Open file at point from text files too

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.4.0] - 2021-04-06
+### Added
+* When launching from a text file, open sxiv with the image at point (using `-n`)
+
 ## [0.3.3] - 2020-08-03
 ### Fixed
 * Error with selected files in a subdirectory (issue #1)

TODO.md

@@ -9,6 +9,11 @@
     * Other options like running recursively, modifying arguments, etc
 6. [ ] When running with a lot of files, sxiv may take some time to start. Signal to the user that it is starting, and let them kill it if they want.
 7. [ ] `sxiv-exclude-strings` does not work recursively, because only the directories are passed to the process. Adding all files to the path might cause it to fail (bash length limit), or take a long time.
+       * Use find(1) to pass the files?
 8. [ ] Make it work in find-dired buffers too
 9. [ ] Bug - sometimes, if a lot of files (usually over 50) are marked in sxiv, the input received by `sxiv-insert-subdirs` is incomplete - the first file name is a trailing segment of an actual existing filename, e.g. if a file is called `"foo/bar_baz.jpg"`, I might get something like `"r_baz.jpg"` as the first element.
+    * I have no idea what's causing this or how to fix it. Help needed! :(
 10. [ ] Optimize startup speed, especially with a large number of files.
+11. [ ] When using a text file, mark files marked in sxiv.
+    * Maybe using multiple-cursors or iedit?
+12. [x] When launching from a text file, open sxiv with the image at point (using `-n`).

sxiv.el

@@ -41,6 +41,12 @@ It must contain \"-o\" for marking in Dired buffers to function."
   "Exclude files whose paths match these strings."
   :type '(repeat string))
 
+(defcustom sxiv-after-exit-functions '(sxiv-dired-mark-files)
+  "Functions run after the sxiv process exits.
+Each function must accept two arguments, the associated process
+and a string, which is output just received from it."
+  :type '(repeat function))
+
 (defvar sxiv--directory nil
   "Directory `sxiv' was called from.
 Used by `sxiv-filter' to know where to mark files.")
@@ -58,7 +64,9 @@ With no marked files, or if not in a Dired buffer, return nil."
 Return PATHS unchanged."
   (cl-loop for path in paths
     ;; If the file does not exist in the current directory...
-    unless (and (file-exists-p (file-name-nondirectory path))
+    when (and (not (file-exists-p (file-name-nondirectory path)))
+              ;; Workaround for what looks like an Emacs issue (see TODO #9)
+              (file-exists-p path)
                 ;; ;; ...I don't understand why this is here!
                 ;; ;; Why would there be a directory in the selected
                 ;; ;; files, seeing as one can't mark directories in
@@ -68,25 +76,48 @@ Return PATHS unchanged."
     do (dired-insert-subdir (file-name-directory path))
     finally return paths))
 
