feat!: rewrote the GUI and model for better testability

The Model was getting unmaintanable mess. This is an attempt to refactor/rewrite the Model so that data of certain type is exposed in standardized way, offering certain standard manipulations for that data type, and on the GUI side, certain standard widgets to tied to that data.

This rewrite closes #72, #106 and #120.

tracker/int.go

@@ -0,0 +1,191 @@
+package tracker
+
+import (
+	"math"
+
+	"github.com/vsariola/sointu/vm"
+)
+
+type (
+	Int struct {
+		IntData
+	}
+
+	IntData interface {
+		Value() int
+		Range() intRange
+
+		setValue(int)
+		change(kind string) func()
+	}
+
+	intRange struct {
+		Min, Max int
+	}
+
+	InstrumentVoices Model
+	TrackVoices      Model
+	SongLength       Model
+	BPM              Model
+	RowsPerPattern   Model
+	RowsPerBeat      Model
+	Step             Model
+	Octave           Model
+)
+
+func (v Int) Add(delta int) (ok bool) {
+	r := v.Range()
+	value := r.Clamp(v.Value() + delta)
+	if value == v.Value() || value < r.Min || value > r.Max {
+		return false
+	}
+	defer v.change("Add")()
+	v.setValue(value)
+	return true
+}
+
+func (v Int) Set(value int) (ok bool) {
+	r := v.Range()
+	value = v.Range().Clamp(value)
+	if value == v.Value() || value < r.Min || value > r.Max {
+		return false
+	}
+	defer v.change("Set")()
+	v.setValue(value)
+	return true
+}
+
+func (r intRange) Clamp(value int) int {
+	return intMax(intMin(value, r.Max), r.Min)
+}
+
+// Model methods
+
+func (m *Model) InstrumentVoices() *InstrumentVoices { return (*InstrumentVoices)(m) }
+func (m *Model) TrackVoices() *TrackVoices           { return (*TrackVoices)(m) }
+func (m *Model) SongLength() *SongLength             { return (*SongLength)(m) }
+func (m *Model) BPM() *BPM                           { return (*BPM)(m) }
+func (m *Model) RowsPerPattern() *RowsPerPattern     { return (*RowsPerPattern)(m) }
+func (m *Model) RowsPerBeat() *RowsPerBeat           { return (*RowsPerBeat)(m) }
+func (m *Model) Step() *Step                         { return (*Step)(m) }
+func (m *Model) Octave() *Octave                     { return (*Octave)(m) }
+
+// BeatsPerMinuteInt
+
+func (v *BPM) Int() Int           { return Int{v} }
+func (v *BPM) Value() int         { return v.d.Song.BPM }
+func (v *BPM) setValue(value int) { v.d.Song.BPM = value }
+func (v *BPM) Range() intRange    { return intRange{1, 999} }
+func (v *BPM) change(kind string) func() {
+	return (*Model)(v).change("BPMInt."+kind, SongChange, MinorChange)
+}
+
+// RowsPerPatternInt
+
+func (v *RowsPerPattern) Int() Int           { return Int{v} }
+func (v *RowsPerPattern) Value() int         { return v.d.Song.Score.RowsPerPattern }
+func (v *RowsPerPattern) setValue(value int) { v.d.Song.Score.RowsPerPattern = value }
+func (v *RowsPerPattern) Range() intRange    { return intRange{1, 256} }
+func (v *RowsPerPattern) change(kind string) func() {
+	return (*Model)(v).change("RowsPerPatternInt."+kind, SongChange, MinorChange)
+}
+
+// SongLengthInt
+
+func (v *SongLength) Int() Int           { return Int{v} }
+func (v *SongLength) Value() int         { return v.d.Song.Score.Length }
+func (v *SongLength) setValue(value int) { v.d.Song.Score.Length = value }
+func (v *SongLength) Range() intRange    { return intRange{1, math.MaxInt32} }
+func (v *SongLength) change(kind string) func() {
+	return (*Model)(v).change("SongLengthInt."+kind, SongChange, MinorChange)
+}
+
+// StepInt
+
+func (v *Step) Int() Int           { return Int{v} }
+func (v *Step) Value() int         { return v.d.Step }
+func (v *Step) setValue(value int) { v.d.Step = value }
+func (v *Step) Range() intRange    { return intRange{0, 8} }
+func (v *Step) change(kind string) func() {
+	return (*Model)(v).change("StepInt"+kind, NoChange, MinorChange)
+}
+
+// OctaveInt
+
+func (v *Octave) Int() Int                  { return Int{v} }
+func (v *Octave) Value() int                { return v.d.Octave }
+func (v *Octave) setValue(value int)        { v.d.Octave = value }
+func (v *Octave) Range() intRange           { return intRange{0, 9} }
+func (v *Octave) change(kind string) func() { return func() {} }
+
+// RowsPerBeatInt
+
+func (v *RowsPerBeat) Int() Int           { return Int{v} }
+func (v *RowsPerBeat) Value() int         { return v.d.Song.RowsPerBeat }
+func (v *RowsPerBeat) setValue(value int) { v.d.Song.RowsPerBeat = value }
+func (v *RowsPerBeat) Range() intRange    { return intRange{1, 32} }
+func (v *RowsPerBeat) change(kind string) func() {
+	return (*Model)(v).change("RowsPerBeatInt."+kind, SongChange, MinorChange)
+}
+
+// InstrumentVoicesInt
+
+func (v *InstrumentVoices) Int() Int {
+	return Int{v}
+}
+
+func (v *InstrumentVoices) Value() int {
+	if v.d.InstrIndex < 0 || v.d.InstrIndex >= len(v.d.Song.Patch) {
+		return 1
+	}
+	return intMax(v.d.Song.Patch[v.d.InstrIndex].NumVoices, 1)
+}
+
+func (v *InstrumentVoices) setValue(value int) {
+	if v.d.InstrIndex < 0 || v.d.InstrIndex >= len(v.d.Song.Patch) {
+		return
+	}
+	v.d.Song.Patch[v.d.InstrIndex].NumVoices = value
+}
+
+func (v *InstrumentVoices) Range() intRange {
+	return intRange{1, vm.MAX_VOICES - v.d.Song.Patch.NumVoices() + v.Value()}
+}
+
+func (v *InstrumentVoices) change(kind string) func() {
+	return (*Model)(v).change("InstrumentVoicesInt."+kind, PatchChange, MinorChange)
+}
+
+// TrackVoicesInt
+
+func (v *TrackVoices) Int() Int {
+	return Int{v}
+}
+
+func (v *TrackVoices) Value() int {
+	t := v.d.Cursor.Track
+	if t < 0 || t >= len(v.d.Song.Score.Tracks) {
+		return 1
+	}
+	return intMax(v.d.Song.Score.Tracks[t].NumVoices, 1)
+}
+
+func (v *TrackVoices) setValue(value int) {
+	t := v.d.Cursor.Track
+	if t < 0 || t >= len(v.d.Song.Score.Tracks) {
+		return
+	}
+	v.d.Song.Score.Tracks[t].NumVoices = value
+}
+
+func (v *TrackVoices) Range() intRange {
+	t := v.d.Cursor.Track
+	if t < 0 || t >= len(v.d.Song.Score.Tracks) {
+		return intRange{1, 1}
+	}
+	return intRange{1, vm.MAX_VOICES - v.d.Song.Score.NumVoices() + v.d.Song.Score.Tracks[t].NumVoices}
+}
+
+func (v *TrackVoices) change(kind string) func() {
+	return (*Model)(v).change("TrackVoicesInt."+kind, ScoreChange, MinorChange)
+}