Add support for automatic reloading the config when it has been changed (based on #50)

deck.go

@@ -13,6 +13,7 @@ import (
 	"time"
 
 	"github.com/atotto/clipboard"
+	"github.com/fsnotify/fsnotify"
 	"github.com/godbus/dbus"
 	"github.com/muesli/streamdeck"
 )
@@ -22,11 +23,12 @@ type Deck struct {
 	File       string
 	Background image.Image
 	Widgets    []Widget
+	Watcher    *fsnotify.Watcher
 }
 
 // LoadDeck loads a deck configuration.
-func LoadDeck(dev *streamdeck.Device, base string, deck string) (*Deck, error) {
-	path, err := expandPath(base, deck)
+func LoadDeck(dev *streamdeck.Device, base string, deckName string) (*Deck, error) {
+	path, err := expandPath(base, deckName)
 	if err != nil {
 		return nil, err
 	}
@@ -71,6 +73,48 @@ func LoadDeck(dev *streamdeck.Device, base string, deck string) (*Deck, error) {
 		d.Widgets = append(d.Widgets, w)
 	}
 
+	d.Watcher, err = fsnotify.NewWatcher()
+	if err == nil {
+		err = d.Watcher.Add(path)
+		if err == nil {
+			go func() {
+				for {
+					select {
+					case event, ok := <-d.Watcher.Events:
+						if !ok {
+							return
+						}
+						if d.File == path {
+							fmt.Printf("Change: %s: %s\n", event.Op, event.Name)
+							err = d.Watcher.Close()
+							if err != nil {
+								fatal(err)
+							}
+							d, err := LoadDeck(dev, base, deckName)
+							if err != nil {
+								fatal(err)
+							}
+							err = dev.Clear()
+							if err != nil {
+								fatal(err)
+							}
+
+							deck = d
+							deck.updateWidgets()
+							return
+						}
+					case err := <-d.Watcher.Errors:
+						fmt.Fprintf(os.Stderr, "Watcher had an error: %s\n", err)
+					}
+				}
+			}()
+		} else {
+			fmt.Fprintf(os.Stderr, "Failed to watch deck, automatic reloading diabled: %s\n", err)
+		}
+	} else {
+		fmt.Fprintf(os.Stderr, "Failed to initialize fsnotify, automatic reloading diabled: %s\n", err)
+	}
+
 	return &d, nil
 }
 
@@ -225,6 +269,10 @@ func (d *Deck) triggerAction(dev *streamdeck.Device, index uint8, hold bool) {
 		}
 
 		if a.Deck != "" {
+			err := d.Watcher.Close()
+			if err != nil {
+				fatal(err)
+			}
 			d, err := LoadDeck(dev, filepath.Dir(d.File), a.Deck)
 			if err != nil {
 				fmt.Fprintln(os.Stderr, "Can't load deck:", err)

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/bendahl/uinput v1.5.0
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/flopp/go-findfont v0.1.0
+	github.com/fsnotify/fsnotify v1.4.7
 	github.com/godbus/dbus v4.1.0+incompatible
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0
 	github.com/jezek/xgb v0.0.0-20210312150743-0e0f116e1240

go.sum

@@ -13,6 +13,8 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/flopp/go-findfont v0.1.0 h1:lPn0BymDUtJo+ZkV01VS3661HL6F4qFlkhcJN55u6mU=
 github.com/flopp/go-findfont v0.1.0/go.mod h1:wKKxRDjD024Rh7VMwoU90i6ikQRCr+JTHB5n4Ejkqvw=
+github.com/fsnotify/fsnotify v1.4.7 h1:IXs+QLmnXW2CcXuY+8Mzv/fWEsPGWxqefPtCP5CnV9I=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/go-ole/go-ole v1.2.6 h1:/Fpf6oFPoeFik9ty7siob0G6Ke8QvQEuVcuChpwXzpY=
 github.com/go-ole/go-ole v1.2.6/go.mod h1:pprOEPIfldk/42T2oK7lQ4v4JSDwmV0As9GaiUsvbm0=
 github.com/godbus/dbus v4.1.0+incompatible h1:WqqLRTsQic3apZUK9qC5sGNfXthmPXzUZ7nQPrNITa4=