Add SequencerSpecificEvent , and empty!(::MIDITrack) (#173)

* add SequencerSpecificEvent support

* add test

* update tests

* implement `empty!(::MIDITrack)`

* add isempty for MIDITrack

* fix typo

Author: NeroBlackstone

CHANGELOG.md

@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
+# v2.7.0
+* New meta event type `SequencerSpecificEvent`.
+* Implement `Base.empty!(::MIDITrack)` and `Base.isempty(t::MIDITrack)`.
 # v2.6.0
 * New functions `metric_time`.
 * New functions `duration_metric_time`.

Project.toml

@@ -1,7 +1,7 @@
 name = "MIDI"
 uuid = "f57c4921-e30c-5f49-b073-3f2f2ada663e"
 repo = "https://github.com/JuliaMusic/MIDI.jl.git"
-version = "2.6.0"
+version = "2.7.0"
 
 [deps]
 FileIO = "5789e2e9-d7fb-5bc7-8068-2c6fae9b9549"

src/events.jl

@@ -60,7 +60,12 @@ const MIDI_EVENTS_DEFS = Dict(
         decode = :(Int.(data)),
         encode = :(UInt8.([event.semitones, event.scale]))
     ),
-
+    0x7f => (
+        type = :SequencerSpecificEvent,
+        fields = ["ssdata::Vector{UInt8}"],
+        decode = :(data),
+        encode = :(event.ssdata)
+    ),
     # MidiEvents
     0x80 => (
         type = :NoteOffEvent,
@@ -124,12 +129,14 @@ function define_type(type, fields, decode, encode_, supertype, typebyte)
             $(fields...)
         end
 
-        """    $($type)(dT::Int, typebyte::UInt8, data::Vector{UInt8})
-        Returns a `$($type)` event from it's byte representation.
-        The parameter `typebyte::UInt8` is its's $(($type <: MetaEvent) ? "metatype" : "status") byte.
-        """
-        function $type(dT::Int, typebyte::UInt8, data::Vector{UInt8})
-            $type(dT, typebyte, $decode...)
+        if !($type.types[end] <: AbstractArray)
+            """    $($type)(dT::Int, typebyte::UInt8, data::Vector{UInt8})
+            Returns a `$($type)` event from it's byte representation.
+            The parameter `typebyte::UInt8` is its's $(($type <: MetaEvent) ? "metatype" : "status") byte.
+            """
+            function $type(dT::Int, typebyte::UInt8, data::Vector{UInt8})
+                $type(dT, typebyte, $decode...)
+            end
         end
 
         if $type <: MetaEvent
@@ -407,3 +414,13 @@ The `PitchBendEvent` informs a MIDI device to modify the pitch in a specific cha
 * `pitch::Int` : Value of the pitch bend.
 """
 PitchBendEvent
+
+"""    SequencerSpecificEvent <: MetaEvent
+The `SequencerSpecificEvent` is used to store vendor-proprietary data in a MIDI file.
+
+## Fields:
+* `dT::Int` : Delta time in ticks.
+* `metatype::UInt8` : Meta type byte of the event.
+* `ssdata::Vector{UInt8}` : Vendor-proprietary data.
+"""
+SequencerSpecificEvent

src/miditrack.jl

@@ -7,6 +7,8 @@
 Track chunks begin with four bytes spelling out "MTrk", followed by the length
 (in bytes) of the track (see [`readvariablelength`](@ref)), followed by a sequence
 of events.
+
+`MIDITrack` implements the `isempty` and `empty!` functions.
 """
 mutable struct MIDITrack
     events::Vector{TrackEvent}
@@ -21,6 +23,8 @@ function Base.show(io::IO, t::MIDITrack)
     print(io, "$(L)-event MIDITrack: $M MIDI, $T Meta, $X Sysex")
 end
 
+Base.empty!(t::MIDITrack) = empty!(t.events)
+Base.isempty(t::MIDITrack)::Bool = isempty(t.events)
 
 function readtrack(f::IO)
 

test/SequencerSpecific.mid

@@ -31,4 +31,22 @@
             @test_throws errtype MIDI.readsysexevent(Int(input[1]), IOBuffer(input[2:length(input)]))
         end
     end
+
+    @testset "SequencerSpecificEvent" begin
+        midi = load("SequencerSpecific.mid")
+        sse = midi.tracks[1].events[1]
+        @test sse isa MIDI.SequencerSpecificEvent
+        sse.ssdata == [0x11, 0x21, 0x53, 0x1F]
+
+        sse = MIDI.SequencerSpecificEvent(0, 0x7f, [0x11, 0x21, 0x53, 0x1F])
+        @test sse.ssdata == [0x11, 0x21, 0x53, 0x1F]
+    end
+
+    @testset "check empty" begin
+        midi = load(testmidi())
+        track = midi.tracks[1]
+        @test !isempty(track)
+        empty!(track)
+        @test isempty(track)
+    end
 end