Hey guys!

I have data stored in vectors that I would like to show in a QTextEdit. What I do now is I create a QTextDocument and a QTextCursor and I append all data as QStrings into that Document like this (altered some things so you can try to compile if needed):

Qt Code: 
  1. QTextDocument* parseDoc(std::vector<double>& time, std::vector<std::array<double,3>>& pos, std::vector<std::array<double,3>>& pos){
  2. 	parsedDocument = new QTextDocument();
  3. 	myDocumentCursor = new QTextCursor(parsedDocument);
  4.  
  5. 	QTextCharFormat textFormat = myDocumentCursor->charFormat();
  6. 	textFormat.setFontFamily("Courier");
  7. 	myDocumentCursor->setCharFormat(textFormat);
  8.  
  9.  
  10.         QString formattedString;
  11. 	formattedString = QString("This is th Data of Some object. It was retrieved on %2\r\n").arg(QDateTime::currentDateTime().toString());
  12. 	myDocumentCursor->insertText(formattedString);
  13.  
  14. 	myDocumentCursor->insertBlock();
  15.  
  16. 	formattedString = QString("Epoch").leftJustified(21, ' ');
  17. 	formattedString.append(QString("Position x-Axis").leftJustified(21, ' '));
  18. 	formattedString.append(QString("Position y-Axis").leftJustified(21, ' '));
  19. 	formattedString.append(QString("Position z-Axis").leftJustified(21, ' '));
  20. 	formattedString.append(QString("Velocity x-Axis").leftJustified(21, ' '));
  21. 	formattedString.append(QString("Velocity y-Axis").leftJustified(21, ' '));
  22. 	formattedString.append(QString("Velocity z-Axis").leftJustified(16, ' '));
  23. 	myDocumentCursor->insertText(formattedString);
  24.  
  25. 	myDocumentCursor->insertBlock();
  26.  
  27.         formattedString.clear();
  28.  
  29. 	for(int i = 0; i < time.size(); i++){
  30.  
  31. 		formattedString = QString("%1     %2     %3     %4     %5     %6     %7").arg(time[i], -16, 'f', -1)
  32. 			.arg(pos[i][0], -16, 'f', -1).arg(pos[i][1], -16, 'f', -1).arg(pos[i][2], -16, 'f', -1)
  33. 			.arg(vel[i][0], -16, 'f', -1).arg(vel[i][1], -16, 'f', -1).arg(vel[i][2], -16, 'f', -1);
  34.  
  35. 		myDocumentCursor->insertText(formattedString);
  36. 		myDocumentCursor->insertBlock();
  37. 	}
  38.  
  39.         return parsedDocument;
  40.  
  41. }
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Basically this works out quite smoothly, just takes a few minutes as I have roughly 500K lines of data. But there are 2 major problems that I ran into: 1. The memory usage after putting all data into the Document is around 1.2GB, 2. It takes a HUGE amount of time(~15min) to display the document in a QTextEdit (via QTextEdit::setDocument(QTextDocument*)).

So obviously I am doing something wrong. So do you guys have an idea what I should be doing differently?