feat(tracker): add simple BPM & octave buttons

tracker/keyevent.go

@@ -70,16 +70,9 @@ func (t *Tracker) KeyEvent(e key.Event) bool {
 			return true
 		case `\`:
 			if e.Modifiers.Contain(key.ModShift) {
-				if t.CurrentOctave < 9 {
+				return t.ChangeBPM(1)
-					t.CurrentOctave++
-					return true
-				}
-			} else {
-				if t.CurrentOctave > 0 {
-					t.CurrentOctave--
-					return true
-				}
 			}
+			return t.ChangeBPM(-1)
 		case key.NameUpArrow:
 			delta := -1
 			if e.Modifiers.Contain(key.ModCtrl) {

tracker/layout.go

@@ -3,14 +3,34 @@ package tracker
 import (
 	"fmt"
 	"image"
+	"log"
 
 	"gioui.org/layout"
 	"gioui.org/op"
 	"gioui.org/op/clip"
 	"gioui.org/op/paint"
 	"gioui.org/unit"
+	"gioui.org/widget"
+	"gioui.org/widget/material"
+
+	"golang.org/x/exp/shiny/materialdesign/icons"
 )
 
+var upIcon *widget.Icon
+var downIcon *widget.Icon
+
+func init() {
+	var err error
+	upIcon, err = widget.NewIcon(icons.NavigationArrowUpward)
+	if err != nil {
+		log.Fatal(err)
+	}
+	downIcon, err = widget.NewIcon(icons.NavigationArrowDownward)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
 func (t *Tracker) Layout(gtx layout.Context) {
 	paint.FillShape(gtx.Ops, black, clip.Rect(image.Rect(0, 0, gtx.Constraints.Max.X, gtx.Constraints.Max.Y)).Op())
 	layout.UniformInset(unit.Dp(2)).Layout(gtx, func(gtx2 layout.Context) layout.Dimensions {
@@ -56,6 +76,20 @@ func (t *Tracker) layoutControls(gtx layout.Context) layout.Dimensions {
 	if !t.Playing {
 		playPat = -1
 	}
+	in := layout.UniformInset(unit.Dp(8))
+
+	for t.OctaveUpBtn.Clicked() {
+		t.ChangeOctave(1)
+	}
+	for t.OctaveDownBtn.Clicked() {
+		t.ChangeOctave(-1)
+	}
+	for t.BPMUpBtn.Clicked() {
+		t.ChangeBPM(1)
+	}
+	for t.BPMDownBtn.Clicked() {
+		t.ChangeBPM(-1)
+	}
 
 	return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
 		layout.Rigid(Raised(t.layoutPatterns(
@@ -66,7 +100,25 @@ func (t *Tracker) layoutControls(gtx layout.Context) layout.Dimensions {
 			playPat,
 		))),
 		layout.Rigid(t.darkLine(false)),
-		layout.Flexed(1, Raised(Label(fmt.Sprintf("Current octave: %v", t.CurrentOctave), white))),
+		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
+			return in.Layout(gtx, material.IconButton(t.Theme, t.OctaveUpBtn, upIcon).Layout)
+		}),
+		layout.Rigid(t.darkLine(false)),
+		layout.Rigid(Raised(Label(fmt.Sprintf("OCT: %v", t.CurrentOctave), white))),
+		layout.Rigid(t.darkLine(false)),
+		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
+			return in.Layout(gtx, material.IconButton(t.Theme, t.OctaveDownBtn, downIcon).Layout)
+		}),
+		layout.Rigid(t.darkLine(false)),
+		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
+			return in.Layout(gtx, material.IconButton(t.Theme, t.BPMUpBtn, upIcon).Layout)
+		}),
+		layout.Rigid(t.darkLine(false)),
+		layout.Rigid(Raised(Label(fmt.Sprintf("BPM: %3v", t.song.BPM), white))),
+		layout.Rigid(t.darkLine(false)),
+		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
+			return in.Layout(gtx, material.IconButton(t.Theme, t.BPMDownBtn, downIcon).Layout)
+		}),
 	)
 }
 

tracker/tracker.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"sync"
 
+	"gioui.org/font/gofont"
 	"gioui.org/widget"
+	"gioui.org/widget/material"
 	"github.com/vsariola/sointu"
 	"github.com/vsariola/sointu/bridge"
 )
@@ -24,7 +26,13 @@ type Tracker struct {
 	ActiveTrack     int
 	CurrentOctave   byte
 	NoteTracking    bool
+	Theme           *material.Theme
+	OctaveUpBtn     *widget.Clickable
+	OctaveDownBtn   *widget.Clickable
+	BPMUpBtn        *widget.Clickable
+	BPMDownBtn      *widget.Clickable
 
+	sequencer    *Sequencer
 	ticked       chan struct{}
 	setPlaying   chan bool
 	rowJump      chan int
@@ -75,9 +83,7 @@ func (t *Tracker) sequencerLoop(closer <-chan struct{}) {
 		panic("cannot create a synth with the default patch")
 	}
 	curVoices := make([]int, 32)
-	sequencer := NewSequencer(synth, 44100*60/(4*t.song.BPM), func() ([]Note, bool) {
+	t.sequencer = NewSequencer(synth, 44100*60/(4*t.song.BPM), func() ([]Note, bool) {
-		t.songPlayMutex.RLock()
-		defer t.songPlayMutex.RUnlock()
 		if !t.Playing {
 			return nil, false
 		}
@@ -121,17 +127,53 @@ func (t *Tracker) sequencerLoop(closer <-chan struct{}) {
 		case <-closer:
 			return
 		default:
-			sequencer.ReadAudio(buffer)
+			t.sequencer.ReadAudio(buffer)
 			output.WriteAudio(buffer)
 		}
 	}
 }
 
+func (t *Tracker) ChangeOctave(delta int) bool {
+	newOctave := int(t.CurrentOctave) + delta
+	if newOctave < 0 {
+		newOctave = 0
+	}
+	if newOctave > 9 {
+		newOctave = 9
+	}
+	if newOctave != int(t.CurrentOctave) {
+		t.CurrentOctave = byte(newOctave)
+		return true
+	}
+	return false
+}
+
+func (t *Tracker) ChangeBPM(delta int) bool {
+	newBPM := t.song.BPM + delta
+	if newBPM < 1 {
+		newBPM = 1
+	}
+	if newBPM > 999 {
+		newBPM = 999
+	}
+	if newBPM != int(t.song.BPM) {
+		t.song.BPM = newBPM
+		t.sequencer.SetRowLength(44100 * 60 / (4 * t.song.BPM))
+		return true
+	}
+	return false
+}
+
 func New(audioContext sointu.AudioContext) *Tracker {
 	t := &Tracker{
+		Theme:         material.NewTheme(gofont.Collection()),
 		QuitButton:    new(widget.Clickable),
 		CurrentOctave: 4,
 		audioContext:  audioContext,
+		OctaveUpBtn:   new(widget.Clickable),
+		OctaveDownBtn: new(widget.Clickable),
+		BPMUpBtn:      new(widget.Clickable),
+		BPMDownBtn:    new(widget.Clickable),
 		setPlaying:    make(chan bool),
 		rowJump:       make(chan int),
 		patternJump:   make(chan int),