summaryrefslogtreecommitdiffstats
path: root/docs/guides/onap-documentation/setup-of-a-doc-dev-system.rst
blob: bdbc84383fa9985d97da95b6f76f4f4b8c282f20 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
.. This work is licensed under a Creative Commons Attribution 4.0 International
.. License. http://creativecommons.org/licenses/by/4.0
.. Copyright (C) 2021 Deutsche Telekom AG



*******************************************
Setup of a Documentation Development System
*******************************************


..
   #########################################################################
   HOW TO FILL THIS SECTION:

   Release Relevance
      Name the ONAP release(s) where this document has a relevance.
      ONAP release number (ONAP release name starting with a capital letter)
      Examples:
      8.0.0 (Honolulu) - 1.0.0 (Amsterdam)
      7.0.1 (Guilin) - 3.0.0 (Casablanca), 1.0.0 (Amsterdam)

   Last Review/Update
      Date of last review and/or update of this document.
      Add "none" for a new document. Add concrete date if reviewed/updated.
      Use en-US format (mm/dd/yyyy).

   Initial Release
      Initial release date of this document.
      Use en-US format (mm/dd/yyyy).

   Author (Company)
      Name of the author and company name. Use comma to separate.
      Example:
      Jane Doe (ACME), John Doe (ACME)

   ! PLEASE DO NOT CHANGE THE STRUCTURE OF THIS SECTION.
   ! PLEASE ADD ONLY REQUESTED INFORMATION BELOW!
   #########################################################################

Release Relevance
   8.0.0 (Honolulu) - 1.0.0 (Amsterdam)

Last Review/Update
   06/02/2021

Initial Release
   05/12/2021

Author (Company)
   Thomas Kulik (Deutsche Telekom AG)

-------------------------------------------------------------------------------

.. contents:: Table of Contents

-------------------------------------------------------------------------------

Introduction
============

This guide provides a detailed description to set up a system suitable to
create, check and preview documentation locally. The targeted readership are
beginners and people interested in creating documentation.

The guide describes the setup of a development system from scratch using the
Ubuntu Desktop version installed in a virtual machine. It includes all required
steps and also some optional ones that may ease your daily work with this
development system. Feel free to adapt it to your needs.

In general, formal ONAP documentation uses the reStructuredText markup language
and the files have an ``.rst`` extension. They are part of almost every ONAP
project and can be found in the ``docs`` directory. The files are automatically
processed and you find the final ONAP documentation build hosted on
`ReadTheDocs <https://docs.onap.org>`__.

-------------------------------------------------------------------------------

VM Configuration
================

.. note:: This section is for information only and should not be understood as
          a requirement.

Ubuntu Image
------------

+----------------------------------------+
| ubuntu-20.04.2.0-desktop-amd64.iso     |
+----------------------------------------+

Please check what image must be used for your type of hardware.

VM Configuration
----------------

+-------------------------+------------+
| Memory                  | 8 GB       |
+-------------------------+------------+
| Processors / Cores each | 2 / 2      |
+-------------------------+------------+
| Hard Disk               | 64 GB      |
+-------------------------+------------+

Depending on your requirements you can modify the values for virtual memory,
processors, cores or hard disk space.

VM Setup
--------

Follow the instructions of your virtualization solution to install Ubuntu in a
virtual machine. Log in after the installation has finished.

-------------------------------------------------------------------------------

Ubuntu Configuration
====================

.. note:: This section is optional and should not be understood as a
   requirement.

Finding Applications
--------------------

The following actions are performed on the Ubuntu desktop. You may use the
desktop search function :guilabel:`Show Applications` (the |ShowApp| symbol in
the bottom left corner) to find the required applications. Later on you need to
start also a :guilabel:`Terminal` window from here.

Software Updates
----------------

Open :guilabel:`Software Updater` and update already installed Ubuntu packages.
You may need to restart the system afterwards.

Language Support
----------------

Open :guilabel:`Language Support`. You are asked to complete the installation.
Select the :guilabel:`Install` button to complete. Continue in the
:guilabel:`Language Support` window and open
:guilabel:`Install / Remove Languages`. Then select your preferred
:guilabel:`<LANGUAGE>`. Choose :guilabel:`Apply` to install the additional
language.

Regional Formats
----------------

Continue to the :guilabel:`Regional Formats` tab. Select a
:guilabel:`<FORMAT>` to show e.g. date, time and numbers in your preferred
format. Press :guilabel:`Close` to close the window.

