Navigation and info when viewing multiple files (i toggles info, `h…

…` for help, left arrow to go back) (#34)

* Stay in viewer and allow arrow navigations to previous image

* Show image name and format and index

ansipixels/ansipixels.go

@@ -107,6 +107,13 @@ func (ap *AnsiPixels) WriteCentered(y int, msg string, args ...interface{}) {
 	_, _ = ap.Out.WriteString(s)
 }
 
+func (ap *AnsiPixels) WriteRight(y int, msg string, args ...interface{}) {
+	s := fmt.Sprintf(msg, args...)
+	x := ap.W - len(s)
+	ap.MoveCursor(x, y)
+	_, _ = ap.Out.WriteString(s)
+}
+
 func (ap *AnsiPixels) ClearEndOfLine() {
 	_, _ = ap.Out.WriteString("\033[K")
 }

ansipixels/fps/fps.go

@@ -30,7 +30,7 @@ func isStopKey(ap *ansipixels.AnsiPixels) bool {
 			ap.Data = ap.Data[0:0:cap(ap.Data)] // reset buffer
 			return false
 		}
-		if key == 'q' || key == 3 || key == 4 {
+		if key == 'q' || key == 'Q' || key == 3 || key == 4 {
 			return true
 		}
 	}
@@ -89,25 +89,55 @@ var fpsColorsJpg []byte
 func imagesViewer(ap *ansipixels.AnsiPixels, imageFiles []string) int {
 	ap.ClearScreen()
 	ap.HideCursor()
-	ap.Data = make([]byte, 1)
-	for _, imageFile := range imageFiles {
-		img, err := ap.ReadImage(imageFile)
+	ap.Data = make([]byte, 3)
+	i := 0
+	l := len(imageFiles)
+	showInfo := l > 1
+	for {
+		if i >= l {
+			i = 0
+		}
+		imageFile := imageFiles[i]
+		img, format, err := ap.ReadImage(imageFile)
 		if err != nil {
 			return log.FErrf("Error reading image %s: %v", imageFile, err)
 		}
 		if err = ap.ShowImage(img, "\033[34m"); err != nil {
 			return log.FErrf("Error showing image: %v", err)
 		}
+		if showInfo {
+			ap.WriteRight(ap.H-1, "%s (%s, %d/%d)", imageFile, format, i+1, l)
+			ap.Out.Flush()
+		}
 		ap.Out.Flush()
-		_, err = ap.In.Read(ap.Data)
+		_, err = ap.In.Read(ap.Data[0:1])
 		if err != nil {
 			return log.FErrf("Error with cursor position request: %v", err)
 		}
-		if isStopKey(ap) {
+		if ap.Data[0] == '?' || ap.Data[0] == 'h' || ap.Data[0] == 'H' {
+			ap.WriteCentered(ap.H/2-1, "Showing %d out of %d images, hit any key to continue,", i+1, l)
+			ap.WriteCentered(ap.H/2, "'q' to exit, left arrow to go back, 'i' to toggle image information")
+			ap.Out.Flush()
+			_, _ = ap.In.Read(ap.Data[0:1])
+		}
+		if ap.Data[0] == 'i' || ap.Data[0] == 'I' {
+			showInfo = !showInfo
+			continue
+		}
+		if ap.Data[0] == 27 {
+			n, _ := ap.In.Read(ap.Data[1:3])
+			ap.Data = ap.Data[:1+n]
+		}
+		// check for left/right arrow to go to next/previous image
+		if len(ap.Data) >= 3 && ap.Data[0] == 27 && ap.Data[1] == '[' && ap.Data[2] == 'D' {
+			i = (i + l - 1) % l
+			continue
+		}
+		if isStopKey(ap) || l == 1 {
 			return 0
 		}
+		i++
 	}
-	return 0
 }
 
 func Main() int { //nolint:funlen,gocognit // color and mode if/else are a bit long.
@@ -177,12 +207,12 @@ func Main() int { //nolint:funlen,gocognit // color and mode if/else are a bit l
 	var err error
 	if *imgFlag == "" {
 		if *trueColorFlag || *colorFlag {
-			background, err = ap.DecodeImage(bytes.NewReader(fpsColorsJpg))
+			background, _, err = ap.DecodeImage(bytes.NewReader(fpsColorsJpg))
 		} else {
-			background, err = ap.DecodeImage(bytes.NewReader(fpsJpg))
+			background, _, err = ap.DecodeImage(bytes.NewReader(fpsJpg))
 		}
 	} else {
-		background, err = ap.ReadImage(*imgFlag)
+		background, _, err = ap.ReadImage(*imgFlag)
 	}
 	if err != nil {
 		return log.FErrf("Error reading image: %v", err)

ansipixels/image.go

@@ -215,23 +215,23 @@ func convertToRGBA(src image.Image) *image.RGBA {
 	return dst
 }
 
-func (ap *AnsiPixels) ReadImage(path string) (*image.RGBA, error) {
+func (ap *AnsiPixels) ReadImage(path string) (*image.RGBA, string, error) {
 	file, err := os.Open(path)
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
 	defer file.Close()
 	return ap.DecodeImage(file)
 }
 
-func (ap *AnsiPixels) DecodeImage(data io.Reader) (*image.RGBA, error) {
+func (ap *AnsiPixels) DecodeImage(data io.Reader) (*image.RGBA, string, error) {
 	// Automatically detect and decode the image format
 	img, format, err := image.Decode(data)
 	if err != nil {
-		return nil, err
+		return nil, "", err
 	}
 	log.Debugf("Image format: %s", format)
-	return convertToRGBA(img), nil
+	return convertToRGBA(img), format, nil
 }
 
 // Color string is the fallback mono color to use when AnsiPixels.TrueColor is false.