feature: epwing dictionary reference navigation improved.

feature: add branch method to handle the reference navigation loadArticle function

feature: refactor epwing loadArticle method

epwing: add previous and next page link

base/globalregex.cc

@@ -66,3 +66,6 @@ QRegularExpression Mdx::styleElment( R"((<style[^>]*>)([\w\W]*?)(<\/style>))",
 
 
 QRegularExpression Zim::linkSpecialChar("[\\.\\/]");
+
+
+QRegularExpression Epwing::refWord(R"([r|p](\d+)at(\d+))", QRegularExpression::CaseInsensitiveOption);

base/globalregex.hh

@@ -50,6 +50,11 @@ class Zim{
   static QRegularExpression linkSpecialChar;
 };
 
+class Epwing{
+ public:
+  static QRegularExpression refWord;
+};
+
 } // namespace RX
 
 #endif // GLOBALREGEX_HH

epwing.cc

@@ -13,6 +13,7 @@
 #include <QtConcurrent>
 #include <set>
 #include <string>
+#include <QObject>
 
 #include "btreeidx.hh"
 #include "folding.hh"
@@ -24,6 +25,7 @@
 #include "utf8.hh"
 #include "filetype.hh"
 #include "ftshelpers.hh"
+#include "base/globalregex.hh"
 
 namespace Epwing {
 
@@ -175,6 +177,9 @@ private:
                     int & articlePage,
                     int & articleOffset );
 
+ void loadArticleNextPage( string & articleHeadword, string & articleText, int & articlePage, int & articleOffset );
+ void loadArticlePreviousPage( string & articleHeadword, string & articleText, int & articlePage, int & articleOffset );
+  
   void loadArticle( int articlePage, int articleOffset, string & articleHeadword,
                     string & articleText );
 
@@ -194,6 +199,8 @@ private:
   friend class EpwingArticleRequest;
   friend class EpwingResourceRequest;
   friend class EpwingWordSearchRequest;
+  string epwing_previous_button(int& articleOffset, int& articlePage);
+  string epwing_next_button(int& articleOffset, int& articlePage);
 };
 
 
@@ -323,6 +330,77 @@ void EpwingDictionary::loadArticle(
   articleText = prefix + articleText + "</div>";
 }
 
+string Epwing::EpwingDictionary::epwing_previous_button(int& articlePage, int& articleOffset)
+{
+    QString previousButton = QString( "p%1At%2" ).arg( articlePage ).arg( articleOffset );
+    string previousLink    = "<p><a class=\"epwing_previous_page\" href=\"gdlookup://localhost/"
+      + previousButton.toStdString() + "\">" + QObject::tr( "Previous Page" ).toStdString() + "</a></p>";
+
+    return previousLink;
+}
+
+void EpwingDictionary::loadArticleNextPage(string & articleHeadword, string & articleText, int & articlePage, int & articleOffset )
+{
+  QString headword, text;
+  EB_Position pos;
+  try
+  {
+    Mutex::Lock _( eBook.getLibMutex() );
+    pos = eBook.getArticleNextPage( headword, text, articlePage, articleOffset, false );
+  }
+  catch( std::exception & e )
+  {
+    text = QString( "Article reading error: %1")
+             .arg( QString::fromUtf8( e.what() ) );
+  }
+
+  articleHeadword = string( headword.toUtf8().data() );
+  articleText = string( text.toUtf8().data() );
+
+  string prefix( "<div class=\"epwing_text\">" );
+  string previousLink = epwing_previous_button(articlePage, articleOffset);
+
+  articleText     = prefix + previousLink + articleText;
+  string nextLink = epwing_next_button(pos.page, pos.offset);
+  articleText = articleText + nextLink;
+  articleText = articleText + "</div>";
+}
+
+string Epwing::EpwingDictionary::epwing_next_button(int& articlePage, int& articleOffset )
+{
+    QString refLink = QString( "r%1At%2" ).arg( articlePage ).arg( articleOffset );
+    string nextLink = "<p><a class=\"epwing_next_page\" href=\"gdlookup://localhost/" + refLink.toStdString() + "\">"
+      + QObject::tr( "Next Page" ).toStdString() + "</a></p>";
+
+    return nextLink;
+}
+
+void EpwingDictionary::loadArticlePreviousPage(
+  string & articleHeadword, string & articleText, int & articlePage, int & articleOffset )
+{
+  QString headword, text;
+  EB_Position pos;
+  try
+  {
+    Mutex::Lock _( eBook.getLibMutex() );
+    pos = eBook.getArticlePreviousPage( headword, text, articlePage, articleOffset, false );
+  } catch( std::exception & e )
+  {
+    text = QString( "Article reading error: %1" ).arg( QString::fromUtf8( e.what() ) );
+  }
+
+  articleHeadword = string( headword.toUtf8().data() );
+  articleText     = string( text.toUtf8().data() );
+
+  string prefix( "<div class=\"epwing_text\">" );
+
+  string previousLink = epwing_previous_button(pos.page, pos.offset );
+  articleText     = prefix + previousLink + articleText;
+  string nextLink = epwing_next_button( articlePage, articleOffset );
+  articleText = articleText + nextLink;
+  articleText = articleText + "</div>";
+}
+
 void EpwingDictionary::loadArticle( int articlePage,
                                     int articleOffset,
                                     string & articleHeadword,
@@ -521,11 +599,7 @@ void EpwingArticleRequest::run()
 