Input Sources
-------------

To change the keyboard layout used e.g. in command line windows, open
:guilabel:`Settings`. Navigate to :guilabel:`Region & Language`. At
:guilabel:`Input Sources` press the :guilabel:`+` sign. Select your preferred
:guilabel:`<INPUTSOURCE>` and use :guilabel:`Add` to add it. Move it to the top
of the list using drag and drop. Close the window. You may need to logout from
the UI and login again to make your changes effective.

Screen Lock
-----------

Open :guilabel:`Settings`. Navigate to :guilabel:`Privacy` >
:guilabel:`Screen Lock` and change settings for :guilabel:`Blank Screen Delay`
and :guilabel:`Automatic Screen Lock` to values of your choice. Close the
window.

-------------------------------------------------------------------------------

Disable sudo password for your user
===================================

.. warning:: This section is optional and should not be understood as a
   requirement. Disabling password authentication for all commands is very
   convenient at use **but it strongly exposes your system to malicious code**.
   For a system dedicated to development it might be OK, but not for a
   production system! Handle with care. You have been warned.

Open a :guilabel:`Terminal` window and start the ``visudo`` editor with ...

.. code-block:: bash

   sudo visudo

and add ``<USER> ALL=(ALL) NOPASSWD:ALL`` to the end of the file. Replace
``<USER>`` with your user name.

-------------------------------------------------------------------------------

Install python3 related packages
================================

.. note:: The main python3 package is preinstalled in Ubuntu 20.04.

Open a :guilabel:`Terminal` window and update the package management system
with ...

.. code-block:: bash

   cd ~
   sudo apt update
   sudo apt -y upgrade

Install python3 related packages with ...

.. code-block:: bash

   sudo apt install -y python3-pip
   sudo apt install -y build-essential
   sudo apt install -y libssl-dev
   sudo apt install -y libffi-dev
   sudo apt install -y python3-dev
   sudo apt install -y python3-venv


Check the python3 version with ...

.. code-block:: bash

   python3 -V

-------------------------------------------------------------------------------

Install git and documentation related packages
==============================================

Install the required packages with ...

.. code-block:: bash

   sudo apt install -y git
   sudo apt install -y git-review
   sudo apt install -y python3-sphinx
   sudo apt install -y python3-doc8
   sudo apt install -y curl
   sudo apt install -y jq

Check the git version with ...

.. code-block:: bash

   git --version

-------------------------------------------------------------------------------

Create virtual environment and activate
=======================================

In this guide, virtual environments are generally located in your home
directory under ``~/environments``. For the development of ONAP documentation
the virtual environment ``onapdocs`` is created. The full path is consequently
``~/environments/onapdocs``.

.. code-block:: bash

   cd ~
   mkdir environments
   cd ~/environments
   python3 -m venv onapdocs
   cd ~/environments/onapdocs
   source bin/activate

To indicate that you are now working in an virtual environment, the prompt of
your terminal has changed. Now it starts with ``(onapdocs)``.

-------------------------------------------------------------------------------

Install required Sphinx packages in activated environment
=========================================================

It is :strong:`important` to activate the ``onapdocs`` environment before you
continue. If not already done, activate environment with ...

.. code-block:: bash

   cd ~/environments/onapdocs
   source bin/activate

To indicate that you are now working in an virtual environment, the prompt of
your terminal has changed. Now it starts with ``(onapdocs)``.

.. important:: Now you are installing packages only for the 'onapdocs' virtual
   environment.

.. code-block:: bash

   pip3 install wheel
   pip3 install sphinx_rtd_theme
   pip3 install sphinxcontrib-blockdiag
   pip3 install sphinxcontrib-needs
   pip3 install sphinxcontrib-nwdiag
   pip3 install sphinxcontrib-seqdiag
   pip3 install sphinxcontrib-swaggerdoc
   pip3 install sphinxcontrib-plantuml
   pip3 install lfdocs-conf
   pip3 install pylint

   which sphinx-build

.. tip:: Remember the path
   ``/home/<USER>/environments/onapdocs/bin/sphinx-build``, you need it later
   to configure a VSC extension.

-------------------------------------------------------------------------------

Install Visual Studio Code (VSC) and update already installed applications
==========================================================================

The following actions are performed on the Ubuntu desktop. You may use the
desktop search function :guilabel:`Show Applications` (the |ShowApp| symbol in
the bottom left corner) to find the required applications.

Open :guilabel:`Ubuntu Software` > :guilabel:`Development`, select
:guilabel:`Visual Studio Code` and press :guilabel:`Install` to install the
integrated development environment (IDE).

