modeline: clean format and use truncate-string-to-width

* modeline.el (modeline-format-main): Using string-width to calculate
  the widths of strings is more accurate than my previous hand-made
  function.

  (modeline-length): This is no longer needed and now marked as
  obsolete.  It is not deleted entirely since per chance some other
  places are still using it.

  (modeline-format-minor-modes, modeline-format-buffer-name): Use
  truncate-string-to-width instead.

1 files changed, 44 insertions, 17 deletions

diff --git a/modeline.el b/modeline.el
index 2d95adf..683bf3d 100644
--- a/modeline.el
+++ b/modeline.el
@@ -1,12 +1,36 @@
-;;; -*- lexical-binding: t; -*-
+;;; modeline.el --- Configurations for the mode line.  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2021  李俊緯
+
+;; Author: 李俊緯 <mmemmew@gmail.com>
+;; Keywords: emulations, tools
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This configures my mode line.
+
+;;; Code:
 
 ;;;###autoload
 (defun modeline-format-main ()
   "The main mode line format."
   (let* ((left (modeline-format-left))
          (right (modeline-format-right))
-         (left-len (modeline-length left))
-         (right-len (modeline-length right))
+         (left-len (string-width left))
+         (right-len (string-width right))
          (middle (propertize " " 'display
                              (make-string
                               (max (- (window-total-width)
@@ -84,7 +108,8 @@
   "Return the length of STR.
 Characters that take up more than one column will be counted with
 1.7 columns."
-  (declare (side-effect-free t) (pure t))
+  (declare (side-effect-free t) (pure t)
+           (obsolete string-width "2021-12-19 13:51:30.332234"))
   (let ((len 0))
     (mapc (lambda (char)
             (let ((name (get-char-code-property char 'name))
@@ -322,18 +347,18 @@ MAP is the local keymap of the text."
             (cond
              ((modeline-active-window-p) 'mode-line)
              ('mode-line-inactive))))
+          (ellipsis
+           (format-mode-line
+            "..."
+            (cond ((modeline-active-window-p) 'mode-line)
+                  ('mode-line-inactive))))
           (orig (cond
                  ((and (not (string= raw ""))
                        (= (aref raw 0) 32))
                   (substring raw 1))
                  (raw))))
-     (cond
-      ((<= (length orig) modeline-minor-modes-name-len-max)
-       orig)
-      ((concat
-        (substring orig 0 (- modeline-minor-modes-name-len-max
-                             3))
-        "..."))))
+     (truncate-string-to-width
+      orig modeline-minor-modes-name-len-max 0 nil ellipsis))
    nil
    "Minor mode
 mouse-1: Display minor mode menu
@@ -392,15 +417,15 @@ This will be displayed in the mode line."
 		      (t 'mode-line-inactive)))
           (name-max (min modeline-buffer-name-len-max
                          (floor (window-width) 2)))
+          (ellipsis
+           (format-mode-line
+            "..."
+            (cond ((modeline-active-window-p) 'mode-line)
+                  ('mode-line-inactive))))
 	  (orig (format-mode-line "%b" face)))
      (concat
       (format-mode-line "%[" face)
-      (cond
-       ((> (length orig) name-max)
-	(concat
-         (substring orig 0 (max (- name-max 3) 1))
-         "..."))
-       (t orig))
+      (truncate-string-to-width orig name-max 0 nil ellipsis)
       (format-mode-line "%]" face)))
    nil
    (concat (buffer-file-name)
@@ -520,3 +545,5 @@ This will be displayed in the mode line."
     )
    (t "")))
 
+(provide 'modeline)
+;;; modeline.el ends here