Content
Some time ago I wrote an article in which I showed how to open a fb2 file with Qt tools. After some time, I noticed a number of shortcomings in it, which I decided to eliminate. Moreover, I found that some fb2 readers also have disadvantages (namely, incorrect display of tables), which prompted me to write this article. For starters, you can read the last article . We will act on the same principle: we form the book string in html format and place it in the QTextBrowser object.
Let me remind you that in order to create an html document, you need to perform 3 actions: open the tag, fill it with content and close it. Therefore, there are 4 options for us: we rewrite from the source file, rewrite with corrections, do nothing (ignore), and conduct special processing.
Introduction
All fb2 format tags can be divided into 3 groups identical to html, similar to html, and others.
Identical tags are shown in table 1.
Table 1 - fb2 and html tags
| description | tag |
|---|---|
| Paragraph | p |
| Link | a |
| Table | table |
| Table row | tr |
| Table cell | td |
| Table header cell | th |
| Superscript | sup |
| Subscript | sub |
| Monospace font | code |
| Bold font | strong |
| Quote | cite |
Similar tags are identical to the html element by purpose, but have different names. All correspondences are given in table 2.
Table 2 - Correspondence between fb2 and html tags
| description | fb2 | html |
|---|---|---|
| Empty line | empty-line | br |
| Italics | emphasis | i |
| Strikethrough | strikethrough | strike |
Algorithm
The file opening algorithm is implemented as the openFB2File function. Other tags do not have clear correspondence with html elements or are similar, but they need special processing (<a>, <body>, <image>). Some of them can simply be ignored (<poem>). To convert the main part (<v>, <date>, <text-author>, <title>, <subtitle>), I suggest that they correspond <p> with some additional attributes. The algorithm is implemented as follows:
QFile f(file);
if (!f.open(QIODevice::ReadOnly | QIODevice::Text))
{
qDebug() << "файл не открыт";
return false;
}
bool ok = true;
QString special;
QString description; // описание видео
// настройки отображения
int fontSize = 20;
if( QSysInfo::productType() == "android" )
fontSize *= 1.8;
QXmlStreamReader sr(&f);
QString rId;
QString rType;
QString opt;
QStringList thisToken;
while( !sr.atEnd() )
{
switch( sr.readNext() )
{
case QXmlStreamReader::NoToken:
qDebug() << "QXmlStreamReader::NoToken";
break;
case QXmlStreamReader::StartDocument:
*book = "<!DOCTYPE HTML><html><body style=\"font-size:%1px; font-family:Sans, Times New Roman;\">";
*book = book->arg(fontSize);
break;
case QXmlStreamReader::EndDocument:
book->append("</body></html>");
break;
case QXmlStreamReader::StartElement:
thisToken.append( sr.name().toString() );
if(thisToken.contains("description")) // ОПИСАНИЕ КНИГИ
{
if( thisToken.back() != "image" ) //пропускаем всё кроме обложки
break; // не выводим
}
if(sr.name().toString() == "title")
{
content->append(""); // добавляем пункт содержания
break;
}
if( sr.name().toString() == "body" )
if( !sr.attributes().isEmpty()
&& sr.attributes().first().value().toString() == "notes")
special = "notes"; // режим примечаний
if(special == "notes")
{
if( sr.name().toString() == "section" )
{
if( sr.attributes().count() > 0 )
{
rId = sr.attributes().at(0).value().toString(); // ссылка на текст
rType = "";
}
}
}
opt = " align=\"justify\"";
if(thisToken.contains("title") )
{
opt = " align=\"center\" style=\"font-size:" +QString::number(int(fontSize * 1.5)) + "px\" ";
if(special == "notes")
{
opt += (" id=\"" + rId + "\"");
}
}
if(thisToken.contains("subtitle") )
{
opt = " align=\"center\" style=\"font-size:" +QString::number(int(fontSize * 1.2)) + "px\" ";
}
if(thisToken.contains("annotation") )
{
opt = " align=\"left\" ";
}
if(sr.name().toString() == "p"
|| sr.name().toString() == "subtitle")
{
book->append("<p"+opt +" >");
break;
}
if( sr.name().toString() == "table" )
{
QString text;
for(int i = 0; i < sr.attributes().count(); i++)
{
if(sr.attributes().at(i).name() == "id")