Open :guilabel:`Ubuntu Software` > :guilabel:`Updates` to ensure that your
installed applications are up to date.

-------------------------------------------------------------------------------

Clone example repo and start VSC (no LF account)
================================================

Clone repo
----------

For a quick start you can clone e.g. the ``doc`` repository even without a
Linux Foundation (LF) account with ...

.. code-block:: bash

   cd ~/environments/onapdocs
   git clone --branch master https://git.onap.org/doc/ ./doc

Start VSC
---------

Start VSC in the ``doc`` repo directory with ...

.. code-block:: bash

   cd doc
   code .

.. tip:: ``~/environments/onapdocs/doc`` is now your ``${workspaceFolder}``
   because you have started VSC (``code``) from here!

-------------------------------------------------------------------------------

Clone example repo and start VSC (LF account used)
==================================================

Prerequisite configuration
--------------------------

If you plan to contribute to the ONAP community and you want to submit changes
to a specific project later on, please refer to the
`ONAP Developer Wiki <https://wiki.onap.org>`__ to get information about all
the prerequisite details.

If you already have a LF account and you have shared your public ssh key you
can finalize the configuration of this development system by updating your ssh
configuration in the ``~/.ssh`` directory by copying over ``config``,
``id_rsa`` and ``id_rsa.pub``

In addition you configure ``git`` and ``git-review`` with ...

.. code-block:: bash

   git config --global user.email "<GIT-EMAIL>"
   git config --global user.name "<GIT-USER>"
   git config --global --add gitreview.username "<GIT-USER>"
   git config --global gitreview.remote origin

Replace ``<GIT-EMAIL>`` and ``<GIT-USER>`` with your account details.

Clone repo
----------

.. code-block:: bash

   cd ~/environments/onapdocs
   git clone --recurse-submodules ssh://<GIT-USER>@gerrit.onap.org:29418/doc

Start VSC
---------

Start VSC in the ``doc`` repo directory with ...

.. code-block:: bash

   cd doc
   code .

.. tip:: ``~/environments/onapdocs/doc`` is now your ``${workspaceFolder}``
   because you have started VSC (``code``) from here!

-------------------------------------------------------------------------------

Disable Telemetry of VSC
========================

In case you want to disable telemetry functionality of Visual Studio Code, open
:guilabel:`File` > :guilabel:`Preferences` > :guilabel:`Settings` and
search for ``telemetry``. Then uncheck
:guilabel:`Telemetry: Enable Crash Reporter` and
:guilabel:`Telemetry: Enable Telemetry`

.. warning:: Extensions may be collecting their own usage data and are not
   controlled by the ``telemetry.enableTelemetry`` setting. Consult the
   specific extension's documentation to learn about its telemetry
   reporting and whether it can be disabled. See also
   https://code.visualstudio.com/docs/getstarted/telemetry

-------------------------------------------------------------------------------

Install VSC extensions and configure reStructuredText extension
===============================================================

Install VSC extensions
----------------------

Extension bring additional power to Visual Studio Code. To search and install
them, open :guilabel:`File` > :guilabel:`Preferences` > :guilabel:`Extensions`
or use the keyboard shortcut ``[Ctrl+Shift+X]``. Then enter the name of the
extension in the :guilabel:`Search Extensions in Marketplace` window.
Press :guilabel:`Install` if you have found the required extension.

Please install ...

+-----------------------+-----------------------------------------+
| Python                | ms-python.python                        |
+-----------------------+-----------------------------------------+
| reStructuredText      | lextudio.restructuredtext               |
+-----------------------+-----------------------------------------+
| Code Spell Checker    | streetsidesoftware.code-spell-checker   |
+-----------------------+-----------------------------------------+
| Prettier              | esbenp.prettier-vscode                  |
+-----------------------+-----------------------------------------+
| GitLens               | eamodio.gitlens                         |
+-----------------------+-----------------------------------------+

Configure reStructuredText extension
------------------------------------

To configure ``reStructuredText`` extension, open :guilabel:`File` >
:guilabel:`Preferences` > :guilabel:`Extensions` or use the keyboard shortcut
``[Ctrl+Shift+X]``. Then enter ``reStructuredText`` in the
:guilabel:`Search Extensions in Marketplace` window. After you have found the
extension press :guilabel:`Manage` (the little |GearSymb| symbol on the right
bottom) and select :guilabel:`Extension Settings`. A new windows in VSC shows
all the parameters. Change the following ones:

 :strong:`Restructuredtext › Linter: Executable Path`
  ``/usr/bin/doc8``

 :strong:`Restructuredtext › Linter: Name`
  ``doc8``

 :strong:`Restructuredtext: Sphinx Build Path`
  ``/home/<USER>/environments/onapdocs/bin/sphinx-build``

Replace ``<USER>`` with your user name.