-(defun sxiv-dired-mark-files (files)
-  "Mark FILES in the current (dired) buffer."
-  (dired-mark-if
-   (and (not (looking-at-p dired-re-dot))
-        (not (eolp))
-        (let ((fn (dired-get-filename t t)))
-          (and fn (--find (equal fn it) files))))
-   "file"))
-
-(defun sxiv-filter (_process output)
-  "Open a `dired' buffer and mark any files marked by the user in `sxiv'.
-Used as process filter for `sxiv'.
-
-OUTPUT is the output of the sxiv process as a string."
+(defun sxiv-dired-mark-files (_process output)
+  "Open a `dired' buffer and mark any files marked by the user in `sxiv'."
   (find-file sxiv--directory)
-  (--> (split-string output "\n")
-       (-drop-last 1 it)
-       (sxiv-insert-subdirs it)
-       (sxiv-dired-mark-files it)))
+  (let ((files (--> (split-string output "\n")
+                 (-drop-last 1 it)
+                 (sxiv-insert-subdirs it))))
+    (dired-mark-if
+     (and (not (looking-at-p dired-re-dot))
+          (not (eolp))
+          (let ((fn (dired-get-filename t t)))
+            (and fn (--find (equal fn it) files))))
+     "file")))
+
+(defun sxiv-filter (process output)
+  "Used as process filter for `sxiv'.
+OUTPUT is the output of the sxiv process as a string."
+  (run-hook-with-args 'sxiv-after-exit-functions process output))
+
+(defun sxiv-paths-raw ()
+  (cond ((sxiv-dired-marked-files-p)
+         (dired-get-marked-files))
+        ((derived-mode-p 'text-mode)
+         (split-string
+          (buffer-substring-no-properties (point-min) (point-max))
+          "\n"))
+        (t (directory-files default-directory))))
+
+(defun sxiv-file-at-point-index (&optional paths)
+  "Return index of file at point.
+PATHS should be a list of relative file names as strings, and is
+required for dired-mode buffers."
+  (cond ((derived-mode-p 'dired-mode)
+         (let* ((path-at-point (dired-file-name-at-point))
+                (image-at-point (and path-at-point
+                                     ;; REVIEW - also check if file is an image?
+                                     (file-regular-p path-at-point)
+                                     (file-relative-name path-at-point)))
+                (index (when image-at-point
+                         (--find-index (equal image-at-point it) paths))))
+           (when index (1+ index))))
+        ((derived-mode-p 'text-mode)
+         (line-number-at-pos))))
 
 (defun sxiv (&optional prefix)
   "Run sxiv(1), the Simple X Image Viewer.
@@ -102,37 +133,21 @@ run recursively (-r).
 If run from a text file containing one file name per line, open
 the files listed."
   (interactive "P")
-  (let* ((path-at-point (dired-file-name-at-point))
-         (fn-at-point   (when (and path-at-point
-                                   ;; REVIEW - also check if file is an image?
-                                   (file-regular-p path-at-point))
-                          (file-relative-name path-at-point)))
-         (paths (cond ((sxiv-dired-marked-files-p)
-                       (dired-get-marked-files))
-                      ((derived-mode-p 'text-mode)
-                       (--> (buffer-substring-no-properties (point-min) (point-max))
-                            (split-string it "\n")))
-                      (t (directory-files default-directory))))
-         (paths (--remove (or (equal it ".")
-                              (equal it "..")
-                              ;; Currently, this takes effect even
-                              ;; when running from a text
-                              ;; file...should that be the case?
-                              (-find (lambda (exclude)
-                                       (string-match-p exclude it))
-                                     sxiv-exclude-strings))
-                          paths))
+  (let* ((paths   (--remove (or (equal it ".") (equal it "..")
+                                ;; Currently, this takes effect even
+                                ;; when running from a text
+                                ;; file...should that be the case?
+                                (-find (lambda (exclude)
+                                         (string-match-p exclude it))
+                                       sxiv-exclude-strings))
+                            (sxiv-paths-raw)))
          ;; recurse with prefix arg, or if every path is a directory
          (recurse (or prefix (-every? #'file-directory-p paths)))
          ;; remove directories if not running recursively
-         (paths (if recurse paths (seq-remove #'file-directory-p paths)))
-         (fn-at-point-index (when fn-at-point
-                              (--find-index (equal fn-at-point it)
-                                            paths)))
-         (fn-at-point-index (when fn-at-point-index
-                              (-> (1+ fn-at-point-index)
-                                  (number-to-string))))
-         (recurse       (if recurse "-r" "")))
+         (paths   (if recurse paths (seq-remove #'file-directory-p paths)))
+         (index   (sxiv-file-at-point-index paths))
+         (index   (when index (number-to-string index)))
+         (recurse (if recurse "-r" "")))
     (setq sxiv--directory default-directory)
     (message "Running sxiv...")
     (make-process :name "sxiv"
@@ -140,8 +155,7 @@ the files listed."
                   :command
                   (append '("sxiv")
                           sxiv-arguments
-                          (when fn-at-point-index
-                            (list "-n" fn-at-point-index))
+                          (when index (list "-n" index))
                           (list recurse "--")
                           paths)
                   :connection-type 'pipe