Add doom/{increase,decrease,reset}-font commands

Borrows the idea from zoom-frm (see #1389).

core/autoload/fonts.el

@@ -0,0 +1,100 @@
+;;; core/autoload/fonts.el -*- lexical-binding: t; -*-
+
+(defvar doom-font-increment 2
+  "How many steps to increase the font size each time `doom/increase-font-size'
+or `doom/decrease-font-size' are invoked.")
+
+(defvar doom-big-font-increment 14
+  "How many steps to increase the font size (with `doom-font' as the base) when
+`doom-big-font-mode' is enabled.")
+
+(defvar doom-change-font-size-hook nil
+  "A hook run after adjusting the font size with `doom/increase-font-size',
+`doom/decrease-font-size', or `doom/reset-font-size'.")
+
+
+;;
+;;; Library
+
+(defun doom--font-name (fontname frame)
+  (when (query-fontset fontname)
+    (when-let* ((ascii (assq 'ascii (aref (fontset-info fontname frame) 2))))
+      (setq fontname (nth 2 ascii))))
+  (or (x-decompose-font-name fontname)
+      (error "Cannot decompose font name")))
+
+;;;###autoload
+(defun doom-adjust-font-size (increment &optional frame)
+  "Increase size of font in FRAME by INCREMENT.
+Interactively, INCREMENT is given by the prefix argument.
+Optional FRAME parameter defaults to current frame."
+  (interactive "p")
+  (let* ((frame (or frame (selected-frame)))
+         (font (frame-parameter frame 'font))
+         (font (doom--font-name font frame)))
+    (let ((new-size (+ (string-to-number (aref font xlfd-regexp-pixelsize-subnum))
+                       increment)))
+      (unless (> new-size 0)
+        (error "Font is to small at %d" new-size))
+      (aset font xlfd-regexp-pixelsize-subnum (number-to-string new-size)))
+    ;; Set point size & width to "*", so frame width will adjust to new font size
+    (aset font xlfd-regexp-pointsize-subnum "*")
+    (aset font xlfd-regexp-avgwidth-subnum "*")
+    (setq font (x-compose-font-name font))
+    (unless (x-list-fonts font)
+      (error "Cannot change font size"))
+    (modify-frame-parameters frame `((font . ,font)))))
+
+
+;;
+;;; Commands
+
+;;;###autoload
+(defun doom/increase-font-size (count)
+  "Enlargens the font size across the current frame."
+  (interactive "p")
+  (let ((zoom-factor (or (frame-parameter nil 'font-scale) 0))
+        (increment (* count doom-font-increment)))
+    (setq zoom-factor (+ zoom-factor increment))
+    (if (= zoom-factor 0)
+        (doom/reset-font-size)
+      (doom-adjust-font-size increment)
+      (modify-frame-parameters nil `((font-scale . ,zoom-factor)))
+      (run-hooks 'doom-change-font-size-hook))))
+
+;;;###autoload
+(defun doom/decrease-font-size (count)
+  "Shrinks the font size across the current frame."
+  (interactive "p")
+  (doom/increase-font-size (- count)))
+
+;;;###autoload
+(defun doom/reset-font-size ()
+  "Reset font size.
+
+Assuming it has been adjusted via `doom/increase-font-size' and
+`doom/decrease-font-size'."
+  (interactive)
+  (let ((zoom-factor (frame-parameter nil 'font-scale)))
+    (if (not zoom-factor)
+        (user-error "Font size hasn't been changed")
+      (set-frame-font doom-font t)
+      (modify-frame-parameters nil '((font-scale)))
+      (run-hooks 'doom-change-font-size-hook))))
+
+;;;###autoload
+(define-minor-mode doom-big-font-mode
+  "A global mode that resizes the font, for streams, screen-sharing and
+presentations.
+
+This uses `doom/increase-font-size' under the hood, and enlargens the font by
+`doom-big-font-increment'."
+  :init-value nil
+  :lighter " BIG"
+  :global t
+  (unless doom-font
+    (user-error "`doom-font' must be set to a valid font"))
+  (let ((frame (selected-frame)))
+    (set-frame-font doom-font t (list frame))
+    (when doom-big-font-mode
+      (doom-adjust-font-size doom-big-font-increment frame))))

core/autoload/hydras.el

@@ -5,9 +5,9 @@
   "
       Text zoom: _j_:zoom in, _k_:zoom out, _0_:reset
 "
-  ("j" text-scale-increase "in")
-  ("k" text-scale-decrease "out")
-  ("0" (text-scale-set 0) "reset"))
+  ("j" doom/increase-font-size "in")
+  ("k" doom/decrease-font-size "out")
+  ("0" doom/reset-font-size "reset"))
 
 ;;;###autoload (autoload 'doom-window-nav-hydra/body "core/autoload/hydras" nil t)
 (defhydra doom-window-nav-hydra (:hint nil)

core/autoload/ui.el

@@ -183,30 +183,3 @@ Inspired from http://demonastery.org/2013/04/emacs-evil-narrow-region/"
          (setq doom--buffer-narrowed-origin nil))
         (t
          (widen))))
-
-
-;;
-;; Modes
-
-;;;###autoload
-(define-minor-mode doom-big-font-mode
-  "A global mode that resizes the font, for streams, screen-sharing and
-presentations.
-
-Uses `doom-big-font' when enabled."
-  :init-value nil
-  :lighter " BIG"
-  :global t
-  (unless doom-big-font
-    (user-error "`doom-big-font' must be set to a valid font"))
-  (unless doom-font
-    (user-error "`doom-font' must be set to a valid font"))
-  (let ((doom-font (if doom-big-font-mode
-                       doom-big-font
-                     doom-font)))
-    (setf (alist-get 'font default-frame-alist)
-          (cond ((null doom-font))
-                ((stringp doom-font) doom-font)
-                ((fontp doom-font) (font-xlfd-name doom-font))
-                ((signal 'wrong-type-argument (list '(fontp stringp) doom-font)))))
-    (set-frame-font doom-font t t)))

core/core-ui.el

@@ -20,10 +20,6 @@ Examples:
   (setq doom-font (font-spec :family \"Fira Mono\" :size 12))
   (setq doom-font \"Terminus (TTF):pixelsize=12:antialias=off\")")
 
-(defvar doom-big-font nil
-  "The font to use when `doom-big-font-mode' is enabled. Expects either a
-`font-spec' or a XFT font string. See `doom-font' for examples.")
-
 (defvar doom-variable-pitch-font nil
   "The font to use for variable-pitch text.