Add some convenience constructors

[PoignardAzur]

Creating types like TextEvent and KeyboardEvent is kind of cumbersome. In Masonry's unit tests, the full expression ends up looking like:

let event = MyTextEvent::Keyboard(KeyboardEvent {
    key: Key::Named(NamedKey::Tab),
    ..Default::default()
})

Some quality-of-life feature I'd like:

• impl From<String> for Key
• impl From<NamedKey> for Key
• KeyboardEvent::key_down() and KeyboardEvent::key_up() constructors.

Thanks for your work!

[madsmtm]

Hmm, I think impl From<String> for Key might be a bit confusing, it could be implemented in potentially two ways:

impl From<String> for Key {
    fn from(s: String) -> Key {
        Key::Character(s)
        // OR
        Key::parse(&s).unwrap()
    }
}

And while it may be fairly clear that we've chosen the former, I suspect the latter is the semantics that people actually want? See relatedly #59.

impl From<NamedKey> for Key makes sense to me, have filed #81 for that.

For key_down/key_up, what are you thinking more specifically?

[PoignardAzur]

Hmm, I think impl From for Key might be a bit confusing, it could be implemented in potentially two ways:

Maybe impl From<char>, then? There would be less ambiguity there.

For key_down/key_up, what are you thinking more specifically?

I'd think of a constructor that would take two parameters, key and code, would set state to Up/Down, and set everything else to default values.