add callback option

wallpaper.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"log"
+	"os/exec"
 
 	"go.i3wm.org/i3"
 )
@@ -17,11 +18,13 @@ func GetWorkspaceWallpaper(workspace string, config Config) string {
 	return file
 }
 
-func GetOutputsWallpapers(config Config) ([]string, error) {
+func GetOutputsWallpapers(config Config) ([]string, []string, error) {
 	files := []string{}
+	screens := []string{}
 	outputs, err := i3.GetOutputs()
+
 	if err != nil {
-		return files, err
+		return files, screens, err
 	}
 
 	for _, output := range outputs {
@@ -30,21 +33,29 @@ func GetOutputsWallpapers(config Config) ([]string, error) {
 
 			if file != "" {
 				files = append(files, file)
+				screens = append(screens, output.Name)
 			}
 		}
 	}
 
-	return files, nil
+	return files, screens, nil
 }
 
 func UpdateWallapers(config Config) {
-	files, err := GetOutputsWallpapers(config)
+	files, screens, err := GetOutputsWallpapers(config)
+
 	if err != nil {
 		log.Printf("[ERROR] %s", err.Error())
 		return
 	}
 
-	cmd, err := FehUpdateWallpapers(files)
+	var cmd *exec.Cmd
+
+	if config.Callback == "" {
+		cmd, err = FehUpdateWallpapers(files)
+	} else {
+		cmd, err = CallbackUpdateWallpapers(config.Callback, files, screens)
+	}
 
 	if err != nil {
 		log.Printf("[ERROR] cmd=%s error=%s", cmd.String(), err.Error())