feat(tracker): add simple instrument editor

tracker/instruments.go

@@ -0,0 +1,121 @@
+package tracker
+
+import (
+	"fmt"
+	"sort"
+
+	"gioui.org/layout"
+	"gioui.org/widget"
+	"gioui.org/widget/material"
+)
+
+type C = layout.Context
+type D = layout.Dimensions
+
+func (t *Tracker) updateInstrumentScroll() {
+	if t.CurrentInstrument > 7 {
+		t.InstrumentList.Position.First = t.CurrentInstrument - 7
+	} else {
+		t.InstrumentList.Position.First = 0
+	}
+}
+
+func (t *Tracker) layoutInstruments() layout.Widget {
+	return func(gtx C) D {
+		return layout.Flex{Axis: layout.Vertical}.Layout(gtx,
+			layout.Rigid(t.layoutInstrumentNames()),
+			layout.Flexed(1, t.layoutInstrumentEditor()))
+	}
+}
+
+func (t *Tracker) layoutInstrumentNames() layout.Widget {
+	return func(gtx C) D {
+		count := len(t.song.Patch.Instruments)
+		if len(t.InstrumentBtns) < count {
+			tail := make([]*widget.Clickable, count-len(t.InstrumentBtns))
+			for t := range tail {
+				tail[t] = new(widget.Clickable)
+			}
+			t.InstrumentBtns = append(t.InstrumentBtns, tail...)
+		}
+		return t.InstrumentList.Layout(gtx, count, func(gtx C, index int) D {
+			for t.InstrumentBtns[index].Clicked() {
+				t.CurrentInstrument = index
+			}
+			btnStyle := material.Button(t.Theme, t.InstrumentBtns[index], fmt.Sprintf("%v", index))
+			btnStyle.Background = transparent
+			return btnStyle.Layout(gtx)
+		})
+	}
+}
+func (t *Tracker) layoutInstrumentEditor() layout.Widget {
+	return func(gtx C) D {
+		return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
+			layout.Rigid(t.layoutUnitList()),
+			layout.Rigid(t.layoutUnitControls()))
+	}
+}
+
+func (t *Tracker) layoutUnitList() layout.Widget {
+	return func(gtx C) D {
+		units := t.song.Patch.Instruments[t.CurrentInstrument].Units
+		count := len(units)
+		if len(t.UnitBtns) < count {
+			tail := make([]*widget.Clickable, count-len(t.UnitBtns))
+			for t := range tail {
+				tail[t] = new(widget.Clickable)
+			}
+			t.UnitBtns = append(t.UnitBtns, tail...)
+		}
+		children := make([]layout.FlexChild, len(t.song.Patch.Instruments[t.CurrentInstrument].Units))
+		for i, u := range t.song.Patch.Instruments[t.CurrentInstrument].Units {
+			for t.UnitBtns[i].Clicked() {
+				t.CurrentUnit = i
+			}
+			btnStyle := material.Button(t.Theme, t.UnitBtns[i], u.Type)
+			btnStyle.Background = transparent
+			children[i] = layout.Rigid(btnStyle.Layout)
+		}
+		return layout.Flex{Axis: layout.Vertical}.Layout(gtx, children...)
+	}
+}
+
+func (t *Tracker) layoutUnitControls() layout.Widget {
+	return func(gtx C) D {
+		params := t.song.Patch.Instruments[t.CurrentInstrument].Units[t.CurrentUnit].Parameters
+		count := len(params)
+		children := make([]layout.FlexChild, 0, count)
+		if len(t.ParameterSliders) < count {
+			tail := make([]*widget.Float, count-len(t.ParameterSliders))
+			for t := range tail {
+				tail[t] = new(widget.Float)
+			}
+			t.ParameterSliders = append(t.ParameterSliders, tail...)
+		}
+		keys := make([]string, 0, len(params))
+		for k := range params {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for i, k := range keys {
+			for t.ParameterSliders[i].Changed() {
+				params[k] = int(t.ParameterSliders[i].Value)
+				// TODO: tracker should have functions to update parameters and
+				// to do this efficiently i.e. not compile the whole patch again
+				t.LoadSong(t.song)
+			}
+			t.ParameterSliders[i].Value = float32(params[k])
+			sliderStyle := material.Slider(t.Theme, t.ParameterSliders[i], 0, 128)
+			k2 := k // avoid k changing in the closure
+			children = append(children, layout.Rigid(func(gtx C) D {
+				return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
+					layout.Rigid(Label(k2, white)),
+					layout.Rigid(func(gtx C) D {
+						gtx.Constraints.Min.X = 200
+						return sliderStyle.Layout(gtx)
+					}))
+			}))
+		}
+		return layout.Flex{Axis: layout.Vertical}.Layout(gtx, children...)
+	}
+}

