refactor(mpris): route capability properties through Capabilities.setFromProp

The six identical Can* arms in UpdatePlayerProperties and the reflection
loop in loadCapabilitiesFromProps both mapped dbus-tagged bool fields;
setFromProp is now the single tag-to-field mapping.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AKi5652rX9cdUDycdU1btS

Author: b0bbywan

backend/mpris/mpris.go

@@ -260,30 +260,8 @@ func (m *MPRISBackend) UpdatePlayerProperties(busName string, changed map[string
 					players[i].Position = val
 					players[i].PositionUpdatedAt = time.Now()
 				}
-			case "CanPlay":
-				if val, ok := extract[bool](variant); ok {
-					players[i].Capabilities.CanPlay = val
-				}
-			case "CanPause":
-				if val, ok := extract[bool](variant); ok {
-					players[i].Capabilities.CanPause = val
-				}
-			case "CanGoNext":
-				if val, ok := extract[bool](variant); ok {
-					players[i].Capabilities.CanGoNext = val
-				}
-			case "CanGoPrevious":
-				if val, ok := extract[bool](variant); ok {
-					players[i].Capabilities.CanGoPrevious = val
-				}
-			case "CanSeek":
-				if val, ok := extract[bool](variant); ok {
-					players[i].Capabilities.CanSeek = val
-				}
-			case "CanControl":
-				if val, ok := extract[bool](variant); ok {
-					players[i].Capabilities.CanControl = val
-				}
+			case "CanPlay", "CanPause", "CanGoNext", "CanGoPrevious", "CanSeek", "CanControl":
+				players[i].Capabilities.setFromProp(key, variant)
 			}
 		}
 

backend/mpris/player.go

@@ -233,34 +233,30 @@ func trackFromSignalMetadata(meta map[string]dbus.Variant) Track {
 	return track
 }
 
-// loadCapabilitiesFromProps loads capabilities from already retrieved properties.
-// Used by loadFromDBus() to avoid additional D-Bus calls.
-// Maps D-Bus properties (CanPlay, CanPause, etc.) to the Capabilities struct
-// using reflection and `dbus` tags.
-func (p *Player) loadCapabilitiesFromProps(props map[string]dbus.Variant) Capabilities {
-	var caps Capabilities
-
-	val := reflect.ValueOf(&caps).Elem()
-	typ := val.Type()
-
-	for i := 0; i < val.NumField(); i++ {
-		field := val.Field(i)
-		fieldType := typ.Field(i)
-
-		// Retrieve dbus tag
-		dbusTag := fieldType.Tag.Get("dbus")
-		if dbusTag == "" {
-			continue
-		}
-
-		// Retrieve property from props
-		if variant, ok := props[dbusTag]; ok {
-			if boolVal, ok := extract[bool](variant); ok {
-				field.SetBool(boolVal)
-			}
+// setFromProp sets the Capabilities field whose `dbus` tag matches name;
+// no-op when no field matches or the variant does not hold a bool.
+func (c *Capabilities) setFromProp(name string, variant dbus.Variant) {
+	val, ok := extract[bool](variant)
+	if !ok {
+		return
+	}
+	v := reflect.ValueOf(c).Elem()
+	typ := v.Type()
+	for i := 0; i < v.NumField(); i++ {
+		if typ.Field(i).Tag.Get("dbus") == name {
+			v.Field(i).SetBool(val)
+			return
 		}
 	}
+}
 
+// loadCapabilitiesFromProps loads capabilities from already retrieved
+// properties, avoiding additional D-Bus calls.
+func (p *Player) loadCapabilitiesFromProps(props map[string]dbus.Variant) Capabilities {
+	var caps Capabilities
+	for name, variant := range props {
+		caps.setFromProp(name, variant)
+	}
 	return caps
 }