Add string reps for preview classes

kittens/choose_files/calibre.go

@@ -212,6 +212,10 @@ func (c *calibre_server_process) ShowMetadata(h *Handler, s ShowData) (offset in
 	return
 }
 
+func (c *calibre_server_process) String() string {
+	return "Calibre"
+}
+
 func NewCalibrePreview(
 	abspath string, metadata fs.FileInfo, opts Settings, WakeupMainThread func() bool,
 ) Preview {

kittens/choose_files/image_preview.go

@@ -42,6 +42,7 @@ type PreviewRenderer interface {
 	Unmarshall(map[string]string) (any, error)
 	Render(string) (map[string][]byte, metadata, *images.ImageData, error)
 	ShowMetadata(h *Handler, s ShowData) int
+	String() string
 }
 
 type render_data struct {
@@ -71,6 +72,9 @@ type ImagePreview struct {
 	WakeupMainThread      func() bool
 }
 
+func (p *ImagePreview) String() string {
+	return fmt.Sprintf("ImagePreview{%#v, ready: %v, renderer: %s}", p.abspath, p.ready.Load(), p.renderer.String())
+}
 func (p *ImagePreview) IsValidForColorScheme(bool) bool { return true }
 func (p *ImagePreview) IsReady() bool                   { return p.ready.Load() || p.render_channel == nil }
 
@@ -213,6 +217,8 @@ func (p *ImagePreview) start_rendering() {
 
 type ImagePreviewRenderer uint
 
+func (p ImagePreviewRenderer) String() string { return "ImagePreviewRenderer" }
+
 func (p ImagePreviewRenderer) Render(abspath string) (ans map[string][]byte, m metadata, img *images.ImageData, err error) {
 	if img, err = images.OpenImageFromPath(abspath); err != nil {
 		return nil, metadata{}, nil, err

kittens/choose_files/preview.go

@@ -29,6 +29,7 @@ type Preview interface {
 	IsValidForColorScheme(light bool) bool
 	Unload()
 	IsReady() bool
+	String() string
 }
 
 type PreviewManager struct {
@@ -82,6 +83,7 @@ type MessagePreview struct {
 	trailers []string
 }
 
+func (p MessagePreview) String() string                  { return fmt.Sprintf("MessagePreview{%#v}", p.title) }
 func (p MessagePreview) IsValidForColorScheme(bool) bool { return true }
 func (p MessagePreview) IsReady() bool                   { return true }
 
@@ -213,6 +215,10 @@ type TextFilePreview struct {
 	metadata                     fs.FileInfo
 }
 
+func (p *TextFilePreview) String() string {
+	return fmt.Sprint("TextFilePreview{%#v, ready: %v}", p.path, p.ready.Load())
+}
+
 func (p *TextFilePreview) IsValidForColorScheme(light bool) bool { return p.light == light }
 
 func (p *TextFilePreview) Unload() {}