tracker/layout.go

@@ -59,6 +59,7 @@ func (t *Tracker) Layout(gtx layout.Context) {
 			layout.Rigid(t.line(true, separatorLineColor)),
 			layout.Flexed(1, t.layoutTracker))
 	})
+	t.updateInstrumentScroll()
 }
 
 func (t *Tracker) layoutTracker(gtx layout.Context) layout.Dimensions {
@@ -184,6 +185,7 @@ func (t *Tracker) layoutControls(gtx layout.Context) layout.Dimensions {
 		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
 			return in.Layout(gtx, enableButton(smallButton(material.IconButton(t.Theme, t.BPMDownBtn, downIcon)), t.song.BPM > 1).Layout)
 		}),
+		layout.Flexed(1, t.layoutInstruments()),
 		layout.Rigid(func(gtx layout.Context) layout.Dimensions {
 			iconBtn := enableButton(material.IconButton(t.Theme, t.NewInstrumentBtn, addIcon), t.song.Patch.TotalVoices() < 32)
 			return in.Layout(gtx, iconBtn.Layout)

tracker/theme.go

@@ -22,6 +22,8 @@ var black = color.RGBA{R: 0, G: 0, B: 0, A: 255}
 var yellow = color.RGBA{R: 255, G: 255, B: 130, A: 255}
 var red = color.RGBA{R: 255, G: 0, B: 0, A: 255}
 
+var transparent = color.RGBA{A: 0}
+
 var primaryColorLight = color.RGBA{R: 243, G: 229, B: 245, A: 255}
 var primaryColor = color.RGBA{R: 206, G: 147, B: 216, A: 255}
 var primaryColorDark = color.RGBA{R: 123, G: 31, B: 162, A: 255}

tracker/tracker.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 
 	"gioui.org/font/gofont"
+	"gioui.org/layout"
 	"gioui.org/widget"
 	"gioui.org/widget/material"
 	"github.com/vsariola/sointu"
@@ -17,22 +18,28 @@ type Tracker struct {
 	song          sointu.Song
 	Playing       bool
 	// protects PlayPattern and PlayRow
-	playRowPatMutex  sync.RWMutex // protects song and playing
-	PlayPattern      int
-	PlayRow          int
-	CursorRow        int
-	CursorColumn     int
-	DisplayPattern   int
-	ActiveTrack      int
-	CurrentOctave    byte
-	NoteTracking     bool
-	Theme            *material.Theme
-	OctaveUpBtn      *widget.Clickable
-	OctaveDownBtn    *widget.Clickable
-	BPMUpBtn         *widget.Clickable
-	BPMDownBtn       *widget.Clickable
-	NewTrackBtn      *widget.Clickable
-	NewInstrumentBtn *widget.Clickable
+	playRowPatMutex   sync.RWMutex // protects song and playing
+	PlayPattern       int
+	PlayRow           int
+	CursorRow         int
+	CursorColumn      int
+	DisplayPattern    int
+	ActiveTrack       int
+	CurrentInstrument int
+	CurrentUnit       int
+	CurrentOctave     byte
+	NoteTracking      bool
+	Theme             *material.Theme
+	OctaveUpBtn       *widget.Clickable
+	OctaveDownBtn     *widget.Clickable
+	BPMUpBtn          *widget.Clickable
+	BPMDownBtn        *widget.Clickable
+	NewTrackBtn       *widget.Clickable
+	NewInstrumentBtn  *widget.Clickable
+	ParameterSliders  []*widget.Float
+	UnitBtns          []*widget.Clickable
+	InstrumentBtns    []*widget.Clickable
+	InstrumentList    *layout.List
 
 	sequencer    *Sequencer
 	ticked       chan struct{}
@@ -75,6 +82,9 @@ func (t *Tracker) LoadSong(song sointu.Song) error {
 	if t.ActiveTrack >= len(song.Tracks) {
 		t.ActiveTrack = len(song.Tracks) - 1
 	}
+	if t.sequencer != nil {
+		t.sequencer.SetSynth(t.synth)
+	}
 	return nil
 }
 
@@ -241,6 +251,7 @@ func New(audioContext sointu.AudioContext) *Tracker {
 		closer:           make(chan struct{}),
 		undoStack:        []sointu.Song{},
 		redoStack:        []sointu.Song{},
+		InstrumentList:   &layout.List{Axis: layout.Horizontal},
 	}
 	t.Theme.Color.Primary = primaryColor
 	t.Theme.Color.InvText = black