Graphical Applications

CoCalc is a modern web-application, but there are many already existing desktop applications. This aspect of CoCalc brings such applications to the web, by running them inside a minimal graphical environment and presenting them to you via the browser. It is even possible to collaboratively work on the same application – although be warned that this is quite confusing!

See this blog post for more screenshot and further explanations.

Maxima in CoCalc

Getting started

In your project, create an X11 Desktop-file (which has the ending *.x11), or use the corresponding button when creating a new file. You should see a split frame editor with

  • on one left side:

  • On the right hand side, there is the view area for X11 windows

Initially, that X11 area is empty and you have to start an application. To get started, we suggest to launch a simple text editor like Gedit or LibreOffice Writer.

Note

You need to click once on the X11 window in order to focus it. This tells it to process any input (mouse clicks, keyboard characters, …)

In the screenshot below, you can see that gedit was typed into the Linux Terminal. After hitting the return key, the application was launched and the window is shown. The characters “asdf” were typed in and then the “Save”-Button at the top right inside the Gedit windows was pressed. This opened up an overlay dialog window. There, type in the filename and click “Save” at the bottom again.

_images/x11-gedit-save.png

Afterwards, this did create a file named file1.txt in the current directory. Go ahead and open it up inside of CoCalc!

Overlay Dialogs

Modal dialogs open up as almost-maximized windows on top of the current window of the application.

Note

An overlay dialog window without a Close, Ok, or Cancel button can be closed by clicking on the application visible in the background; i.e. the surrounding area of the dialog.

_images/x11-inkscape-dialog.png

Window Tabs

When you open up multiple applications (or a single application opens multiple windows), they appear as tabs at the top of the X11 view area. In the screenshot below, you can see that the text file was also opened up in LibreOffice Writer:

_images/x11-libreoffice-tabs.png

Note

Sometimes, applications open up additional dialog windows, which show up as tabs at the top. In order to respond to the application’s dialog window, you have to click on the appropriate tab to open it up and take appropriate actions. (e.g. confirming a certain operation, etc.)

Keyboard Layout

CoCalc will try (badly) to guess your keyboard layout based on your browser’s default language settings. This does NOT work well. Instead, you should explicitly select your keyboard layout in Account preferences:

  1. Open up your Account Settings

  2. In the tab “Preferences”, look for the panel “Editor settings”

  3. Inside “Editor Settings”, look for Keyboard layout (for X11 Desktop)

Note

Many languages like “German” will only work well with the variant “no dead keys”.

Zoom

CoCalc tries to match its virtual desktop size to the size of the frame inside your browser window. It will also calculate an appropriate zoom level based on the resolution of your screen. However, this might not always work.

At the top of the X11 area are zoom controls, which allow you to change the resolution. Sometimes, it might also be necessary to change some settings within the application itself (some zoom related ones in its preferences), or to change the size of the panel or browser window itself. CoCalc dynamically resizes the desktop and the application will redraw accordingly.

Terminal

Inside the small Linux Terminal on the side, you can run programs or your own scripts. For example, this could be a Python script, or even a full application: try this matplotlib: Embedding In Wx5 example.

Behind the scenes, after the X11 environment starts up, the $DISPLAY variable is set to tell the application where to show the graphical window. Please wait until it is initialized, which you can see after the connection indicator at the top right next to “X11” vanishes. Otherwise, you’ll get this error message Unable to access the X Display, is $DISPLAY set properly?.

Example script (you can also run it interactively in an ipython3 shell):

import matplotlib
matplotlib.use('wxAgg')
import numpy as np
import matplotlib.pyplot as plt
plt.plot(np.random.randn(1000).cumsum())
plt.show()

Technical Status

  • Desktop (works well):

    • Chrome version 66+ is fully supported

    • Copy does not work on Firefox or Safari

  • Mobile (does NOT work):

    • Viewing the desktop should mostly work

    • Touch events barely work at all.

    • Even an external keyboard will NOT work on an iPad (keys will be stuck, etc.).

Installed Applications

Note

Unless otherwise noted, the application’s name is also the command to start the executable. For most applications you can find a launcher button:

_images/x11-launcher-buttons.png

Name

Description

Category

Status

auctex

latex

?

avogadro

Advanced molecule editor and visualizer

chem

OK

blender

3D graphics (to visualize wireframes)

graphics

OK

cadabra2-gtk

A field-theory motivated approach to computer algebra

physics

OK

code

Visual Studio code

code

OK

darktable

photography workflow application and raw developer

paint

OK

google-chrome

Chrome Web-browser

web

Randomly crashes due to Docker security requirements

dia

Drawing graphics

graphics

Mostly OK

emacs

Powerful text editor, code, and everything else

code, text

OK

firefox

Web-browser

web

Crashes

gchempaint

Draw chemical formulas (no single-window mode, though)

chem

?

