I was able to make a program that has a menu on it. At first, the program is running smoothly. The problem starts to appear when, at a certain point in the program, the user starts inputting something and then navigating the menus again.
Sometimes it will print out integers/characters that were previously entered by the user when pressing the ENTER key in the menu.
I managed to block the inputs with cin.ignore(). But how can I eliminate the display of the (I don't know if its excess or garbage) inside the input buffer whenever the user presses the LEFT and RIGHT arrow keys? Or I think there's even one for UP and DOWN arrow key?
int main()
{
color(FG_WHITE);
bool progFinished = false;
while (!progFinished) {
cout << "[ACTIVITY FOR 26 FEBRUARY 2018]\n";
vector<string> menu = { "Currency Converter","Student Information System" };
int choice = menu_std(menu, FG_YELLOW, false);
bool currencyFinished = false;
bool studentFinished = false;
switch (choice) {
case 0:
while (!currencyFinished) {
cout << "\n\n[CURRENCY CONVERT]\n";
vector<string> curr_menu = { "PHP TO OTHERS","USD TO PHP","YEN TO PHP","EUR TO PHP","BHD TO PHP" };
int currency = menu_std(curr_menu, FG_YELLOW, false);
double value = validation("\nEnter the value", 0, false);
CurrencyConverter convert(currency, value);
cout << "\n\nConvert again? ";
currencyFinished = !menu_yn(FG_YELLOW);
}
system("cls");
break;
case 1:
Studentv2 stud;
stud.LoadFile();
while (!studentFinished) {
cout << "\n\n[STUDENT INFO SYSTEM]\n";
vector<string> stud_menu = { "Add Student","View All Students" };
int stud_choice = menu_std(stud_menu, FG_YELLOW, false);
switch (stud_choice) {
case 0:
stud.AddStudent();
cout << "\n\nDo you want to continue with the Student Info System? ";
stud.SaveFile();
studentFinished = !menu_yn(FG_YELLOW);
break;
case 1:
stud.DisplayStudentInformation();
cout << "\n\nDo you want to continue with the Student Info System? ";
studentFinished = !menu_yn(FG_YELLOW);
break;
}
}
system("cls");
break;
}
cout << "\nContinue using the program? ";
progFinished = !menu_yn(FG_YELLOW);
system("cls");
}
cout << "Press any key to exit.\n";
cin.get();
return 0;
}
Code snippets for some of the functions I used inside my program. Function menu_std():
int menu_std(std::vector<std::string> &menu, WORD atrribute, bool argument)
{
sleep_for(milliseconds(150));
int elements = menu.size();
int elements_max_size = menu.size() - 1;
int menu_position = 0;
COORD position = getcoordinates();
while (true) {
for (int i = 0; i < elements; i++) {
move(position.X, position.Y + i);
if (i == menu_position) {
color(atrribute);
std::cout << menu[i];
color(FG_WHITE);
}
else {
std::cout << menu[i];
}
}
while (true) {
if (GetAsyncKeyState(VK_UP) < 0 && menu_position != 0) {
menu_position--;
break;
}
if (GetAsyncKeyState(VK_DOWN) < 0 && menu_position != elements_max_size) {
menu_position++;
break;
}
if (GetAsyncKeyState(VK_RETURN) < 0) {
std::cin.ignore(10000, '\n');
if (argument == true) {
sleep_for(milliseconds(100));
COORD previous = getcoordinates();
std::cout << "\n\nAre you sure? ";
bool sure = menu_yn(atrribute);
if (sure) {
clear_output(previous);
return menu_position;
}
else {
clear_output(previous);
break;
}
}
else {
return menu_position;
}
}
sleep_for(milliseconds(50));
}
sleep_for(milliseconds(175));
}
}
Function menu_yn():
bool menu_yn(WORD attribute)
{
sleep_for(milliseconds(150));
COORD currentpos = getcoordinates();
int pos = 0;
while (true) {
move(currentpos);
switch (pos) {
case 0:
color(attribute);
std::cout << "YES";
color(FG_WHITE);
std::cout << " NO";
break;
case 1:
std::cout << "YES";
color(attribute);
std::cout << " NO";
color(FG_WHITE);
break;
}
while (true) {
if (GetAsyncKeyState(VK_RIGHT) < 0 && pos != 1) {
pos++;
break;
}
if (GetAsyncKeyState(VK_LEFT) < 0 && pos != 0) {
pos--;
break;
}
if (GetAsyncKeyState(VK_RETURN) < 0) {
std::cin.ignore(10000, '\n');
if (pos == 0) {
return true;
}
else if (pos == 1) {
return false;
}
}
}
sleep_for(milliseconds(175));
}
}
Function validation()
double validation(std::string question, double limit, bool argument)
{
double userInput;
while (true) {
std::cout << question << " >> ";
while (!(std::cin >> userInput)) {
std::cout << "Error: Non-integer input. " << question << " >> ";;
std::cin.clear();
std::cin.ignore(256, '\n');
}
std::cin.ignore(10000, '\n');
while (userInput > limit && limit != 0) {
std::cout << "Error: Input out-of-bounds. " << question << " >> ";
std::cin >> userInput;
std::cin.ignore(10000, '\n');
}
if (argument) {
return (userInput <= 0) ? 1 : userInput;
}
else {
return userInput;
}
}
}
Screenshot of the problem:
There are numbers appearing whenever I press enter on the menu. I suspect that it comes whenever the user presses the arrow keys before entering the enter.
