KLFPosSearchable minimal example

This example lets you search with arbitrary regular expressions inside a QTextBrowser. It will present matches as selected text.

 class TextDocumentSearchable : public KLFPosSearchable, public QObject
 {
 public:
   struct TextCursorPosData : public Pos::PosData
   {
     TextCursorPosData(const QTextCursor& c = QTextCursor()) : cursor(c) { }

     QTextCursor cursor;
 
     bool equals(Pos::PosData * other) const {
       return cursor == dynamic_cast<TextCursorPosData*>(other)->cursor;
     }
   };
 
   TextDocumentSearchable(QTextBrowser *b) : QObject(b), br(b), doc(br->document()) { }
 
   Pos searchFind(const QString& querystring, const Pos& fromPos, bool forward)
   {
     QTextCursor pos;
     if (fromPos.valid()) {
       pos = fromPos.data<TextCursorPosData>()->cursor;
       // don't return 'fromPos' if it matches
       pos.movePosition(forward?QTextCursor::Right:QTextCursor::Left);
     }
 
     QRegExp rx(querystring);
     rx.setCaseSensitivity(querystring.contains(QRegExp("[A-Z]"))?Qt::CaseSensitive:Qt::CaseInsensitive);
     if (!forward && pos.isNull()) {
       pos = QTextCursor(doc); pos.movePosition(QTextCursor::End);
     }
     // *** Perform the Search ***
     pos = doc->find(rx, pos, (!forward)?QTextDocument::FindBackward:(QTextDocument::FindFlags)0);
     klfDbg("searched, returned pos="<<pos.position()) ;
     if (pos.isNull()) {
       return Pos();
     }
     // store into pos cursor the exact match position and length
     pos.movePosition(QTextCursor::Right, QTextCursor::KeepAnchor, rx.matchedLength());
     // and now, return the position
     Pos foundPos = Pos();
     foundPos.posdata = new TextCursorPosData(pos);
     return foundPos;
   }
   void searchAborted()
   {
     br->setTextCursor(QTextCursor(doc));
   }
   void searchMoveToPos(const Pos& p)
   {
     if (p.valid())
       br->setTextCursor(p.data<TextCursorPosData>()->cursor);
     else
       br->setTextCursor(QTextCursor(doc));
   }
 
 private:
   QTextBrowser *br;
   QTextDocument *doc;
 };

You could then use that class as follows:

   // ... for example, in a dialog constructor ...

   QTextBrowser *textBrowser = new QTextBrowser(this);
   textBrowser->setPlainText(...);

   TextDocumentSearchable * s = new TextDocumentSearchable(textBrowser);

   KLFSearchBar *searchbar = new KLFSearchBar(this);
   searchbar->setSearchTarget(s);

   // ...