How to make the Admin interface language switch based on node content? How can I make the Administration interface language be the same as the Editing content?

By example. If I edit a French content, I would like my interface in French.
If I edit an English content, I would like my interface in English.
On D7 you'll find a language detection and selection page at admin/config/regional/language/configure:



If you enable and put "URL Determine the language from the URL (Path prefix or domain)" on top the system will show the interface in French for nodes (and other content) in French and it will be English for English content.