qDebug() << sr.attributes().at(i).value().toString();
if(sr.attributes().at(i).name() == "style")
text.append( "style=\"" +sr.attributes().at(i).value().toString()+ ";\"" );
}
book->append("<table border=1 align=\"center\" style=\"border:solid;\" " + text + ">");
break;
}
if( sr.name().toString() == "tr" )
{
QString text;
if(!thisToken.contains("table"))
qDebug() << "ошибка в таблице";
for(int i = 0; i < sr.attributes().count(); i++)
{
if(sr.attributes().at(i).name() == "aling")
text.append( "aling=\"" +sr.attributes().at(i).value().toString()+ "\"" );
else
qDebug() << "<tr>" << sr.attributes().at(i).name() << sr.attributes().at(i).value().toString();
}
book->append("<tr " + text + ">");
break;
} //
if( sr.name().toString() == "td"
|| sr.name().toString() == "th" )
{
if(!thisToken.contains("table"))
qDebug() << "ошибка в таблице";
QString text;
for(int i = 0; i < sr.attributes().count(); i++)
{
if(sr.attributes().at(i).name() == "aling")
text.append( "aling=\"" +sr.attributes().at(i).value().toString()+ "\" " );
else if(sr.attributes().at(i).name() == "valing")
text.append( "valing=\"" +sr.attributes().at(i).value().toString()+ "\" " );
else if(sr.attributes().at(i).name() == "colspan")
text.append( "colspan=" +sr.attributes().at(i).value().toString()+ " " );
else if(sr.attributes().at(i).name() == "rowspan")
text.append( "rowspan=" +sr.attributes().at(i).value().toString()+ " " );
else
qDebug() << "<td th>" << sr.attributes().at(i).name() << sr.attributes().at(i).value().toString();
}
book->append( "<"+sr.name().toString()+ " " + text +">" );
break;
}
if( sr.name().toString() == "empty-line" )
{
book->append("<br/>");
break;
}
if(sr.name().toString() == "strong"
|| sr.name().toString() == "sup"
|| sr.name().toString() == "sub"
|| sr.name().toString() == "code"
|| sr.name().toString() == "cite")
{
book->append( "<" + sr.name().toString() + ">");
break;
}
if(sr.name().toString() == "emphasis")
{
book->append( "<i>" );
break;
}
if( sr.name().toString() == "v" )
{
book->append("<p align=\"left\" style=\"margin-left:25px;\">");
break;
}
if(sr.name().toString() == "strikethrough")
{
book->append( "<strike>" );
break;
}
if( sr.name().toString() == "a" ) // метка примечания
{
rId = "";
for(int i = 0; i < sr.attributes().count(); i++)
{
if(sr.attributes().at(i).name() == "type" )
{
//rType = sr.attributes().at(i).value().toString();
}
if(sr.attributes().at(i).name() == "href")
{
rId = sr.attributes().at(i).value().toString();
}
}
book->append("<a href=\"" + rId + "\"> ");
//qDebug() << "a" << rId;
}
if(sr.name().toString() == "poem"
|| sr.name().toString() == "stanza"
|| sr.name().toString() == "epigraph")
{
break;
}
if(sr.name().toString() == "text-author" ) // автор текстта
{
book->append( "<p align=\"justify\" style=\"margin-left:45px;\">" );
break;
}
if(sr.name().toString() == "date" ) // автор текстта
{
book->append( "<p align=\"justify\" style=\"margin-left:45px;\">" );
break;
}
if( sr.name().toString() == "image" ) // расположение рисунков
{
if(sr.attributes().count() > 0)
book->append("<p align=\"center\">"+sr.attributes().at(0).value().toString() + "#" + "</p>");
}
if(sr.name() == "binary") // хранилище рисунков
{
if(sr.attributes().at(0).name() == "id")
{
rId = sr.attributes().at(0).value().toString();
rType = sr.attributes().at(1).value().toString();
}
if(sr.attributes().at(1).name() == "id")
{
rId = sr.attributes().at(1).value().toString();
rType = sr.attributes().at(0).value().toString();
}
}
break;
case QXmlStreamReader::EndElement:
if( thisToken.last() == sr.name().toString() )
{
thisToken.removeLast();
}
else
qDebug() << "error token";
if(thisToken.contains("description")) // ОПИСАНИЕ КНИГИ
{
break; // не выводим
}
if( sr.name().toString() == "p"
|| sr.name().toString() == "subtitle"
|| sr.name().toString() == "v"
|| sr.name().toString() == "date"
|| sr.name().toString() == "text-author")
{
book->append("</p>");
break;
}
if(sr.name().toString() == "td"
|| sr.name().toString() == "th"
|| sr.name().toString() == "tr"
|| sr.name().toString() == "table"
|| sr.name().toString() == "sup"
|| sr.name().toString() == "sub"
|| sr.name().toString() == "strong"
