8

Similar to this question, I'd like a tool/minor mode to quickly preview my files by merely having the cursor positioned over them (e.g. the currently selected file is displayed in the active buffer window). I don't care about depressing events and I don't want an overlay. If it's selected, I want it displayed in the active window. Pressing enter and switching to the buffer is too slow to skim through a bunch of raw data files. How could I do this?

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wdkrnls
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  • For those users who use OSX, there is a native application called `qlmanage` that can be used to display the file contents or pdf or image. Another forum participant has written a function to delete subsequent processes when viewing multiple items (one after another) with said application. Here is the link to the relevant thread: http://stackoverflow.com/questions/20023458/how-to-delete-process-with-similar-name-one-at-a-time-from-newest-to-oldest I currently have it set up so that I can use the arrow key up or down in a file manager mode and `qlmanage` displays the file contents at point. – lawlist Mar 28 '15 at 02:44

2 Answers2

11

I discovered this functionality is already built-in to Helm. To use it, use the up and down arrows and press C-up/C-down.

akaihola
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wdkrnls
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    Thank you for mentioning this. There is always something else simple yet amazing to learn about Helm! –  Mar 29 '15 at 11:08
  • I remember that this used to work at one point, but I tried it recently and got the error message `"Helm-follow-mode allowed only on images, disabling"`. I tried removing the bit that checks that, and helm-follow-mode appears to still work with regular files, though it's a bit slow to open each file. Does anyone know why they changed this behavior? – 0x5453 May 02 '18 at 17:35
4

This StackOverflow question is the same as yours. And the accepted answer by the OP is a good one. There are other good answers there, as well.

Similarly, this question to help-gnu-emacs@gnu.org is essentially the same also.

My own answer to both questions is to use Icicles and to define this command:

    (defun my-find-file ()
      "Like `icicle-find-file', but alt action views file temporarily.
    Alternate action keys such as `C-S-down' visit the candidate file in
    `view-mode' and kill the buffer of the last such viewed candidate."
      (interactive)
      (let ((icicle-candidate-alt-action-fn
             (lambda (file)
               (when (and my-last-viewed
                          (get-file-buffer my-last-viewed))
                 (kill-buffer (get-file-buffer my-last-viewed)))
               (setq my-last-viewed  (abbreviate-file-name file))
               (view-file file)
               (select-frame-set-input-focus
                  (window-frame (active-minibuffer-window))))))
        (icicle-find-file-of-content)))

    (defvar my-last-viewed nil
      "Last file viewed by alternate action of `my-find-file'.")

Then you can:

  1. Use M-x my-find-file (or bind it to a key - e.g., C-x C-f).
  2. Optionally type part of a file name, to limit the matching names.
  3. Optionally use down or up to cycle among file names.
  4. Use C-S-down to visit the next file in order.
  5. Repeat #4 to see other files in order.
  6. Repeat #2 or #3 to see other sets of files.
  7. End with RET to choose a file to visit or C-g to cancel.

See the linked posts for more info.

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Drew
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    I know its your right to choose your development model. As a user I would like it be on github or in some git repository rather than emacswiki. You don't need to reply to me, just writing here to let you know what I feel. Thanks by the way, for your long continuing efforts in helping emacs users. – kindahero Oct 23 '14 at 03:36
  • @kindahero: FWIW, all of my libraries are also on [MELPA](www.melpa.org). – Drew Oct 23 '14 at 15:38