How can I render long lines

[Jaakko Seppälä <jaakko j seppala gmail com>]

I have found tree text editors which uses gtk+. None of them can show
correctly the characters on a particular text file which contains a
huge number of characters on one line. Is it possible to write a text
editor which uses GTK+ and shows correctly the file which is created
by the following code:

#include <iostream>
#include <fstream>
using namespace std;

int main () {
  ofstream myfile;
  myfile.open ("example.txt");
  for (long i=0;i<200000;++i) {
    myfile << "123";
  }
  myfile.close();
  return 0;
}
?