Question

I am a beginner in my fourth week learning C++; I had been working on CodeBlocks, but due to my interest in making GUIs I switched to Qt Creator. Back in CodeBlocks I had created a function that would avoid all the repetition in the code below, only changing the “TXT FILE”. However, with Qt Creator’s “specialized” C++ I am having trouble making sense of how to create a function to avoid all this repetition.

Any ideas? (I’m too far into this Qt project to go back to CodeBlocks.)

The “TXT FILE” changes depending on which RadioButton the user selects.

void MovierRec::on_searchButton_clicked()
{
    int randomValue = qrand() % 100;
    QList<QString> titles;
    if(ui->modernButton->isChecked())
           {
               QFile myfile(":/classics.txt");
               if (myfile.open(QIODevice::ReadOnly))
               {
                   QTextStream in(&myfile);
                   while (!in.atEnd())
                   {
                       QString line = in.readLine();
                       titles.append(line);
                   }
                   myfile.close();
                   ui->textBrowser->setPlainText (titles[randomValue]);
                }
           }
    else if(ui->romanceButton->isChecked())
           {
               QFile myfile(":/romance.txt");
               if (myfile.open(QIODevice::ReadOnly))
               {
                   QTextStream in(&myfile);
                   while (!in.atEnd())
                   {
                       QString line = in.readLine();
                       titles.append(line);
                   }
                   myfile.close();
                   ui->textBrowser->setPlainText (titles[randomValue]);
                }
           }

    else if(ui->scifiButton->isChecked())
           {
               QFile myfile(":/scifi.txt");
               if (myfile.open(QIODevice::ReadOnly))
               {
                   QTextStream in(&myfile);
                   while (!in.atEnd())
                   {
                       QString line = in.readLine();
                       //titles.append(line);
                   }
                   myfile.close();
                   ui->textBrowser->setPlainText (titles[randomValue]);
                }
           }

Answer 1

This is generic programming issue, could refactor code in a better way:

// I didn't dig into every line of the code. just provide the refactor idea here
void getTitle(const QString& file_name, QList<QString>& titles;)
{
   QFile myfile(file_name);
   if (myfile.open(QIODevice::ReadOnly))
   {
     QTextStream in(&myfile);
     while (!in.atEnd())
     {
       QString line = in.readLine();
       titles.append(line);
     }
   myfile.close();
 }
}

void MovierRec::on_searchButton_clicked()
{
    int randomValue = qrand() % 100;
    QList<QString> titles;
    if(ui->modernButton->isChecked())
    {
        getTitle("classics.txt", titles);       
    }
    else if(ui->romanceButton->isChecked())
    {
        getTitle("romance.txt", titles);       
    }
    else if(ui->scifiButton->isChecked())
    {
        getTitle("scifi.txt", titles);
   }
   ui->textBrowser->setPlainText(titles[randomValue]); // move the dup action to the end
 }