Event::operator bool

[trustytrojan]

Description

This PR aims to simplify the usage of Event when polling events from a RenderWindow. Instead of having to initialize an Event on the stack and pass it by reference to pollEvent/waitEvent, this PR makes the methods return an Event, which can be converted to a bool based on whether its subtype is Empty.

There was discussion about having pollEvent and waitEvent return std::optional<Event>, but considering Event already uses subtyping to determine if it contains event data, letting Event be convertible to bool (based on whether the inner data was of type Event::Empty) sounded like the better option. Plus, we can avoid the clunky -> syntax used for accessing members of an std::optional's inner type.

Tasks

• Tested on Linux
• Tested on Windows
• Tested on macOS
• Tested on iOS
• Tested on Android

How to test this PR?

Use an sf::RenderWindow while processing events.

#include <SFML/Graphics.hpp>

int main()
{
    sf::RenderWindow window(sf::VideoMode({1280, 720}), "Minimal, complete and verifiable example");
    window.setFramerateLimit(60);

    while (window.isOpen())
    {
        while (const auto event = window.pollEvent())
        {
            if (event.is<sf::Event::Closed>())
                window.close();
        }

        window.clear();
        window.display();
    }
}

[ChrisThrasher]

I like this! It's great to remove output parameters without adding any extra ergonomic issues.

[coveralls]

Pull Request Test Coverage Report for Build 8934117997

Details

• 12 of 14 (85.71%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 51.897%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/SFML/Window/WindowImpl.cpp	0	2	0.0%

Totals
Change from base Build 8932890594:	0.01%
Covered Lines:	10474
Relevant Lines:	19002

---

💛 - Coveralls

[ChrisThrasher]

Cleaned up the commit history to prepare for merge. No changes made.

[trustytrojan]

Looks like a macos build failed because it took too long to clone? Any way to re-trigger it?

[eXpl0it3r]

Nothing you can do, I've rerun the failed job.