Request feature to read typed keys

[john01dav]

The crate already supports determining if a particular key is down or not, but this is not sufficient to accept text input in a natural way. There are two specific goals that can't be fulfilled:

• When a key is pressed and held, there will be many typing events in a particular OS-defined pattern. To demonstrate this, hold down any letter on your keyboard and notice that the time between the first and second characters that are typed is different from after the 3rd, 4th, etc. Also, note that the exact intervals are OS-defined, and are often configurable in system settings.
• In some cases, someone may want to type a character that requires a complicated series of key presses, in an OS-defined way. For example, consider the Linux compose key. When it is set to right alt, one can press right alt, then a, then ' to type á or right alt then ? then ? again to type ¿, where ? is typed with the shift key. There are many thousands of such combinations.

A proper event or mechanism to look at typed keys, as opposed to pressed keys, is needed to capture this complicated and OS-specific behavior. To provide this, I propose a new method on the minifb::Window struct, fn get_next_typed_char() -> Option<char> that, when called repeatedly, will give all characters that have been typed in the order that they were typed, then None once all types characters have been returned. This method could then be polled frequently (e.g. every frame) to get new information, that is simply passed along from the underlying OS-specific API. Note, however, that this is just one way to implement this, and that another method may be more convenient given the platform-specific underlying APIs (which are unknown to me).

[john01dav]

I found a solution, minifb::window::set_input_callback. I didn't originally find it because I expected to see something with the name "typed" in it, as other libraries have.

[john01dav]

I'm trying to use this feature (on library version 0.19.3 from crates.io), and it appears to not be working. I'm taking the u32 from the input callback and passing it to char::from_u32 (discarding any that don't have a mapping, although no discards are actually happening so that's not the problem) then appending to a string to allow the user to type, but when I use a compose key or even try to type a capitol letter, it does not work instead typing the key sequence (aside from alt of course) in the former case and the lowercase letter in the latter case. This is on Debian 11 under X11 and Gnome. I can provide a minimum, complete, verifiable example if that would be helpful