.emacs.d/init.d/basics/ui.el

;;; ui.el --- Configure user interfaces. -*- lexical-binding: t; -*-

;;; Commentary:
;; * treemacs

;;; Code:

;; Directory tree.

(require 'basics/package-management)

(use-package treemacs
  :after (display-line-numbers doom-themes hl-line)
  :commands (my/treemacs-show-maybe)
  :custom ((treemacs-project-follow-cleanup t) ; Collapse projects when leaving.
           (treemacs-silent-refresh t))        ; No log message on refresh.
  :config (progn
            ;; (treemacs-tag-follow-mode)
            (make-face 'hl-line-treemacs-face)
            (when (>= emacs-major-version 27)
              (set-face-attribute 'hl-line-treemacs-face nil
                                  :extend t))
            (defun my/treemacs-set-hl-line ()
              (set (make-local-variable 'hl-line-face)
                   'hl-line-treemacs-face))
            (defun my/treemacs-show-maybe ()
              (when (and (>= (frame-width) 120)
                         (file-exists-p treemacs-persist-file)
                         (<= (length (frame-list)) 2))
                (treemacs-select-window)
                (other-window 1))))
  :bind (("<f9>" . treemacs-select-window) ; Focus treemacs.
         ("C-<f9>" . treemacs)             ; Toggle treemacs.
         ("M-<f9>" . treemacs-add-and-display-current-project)
         (:map treemacs-mode-map
               ("<mouse-1>" . treemacs-single-click-expand-action)))
:hook ((treemacs-mode . my/disable-line-numbers)
       (treemacs-mode . my/treemacs-set-hl-line)
       (after-init . (lambda () (when (display-graphic-p)
                                  (my/treemacs-show-maybe))))
       (server-after-make-frame . my/treemacs-show-maybe)))

(use-package treemacs-projectile
  :demand t
  :after (treemacs projectile))

(use-package treemacs-magit
  :demand t
  :after (treemacs magit))

;; Shows tabs of all visible buffers per window.
(when (>= emacs-major-version 27)
  (use-package tab-line
    :defer 4
    :custom-face
    (tab-line ((t (:inherit ruler-mode-default))))
    (tab-line-tab ((t (:inherit ruler-mode-default))))
    (tab-line-tab-inactive ((t (:inherit tab-line-tab))))
    (tab-line-tab-current ((t (:inherit ruler-mode-fill-column))))
    (tab-line-highlight ((t (:inherit tab-line-tab-current))))))

(provide 'basics/ui)
;;; ui.el ends here