filebrowser/http/thumbnail.go
2020-06-08 23:09:06 +08:00

93 lines
2.1 KiB
Go

package http
import (
"github.com/disintegration/imaging"
"github.com/filebrowser/filebrowser/v2/errors"
"github.com/filebrowser/filebrowser/v2/files"
"image"
"image/gif"
"image/jpeg"
"image/png"
"mime"
"net/http"
"net/url"
)
var thumbnailHandler = withUser(func(w http.ResponseWriter, r *http.Request, d *data) (int, error) {
if !d.user.Perm.Download {
return http.StatusAccepted, nil
}
file, err := files.NewFileInfo(files.FileOptions{
Fs: d.user.Fs,
Path: r.URL.Path,
Modify: d.user.Perm.Modify,
Expand: true,
Checker: d,
})
if err != nil {
return errToStatus(err), err
}
if file.IsDir || file.Type != "image" {
return http.StatusNotFound, nil
}
return thumbnailFileHandler(w, r, file)
})
func thumbnailFileHandler(w http.ResponseWriter, r *http.Request, file *files.FileInfo) (int, error) {
fd, err := file.Fs.Open(file.Path)
if err != nil {
return errToStatus(err), err
}
defer fd.Close()
if r.URL.Query().Get("inline") == "true" {
w.Header().Set("Content-Disposition", "inline")
} else {
// As per RFC6266 section 4.3
w.Header().Set("Content-Disposition", "attachment; filename*=utf-8''"+url.PathEscape(file.Name))
}
srcImg, err := imaging.Decode(fd, imaging.AutoOrientation(true))
if err != nil {
return errToStatus(err), err
}
dstImg := fitResizeImage(srcImg)
w.Header().Add("Content-Type", mime.TypeByExtension(file.Extension))
err = func() error {
switch file.Extension {
case ".jpg", ".jpeg":
return jpeg.Encode(w, dstImg, nil)
case ".png":
return png.Encode(w, dstImg)
case ".gif":
return gif.Encode(w, dstImg, nil)
default:
return errors.ErrNotExist
}
}()
if err != nil {
return errToStatus(err), err
}
return 0, nil
}
const maxSize = 1080
func fitResizeImage(srcImage image.Image) image.Image {
width := srcImage.Bounds().Dx()
height := srcImage.Bounds().Dy()
if width > maxSize && width > height {
width = maxSize
height = 0
} else if height > maxSize && height > width {
width = 0
height = maxSize
} else {
return srcImage
}
return imaging.Resize(srcImage, width, height, imaging.NearestNeighbor)
}