     try
     {
-      dict.loadArticle( chain[ x ].articleOffset,
-                        headword,
-                        articleText,
-                        articlePage,
-                        articleOffset );
+      dict.loadArticle( chain[ x ].articleOffset, headword, articleText, articlePage, articleOffset );
     }
     catch(...)
     {
@@ -562,7 +636,11 @@ void EpwingArticleRequest::run()
     getBuiltInArticle( alts[ x ], pages, offsets, alternateArticles );
   }
 
-  if ( mainArticles.empty() && alternateArticles.empty() )
+
+  QRegularExpressionMatch m = RX::Epwing::refWord.match( gd::toQString( word ) );
+  bool ref                  = m.hasMatch();
+
+  if ( mainArticles.empty() && alternateArticles.empty() && !ref)
   {
     // No such word
     finish();
@@ -589,6 +667,26 @@ void EpwingArticleRequest::run()
       result += i->second.second;
   }
 
+  {
+    QRegularExpressionMatch m = RX::Epwing::refWord.match( gd::toQString( word ) );
+    if( m.hasMatch() )
+    {
+      string headword, articleText;
+      int articlePage   = m.captured( 1 ).toInt();
+      int articleOffset = m.captured( 2 ).toInt();
+      if( word[ 0 ] =='r' )
+        dict.loadArticleNextPage( headword, articleText, articlePage, articleOffset );
+      else
+      {
+        //starts with p
+        dict.loadArticlePreviousPage( headword, articleText, articlePage, articleOffset );
+      }
+
+      result += articleText;
+
+    }
+  }
+
   result += "</div>";
 
   Mutex::Lock _( dataMutex );

epwing_book.cc

@@ -14,7 +14,7 @@
 #include "wstring_qt.hh"
 #include "folding.hh"
 #include "epwing_charmap.hh"
-
+#include "htmlescape.hh"
 #if defined( Q_OS_WIN32 ) || defined( Q_OS_MAC )
 #define _FILE_OFFSET_BITS 64
 #endif
@@ -687,18 +687,7 @@ QString EpwingBook::getText( int page, int offset, bool text_only )
 {
   error_string.clear();
 
-  EB_Position pos;
-  pos.page = page;
-  pos.offset = offset;
-  currentPosition = pos;
-
-  EB_Error_Code ret = eb_seek_text(&book, &pos);
-  if( ret != EB_SUCCESS )
-  {
-    setErrorString( "eb_seek_text", ret );
-    currentPosition.page = 0;
-    throw exEbLibrary( error_string.toUtf8().data() );
-  }
+  seekBookThrow( page, offset );
 
   QByteArray buf;
   char buffer[ TextBufferSize + 1 ];
@@ -710,7 +699,7 @@ QString EpwingBook::getText( int page, int offset, bool text_only )
 
   for( ; ; )
   {
-    ret = eb_read_text( &book, &appendix, &hookSet, &container,
+    EB_Error_Code ret = eb_read_text( &book, &appendix, &hookSet, &container,
                         TextBufferSize, buffer, &buffer_length );
 
     if( ret != EB_SUCCESS )
@@ -737,6 +726,129 @@ QString EpwingBook::getText( int page, int offset, bool text_only )
   return text;
 }
 
