Projectile switch between opened projects

Question

I often have to work with multiple related projects and switching between them can become hard. I use counsel-projectile and it really makes everything easier. To be clear, I am not talking about counsel-projectile-switch-to-buffer or counsel-projectile-switch-to-project. I already use those functions and they are really useful.

What I would want is a function or a package that could display all opened projectile projects with ivy or helm and let me choose a candidate. When the candidate would be selected, the last buffer opened in that project would be opened. It would be basically a counsel-switch-buffer but with projects. If possible the last visited project would display first.

An example of this would be this package: persp-projectile, but unfortunately it does not work for me most of the times.

What I currently use is centaur-tabs and it has the function centaur-tabs-counsel-switch-group with centaur-tabs-group-by-projectile-project which is the closest thing of what I want. It only misses to place the last project on top of the candidates. But the real problem is that I don't even use the tab functionality and it makes Emacs have some small bugs sometimes (eg. hiding helm candidates on emacsclient).

So if there was a simple custom function with ivy and projectile I would really appreciate it.

[Edit]

projectile-switch-open-project does almost what I want but it triggers find-file. I would want it to just go to the last opened buffer on the project.

Answer 1

What I would want is a function or a package that could display all opened projectile projects with ivy or helm and let me choose a candidate. When the candidate would be selected, the last buffer opened in that project would be opened. It would be basically a counsel-switch-buffer but with projects. If possible the last visited project would display first.

Emacs has had rudimentary project support built-in since v25 via project.el, but it's recently seen a lot of interest and new features in v28, including project switching. The good news is you don't have to wait until v28 is released to avail of them; you can install project.el on Emacs 26 or later from GNU ELPA: http://elpa.gnu.org/packages/project.html.

Its project-switching interface revolves around the command project-switch-project (bound to C-xpp by default). Quoth its entry in the Emacs manual at (info "(emacs) Switching Projects"):

28.2.3 Switching Projects
-------------------------

‘C-x p p’
     Run an Emacs command for another project
     (‘project-switch-project’).

   Commands that operate on project files (see Project File
Commands) will conveniently prompt you for a project directory when no
project is current.  When you are inside some project, but you want to
operate on a different project, use the ‘C-x p p’ command
(‘project-switch-project’).  This command prompts you to choose a
directory among known project roots, and then displays the menu of
available commands to operate on the project you choose.  The variable
‘project-switch-commands’ controls which commands are available in the
menu, and which key invokes each command.

   The variable ‘project-list-file’ names the file in which Emacs
records the list of known projects.  It defaults to the file ‘projects’
in ‘user-emacs-directory’ (see Find Init).

This command first prompts for a project with most-recently-used-first completion. Here it is in action with Ivy:

[As usual, you can of course customise this display using either built-in or Ivy-specific options.]

After selecting a project, the command dispatches on project-related commands found in the variable project-switch-commands. Here's the default set:

For buffer switching, you can modify project-switch-commands to include the commmand project-switch-to-buffer:

(with-eval-after-load 'project
  (push '(?b "Switch buffer" project-switch-to-buffer)
        project-switch-commands))

The prompt is now:

Finally, project-switch-to-buffer prompts for a buffer in the selected project. Here it is in action with Ivy:

Please send any feature requests or bug reports to the Emacs developers using M-xreport-emacs-bugRET.

Answer 2

As @Swedgin said in comments projectile-switch-open-project will work without doing nothing more.

Given that you want to switch to an open project buffer, you should also customize projectile-switch-project-action accordingly with your needs, in this case I'd say it's either:

• projectile-switch-to-buffer
• counsel-projectile-switch-to-buffer
• a custom function that will switch buffer to the car of projectile-project-buffer-files, which should be the last project opened buffer, corresponding to a file.

---

Also you can modify counsel-projectile to read open projects lists.

projectile-open-projects and projectile-relevant-open-projects returns the list of currently open projects, so ultimately it's a matter of using them as ivy-read candidates list.

Check counsel-projectile-switch-project implementation.

At first look I'd say that changing

(if counsel-projectile-remove-current-project
    (projectile-relevant-known-projects)
  projectile-known-projects)

to

(if counsel-projectile-remove-current-project
    (projectile-relevant-open-projects)
  (projectile-open-projects))

Will do the core of it, but cannot test it right now, neither giving it the finishing touches to make it play well without losing the original behavior.

I - or someone else - will extend the response later.

Answer 3

Try this.

(defun smart-switch-project ()                                                                                                                                                                                     
  "Open latest edited buffer when switched the  exist project, find files when switched to a new project."                                                                                                         
  (if  (null (projectile-project-buffer-files ))                                                                                                                                                                   
    (projectile-find-file)                                                                                                                                                                                         
    (switch-to-buffer (get-buffer (car (projectile-project-buffer-files)))))                                                                                                                                       
)                                                                                                                                                                                                                  
(setq projectile-switch-project-action 'smart-switch-project)