How to RUN my Plain C++ App Code on Qt GUI

[Denmikz]

Hi. I just want to know how to run my c++ code to my qt gui and display its output through a QTextEdit widget. I'm new to qt gui and I've researched for a week now and failed to solve my problem and now my last resort is to ask you here on the forums on how to do it.
Here is my code:
#include <iostream>
#include <stdlib.h>
#include <ctime>
#include <fstream>
#include <conio.h>
#include <string.h>

using namespace std;

int countlines();
string getRandomLine();
string getAnswer(string);
void getChoices(string*,string);

int main()
{
int numberOfItems = countlines();
string questions[numberOfItems];
string answers[numberOfItems];
string choices[numberOfItems][4];

string temp;
int i = 0;
int o = 0;

cout << "Loading questions...";
while(i < numberOfItems)
{



    temp = getRandomLine();
    while(o < numberOfItems)
    {
        if(questions[o] == temp)
        {
            temp = getRandomLine();
            o = 0;
        }else{
            o++;
        }
    }
    questions[i] = temp;

    o=0;
    i++;
}
i = 0;
while(i < numberOfItems)
{
    answers[i] = getAnswer(questions[i]);
    i++;
}

i = 0;
while(i < numberOfItems)
{
    getChoices(choices[i],answers[i]);
    i++;
}

system("cls");

int answer[numberOfItems];

i = 0;
while(i < numberOfItems)
{
    cout << questions[i] << endl;
    for(int o=0;o<4;o++)
        cout << o+1 << "]" << choices[i][o] << endl;
    cin >> answer[i];

    i++;
}
int correct = 0;
i = 0;
while(i < numberOfItems)
{
    if(choices[i][answer[i] - 1] == answers[i])
        correct++;

    i++;
}

cout << correct << " imong score!!";

return 0;

}

void getChoices(string choice[],string answer)
{
string line;

int maxLine = countlines();
bool found = false;

ifstream myfile("sample.txt");
while(getline(myfile,line))
{
    if(found)
    {
        choice[0] = line.substr(0,line.find(" "));
        line = line.substr(line.find(" ")+1);
        choice[1] = line.substr(0,line.find(" "));
        line = line.substr(line.find(" ")+1);
        choice[2] = line.substr(0,line.find(" "));
        line = line.substr(line.find(" ")+1);
        choice[3] = line.substr(0,line.find(" "));
        return;
    }
    if(answer == line)
    {
        found = true;
    }
}

}

string getAnswer(string question)
{
string line;

int maxLine = countlines();
bool found = false;

ifstream myfile("sample.txt");
while(getline(myfile,line))
{
    if(found){
        return line;
    }
    if(question == line)
    {
        found = true;
    }
}

}

string getRandomLine()
{
string line;

int maxLine = countlines();
int random;
srand(time(0));
random = rand() % maxLine;
random = random * 3;
int count = 0;
ifstream myfile ("sample.txt");

while (getline (myfile,line))
{
    if(random == count)
    {
        line;
        break;
    }
    count++;
}
myfile.close();

return line;

}

int countlines()
{
string line;
int count = 0;

ifstream myfile ("sample.txt");

if(myfile.is_open())
{
    while (getline (myfile,line))
    {
        count++;
    }
    count /= 3;
    myfile.close();
}
else
{
    cout << "Unable to open file";
}

return count;

}

[michelson]

Not sure if thats what you want but you can (i guess - not tested) display your code by reading .cpp and/or .h file and apending text you read to QTextBrowser like:

File inputFile(/*path to your cpp file*/);
if (inputFile.open(QIODevice::ReadOnly))
{
   QTextStream in(&inputFile);
   while (!in.atEnd())
   {
      QString line = in.readLine();
      your_text_browser.append(line);
   }
   inputFile.close();
}

Repeat this procedure with .h file if needed.

[Denmikz]

@michelson I'm very sorry to confuse you on my question. Okay, so my code there is a part of my Multiple Choice Quiz Application and that code is the one that's going to read a text file that contains the questions and answers for the quiz. I just want to know how I can display this line to the QTextEdit widget I mentioned:
while(i < numberOfItems)
{
cout << questions[i] << endl;
for(int o=0;o<4;o++)
cout << o+1 << "]" << choices[i][o] << endl; <----------- This one. I want it to be displayed on the QTextEdit widget.
cin >> answer[i];

i++;

}

[Pablo J. Rogina]

@Denmikz what about the code editor or syntax highlighter examples?

[Denmikz]

@Pablo-J.-Rogina again I'm sorry for the confusion. I already edited my post to make things clearer. sorry for my mistake english is not my main language. :)

[michelson]

First of all if you need ONLY to display text I'd go for QLabel rather than QTextEdit. If not you can eaisily append text to QTextEdit by running QTextEdit::append(QString) function ( http://doc.qt.io/qt-4.8/qtextedit.html#append ) so your code would look like this:

while(i < numberOfItems)
{
    cout << questions[i] << endl;
    for(int o=0;o<4;o++)
        your_text_edit.append(choices[i][o]);
    cin >> answer[i];
    i++;
}

Of course assuming choices table is holding QStrings.

[Denmikz]

@michelson oh okay. but will it run? because i and o there are both int or do I have to convert those to QString?

[michelson]

Dude, I meant in the array choices you hold QStrings so the definition of it (which is missing in code included above) would be like:

QString choices[10][4];

[Denmikz]

@michelson oh sorry my bad. I'm going to try it now. Thanks for your help. :)

[Denmikz]

@michelson I just did what you told me to do on my code and my app compiled but when I push the pushbutton assigned to trigger the code nothing displayed on my QTextEdit.

[michelson]

Are you sure that choices is filled with non-empty QStrings?
Try filling it "by hand" like:

choices[0][0] = "Choice [0][0]";
choices[0][1] = "Choice [0][1]";
choices[0][2] = "Choice [0][2]";
choices[0][3] = "Choice [0][3]";
choices[1][0] = "Choice [1][0]";
choices[1][1] = "Choice [1][1]";
choices[1][2] = "Choice [1][2]";
choices[1][3] = "Choice [1][3]";

i dont know the exact dimensions of it but I guess two levels are enough for tests. If nothing displays this time we will try to figure it out.