+void EpwingBook::seekBookThrow( int page, int offset )
+{
+  EB_Position pos;
+  pos.page        = page;
+  pos.offset      = offset;
+  currentPosition = pos;
+
+  EB_Error_Code ret = eb_seek_text( &book, &pos );
+  if( ret != EB_SUCCESS )
+  {
+    setErrorString( "eb_seek_text", ret );
+    currentPosition.page = 0;
+    throw exEbLibrary( error_string.toUtf8().data() );
+  }
+}
+
+  QString EpwingBook::getTextWithLength( int page, int offset, int total, EB_Position & pos )
+{
+  error_string.clear();
+  int currentLength = 0;
+
+  seekBookThrow( page, offset );
+
+  QByteArray buf;
+  char buffer[ TextBufferSize + 1 ];
+  ssize_t buffer_length;
+  EContainer container( this, false );
+
+  prepareToRead();
+
+  for( ;; )
+  {
+    EB_Error_Code ret = eb_read_text( &book, &appendix, &hookSet, &container, TextBufferSize, buffer, &buffer_length );
+
+    if( ret != EB_SUCCESS )
+    {
+      setErrorString( "eb_read_text", ret );
+      break;
+    }
+
+    buf += QByteArray( buffer, buffer_length );
+    currentLength += buffer_length;
+
+    if( currentLength > total || buffer_length == 0 )
+      break;
+
+    if( buf.length() > TextSizeLimit )
+    {
+      error_string         = "Data too large";
+      currentPosition.page = 0;
+      return QString();
+    }
+
+    ret = eb_forward_text( &book, &appendix );
+    if( ret != EB_SUCCESS )
+    {
+      setErrorString( "eb_seek_text", ret );
+      currentPosition.page = 0;
+      throw exEbLibrary( error_string.toUtf8().data() );
+    }
+  }
+
+  eb_tell_text( &book, &pos );
+  QString text = QString::fromUtf8( buf.data(), buf.size() ).trimmed();
+  finalizeText( text );
+  return text;
+}
+
+QString EpwingBook::getPreviousTextWithLength( int page, int offset, int total, EB_Position & pos )
+{
+  error_string.clear();
+  int currentLength = 0;
+
+  QByteArray buf;
+  char buffer[ TextBufferSize + 1 ];
+  ssize_t buffer_length;
+  EContainer container( this, false );
+
+  prepareToRead();
+
+  for( ;; )
+  {
+    seekBookThrow( page, offset );
+    EB_Error_Code ret = eb_backward_text( &book, &appendix );
+    if( ret != EB_SUCCESS )
+    {
+      setErrorString( "eb_backward_text", ret );
+      currentPosition.page = 0;
+      throw exEbLibrary( error_string.toUtf8().data() );
+    }
+    eb_tell_text( &book, &pos );
+    page   = pos.page;
+    offset = pos.offset;
+
+    ret = eb_read_text( &book, &appendix, &hookSet, &container, TextBufferSize, buffer, &buffer_length );
+
+    if( ret != EB_SUCCESS )
+    {
+      setErrorString( "eb_read_text", ret );
+      break;
+    }
+
+    buf.prepend( QByteArray( buffer, buffer_length ));
+    currentLength += buffer_length;
+
+    if( currentLength > total || buffer_length == 0 )
+      break;
+
+    if( buf.length() > TextSizeLimit )
+    {
+      error_string         = "Data too large";
+      currentPosition.page = 0;
+      return QString();
+    }
+  }
+
+  QString text = QString::fromUtf8( buf.data(), buf.size() ).trimmed();
+  finalizeText( text );
+  return text;
+}
+
+  
+
 void EpwingBook::getReferencesFromText( int page, int offset )
 {
   error_string.clear();
@@ -934,6 +1046,7 @@ bool EpwingBook::processRef( EpwingHeadword & head)
     pos.page   = epos.first;
     pos.offset = epos.second;
 
+    // epwing ebook use ref link to navigate , the headword(at such position) usually has no meaningful point.
     if( readHeadword( pos, head.headword, true ) )
     {
       if( head.headword.isEmpty() || head.headword.contains( badLinks ) )
@@ -944,13 +1057,16 @@ bool EpwingBook::processRef( EpwingHeadword & head)
       head.page   = pos.page;
       head.offset = pos.offset;
       auto key    = ( (uint64_t)pos.page ) << 32 | ( pos.offset );
-      if( !allRefPositions.contains( key ) )
+      //this  only add the existed reference point which has already in the headwords as another headword(rxxxxAtxxxx) in the headword list.
+      //this will make the loadarticle's real reference link judgement easier.
+
+      if( allRefPositions.contains( key ) )
       {
         // fixed the reference headword ,to avoid the headword collision with other entry .
         //if(!allHeadwordPositions.contains(key))
         head.headword = QString( "r%1At%2" ).arg( pos.page ).arg( pos.offset );
 
