more refactoring

filetypes/filetypes.go

@@ -2,6 +2,10 @@ package filetypes
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
 
 	tk "modernc.org/tk9.0"
 )
@@ -95,3 +99,19 @@ func GetTkTypes(fds []FileDescription) []tk.FileType {
 	}
 	return fts
 }
+
+func IsImage(entry os.DirEntry) bool {
+	if entry.IsDir() {
+		return false
+	}
+	ext := filepath.Ext(entry.Name())
+	if ext == "" {
+		return false
+	}
+	for _, ft := range Valid {
+		if slices.Contains(ft.MacExtensions, strings.ToLower(ext[1:])) {
+			return true
+		}
+	}
+	return false
+}

main.go

@@ -18,6 +18,12 @@ import (
 	tk "modernc.org/tk9.0"
 )
 
+type state struct {
+	currentDirectory string
+	currentFile      string
+	images           []string
+}
+
 //go:embed noise.png
 var noise []byte // this is a default image
 
@@ -31,11 +37,10 @@ var fileList *tk.ToplevelWidget
 var lb *tk.ListboxWidget
 var img = tk.Label()
 var fileListBindVar = tk.Variable("FileList")
+var directoryState state
 
-var directoryState struct {
+func (d state) pathToImageAtIndex(i int) string {
-	currentDirectory string
+	return filepath.Join(directoryState.currentDirectory, directoryState.images[i])
-	currentFile      string
-	images           []string
 }
 
 func must[T any](t T, err error) T {
@@ -49,33 +54,38 @@ func checkErr[T any](_ T, err error) bool {
 	return err == nil
 }
 
-func isImage(entry os.DirEntry) bool {
-	if entry.IsDir() {
-		return false
-	}
-	ext := filepath.Ext(entry.Name())
-	if ext == "" {
-		return false
-	}
-	for _, ft := range validFileTypes {
-		if slices.Contains(ft.MacExtensions, ext[1:]) {
-			return true
-		}
-	}
-	return false
-}
-
 func newFileInDirectory() {
 	files := tk.GetOpenFile(tk.Filetypes(filetypes.GetTkTypes(validFileTypes)), tk.Multiple(false))
 	if len(files) < 1 || files[0] == "" {
 		log.Println("no file chosen")
 		return
 	}
-	file := strings.Join(files, " ") // GetOpenFile returns an array split on spaces!
+	// GetOpenFile returns an array split on spaces!
-	openFileAndDirectory(file)
+	newBrowse(strings.Join(files, " "))
 }
 
-func openFileAndDirectory(file string) {
+func newDirectory() {
+	dir := tk.ChooseDirectory()
+	if dir == "" {
+		log.Println("no directory chosen")
+		return
+	}
+	dirfiles, err := os.ReadDir(dir)
+	if err != nil {
+		log.Println("could not read chosen directory")
+		return
+	}
+	for _, v := range dirfiles {
+		// loop until we find an image to start the browser with
+		if filetypes.IsImage(v) {
+			newBrowse(filepath.Join(dir, v.Name()))
+			return
+		}
+	}
+	log.Printf("no images found in dir: %s", dir)
+}
+
+func newBrowse(file string) {
 	directoryState.currentFile = filepath.Base(file)
 	directoryState.currentDirectory = filepath.Dir(file)
 	dirfiles, err := os.ReadDir(directoryState.currentDirectory)
@@ -85,34 +95,13 @@ func openFileAndDirectory(file string) {
 	}
 	directoryState.images = []string{}
 	for _, v := range dirfiles {
-		if isImage(v) {
+		if filetypes.IsImage(v) {
 			directoryState.images = append(directoryState.images, v.Name())
 		}
 	}
 	updateImage(file)
 }
 
-func newDirectory() {
-	dir := tk.ChooseDirectory()
-	if dir == "" {
-		log.Println("no directory chosen")
-		return
-	}
-	directoryState.currentDirectory = dir
-	dirfiles, err := os.ReadDir(directoryState.currentDirectory)
-	if err != nil {
-		log.Println(err)
-		return
-	}
-	directoryState.images = []string{}
-	for _, v := range dirfiles {
-		if isImage(v) {
-			directoryState.images = append(directoryState.images, v.Name())
-		}
-	}
-	updateImage(filepath.Join(directoryState.currentDirectory, directoryState.images[0]))
-}
-
 func updateImage(file string) {
 	var i image.Image
 
@@ -181,7 +170,7 @@ func constructFileList() {
 	tk.Pack(lb)
 	tk.Bind(lb, "<<ListboxSelect>>", tk.Command(func() {
 		selection := lb.Curselection()
-		updateImage(filepath.Join(directoryState.currentDirectory, directoryState.images[selection[0]]))
+		updateImage(directoryState.pathToImageAtIndex(selection[0]))
 	}))
 	tk.Bind(fileList, "<Destroy>", tk.Command(func(e *tk.Event) {
 		// list closed by user click on <x>
@@ -221,12 +210,12 @@ func keyPress(e *tk.Event) {
 		}
 	case "Up", "Left":
 		if curr > 0 {
-			updateImage(filepath.Join(directoryState.currentDirectory, directoryState.images[curr-1]))
+			updateImage(directoryState.pathToImageAtIndex(curr - 1))
 			moveSelectInFileList(curr - 1)
 		}
 	case "Down", "Right":
 		if curr < len(directoryState.images)-1 && curr != -1 {
-			updateImage(filepath.Join(directoryState.currentDirectory, directoryState.images[curr+1]))
+			updateImage(directoryState.pathToImageAtIndex(curr + 1))
 			moveSelectInFileList(curr + 1)
 		}
 	}
@@ -234,7 +223,7 @@ func keyPress(e *tk.Event) {
 
 func main() {
 	tk.App.IconPhoto(tk.NewPhoto(tk.Data(icon)))
-	tk.MacOpenDocument(openFileAndDirectory)
+	tk.MacOpenDocument(newBrowse)
 
 	menubar := tk.Menu()
 	fileMenu := menubar.Menu()