QTextEdit loading takes long time

[patrik08]

Build a less (unix http://linux.about.com/library/cmd/blcmdl1_less.htm ) similar function .... and limit him to 20-30 line....

and as slot a vertical slider...... tickintervall 30-20

and get line from file ..... chanche this code to get line start and end...

is very fast....

QString Sqlitedb::file_get_line(QString fullFileName,int linenr)
{
    QString result;  
    QFile file( fullFileName );
    if( file.open( QIODevice::ReadOnly | QIODevice::Text ) ) {
       QTextStream in( &file );
       int currentLineNr = 0; // or 1
       while( ! in.atEnd() ) {
          QString line( in.readLine() );
          if( currentLineNr == linenr ) {   /* only rewrite here .. lineNr */
             result = line;
             break;
          }
          currentLineNr += 1;
          /*qDebug() << "### linerr  " << currentLineNr; */
       }
    }
    return result;
}

QString Sqlitedb::file_get_line(QString fullFileName,int linenr)
{
    QString result;  
    QFile file( fullFileName );
    if( file.open( QIODevice::ReadOnly | QIODevice::Text ) ) {
       QTextStream in( &file );
       int currentLineNr = 0; // or 1
       while( ! in.atEnd() ) {
          QString line( in.readLine() );
          if( currentLineNr == linenr ) {   /* only rewrite here .. lineNr */
             result = line;
             break;
          }
          currentLineNr += 1;
          /*qDebug() << "### linerr  " << currentLineNr; */
       }
    }
    return result;
}

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[wysota]

This would be a crude and nasty hack which would break all of QTextEdit functionality like redo/undo, searching for text, etc. The proper way is to use QTextDocument. Trust me on that If in doubt, read the docs.

[yeaiping]

Comment. I meet same question.