SFML mouse button released is spamming

Question

I am using SFML and C++ and I am getting an odd problem,

Here is my main game update method

while (renderService.Window.isOpen())
{
    //Poll events
    sf::Event event;
    while (renderService.Window.pollEvent(event))
    {
        if (event.type == sf::Event::Closed)
            renderService.Window.close();
        running = false;
    }

    MouseMovment(event);
    MouseClick(event);
    Update();
    Draw();
}

and here is my MouseClick method

void Game::MouseClick(sf::Event event)
{
sf::Vector2i position = sf::Mouse::getPosition(renderService.Window);

    if (event.mouseButton.button == sf::Mouse::Left && event.type == sf::Event::MouseButtonReleased)
    {
        std::cout << "Mouse released" << std::endl;
    }
}

now here is the weird part, in my console sometimes my cout will be spammed like 10/20 times, but sometimes it will work perfectly, am I calling the event wrongly?

Answer 1

You're doing it wrong, suppose that a MouseButtonReleased event is fired and your polling function grabs it (follows the numbers in the comments):

while (renderService.Window.isOpen()) // 4) The loop starts again
{
    //Poll events
    sf::Event event; 
    while (renderService.Window.pollEvent(event)) // 1) Grabs the event // 5) No more events
    {
        if (event.type == sf::Event::Closed) // 2) Nope, it's not this one
            renderService.Window.close();
        running = false;
    }

    MouseMovment(event);
    MouseClick(event); // 3) Yes, handle it // 6) Uses the unmodified event variable - undefined behavior
    Update();
    Draw();
}

you should rather do something like:

sf::Event event;

// while there are pending events...
while (window.pollEvent(event))
{
    // check the type of the event...
    switch (event.type)
    {
        // window closed
        case sf::Event::Closed:
            ...
            break;

        // mouse button released
        case sf::Event::MouseButtonReleased:
        {
           if (event.mouseButton.button == sf::Mouse::Left)
            ...
        } break;

        // we don't process other types of events
        default:
            break;
    }

}