Only in case the preview creates an error message, try ...

  :strong:`Restructuredtext: Conf Path`
   ``${workspaceFolder}/docs``

Close the :guilabel:`Extension Settings` window.

-------------------------------------------------------------------------------

Open a .rst file and preview it in VSC
======================================

Open .rst file
--------------

Select :guilabel:`View` > :guilabel:`Explorer`. Alternatively you can use the
|FileExpl| symbol in the upper left corner. Expand the ``docs`` folder by
clicking on the ``>`` symbol. Select the file ``index.rst``. The code shows up
in the right pane window of VSC.

Problem Window
--------------

You may see problems with the reStructuredText markup because the code is
underlined in various colors. For the details select :guilabel:`View` >
:guilabel:`Problems` to open an additional window at the bottom of VSC.

When you select a specific entry in the problem list, the code window is
updated to show the related line in the code.

Preview
-------

Now select :guilabel:`Preview To The Side` (the |Preview| symbol on the top
right) or use keyboard shortcut ``[Ctrl+k Ctrl+r]`` to open the preview window
on the right hand side. This may take a few seconds. The preview shows up and
renders the ``index.rst`` as it would look like on ReadTheDocs.

Tips and Tricks
---------------

The learnings are ...

.. tip::
   - Start VSC always in the ``docs`` directory of the repository. Use the
     command ``code .``. Then navigate via VSC's :guilabel:`Explorer`
     |FileExpl| to the directory which contains the file you like to edit. VSC
     may ask you, which ``conf.py`` VSC should use. Choose the one which
     resides in the directory where you have started VSC. Check also the (blue)
     bottom line of VSC. There you see which ``conf.py`` is currently in use.
     The content of ``conf.py`` affects how the documentation is presented.
   - VSC may claim that some packages require an update. This can be easily
     fixed. VSC offers automatically to install or update the package.
   - VSC may ask you to install ``snooty``. Please install.
   - Select the correct environment in the (blue) bottom line
     ``'onapdocs':venv``. Have also a view on the other interesting
     information (e.g. the ``conf.py`` which is currently in use).
   - First, close and reopen preview if preview is not shown properly.
   - Second, close and reopen VSC if preview is not shown properly.
   - Save your file if an error does not disappear after you have corrected it.
   - You can not navigate within the document structure by clicking the links
     in the preview. You always have to choose the correct file in the VSC
     :guilabel:`Explorer` window.

That's it!
----------

Congratulations, well done! You have configured a system well suited to
develop ONAP documentation and to master the challenges of reStructuredText.
Now have a look at all the different elements of reStructuredText and learn how
to use them properly. Or maybe you like to do some optional configurations at
your system first.

-------------------------------------------------------------------------------

Optional VSC Configuration
==========================

Add Ruler
---------

To add a ruler that indicates the line end at 79 characters, open
:guilabel:`File` > :guilabel:`Preferences` > :guilabel:`Settings` and enter
``ruler`` in the :guilabel:`Search settings` field. In
:guilabel:`Editor: Rulers` click on :guilabel:`Edit in settings.json` and add
the value ``79``. The result should look like this:

.. code-block:: bash

    "editor.rulers": [
        79
    ]

Disable Synchronized Scrolling of Editor and Preview
----------------------------------------------------

To disable the synchronized scrolling of editor and preview, open
:guilabel:`File` > :guilabel:`Preferences` > :guilabel:`Settings` and
search for ``Restructuredtext › Preview: Scroll``. Then uncheck
:guilabel:`Restructuredtext › Preview: Scroll Editor With Preview` and
:guilabel:`Restructuredtext › Preview: Scroll Preview With Editor`

-------------------------------------------------------------------------------

Miscellaneous
=============

.. note:: This section is optional and should not be understood as a
   requirement.

Firefox Add-ons
---------------

Open :guilabel:`Add-Ons and Themes`, then search and install the following
add-ons:

+------------------------------+-------------------------------+
| I don't care about cookies   | Get rid of cookie warnings.   |
+------------------------------+-------------------------------+
| UBlock Origin                | A wide-spectrum blocker.      |
+------------------------------+-------------------------------+
| LastPass Password Manager    | Used in the Linux Foundation. |
+------------------------------+-------------------------------+

ReText Editor
-------------

Install this simple editor with ...

