120  * The purpose of this class is to pass information about the output format to
 121  * methods that write help, and to abstract away most of the details of
 122  * different output formats.
 123  *
 124  * The state of a context object (excluding the fact that the output file is
 125  * written to) does not change after initial construction of the object.
 126  * Copying creates a context objects that share state with the source.
 127  *
 128  * \inlibraryapi
 129  * \ingroup module_onlinehelp
 130  */
 131 class HelpWriterContext
 132 {
 133     public:
 134         /*! \brief
 135          * Initializes a context with the given output writer and format.
 136          *
 137          * \throws std::bad_alloc if out of memory.
 138          */
 139         HelpWriterContext(TextWriter *writer, HelpOutputFormat format);
 140         /*! \brief
 141          * Initializes a context with the given output writer, format and links.
 142          *
 143          * \throws std::bad_alloc if out of memory.
 144          *
 145          * A reference to \p links is stored until the HelpWriterContext
 146          * is destructed.  The caller is responsible for ensuring that the
 147          * links object remains valid long enough.
 148          */
 149         HelpWriterContext(TextWriter *writer, HelpOutputFormat format,
 150                           const HelpLinks *links);
 151         //! Creates a copy of the context.
 152         HelpWriterContext(const HelpWriterContext &other);
 153         ~HelpWriterContext();
 154
 155         /*! \brief
 156          * Adds a string replacement for markup subsitution.
 157          *
 158          * \param[in] search   Text to replace in input.
 159          * \param[in] replace  Text that each occurrence of \p search is
 160          *     replaced with.
 161          * \throws std::bad_alloc if out of memory.
 162          *
 163          * \todo
 164          * Improve semantics if the same \p search item is set multiple
 165          * times.
 166          */
 167         void setReplacement(const std::string &search,
 168                             const std::string &replace);
 169
 170         /*! \brief
 171          * Returns the active output format.
 172          *
 173          * Does not throw.
 174          */
 175         HelpOutputFormat outputFormat() const;
 176         /*! \brief
 177          * Returns the raw writer for writing the help.
 178          *
 179          * Using this writer directly should be avoided, as it requires one to
 180          * have different code for each output format.
 181          * Using other methods in this class should be preferred.
 182          *
 183          * Does not throw.
 184          */
 185         TextWriter &outputFile() const;
 186
 187         /*! \brief
 188          * Creates a subsection in the output help.
 189          *
 190          * \param[in] title  Title for the subsection.
 191          * \throws    std::bad_alloc if out of memory.
 192          * \throws    FileIOError on any I/O error.
 193          *
 194          * Writes \p title using writeTitle() and makes any further
 195          * writeTitle() calls write headings one level deeper.
 196          *
 197          * Typical use for writing a subsection is to create a copy of the
 198          * context for the parent section, and then call enterSubSection() on
 199          * the copy.
 200          * The whole subsection should be written out using the returned
 201          * context before calling any further methods in the parent context.
 202          *
 203          * This method is only necessary if the subsection will contain further
 204          * subsections.  If there is only one level of subsections, it is
 205          * possible to use writeTitle() directly.
 206          */
 207         void enterSubSection(const std::string &title);
 208
 209         /*! \brief
 210          * Substitutes markup used in help text and wraps lines.
 211          *
 212          * \param[in] settings Line wrapper settings.
 213          * \param[in] text     Text to substitute.
 214          * \returns   \p text with markup substituted and wrapped.
 215          * \throws    std::bad_alloc if out of memory.
 216          *
 217          * \see TextLineWrapper::wrapToString()
 218          */
 219         std::string
 220         substituteMarkupAndWrapToString(const TextLineWrapperSettings &settings,
 221                                         const std::string             &text) const;
 222         /*! \brief
 223          * Substitutes markup used in help text and wraps lines.
 224          *
 225          * \param[in] settings Line wrapper settings.
 226          * \param[in] text     Text to substitute.
 227          * \returns   \p text with markup substituted and wrapped as a list of
 228          *      lines.
 229          * \throws    std::bad_alloc if out of memory.
 230          *
 231          * \see TextLineWrapper::wrapToVector()
 232          */
 233         std::vector<std::string>
 234         substituteMarkupAndWrapToVector(const TextLineWrapperSettings &settings,
 235                                         const std::string             &text) const;
 236         /*! \brief
 237          * Writes a title for the current help topic.
 238          *
 239          * \param[in] title  Title to write.
 240          * \throws    std::bad_alloc if out of memory.
 241          * \throws    FileIOError on any I/O error.
 242          */
 243         void writeTitle(const std::string &title) const;
 244         /*! \brief
 245          * Writes a formatted text block into the output.
 246          *
 247          * \param[in] text  Text to format.
 248          * \throws    std::bad_alloc if out of memory.
 249          * \throws    FileIOError on any I/O error.
 250          *
 251          * Convenience function that calls substituteMarkupAndWrapToString()
 252          * and writes the result directly to the output file.
 253          */
 254         void writeTextBlock(const std::string &text) const;
 255         /*! \brief
 256          * Ensures a paragraph break (empty line) in the output.
 257          *
 258          * Calls at the beginning and end of output do not produce extra empty
 259          * lines, and consencutive calls only result in a single empty line.
 260          * This allows calling the method before and after all output that
 261          * needs to appear separated as empty lines.
 262          */
 263         void paragraphBreak() const;
 264         /*! \brief
 265          * Starts writing a list of options.
 266          *
 267          * Prints any necessary headers for a list of options formatted with
 268          * writeOptionItem().
 269          */
 270         void writeOptionListStart() const;
 271         /*! \brief
 272          * Writes an entry for a single option into the output.
 273          *
 274          * \param[in] name  Name of the option.
 275          * \param[in] value        Placeholder for option value.
 276          * \param[in] defaultValue Default value for the option.
 277          * \param[in] info         Additional (brief) info/attributes for the
 278          *      option.
 279          * \param[in] description  Full description of the option.
 280          */
 281         void writeOptionItem(
 282             const std::string &name, const std::string &value,
 283             const std::string &defaultValue, const std::string &info,
 284             const std::string &description) const;
 285         /*! \brief
 286          * Finishes writing a list of options.
 287          *
 288          * Prints any necessary footers for a list of options formatted with
 289          * writeOptionItem().
 290          */
 291         void writeOptionListEnd() const;
 292
 293     private:
 294         class Impl;
 295
 296         /*! \brief
 297          * Constructs a context object with the given implementation class.
 298          *
 299          * \param[in] impl  Implementation object.
 300          *
 301          * Does not throw.
 302          */
 303         explicit HelpWriterContext(Impl *impl);
 304
 305         PrivateImplPointer<Impl> impl_;
 306
 307         GMX_DISALLOW_ASSIGN(HelpWriterContext);
 308 };
 309
 310 } // namespace gmx
 311
 312 #endif