From a34b3365b4d3f9fcdb61704f62ea5080c060599f Mon Sep 17 00:00:00 2001
From: Christian Muehlhaeuser <muesli@gmail.com>
Date: Sun, 30 May 2021 00:48:33 +0200
Subject: [PATCH] Let Update return an optional error and handle it during
 widget updates

---
 deck.go                 |  4 +++-
 widget.go               |  2 +-
 widget_button.go        | 12 ++++++------
 widget_recent_window.go |  9 +++------
 widget_time.go          | 11 ++++-------
 widget_top.go           |  9 +++------
 6 files changed, 20 insertions(+), 27 deletions(-)

diff --git a/deck.go b/deck.go
index ccc7db6..9f7086f 100644
--- a/deck.go
+++ b/deck.go
@@ -170,6 +170,8 @@ func (d *Deck) triggerAction(index uint8, hold bool) {
 // updateWidgets updates/repaints all the widgets.
 func (d *Deck) updateWidgets() {
 	for _, w := range d.Widgets {
-		w.Update(&dev)
+		if err := w.Update(&dev); err != nil {
+			log.Fatalf("error: %v", err)
+		}
 	}
 }
diff --git a/widget.go b/widget.go
index d129a9c..f28d5a8 100644
--- a/widget.go
+++ b/widget.go
@@ -16,7 +16,7 @@ import (
 
 type Widget interface {
 	Key() uint8
-	Update(dev *streamdeck.Device)
+	Update(dev *streamdeck.Device) error
 	Action() *ActionConfig
 	ActionHold() *ActionConfig
 	TriggerAction()
diff --git a/widget_button.go b/widget_button.go
index 870df21..a992109 100644
--- a/widget_button.go
+++ b/widget_button.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"image"
-	"log"
 	"sync"
 
 	"github.com/muesli/streamdeck"
@@ -17,7 +16,9 @@ type ButtonWidget struct {
 	init sync.Once
 }
 
-func (w *ButtonWidget) Update(dev *streamdeck.Device) {
+func (w *ButtonWidget) Update(dev *streamdeck.Device) error {
+	var err error
+
 	w.init.Do(func() {
 		size := int(dev.Pixels)
 		margin := size / 18
@@ -42,9 +43,8 @@ func (w *ButtonWidget) Update(dev *streamdeck.Device) {
 			_ = drawImage(img, w.icon, height, image.Pt(-1, -1))
 		}
 
-		err := dev.SetImage(w.key, img)
-		if err != nil {
-			log.Fatal(err)
-		}
+		err = dev.SetImage(w.key, img)
 	})
+
+	return err
 }
diff --git a/widget_recent_window.go b/widget_recent_window.go
index 062477c..0ca4634 100644
--- a/widget_recent_window.go
+++ b/widget_recent_window.go
@@ -16,13 +16,13 @@ type RecentWindowWidget struct {
 	lastClass string
 }
 
-func (w *RecentWindowWidget) Update(dev *streamdeck.Device) {
+func (w *RecentWindowWidget) Update(dev *streamdeck.Device) error {
 	img := image.NewRGBA(image.Rect(0, 0, int(dev.Pixels), int(dev.Pixels)))
 
 	size := int(dev.Pixels)
 	if int(w.window) < len(recentWindows) {
 		if w.lastClass == recentWindows[w.window].Class {
-			return
+			return nil
 		}
 		w.lastClass = recentWindows[w.window].Class
 
@@ -30,10 +30,7 @@ func (w *RecentWindowWidget) Update(dev *streamdeck.Device) {
 		draw.Draw(img, image.Rect(4, 4, size-4, size-4), icon, image.Point{0, 0}, draw.Src)
 	}
 
-	err := dev.SetImage(w.key, img)
-	if err != nil {
-		log.Fatal(err)
-	}
+	return dev.SetImage(w.key, img)
 }
 
 func (w *RecentWindowWidget) TriggerAction() {
diff --git a/widget_time.go b/widget_time.go
index 10f46de..11bfe27 100644
--- a/widget_time.go
+++ b/widget_time.go
@@ -1,8 +1,8 @@
 package main
 
 import (
+	"fmt"
 	"image"
-	"log"
 	"strings"
 	"time"
 
@@ -41,7 +41,7 @@ func formatTime(t time.Time, format string) string {
 	return t.Format(format)
 }
 
-func (w *TimeWidget) Update(dev *streamdeck.Device) {
+func (w *TimeWidget) Update(dev *streamdeck.Device) error {
 	size := int(dev.Pixels)
 	margin := size / 18
 	height := size - (margin * 2)
@@ -51,7 +51,7 @@ func (w *TimeWidget) Update(dev *streamdeck.Device) {
 	fonts := strings.Split(w.font, ";")
 
 	if len(formats) == 0 {
-		return
+		return fmt.Errorf("no time format supplied")
 	}
 	for len(fonts) < len(formats) {
 		fonts = append(fonts, "regular")
@@ -70,8 +70,5 @@ func (w *TimeWidget) Update(dev *streamdeck.Device) {
 			image.Pt(-1, -1))
 	}
 
-	err := dev.SetImage(w.key, img)
-	if err != nil {
-		log.Fatal(err)
-	}
+	return dev.SetImage(w.key, img)
 }
diff --git a/widget_top.go b/widget_top.go
index 7823c6d..954ea94 100644
--- a/widget_top.go
+++ b/widget_top.go
@@ -21,7 +21,7 @@ type TopWidget struct {
 	lastValue float64
 }
 
-func (w *TopWidget) Update(dev *streamdeck.Device) {
+func (w *TopWidget) Update(dev *streamdeck.Device) error {
 	var value float64
 	var label string
 
@@ -48,7 +48,7 @@ func (w *TopWidget) Update(dev *streamdeck.Device) {
 	}
 
 	if w.lastValue == value {
-		return
+		return nil
 	}
 	w.lastValue = value
 
@@ -98,8 +98,5 @@ func (w *TopWidget) Update(dev *streamdeck.Device) {
 		-1,
 		image.Pt(-1, -1))
 
-	err = dev.SetImage(w.key, img)
-	if err != nil {
-		log.Fatal(err)
-	}
+	return dev.SetImage(w.key, img)
 }