-        allRefPositions[ key ] = true;
+        //allRefPositions[ key ] = true;
 
         try
         {
@@ -1080,6 +1196,10 @@ void EpwingBook::fixHeadword( QString & headword )
   //if( isHeadwordCorrect( fixed ) )
   //  headword = fixed;
 
+  //remove leading number and space.
+  QRegularExpression leadingNumAndSpace( R"(^[\d\s]+\b)" );
+  fixed.remove( leadingNumAndSpace );
+
   headword = fixed;
 }
 
@@ -1087,28 +1207,30 @@ void EpwingBook::getArticle( QString & headword, QString & articleText,
                              int page, int offset, bool text_only)
 {
   error_string.clear();
-  char buffer[ TextBufferSize + 1 ];
 
-  EB_Position pos;
-  pos.page = page;
-  pos.offset = offset;
+  seekBookThrow( page, offset );
 
-  currentPosition = pos;
+  readHeadword( headword, text_only );
 
-  EB_Error_Code ret = eb_seek_text( &book, &pos );
-  if( ret != EB_SUCCESS )
-  {
-    setErrorString( "eb_seek_text", ret );
-    throw exEbLibrary( error_string.toUtf8().data() );
-  }
+  QString hw = Html::unescape( headword, true );
+  fixHeadword( hw );
 
+  auto parts = hw.split( QChar::Space, Qt::SkipEmptyParts );
+  articleText = getText( page, offset, text_only );
+
+}
+
+void EpwingBook::readHeadword(QString & headword, bool text_only)
+{
   EContainer container( this, text_only );
   ssize_t length;
 
   prepareToRead();
 
-  ret = eb_read_heading( &book, &appendix, &hookSet, &container,
-                         TextBufferSize, buffer, &length );
+  char buffer[ TextBufferSize + 1 ];
+
+  EB_Error_Code ret = eb_read_heading( &book, &appendix, &hookSet, &container,
+    TextBufferSize, buffer, &length );
   if( ret != EB_SUCCESS )
   {
     setErrorString( "eb_read_heading", ret );
@@ -1120,8 +1242,35 @@ void EpwingBook::getArticle( QString & headword, QString & articleText,
 
   if( text_only )
     fixHeadword( headword );
+}
 
-  articleText = getText( pos.page, pos.offset, text_only);
+EB_Position EpwingBook::getArticleNextPage(
+  QString & headword, QString & articleText,
+  int page, int offset, bool text_only)
+{
+  error_string.clear();
+
+  seekBookThrow( page, offset );
+
+  readHeadword( headword, text_only );
+
+  EB_Position pos;
+  articleText = getTextWithLength( page, offset, 4000, pos);
+  return pos;
+}
+
+EB_Position EpwingBook::getArticlePreviousPage(
+  QString & headword, QString & articleText, int page, int offset, bool text_only )
+{
+  error_string.clear();
+
+  seekBookThrow( page, offset );
+
+  readHeadword( headword, text_only );
+
+  EB_Position pos;
+  articleText = getPreviousTextWithLength( page, offset, 4000, pos );
+  return pos;
 }
 
 const char * EpwingBook::beginDecoration( unsigned int code )

epwing_book.hh

@@ -100,6 +100,9 @@ class EpwingBook
 
   // Retrieve article text from dictionary
   QString getText( int page, int offset, bool text_only);
+  void seekBookThrow( int page, int offset );
+  QString getTextWithLength( int page, int offset, int total, EB_Position & pos );
+  QString getPreviousTextWithLength( int page, int offset, int total, EB_Position & pos );
 
   unsigned int normalizeDecorationCode( unsigned int code );
 
@@ -196,7 +199,11 @@ public:
   // Retrieve article from dictionary
   void getArticle( QString & headword, QString & articleText,
                    int page, int offset, bool text_only );
+  void readHeadword( QString & headword, bool text_only);
 
+  EB_Position getArticleNextPage( QString & headword, QString & articleText,
+    int page, int offset, bool text_only );
+  EB_Position getArticlePreviousPage( QString & headword, QString & articleText, int page, int offset, bool text_only );
   const char * beginDecoration( unsigned int code );
   const char * endDecoration( unsigned int code );