refactor(tracker/gioui): unify default & user config yaml handling

tracker/gioui/keybindings.go

@@ -24,33 +24,17 @@ type (
 var keyBindingMap = map[key.Event]string{}
 var keyActionMap = map[KeyAction]string{} // holds an informative string of the first key bound to an action
 
-func loadCustomKeyBindings() []KeyBinding {
-	var keyBindings []KeyBinding
-	_, err := ReadCustomConfigYml("keybindings.yml", &keyBindings)
-	if err != nil {
-		return nil
-	}
-	if len(keyBindings) == 0 {
-		return nil
-	}
-	return keyBindings
-}
-
 //go:embed keybindings.yml
-var defaultKeyBindingsYaml []byte
+var defaultKeyBindings []byte
-
-func loadDefaultKeyBindings() []KeyBinding {
-	var keyBindings []KeyBinding
-	err := yaml.UnmarshalStrict(defaultKeyBindingsYaml, &keyBindings)
-	if err != nil {
-		panic(fmt.Errorf("failed to unmarshal keybindings: %w", err))
-	}
-	return keyBindings
-}
 
 func init() {
-	keyBindings := loadDefaultKeyBindings()
+	var keyBindings, userKeybindings []KeyBinding
-	keyBindings = append(keyBindings, loadCustomKeyBindings()...)
+	if err := yaml.UnmarshalStrict(defaultKeyBindings, &keyBindings); err != nil {
+		panic(fmt.Errorf("failed to unmarshal default keybindings: %w", err))
+	}
+	if err := ReadCustomConfig("keybindings.yml", &userKeybindings); err == nil {
+		keyBindings = append(keyBindings, userKeybindings...)
+	}
 
 	for _, kb := range keyBindings {
 		var mods key.Modifiers

tracker/gioui/preferences.go

@@ -13,8 +13,7 @@ import (
 
 type (
 	Preferences struct {
-		Window   WindowPreferences
+		Window WindowPreferences
-		YmlError error
 	}
 
 	WindowPreferences struct {
@@ -25,39 +24,39 @@ type (
 )
 
 //go:embed preferences.yml
-var defaultPreferencesYaml []byte
+var defaultPreferences []byte
 
-func loadDefaultPreferences() Preferences {
+// ReadCustomConfig modifies the target argument, i.e. needs a pointer. Just
-	var preferences Preferences
+// fails silently if the file cannot be found/read, but will warn about
-	err := yaml.UnmarshalStrict(defaultPreferencesYaml, &preferences)
+// malformed files.
-	if err != nil {
+func ReadCustomConfig(filename string, target any) error {
-		panic(fmt.Errorf("failed to unmarshal preferences: %w", err))
-	}
-	return preferences
-}
-
-// ReadCustomConfigYml modifies the target argument, i.e. needs a pointer
-func ReadCustomConfigYml(filename string, target interface{}) (exists bool, err error) {
 	configDir, err := os.UserConfigDir()
 	if err != nil {
-		return false, err
+		return nil
 	}
 	path := filepath.Join(configDir, "sointu", filename)
-	bytes, err2 := os.ReadFile(path)
+	bytes, err := os.ReadFile(path)
-	if err2 != nil {
+	if err != nil {
-		return false, err2
+		return nil
 	}
-	err = yaml.Unmarshal(bytes, target)
+	if err := yaml.Unmarshal(bytes, target); err != nil {
-	return true, err
+		return fmt.Errorf("ReadCustomConfig %v: %w", filename, err)
+	}
+	return nil
 }
 
-func MakePreferences() Preferences {
+// ReadConfig first unmarshals the defaultConfig which should be the embedded
-	preferences := loadDefaultPreferences()
+// default config, and then tries to read the custom config with
-	exists, err := ReadCustomConfigYml("preferences.yml", &preferences)
+// ReadCustomConfig. It panics right away if the embedded defaultConfig could
-	if exists {
+// not be parsed as yaml as this should never happen except during development.
-		preferences.YmlError = err
+// The returned error should be treated as a warning: this function will always
+// return at least the default config, and the warning will just tell if there
+// was a problem parsing the custom config.
+func ReadConfig(defaultConfig []byte, path string, target any) (warn error) {
+	if err := yaml.UnmarshalStrict(defaultConfig, target); err != nil {
+		panic(fmt.Errorf("ReadConfig %v failed to unmarshal the embedded default config: %w", path, err))
 	}
-	return preferences
+	return ReadCustomConfig(path, target)
 }
 
 func (p Preferences) WindowSize() (unit.Dp, unit.Dp) {

tracker/gioui/theme.go

@@ -2,14 +2,12 @@ package gioui
 
 import (
 	_ "embed"
-	"fmt"
 	"image/color"
 
