refactor(go): Move everything from go4k to root package sointu

tracker/tracker.go

@@ -0,0 +1,67 @@
+package tracker
+
+import (
+	"fmt"
+	"gioui.org/widget"
+	"github.com/vsariola/sointu"
+	"github.com/vsariola/sointu/audio"
+	"github.com/vsariola/sointu/bridge"
+)
+
+type Tracker struct {
+	QuitButton     *widget.Clickable
+	song           sointu.Song
+	CursorRow      int
+	CursorColumn   int
+	DisplayPattern int
+	PlayPattern    int32
+	PlayRow        int32
+	ActiveTrack    int
+	CurrentOctave  byte
+	Playing        bool
+	ticked         chan struct{}
+	setPlaying     chan bool
+	rowJump        chan int
+	patternJump    chan int
+	player         audio.Player
+	synth          sointu.Synth
+	playBuffer     []float32
+	closer         chan struct{}
+}
+
+func (t *Tracker) LoadSong(song sointu.Song) error {
+	if err := song.Validate(); err != nil {
+		return fmt.Errorf("invalid song: %w", err)
+	}
+	t.song = song
+	if synth, err := bridge.Synth(song.Patch); err != nil {
+		fmt.Printf("error loading synth: %v\n", err)
+		t.synth = nil
+	} else {
+		t.synth = synth
+	}
+	return nil
+}
+
+func (t *Tracker) Close() {
+	t.player.Close()
+	t.closer <- struct{}{}
+}
+
+func New(player audio.Player) *Tracker {
+	t := &Tracker{
+		QuitButton:    new(widget.Clickable),
+		CurrentOctave: 4,
+		player:        player,
+		setPlaying:    make(chan bool),
+		rowJump:       make(chan int),
+		patternJump:   make(chan int),
+		ticked:        make(chan struct{}),
+		closer:        make(chan struct{}),
+	}
+	go t.sequencerLoop(t.closer)
+	if err := t.LoadSong(defaultSong); err != nil {
+		panic(fmt.Errorf("cannot load default song: %w", err))
+	}
+	return t
+}