.. code-block:: bash

   sudo apt install -y retext

-------------------------------------------------------------------------------

Helpful Resources
=================

This is a collection of helpful resources if you want to extend and deepen your
knowledge.

Documentation
-------------

- `Write The Docs: Documentation Guide <https://www.writethedocs.org/guide>`__

Git
---

- `How To Install Git on Ubuntu 20.04 <https://www.digitalocean.com/community/tutorials/how-to-install-git-on-ubuntu-20-04>`__

Python
------

- `Install Python for Most Features <https://docs.restructuredtext.net/articles/prerequisites.html#install-python-for-most-features>`__
- `How To Install Python 3 and Set Up a Programming Environment on an Ubuntu 20.04 Server <https://www.digitalocean.com/community/tutorials/how-to-install-python-3-and-set-up-a-programming-environment-on-an-ubuntu-20-04-server>`__
- `Using Python environments in VS Code <https://code.visualstudio.com/docs/python/environments>`__
- `Getting Started with Python in VS Code <https://code.visualstudio.com/docs/python/python-tutorial>`__
- `Linux Foundation Docs Conf <https://pypi.org/project/lfdocs-conf/>`__

ReadTheDocs Sphinx Theme
------------------------

- `ReadTheDocs Sphinx Theme (Recommended Reading!) <https://sphinx-rtd-theme.readthedocs.io/en/stable/>`__
- `ReadTheDocs Sphinx Theme Configuration <https://sphinx-rtd-theme.readthedocs.io/en/latest/configuring.html>`__

reStructuredText
----------------

- `reStructuredText Directives <https://docutils.sourceforge.io/docs/ref/rst/directives.html>`__
- `reStructuredText and Sphinx Cheat Sheet I <https://thomas-cokelaer.info/tutorials/sphinx/rest_syntax.html>`__
- `reStructuredText and Sphinx Cheat Sheet II <https://docs.typo3.org/m/typo3/docs-how-to-document/master/en-us/WritingReST/CheatSheet.html>`__
- `Online reStructuredText Editor <http://rst.ninjs.org/#>`__

Ubuntu
------

- `Virtualized Ubuntu Desktop Edition <https://linuxconfig.org/ubuntu-20-04-system-requirements>`__

Visual Studio Code (VSC)
------------------------

- `VSC Basic Editing <https://code.visualstudio.com/docs/editor/codebasics>`__
- `Code Formatting with Prettier in Visual Studio Code <https://www.digitalocean.com/community/tutorials/code-formatting-with-prettier-in-visual-studio-code>`__
- `VSC Icons <https://github.com/microsoft/vscode-icons>`__

-------------------------------------------------------------------------------

Backlog
=======

There are still some open topics or issues in this guide. They are subject
for one of the upcoming releases.

 - consider ``pandoc`` in this guide?
 - VSC / reStructuredText Extension Settings / reStructuredText: Sphinx Build
   Path: ${workspaceRoot} , ${workspaceFolder} , any alternatives?
 - link to full ``ssh`` install/config?
 - link to full ``git`` install/config?
 - how to limit line width to improve readability? setting in conf.py?
 - keyboard shortcut ``[Ctrl+Shift+X]`` or :kbd:`Ctrl` + :kbd:`Shift` +
   :kbd:`X` Is this a problem in the RTD theme?
 - use ``menuselection``
   :menuselection:`My --> Software --> Some menu --> Some sub menu 1`?
 - evaluate and add VSC extension to "draw" tables in an aided way
 - add infos for config files, e.g. ``conf.py``, ``conf.yaml``
 - find the reason for VSC error message
   ``Substitution definition "ShowApp" empty or invalid.``
 - find the reason for VSC error message
   ``Unexpected indentation``
 - find a solution to wrap lines in VSC automatically (79 chars limit)
 - evaluate ``snooty`` and describe functionality (build in? not a extension?)
 - add a table explaining the role of installed packages/extensions in every
   section

..
   #########################################################################
   EMBEDDED PICTURES & ICONS BELOW
   #########################################################################

.. |ShowApp| image:: ./media/view-app-grid-symbolic.svg
   :width: 20

.. |Preview| image:: ./media/PreviewOnRightPane_16x.svg
   :width: 20

.. |FileExpl| image:: ./media/files.svg
   :width: 20

.. |GearSymb| image:: ./media/gear.svg
   :width: 20