feat(tracker): copy instrument to & paste from clipboard

Closes #25

tracker/instruments.go

@@ -4,6 +4,7 @@ import (
 	"image"
 	"strconv"
 
+	"gioui.org/io/clipboard"
 	"gioui.org/io/pointer"
 	"gioui.org/layout"
 	"gioui.org/op"
@@ -12,6 +13,7 @@ import (
 	"gioui.org/widget"
 	"gioui.org/widget/material"
 	"golang.org/x/exp/shiny/materialdesign/icons"
+	"gopkg.in/yaml.v3"
 )
 
 var instrumentPointerTag = false
@@ -63,6 +65,11 @@ func (t *Tracker) layoutInstruments(gtx C) D {
 
 func (t *Tracker) layoutInstrumentHeader(gtx C) D {
 	header := func(gtx C) D {
+		copyInstrumentBtnStyle := material.IconButton(t.Theme, t.CopyInstrumentBtn, widgetForIcon(icons.ContentContentCopy))
+		copyInstrumentBtnStyle.Background = transparent
+		copyInstrumentBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
+		copyInstrumentBtnStyle.Color = primaryColor
+
 		deleteInstrumentBtnStyle := material.IconButton(t.Theme, t.DeleteInstrumentBtn, widgetForIcon(icons.ActionDelete))
 		deleteInstrumentBtnStyle.Background = transparent
 		deleteInstrumentBtnStyle.Inset = layout.UniformInset(unit.Dp(6))
@@ -88,8 +95,15 @@ func (t *Tracker) layoutInstrumentHeader(gtx C) D {
 				return dims
 			}),
 			layout.Flexed(1, func(gtx C) D { return layout.Dimensions{Size: gtx.Constraints.Min} }),
+			layout.Rigid(copyInstrumentBtnStyle.Layout),
 			layout.Rigid(deleteInstrumentBtnStyle.Layout))
 	}
+	for t.CopyInstrumentBtn.Clicked() {
+		contents, err := yaml.Marshal(t.song.Patch.Instruments[t.CurrentInstrument])
+		if err == nil {
+			clipboard.WriteOp{Text: string(contents)}.Add(gtx.Ops)
+		}
+	}
 	for t.DeleteInstrumentBtn.Clicked() {
 		t.DeleteInstrument()
 	}

tracker/run.go

@@ -24,7 +24,7 @@ func (t *Tracker) Run(w *app.Window) error {
 					w.Invalidate()
 				}
 			case clipboard.Event:
-				err := t.UnmarshalSong([]byte(e.Text))
+				err := t.UnmarshalContent([]byte(e.Text))
 				if err == nil {
 					w.Invalidate()
 				}

tracker/tracker.go

@@ -60,6 +60,7 @@ type Tracker struct {
 	SubtractOctaveBtn     *widget.Clickable
 	SongLength            *NumberInput
 	PanicBtn              *widget.Clickable
+	CopyInstrumentBtn     *widget.Clickable
 	ParameterSliders      []*widget.Float
 	ParameterList         *layout.List
 	UnitDragList          *DragList
@@ -100,7 +101,18 @@ func (t *Tracker) LoadSong(song sointu.Song) error {
 	return nil
 }
 
-func (t *Tracker) UnmarshalSong(bytes []byte) error {
+func (t *Tracker) UnmarshalContent(bytes []byte) error {
+	var instr sointu.Instrument
+	if errJSON := json.Unmarshal(bytes, &instr); errJSON == nil {
+		if t.SetInstrument(instr) {
+			return nil
+		}
+	}
+	if errYaml := yaml.Unmarshal(bytes, &instr); errYaml == nil {
+		if t.SetInstrument(instr) {
+			return nil
+		}
+	}
 	var song sointu.Song
 	if errJSON := json.Unmarshal(bytes, &song); errJSON != nil {
 		if errYaml := yaml.Unmarshal(bytes, &song); errYaml != nil {
@@ -149,6 +161,16 @@ func (t *Tracker) ChangeOctave(delta int) bool {
 	return false
 }
 
+func (t *Tracker) SetInstrument(instrument sointu.Instrument) bool {
+	if len(instrument.Units) > 0 {
+		t.SaveUndo()
+		t.song.Patch.Instruments[t.CurrentInstrument] = instrument
+		t.sequencer.SetPatch(t.song.Patch)
+		return true
+	}
+	return false
+}
+
 func (t *Tracker) SetInstrumentVoices(value int) bool {
 	if value < 1 {
 		value = 1
@@ -674,6 +696,7 @@ func New(audioContext sointu.AudioContext, synthService sointu.SynthService) *Tr
 		DeleteUnitBtn:         new(widget.Clickable),
 		ClearUnitBtn:          new(widget.Clickable),
 		PanicBtn:              new(widget.Clickable),
+		CopyInstrumentBtn:     new(widget.Clickable),
 		Menus:                 make([]Menu, 2),
 		MenuBar:               make([]widget.Clickable, 2),
 		UnitDragList:          &DragList{List: &layout.List{Axis: layout.Vertical}},