subtree(users/wpcarro): docking briefcase at '24f5a642'

git-subtree-dir: users/wpcarro
git-subtree-mainline: 464bbcb15c
git-subtree-split: 24f5a642af
Change-Id: I6105b3762b79126b3488359c95978cadb3efa789

users/wpcarro/emacs/.emacs.d/wpc/modeline.el

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+;;; modeline.el --- Customize my mode-line -*- lexical-binding: t -*-
+
+;; Author: William Carroll <wpcarro@gmail.com>
+;; Version: 0.0.1
+;; Package-Requires: ((emacs "25.1"))
+;; Homepage: https://user.git.corp.google.com/wpcarro/briefcase
+
+;;; Commentary:
+;; Because I use EXWM, I treat my Emacs mode-line like my system bar: I need to
+;; quickly check the system time, and I expect it to be at the bottom-right of
+;; my Emacs frame.  I used doom-modeline for awhile, which is an impressive
+;; package, but it conditionally colorizes on the modeline for the active
+;; buffer.  So if my bottom-right window is inactive, I cannot see the time.
+;;
+;; My friend, @tazjin, has a modeline setup that I think is more compatible with
+;; EXWM, so I'm going to base my setup off of his.
+
+;;; Code:
+
+(use-package telephone-line)
+
+(defun modeline-bottom-right-window? ()
+  "Determines whether the last (i.e.
+bottom-right) window of the
+active frame is showing the buffer in which this function is
+  executed."
+  (let* ((frame (selected-frame))
+         (right-windows (window-at-side-list frame 'right))
+         (bottom-windows (window-at-side-list frame 'bottom))
+         (last-window (car (seq-intersection right-windows bottom-windows))))
+    (eq (current-buffer) (window-buffer last-window))))
+
+(defun modeline-maybe-render-time ()
+  "Conditionally renders the `mode-line-misc-info' string.
+
+  The idea is to not display information like the current time,
+  load, battery levels on all buffers."
+  (when (modeline-bottom-right-window?)
+    (telephone-line-raw mode-line-misc-info t)))
+
+(defun modeline-setup ()
+  "Render my custom modeline."
+  (telephone-line-defsegment telephone-line-last-window-segment ()
+    (modeline-maybe-render-time))
+  ;; Display the current EXWM workspace index in the mode-line
+  (telephone-line-defsegment telephone-line-exwm-workspace-index ()
+    (when (modeline-bottom-right-window?)
+      (format "[%s]" exwm-workspace-current-index)))
+  ;; Define a highlight font for ~ important ~ information in the last
+  ;; window.
+  (defface special-highlight
+    '((t (:foreground "white" :background "#5f627f"))) "")
+  (add-to-list 'telephone-line-faces
+               '(highlight . (special-highlight . special-highlight)))
+  (setq telephone-line-lhs
+        '((nil . (telephone-line-position-segment))
+          (accent . (telephone-line-buffer-segment))))
+  (setq telephone-line-rhs
+        '((accent . (telephone-line-major-mode-segment))
+          (nil . (telephone-line-last-window-segment
+                  telephone-line-exwm-workspace-index))))
+  (setq telephone-line-primary-left-separator 'telephone-line-tan-left
+        telephone-line-primary-right-separator 'telephone-line-tan-right
+        telephone-line-secondary-left-separator 'telephone-line-tan-hollow-left
+        telephone-line-secondary-right-separator 'telephone-line-tan-hollow-right)
+  (telephone-line-mode 1))
+
+(provide 'modeline)
+;;; modeline.el ends here