Multiple key presses SFML - c++

Question

I'm trying to detect keyPress only once, but it goes for random amount of presses. I'm using keyrelease, and it work normally if I have breakpoint.
while (window.isOpen()) {
sf::Event event;
while (window.pollEvent(event)) {
if (event.type == sf::Event::Closed) {
window.close();
} else {
characterScreen.handleEvent(event, window);
}
}
bool keyReleased = event.type == sf::Event::KeyPressed;
bool rightArrowKey = event.key.code == sf::Keyboard::Right;
bool leftArrowKey = event.key.code == sf::Keyboard::Left;
if (keyReleased&&leftArrowKey)
{
if (selectedCharacter == 0)
{
selectedCharacter = characterList.size() - 1;
}
else
{
selectedCharacter--;
}
changeCharacters(characterList[selectedCharacter], font, characterScreen);
std::cout << "left pressed" << std::endl;
keyReleased = false;
std::cout << keyReleased << std::endl;
}
else if (keyReleased && rightArrowKey)
{
if (selectedCharacter == characterList.size()-1)
{
selectedCharacter = 0;
}
else
{
selectedCharacter++;
}
changeCharacters(characterList[selectedCharacter], font, characterScreen);
}
window.clear(sf::Color::White);
characterScreen.update();
characterScreen.render(window);
window.display();
}
I've tryed window.setKeyRepeatEnabled(false); and keypressed, still nothing. Tryed different keyboard aswell.

Answer 1

When using (C)SMFL, we generally have a main loop condition rendering the main frame (the windows) and checking events, it can be an infinite loop (such as while (1)) or a more recomanded one like your while (window.isOpen()).
It means that the windows and all events listener are refreshed / updated each loop's turn, so if you press a key on your keyboard, you will trigger your keyboard's event listener, fine, and you will continue your code until re-enter in your main loop, and re-refreshing the windows and re-updating your event listener.
What the point of explaining that ? it just means by only pressing once a key, your computer will process maybe 10, 100 or maybe 1000 iteration of your main loop (depending on it's performances and more). So it's "normal" to works fine when you use convenient features like breakpoints, but in reality you can't.
You have a lot of possibilities, bad ones (like "use delay / pause" who's not recommended since it will halt your window's refresh and can be interpreted by a crash by your OS) or good ones like tampon variables, who'll cancel the entrance of some conditions by their state:
Example:
bool tmp_var = false;
while (window.isOpen()) {
// Warn, you called your variable keyReleased but it check keyPressed
if (event.type == sf::Event::KeyPressed && tmp_var == false) {
// Check wich key is pressed and perform required actions
tmp_var = true;
} else if (event.type == sf::Event::KeyReleased) {
tmp_var = false;
}
}
Note that the code can be not correct, I wanted to point out the reasoning