Add support for automatic reloading the config when it has been changed

Author: Nikos Verschore

deck.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"github.com/atotto/clipboard"
+	"github.com/fsnotify/fsnotify"
 	"github.com/godbus/dbus"
 	"github.com/muesli/streamdeck"
 )
@@ -24,11 +25,12 @@ type Deck struct {
 }
 
 // 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
 	}
+	currentDeck = path
 	fmt.Println("Loading deck:", path)
 
 	dc, err := LoadConfig(path)
@@ -70,6 +72,42 @@ func LoadDeck(dev *streamdeck.Device, base string, deck string) (*Deck, error) {
 		d.Widgets = append(d.Widgets, w)
 	}
 
+	watcher, err := fsnotify.NewWatcher()
+	if err == nil {
+		err = watcher.Add(path)
+		if err == nil {
+
+			go func() {
+				for {
+					select {
+					case event := <-watcher.Events:
+						if currentDeck == path {
+							fmt.Printf("Change:  %s: %s\n", event.Op, event.Name)
+							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 error := <-watcher.Errors:
+						fmt.Printf("Watcher had an error: %s\n", error)
+					}
+				}
+			}()
+		} else {
+			fmt.Printf("Failed to watch deck, automatic reloading diabled: %s\n", err)
+		}
+	} else {
+		fmt.Printf("Failed to initialize fsnotify, automatic reloading diabled: %s\n", err)
+	}
+
 	return &d, nil
 }
 

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/atotto/clipboard v0.1.4
 	github.com/bendahl/uinput v1.4.1
 	github.com/flopp/go-findfont v0.1.0
+	github.com/fsnotify/fsnotify v1.4.7
 	github.com/go-ole/go-ole v1.2.4 // indirect
 	github.com/godbus/dbus v4.1.0+incompatible
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0

go.sum

@@ -32,6 +32,7 @@ github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZm
 github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
 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/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
 github.com/go-kit/kit v0.8.0/go.mod h1:xBxKIO96dXMWWy0MnWVtmwkA9/13aqxPnvrjFYMA2as=

main.go

@@ -18,7 +18,8 @@ import (
 )
 
 var (
-	deck *Deck
+	deck        *Deck
+	currentDeck string
 
 	dbusConn *dbus.Conn
 	keyboard uinput.Keyboard