gedit

text

OK

gitk

Explore a Git repository (in current directory)

git

OK

gitg

Simplified interface for working with Git

git

OK

gimp

Draw and edit images. (make sure to switch to “single window mode” in the “Window” menu)

paint

OK

gnome-calculator

Classical calculator

math

OK

gnumeric

Spreadsheet calculations and statistics

stats

OK

gschem

schematic capture program/tool part of gEDA

physics

OK

gvim

Graphical version of the famous VIM editor

text

OK

idle

Minimalistic Python IDE

code

OK

inkscape

Professional vector graphics editor

graphics

OK

jedit

Java-based text editor

text

?

kbibtex

Reference management software primarily for BibTeX

latex

OK

kexi-3.1

Microsoft Access for Linux

db

OK

kile

LaTeX editor, but probably use texmaker instead …

latex

OK

krita

Painting tool designed for concept artists

paint

OK

latexdraw

Draw PSTricks, etc.

latex, graphics

flickers :-(

libreoffice

Office suite consisting of: localc, lowriter, loimpress, lobase, …

office

OK

lyx

LyX combines the power and flexibility of TeX/LaTeX with the ease of use of a graphical interface.

latex

OK

meld

a visual diff and merge tool targeted at developers

code

OK

nteract

Jupyter Notebook compatible UI

calc

OK

octave

Octave

calc

OK

okular

PDF reader and annotator (Tools → Review)

pdf

OK

OpenModelica

Modeling and simulation environment. Command: OMEdit & co.

physics

OK

pcb-gtk

printed circuit board editor

physics

OK

pinta

simple paint app for images

paint

OK

psppire

PSPP is an open-source version of SPSS

stats

OK

RCommander

graphical UI for R: start by require(Rcmdr)

stats

OK

rstudio

Open source R IDE. On high resolution displays set Tools → Global Options → Appearance → Zoom → 200%

stats

OK

scribus

a page layout program

office

OK

SnapPy in Sage

Run via sage -python -m snappy.app

math

Arrow keys

spyder3

a powerful scientific environment for Python

math

OK

texmacs

LaTeX editor

latex

OK

texmaker

Powerful, easy to use and elegant LaTeX editor

latex

OK

texstudio

Make writing LaTeX as easy and comfortable as possible

latex

OK

thunderbird

Email client

office

OK

tikzit

A super simple GUI editor for graphs and string diagrams

latex, graphics

?

tuxpaint

Children’s paint program

paint

OK

wxmaxima

Computer algebra system Maxima

math

OK

xedit

Old graphical text editor in X

edit

OK

xournal

Draw notes or annotate a PDF

pdf

OK

xpaint

Old paint program

paint

OK

Categories

Category

Description

math

mathematics

chem

chemistry applications

stats

statistics, data analysis, …

physics

tools for physics, engineering, modeling, etc.

office

productivity apps for authoring text, presentations, spreadsheets, etc. (doc, docx, odt, ppt, xml, xmlx, ods, …

latex

editor for working with LaTeX documents

text

general purpose text editors

code

tools for software development (IDE, etc.)

git

working with Git

db

graphical database interfaces

paint

raster graphics editor

graphics

vector graphics editor

pdf

for reading, editing, annotating PDFs

Tips & Tricks

RStudio with CoCalc

There are a number of ways to use RStudio in CoCalc. You can create X11 Desktop as explained above, then click the RStudio button at the bottom left and wait about 20 seconds. The advantage is real-time collaboration just as with any other X11 application, but the response time may be slow, so it may be better to launch RStudio from Servers tab:

Launching RStudio Server

Launching RStudio Server

If you need more powerful compute resources, use Compute Servers with R Statistics image. Here CoCalc’s CEO and Founder William Stein explains how to run it:


You can also use R in CoCalc via:

High-resolution HDPI displays

If the visible buttons/controls are small, especially if you have a high-res display, and zooming alone doesn’t really help much, enable HDPI rendering. That’s available for some of the applications in their respective configuration dialogs.

In RStudio you can go to Tools → Global Options → Appearance → Zoom → 200%.

In Spyder Enable auto high DPI scaling option is available via the Tools > Preferences menu or the wrench-icon:

Enable auto high DPI scaling in Spyder

Enable auto high DPI scaling in Spyder

Is Scilab broken?

In theory, Scilab should work in this Graphical Applications editor, but there is a long standing issue in Ubuntu Linux about this.

As of May 2019, it works, but maybe it’s broken again ¯\_(ツ)_/¯ ?

_images/x11-scilab-2019-05-04.png