Emitting mouse sequences?

[eaglgenes101]

Understandably, emitting escape sequences to generate terminal mouse sequences is rather niche, but is it within the scope of this project? I'm thinking of using it as part of a terminal multiplexer for forwarding mouse events to pseudoterminals.

[zrzka]

Thanks for the issue. To answer your question, it really depends on how we're looking at the anes crate.

• One view can be - foundation for crates like crossterm and then it's really out of scope.
  • These crates needs to emit stuff like colors, text attributes, move the cursor, ...
  • Consume input events mouse, key, resize, ...
  • But they do not need to emit mouse events for example.
• Another view can be - anes states that it provides & parses ANSI escape sequences. Mouse event is an ANSI escape sequence for sure and then it isn't out of scope.

I wrote this crate for the first use case and it doesn't make much sense to add support for this. It's also a bit complicated, see below.

---

There's no single ANSI escape sequence type for mouse events. We have:

• X10 compatibility mode - ESC [ M CB Cx Cy (6 bytes only)
• Xterm - ESC [ < Cb ; Cx ; Cy (;) (M or m)
• rxvt - ESC [ Cb ; Cx ; Cy ; M

Let's say we will implement Display for the Mouse enum:

https://github.com/zrzka/anes-rs/blob/378ac7461ecac29fde9e10df7b08359d1315a9ad/anes/src/parser/types.rs#L52-L65

Which variant should we emit? X10 compatibility mode? Xterm mode? Rxvt mode? Add special method just for the mouse to emit correct variant? We can introduce another enum like:

enum Mouse {
  Xterm(...),
  X10(...),
  Rxvt(...),
}

Then we will know what to emit, but we will complicate it for the Parser users - they want to know which mouse button was used & the location. They don't care about ANSI escape sequence type.

---

There's one thing you can do to forward mouse events. Skip the Parser and use Engine & Provide. Unfortunately, both these types are private, but I can make them public. Then you can implement your own provide_csi_sequence in this way:

impl Provider for MyType {
    fn provide_csi_sequence(&mut self, parameters: &[u64], ignored_count: usize, ch: char) {
        if ch == 'm' || ch == 'M' {
            // Mouse event - reconstruct ANSI sequence & forward it
        } else {
            // Not a mouse event
        }
    }
}

---

Not sure if I helped you. Thoughts?

[eaglgenes101]

I think this makes sense. Thanks. The changes you floated will probably be helpful if they do come in a release, but I can make do without as well.

[zrzka]

@eaglgenes101 so for now, I'd recommend to copy & paste Engine & Provide to your code base. I'm still thinking how to expose these two types (directly via anes crate, move just these two types to a separate crate like anes-parser, ...). No decision made yet and I do not want to block you while thinking what would be the best option.