Is there a way to implement readonly files in Theia?

[vinayb21]

Mark files as readonly and when the file tree is loaded, the files should be shown with a readonly file icon (or) a label should be shown that this file is a readonly file.

[akosyakov]

Only with a custom extension. You will need to customize NavigatorWidget to render such files differently. You also will need to customize FileResourceProvider to avoid creation of FileResource for such files and instead provide a custom ResourceProvider creating readonly Resource. See https://github.com/theia-ide/theia/blob/master/packages/core/src/common/resource.ts