gnomenautilus
Nautilus properties offer the choices Never, Local files only and Always for generating previews for files.
How does it decide what is a local file, and what is not?
What I'm trying to do is get more detailed control over what folders get thumbnails/previews generated. Is there some config file I can change to get more detailed control over this?
I think Ubuntu uses the file header to identify file type and generate the thumbnail on that basis , but in windows a file containing meta data named Thumbnail.db would be updated when windows explorer scan file types (based on the file extension).
This document supports my answer . http://specifications.freedesktop.org/thumbnail-spec/thumbnail-spec-latest.html#CREATION
Ubuntu uses Nautilus that complies with Freedesktop implementation, that uses file MIMEtype . Visit above link for more specifications.
Thumbnailers in repositories and PPAs
A number of thumbnailers are pre-packaged and can be easily installed from the software center or the command line. These thumbnailers don't require any additional configuration and should work right after restarting nautilus. You can do so with:
nautilus -q
Please consider reading these Q&As before installing anything from a PPA:
What are PPAs and how do I use them?
Are PPA's safe to add to my system and what are some "red flags" to watch out for?
Custom thumbnailing scripts on Ubuntu 11.04 and above
Custom thumbnailers that aren't available in repositories have to be installed manually. These are the steps you will have to take to install them:
Check out whether the script has any dependecies listed. If so, install them first.
Download the script and make it executable with chmod a+x filethumbnailer or via Nautilus
Designate a folder in your file system for all future thumbnailers and move the script to it, e.g.
mkdir $HOME/.scripts/thumbnailers && mv filethumbnailer $HOME/.scripts/thumbnailers
Next you will have to register your script with Nautilus. To do so create a thumbnailer entry in /usr/share/thumbnailers. The entry should follow the naming scheme foo.thumbnailer where foo is an expression of your choice (here file):
gksudo gedit /usr/share/thumbnailers/file.thumbnailer
The thumbnailer specifications follow this scheme:
[Thumbnailer Entry]
Exec=$HOME/.scripts/thumbnailers/file.thumbnailer %i %o %s
MimeType=application/file;
The Exec entry points to your thumbnailer script while the MimeType field designates the related MimeTypes. Possible variables are:
%i Input file path
%u Input file URI
%o Output file path
%s Thumbnail size (vertical)
The specifications and variables will vary with each script. Simply copy and paste the content of the respective text box into the file and save it.
The thumbnailers should be up and running after restarting nautilus (nautilus -q).
Custom thumbnailing scripts on Ubuntu 11.04 and below
Earlier versions of Ubuntu rely on GConf for thumbnailer associations. See here for more information.
Sources:
https://live.gnome.org/ThumbnailerSpec
https://bugzilla.redhat.com/show_bug.cgi?id=636819#c29
https://bugs.launchpad.net/ubuntu/+source/gnome-exe-thumbnailer/+bug/752578
http://ubuntuforums.org/showthread.php?t=1881360
CHM files
Overview
Description: With this script you'll get thumbnails of your chm files in the nautilus file manager. The script uses the largest image from the homepage of the chm file to generate the thumbnail, usually this will be an image of the front cover.
Creator: monraaf (http://ubuntuforums.org/showthread.php?t=1159569)
Dependencies:
sudo apt-get install python-beautifulsoup python-chm imagemagick
Thumbnailer entry
[Thumbnailer Entry]
Exec=$HOME/.scripts/thumbnailers/chmthumbnailer %i %o %s
MimeType=application/vnd.ms-htmlhelp;application/x-chm;
Script
#!/usr/bin/env python
import sys, os
from chm import chm
from BeautifulSoup import BeautifulSoup
class ChmThumbNailer(object):
def __init__(self):
self.chm = chm.CHMFile()
def thumbnail(self, ifile, ofile, sz):
if self.chm.LoadCHM(ifile) == 0:
return 1
bestname = None
bestsize = 0
base = self.chm.home.rpartition('/')[0] + '/'
size, data = self.getfile(self.chm.home)
if size > 0:
if self.chm.home.endswith(('jpg','gif','bmp')):
self.write(ofile, sz, data)
else:
soup = BeautifulSoup(data)
imgs = soup.findAll('img')
for img in imgs:
name = base + img.get("src","")
size, data = self.getfile(name)
if size > bestsize:
bestsize = size
bestname = name
if bestname != None:
size, data = self.getfile(bestname)
if size > 0:
self.write(ofile, sz, data)
self.chm.CloseCHM()
def write(self, ofile, sz, data):
fd = os.popen('convert - -resize %sx%s "%s"' % (sz, sz, ofile), "w")
fd.write(data)
fd.close()
def getfile(self,name):
(ret, ui) = self.chm.ResolveObject(name)
if ret == 1:
return (0, '')
return self.chm.RetrieveObject(ui)
if len(sys.argv) > 3:
chm = ChmThumbNailer()
chm.thumbnail(sys.argv[1], sys.argv[2], sys.argv[3])
EPUB files
Overview
Description: epub-thumbnailer is a simple script that tries to find a cover in an epub file and creates a thumbnail for it.