|| sr.name().toString() == "code"
|| sr.name().toString() == "cite")
{
book->append( "</"+sr.name().toString()+">" );
break;
}
if( sr.name().toString() == "a" )
{
rId.remove("#");
book->append( "</a><span id=\"" + rId + "___" + "\"></span>" );
qDebug() << "id" << rId + "___";
break;
}
if(sr.name().toString() == "emphasis")
{
book->append( "</i>" );
break;
}
if(sr.name().toString() == "strikethrough")
{
book->append( "</strike>" );
break;
}
if(sr.name().toString() == "stanza") // конец строфы
{
//book->append("<br/>");
break;
}
if(sr.name().toString() == "epigraph"
|| sr.name().toString() == "poem")
{
break;
}
if(special == "notes") // режим извлечения примечаний
{
if( sr.name().toString() == "body" )
{
special = "";
}
if( sr.name().toString() == "section" )
{
book->insert(book->lastIndexOf("<"), "<a href=\"#" + rId + "___" + "\"> назад</a>");
}
}
break;
case QXmlStreamReader::Characters:
if( sr.text().toString() == "" )
{
//qDebug() << "isEmpty";
break;
}
if( sr.text().toString() == "\n" )
{
//qDebug() << "isEmpty";
break;
}
if(thisToken.contains("description")) // ОПИСАНИЕ КНИГИ
{
description.append(sr.text().toString() + " "); // не выводим
break;
}
if(thisToken.contains( "binary" ) ) // для рисунков
{
QString image = "<img src=\"data:"
+ rType +";base64,"
+ sr.text().toString()
+ "\"/>";
book->replace("#"+rId +"#", image);
rId = "";
rType = "";
break;
}
if(thisToken.contains("div"))
{
qDebug() << "div" << sr.text().toString();
break;
}
if(thisToken.back() == "FictionBook")
{
qDebug() << "FictionBook" << sr.text().toString();
break;
}
if( thisToken.contains("title") ) // формируем содержание
{
content->back() += " " + sr.text().toString();//content->back()=="" ? "" : " " +
// qDebug() << "title" << sr.text().toString();
}
if(special == "notes" && !thisToken.contains("title") ) // добавление текста примечания
{
rType += " ";
rType += sr.text().toString();
//break;
}
if(thisToken.back() == "p"
|| thisToken.back() == "subtitle"
|| thisToken.back() == "v"
|| thisToken.back() == "emphasis"
|| thisToken.back() == "strong"
|| thisToken.back() == "strikethrough"
|| thisToken.back() == "sup"
|| thisToken.back() == "sub"
|| thisToken.back() == "td"
|| thisToken.back() == "th"
|| thisToken.back() == "code"
|| thisToken.back() == "cite"
|| thisToken.back() == "text-author" // ??
|| thisToken.back() == "date"
)
{
book->append( sr.text().toString() );
break;
}
if(thisToken.back() == "section")
{
break;
}
if(thisToken.back() == "body")
{
break;
}
if(thisToken.back() == "table"
|| thisToken.back() == "tr"
|| thisToken.back() == "title"
|| thisToken.back() == "poem"
|| thisToken.back() == "stanza")
{
//book->append( sr.text().toString() );
break;
}
if(thisToken.back() == "annotation")
{
qDebug() << "annotation" << sr.text().toString();
break;
}
if(thisToken.back() == "a")
{
book->append( sr.text().toString() );
break;
}
//все прочие тэги
if( !sr.text().toString().isEmpty() )
{
qDebug() << thisToken.back() << "исключение" ;
book->append("<span> " + sr.text().toString() + "</span>");
}
break;
}
}
f.close();
The file open function is launched by pressing the button:
ui->textBrowser->clear();
QString text;
QStringList content;
if(name.endsWith(".fb2"))
{
openerTextFiles otf;
otf.openFB2File(name, &text, &content);
ui->textBrowser->setText(text);
ui->textBrowser->verticalScrollBar()->setValue(0);
}
Now the generated html page can be easily saved
QFile file(name);
if ( !file.open(QIODevice::WriteOnly | QIODevice::Text) )
return;
QTextStream out(&file);
out << ui->textBrowser->toHtml();
file.close();
Our reader is ready.
The source code can be downloaded [here] (https://cloud.mail.ru/public/2aN1/5GQW1s6Rb).
добавил функцию чтения из fb2.zip чеоез QZipReader
в.pro добавить: QT += gui-private,
в .h :
ридер через QByteArray сделал
ну у меня несколько компактней получилось
```
и с навигацией вы круто заморочилить - QTextBrowser отслеживает нажатие на линки
```
Спасибо за комментарии, а zip-архивация пригодится для открытия книг fb3 и epub. Это работает на Qt без дополнительных библиотек? Я сделал архиватор, но qzipwriter_p.h и qzipreader_p.h, а ещё zlib качал отдельно.