Focus a buffer window if already visible; open a window with the buffer if not

Question

I'd like to use a single function (and later keybind it to a single key) that would do the following:

• if treemacs is visible in the frame, focus to its window;
• if not, call treemacs.

I took a look at window-buffer and get-buffer-window, however it's not clear how would I utilize those functions: I don't have a buffer in a variable to start with, and programmatically predicting a treemacs buffer name kinda seems like an non-trivial task (buffer-name gives me something like " *Treemacs-Scoped-Buffer-#<framec *scratch* (projectile-project) - GNU Emacs at HOST 0x555ed35d4cc8>*").

Do I have to loop through all the visible windows, get displayed buffer names and match them against " *Treemacs-Scoped-Buffer" instead? Is there a better way, say a treemacs specific treemacs-visible-p that would tell me the info I need? Or do I approach the problem incorrectly?

Answer 1

The function treemacs-select-window may do what you are looking for.

From treemacs.el:

(treemacs-select-window)

Select the treemacs window if it is visible.
Bring it to the foreground if it is not visible.
Initialise a new treemacs buffer as calling ‘treemacs’ would if there is no
treemacs buffer for this frame.