Creator: Mariano Simone (https://github.com/marianosimone/epub-thumbnailer)
Dependencies: none listed, worked fine right away
Thumbnailer Entry
[Thumbnailer Entry]
Exec=$HOME/.scripts/thumbnailers/epubthumbnailer %i %o %s
MimeType=application/epub+zip;
Script
#!/usr/bin/python
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Author: Mariano Simone (marianosimone@gmail.com)
# Version: 1.0
# Name: epub-thumbnailer
# Description: An implementation of a cover thumbnailer for epub files
# Installation: see README
import zipfile
import sys
import Image
import os
import re
from xml.dom import minidom
from StringIO import StringIO
def get_cover_from_manifest(epub):
img_ext_regex = re.compile("^.*\.(jpg|jpeg|png)$")
# open the main container
container = epub.open("META-INF/container.xml")
container_root = minidom.parseString(container.read())
# locate the rootfile
elem = container_root.getElementsByTagName("rootfile")[0]
rootfile_path = elem.getAttribute("full-path")
# open the rootfile
rootfile = epub.open(rootfile_path)
rootfile_root = minidom.parseString(rootfile.read())
# find the manifest element
manifest = rootfile_root.getElementsByTagName("manifest")[0]
for item in manifest.getElementsByTagName("item"):
item_id = item.getAttribute("id")
item_href = item.getAttribute("href")
if "cover" in item_id and img_ext_regex.match(item_href.lower()):
cover_path = os.path.join(os.path.dirname(rootfile_path),
item_href)
return cover_path
return None
def get_cover_by_filename(epub):
cover_regex = re.compile(".*cover.*\.(jpg|jpeg|png)")
for fileinfo in epub.filelist:
if cover_regex.match(os.path.basename(fileinfo.filename).lower()):
return fileinfo.filename
return None
def extract_cover(cover_path):
if cover_path:
cover = epub.open(cover_path)
im = Image.open(StringIO(cover.read()))
im.thumbnail((size, size), Image.ANTIALIAS)
im.save(output_file, "PNG")
return True
return False
# Which file are we working with?
input_file = sys.argv[1]
# Where do does the file have to be saved?
output_file = sys.argv[2]
# Required size?
size = int(sys.argv[3])
# An epub is just a zip
epub = zipfile.ZipFile(input_file, "r")
extraction_strategies = [get_cover_from_manifest, get_cover_by_filename]
for strategy in extraction_strategies:
try:
cover_path = strategy(epub)
if extract_cover(cover_path):
exit(0)
except Exception as ex:
print "Error getting cover using %s: " % strategy.__name__, ex
exit(1)
EXE files
Overview
Description: gnome-exe-thumbnailer is a thumbnailer for Gnome that will give Windows .exe files an icon based on their embedded icon and a generic "Wine program" icon. If the program has normal execute permissions, then the standard embedded icon will be shown. This thumbnailer will also give a thumbnail icon for .jar, .py, and similar executable programs.
Availability: official repositories
Installation
sudo apt-get install gnome-exe-thumbnailer
ODP/ODS/ODT and other LibreOffice and Open Office files
Overview
Description: ooo-thumbnailer is a LibreOffice, OpenOffice.org and Microsoft Office document thumbnailer that can be used by Nautilus to create thumbnails for your documents, spreadsheets, presentations and drawings.
Availability: developer's PPA (most recent version that's compatible with LibreOffice in Ubuntu 12.04 and up)
Installation
sudo add-apt-repository ppa:flimm/ooo-thumbnailer && apt-get update && apt-get install ooo-thumbnailer
Best Answer
Local files are the files actually on your discs.
Nautilus can also show files from filesystems available through the GVFS system. This includes (but is probably not limited to):
Those are all not local files since the files them self reside on someone else's system.
Changing if preview should be shown for specific files is done on an extension or mine type based method through the command gsettings.
(in early versions of Ubuntu when gsettings was introduced Nautilus did not abide these though). The manual method of turning thumbnails off would then be
rm -r ~/.thumbnails && ln -s /dev/null .thumbnailsJust in case you are interested (but side stepping the answer): there is someone that made Gloobus Preview and it seems to have a bit more options.
It uses (/can use) gnome-sushi for thumbnails and this seems to generate them quicker than the how Nautilus does. Gnome-sushi seems to be installable seperate too (see the link).
(I did not test either of these programs though)