Add a menu entry to select between available color schemes

Issue Report Checklist

• Searched the issues page for similar reports
• Read the relevant sections of the Spyder Troubleshooting Guide and followed its advice
• Reproduced the issue after updating with conda update spyder (or pip, if not using Anaconda)
• N/A Could not reproduce inside jupyter qtconsole (if console-related)
• N/A Tried basic troubleshooting (if a bug/error)
• Completed the Problem Description, Steps to Reproduce and Version sections below

Problem Description

I generally prefer working with a dark background on the editor (I use the Spyder Dark colour scheme). However, when working with others or showing work on a big screen / projector, it’s useful to have a quick method of switching to a light background (e.g. Spyder colour scheme). It would be really nice if a keyboard shortcut could be set up to switch between two specified colour schemes.

What steps reproduce the problem?

1. Go to keyboard shortcuts configuration page
2. Search in vain for anything colour scheme related

Versions

• Spyder version: 3.3.1
• Python version: 3.7.1
• Qt version: 5.6.2
• PyQt version: 5.6
• Operating System name/version: Windows 10

(P.S. If you’re suggesting in the template that people go to Help…About Spyder for this information, it would be really nice if it was copy-able for pasting in here rather than having to type it and risk making a mistake)

Dependencies

IPython >=4.0     :  7.1.1 (OK)
cython >=0.21     :  0.29 (OK)
jedi >=0.9.0      :  0.13.1 (OK)
matplotlib >=2.0.0:  2.2.2 (OK)
nbconvert >=4.0   :  5.3.1 (OK)
numpy >=1.7       :  1.15.3 (OK)
pandas >=0.13.1   :  0.23.4 (OK)
pycodestyle >=2.3 :  2.4.0 (OK)
pyflakes >=0.6.0  :  2.0.0 (OK)
pygments >=2.0    :  2.2.0 (OK)
pylint >=0.25     :  2.1.1 (OK)
qtconsole >=4.2.0 :  4.4.2 (OK)
rope >=0.9.4      :  0.11.0 (OK)
sphinx >=0.6.6    :  1.8.1 (OK)
sympy >=0.7.3     :  1.3 (OK)

[jnsebgosselin]

To get the advantages of both without too much work, you could make the first/last item in the submenu be “Restore last syntax scheme” with the shortcut, followed by a menu separator and the last 5 schemes in order, or just list the schemes in MRU order as I proposed, but assign to the first one a configurable “Restore last syntax scheme” shortcut.

But as you said yourself, adding a list, albeit shorter, doesn’t really help to speed up switching between syntax schemes faster. So do we really need to add that flexibility in the menu when that flexibility is already provided in the Preferences?

[jnsebgosselin]

From PR https://github.com/spyder-ide/spyder/pull/8426#issuecomment-447191759 :

I’m not a developer, but just a normal user. From my using scenario, it’ll be helpful to have a submenu to switch color schemes (without considering the implementation or delay detail), but it won’t hurt without it. I can change that via preferences, and an even better thing is I can preview the effect via preferences.

What will be very helpful is a convenient way to switch between dark mode and light mode by user base on the time or the environment. Maybe one can select one color scheme as the default light mode and one as the default dark mode.

Thank you @gepcel for your input on this. Another idea would be to add an action to the source menu that switch to last used color scheme.

Another option would be to add two actions instead, one that switch to previous color scheme and one that switch to next color scheme. Then, I think keyboard shortcuts to these actions could even be added. I think this would allow to address the original issue and @ccordoba12’s concerns about not having a “single dark or light color scheme we could go to.”