 	"gioui.org/text"
 	"gioui.org/widget"
 	"gioui.org/widget/material"
 	"golang.org/x/exp/shiny/materialdesign/icons"
-	"gopkg.in/yaml.v2"
 )
 
 type Theme struct {
@@ -120,19 +118,16 @@ type CursorStyle struct {
 //go:embed theme.yml
 var defaultTheme []byte
 
-func NewTheme() *Theme {
+// NewTheme returns a new theme and potentially a warning if the theme file was not found or could not be read
-	var theme Theme
+func NewTheme() (*Theme, error) {
-	err := yaml.UnmarshalStrict(defaultTheme, &theme)
+	var ret Theme
-	if err != nil {
+	warn := ReadConfig(defaultTheme, "theme.yml", &ret)
-		panic(fmt.Errorf("failed to default theme: %w", err))
+	ret.Material.Shaper = &text.Shaper{}
-	}
+	ret.Material.Icon.CheckBoxChecked = must(widget.NewIcon(icons.ToggleCheckBox))
-	ReadCustomConfigYml("theme.yml", &theme)
+	ret.Material.Icon.CheckBoxUnchecked = must(widget.NewIcon(icons.ToggleCheckBoxOutlineBlank))
-	theme.Material.Shaper = &text.Shaper{}
+	ret.Material.Icon.RadioChecked = must(widget.NewIcon(icons.ToggleRadioButtonChecked))
-	theme.Material.Icon.CheckBoxChecked = must(widget.NewIcon(icons.ToggleCheckBox))
+	ret.Material.Icon.RadioUnchecked = must(widget.NewIcon(icons.ToggleRadioButtonUnchecked))
-	theme.Material.Icon.CheckBoxUnchecked = must(widget.NewIcon(icons.ToggleCheckBoxOutlineBlank))
+	return &ret, warn
-	theme.Material.Icon.RadioChecked = must(widget.NewIcon(icons.ToggleRadioButtonChecked))
-	theme.Material.Icon.RadioUnchecked = must(widget.NewIcon(icons.ToggleRadioButtonUnchecked))
-	return &theme
 }
 
 func must[T any](ic T, err error) T {

tracker/gioui/tracker.go

@@ -71,7 +71,6 @@ var ZoomFactors = []float32{.25, 1. / 3, .5, 2. / 3, .75, .8, 1, 1.1, 1.25, 1.5,
 
 func NewTracker(model *tracker.Model) *Tracker {
 	t := &Tracker{
-		Theme:             NewTheme(),
 		OctaveNumberInput: NewNumberInput(model.Octave().Int()),
 		InstrumentVoices:  NewNumberInput(model.InstrumentVoices().Int()),
 
@@ -93,15 +92,23 @@ func NewTracker(model *tracker.Model) *Tracker {
 		Model: model,
 
 		filePathString: model.FilePath().String(),
-		preferences:    MakePreferences(),
+	}
+	t.PopupAlert = NewPopupAlert(model.Alerts())
+	var warn error
+	if t.Theme, warn = NewTheme(); warn != nil {
+		model.Alerts().AddAlert(tracker.Alert{
+			Priority: tracker.Warning,
+			Message:  warn.Error(),
+			Duration: 10 * time.Second,
+		})
 	}
 	t.Theme.Material.Shaper = text.NewShaper(text.WithCollection(gofont.Collection()))
-	t.PopupAlert = NewPopupAlert(model.Alerts())
+	if warn := ReadConfig(defaultPreferences, "preferences.yml", &t.preferences); warn != nil {
-	if t.preferences.YmlError != nil {
+		model.Alerts().AddAlert(tracker.Alert{
-		model.Alerts().Add(
+			Priority: tracker.Warning,
-			fmt.Sprintf("Preferences YML Error: %s", t.preferences.YmlError),
+			Message:  warn.Error(),
-			tracker.Warning,
+			Duration: 10 * time.Second,
-		)
+		})
 	}
 	t.TrackEditor.scrollTable.Focus()
 	return t