Theia: [editor] Support editing the same file in multiple editors?

[marechal-p]

VS Code can open the same file in multiple editors:

What about supporting this in Theia as well?

[phaumer]

This is essential for our audiences that edit very large program files and want to see different parts of a file next to each other. So more than two splits is also desired.

I assume that the editor manager would need to be extended to index different instances of the same file with some extended URI scheme (e.g. by adding a number).

[dannaf]

For me this would also be a useful feature.

The closest thing I found is the 'Compare With...' feature, which views two different versions of a file side by side. But that feature locks the scroll of the two editor tabs together, and also shows different versions of the file. Maybe a quick implementation can be made by having a 'Compare With...'-like version that just doesn't lock the two tabs' scrolling, and compares against the same version of the file?

[vince-fugnitto]

cc @marcdumais-work

[akosyakov]

It should be feasible to implement by adding a counter in editor widget options. URI should not be changed.