midi-msg 0.8.2

A (eventually) complete representation of the MIDI 1.0 Detailed Specification and its many extensions and addenda, allowing for the serialization and deserialization of MIDI byte streams to and from a typed representation.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92

use super::parse_error::*;
use alloc::vec::Vec;

/// A fairly limited set of messages used for device synchronization.
/// Used in [`MidiMsg`](crate::MidiMsg).
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum SystemRealTimeMsg {
    /// Used to synchronize clocks. Sent at a rate of 24 per quarter note.
    TimingClock,
    /// Start at the beginning of the song or sequence.
    Start,
    /// Continue from the current location in the song or sequence.
    Continue,
    /// Stop playback.
    Stop,
    /// Sent every 300ms or less whenever other MIDI data is not sent.
    /// Used to indicate that the given device is still connected.
    ActiveSensing,
    /// Request that all devices are reset to their power-up state.
    ///
    /// This is not a valid message in a MIDI file, since it overlaps
    /// with the MIDI file's Meta messages. If you add this message to a
    /// MIDI file, it will be ignored upon serialization.
    SystemReset,
}

impl SystemRealTimeMsg {
    pub(crate) fn extend_midi(&self, v: &mut Vec<u8>) {
        match self {
            Self::TimingClock => v.push(0xF8),
            Self::Start => v.push(0xFA),
            Self::Continue => v.push(0xFB),
            Self::Stop => v.push(0xFC),
            Self::ActiveSensing => v.push(0xFE),
            Self::SystemReset => v.push(0xFF),
        }
    }

    pub(crate) fn from_midi(m: &[u8]) -> Result<(Self, usize), ParseError> {
        match m.first() {
            Some(0xF8) => Ok((Self::TimingClock, 1)),
            Some(0xFA) => Ok((Self::Start, 1)),
            Some(0xFB) => Ok((Self::Continue, 1)),
            Some(0xFC) => Ok((Self::Stop, 1)),
            Some(0xFE) => Ok((Self::ActiveSensing, 1)),
            Some(0xFF) => Ok((Self::SystemReset, 1)),
            Some(x) => Err(ParseError::UndefinedSystemRealTimeMessage(*x)),
            None => panic!("Should not be reachable"),
        }
    }
}

#[cfg(test)]
mod tests {
    use crate::*;
    extern crate std;
    use std::vec;

    #[test]
    fn serialize_system_real_time_msg() {
        assert_eq!(
            MidiMsg::SystemRealTime {
                msg: SystemRealTimeMsg::TimingClock
            }
            .to_midi(),
            vec![0xF8]
        );
    }

    #[test]
    fn deserialize_system_real_time_msg() {
        let mut ctx = ReceiverContext::new();

        test_serialization(
            MidiMsg::SystemRealTime {
                msg: SystemRealTimeMsg::TimingClock,
            },
            &mut ctx,
        );
    }

    #[test]
    fn serde_system_reset() {
        let system_reset = MidiMsg::SystemRealTime {
            msg: SystemRealTimeMsg::SystemReset,
        };
        assert_eq!(
            MidiMsg::from_midi_with_context(&system_reset.to_midi(), &mut ReceiverContext::new()),
            Ok((system_reset, 1)),
        );
    }
}