X11 Graphical Desktop — CoCalc Manual documentation (original) (raw)

• Getting started
  • Overlay Dialogs
  • Window Tabs
  • Keyboard Layout
  • Zoom
  • Terminal
  • Technical Status
• Installed Applications
• Tips & Tricks
  • High-resolution HDPI displays
  • Is Scilab broken?

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.

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:
  • a Linux Terminal and
  • launcher buttons for starting applications
• 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.

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.

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:

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 messageUnable 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:

Categories

Tips & Tricks

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 R IDE 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

Is Scilab broken?

In theory, Scilab should work in this X11 Graphical Desktop 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)_/¯ ?