maintain dir state as int, not string

main.go

@@ -7,7 +7,6 @@ import (
 	"log"
 	"os"
 	"path/filepath"
-	"slices"
 	"strconv"
 	"strings"
 
@@ -19,9 +18,9 @@ import (
 )
 
 type state struct {
-	currentDirectory string
-	currentFile      string
-	images           []string
+	dir    string
+	i      int
+	images []string
 }
 
 //go:embed noise.png
@@ -40,7 +39,7 @@ var fileListBindVar = tk.Variable("FileList")
 var directoryState state
 
 func (d state) pathToImageAtIndex(i int) string {
-	return filepath.Join(directoryState.currentDirectory, directoryState.images[i])
+	return filepath.Join(directoryState.dir, directoryState.images[i])
 }
 
 func must[T any](t T, err error) T {
@@ -86,9 +85,8 @@ func newDirectory() {
 }
 
 func newBrowse(file string) {
-	directoryState.currentFile = filepath.Base(file)
-	directoryState.currentDirectory = filepath.Dir(file)
-	dirfiles, err := os.ReadDir(directoryState.currentDirectory)
+	directoryState.dir = filepath.Dir(file)
+	dirfiles, err := os.ReadDir(directoryState.dir)
 	if err != nil {
 		log.Printf("could not open dir: %v", err)
 		return
@@ -131,7 +129,6 @@ func updateImage(file string) {
 		imaging.CatmullRom,
 	)
 	repaint(filepath.Base(file), tk.Data(i))
-	directoryState.currentFile = filepath.Base(file)
 }
 
 func repaint(name string, data tk.Opt) {
@@ -148,6 +145,7 @@ func repaint(name string, data tk.Opt) {
 	tk.App.Center()
 }
 
+// TODO: make this use withdraw/deiconify
 func destroyFileList(destroy bool) {
 	if destroy {
 		tk.Destroy(fileList)
@@ -163,7 +161,7 @@ func constructFileList() {
 	lb = fileList.Listbox(tk.Height(0))
 	for i := range directoryState.images {
 		lb.Insert("end", directoryState.images[i])
-		if i == slices.Index(directoryState.images, directoryState.currentFile) {
+		if i == directoryState.i {
 			lb.SelectionSet(i)
 		}
 	}
@@ -188,6 +186,7 @@ func menuSelect() {
 }
 
 func moveSelectInFileList(target int) {
+	directoryState.i = target
 	if lb != nil {
 		lb.SelectionClear("0", "end")
 		lb.SelectionSet(target)
@@ -196,7 +195,7 @@ func moveSelectInFileList(target int) {
 }
 
 func keyPress(e *tk.Event) {
-	curr := slices.Index(directoryState.images, directoryState.currentFile)
+	curr := directoryState.i
 	switch e.Keysym {
 	case ".":
 		log.Printf("state: %+v", directoryState)