;;; early-init.el --- frames conf. -*- lexical-binding:t;no-byte-compile:t -*-

;; Copyright (C) 2020-2023  Sean Whitton <spwhitton@spwhitton.name>
;;
;; This file 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 file 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 file.  If not, see <https://www.gnu.org/licenses/>.

(let ((in-tree
       ;; `installation-directory' is normally nil when running an installed
       ;; Emacs.  If I've installed Emacs somewhere under HOME, then I can
       ;; ensure that it is indeed nil when running that build.
       ;; Thus, if `installation-directory' is non-nil and under HOME, we can
       ;; be sure that we are running an uninstalled executable.
       (and installation-directory
	    (file-in-directory-p installation-directory
				 (expand-file-name "~/")))))
  (when in-tree
    ;; Make packages compiled against my emacs-snapshot Debian packages
    ;; available to in-tree builds.  (Previously we patched the code computing
    ;; the default value of `package-directory-list' in those builds.)
    (when (file-directory-p "/usr/share/emacs-snapshot/site-lisp/elpa")
      (add-to-list 'package-directory-list
		   "/usr/share/emacs-snapshot/site-lisp/elpa" t))

    ;; Run Debian's site-start library site-run-file for in-tree builds too.
    ;; (Used to do this by patching `command-line' in those builds.)
    (when (file-readable-p "/etc/emacs/site-start.d/00debian.el")
      (load "/etc/emacs/site-start.d/00debian.el")))

  (setq frame-title-format
	(format "%%b — %s%c%s@%s"
		(if (stringp (daemonp)) (daemonp) "Emacs")
		(if in-tree ?: ?-) emacs-version system-name)
	icon-title-format t))


;;; Per docstring for `after-make-frame-functions', these additions to that
;;; list of functions are made in this file in order that they can affect the
;;; initial frame.

(defun spw/set-fontset-fonts (frame)
  "Set some fonts for specific charsets.
This has to happen after there's at least one graphical frame, or the fonts
won't be found."
  (when (display-graphic-p frame)
    (setq after-make-frame-functions
	  (delq #'spw/set-fontset-fonts after-make-frame-functions))
    (let ((spec (font-spec :name "Noto Serif CJK JP")))
      (dolist (charset '(kana han symbol cjk-misc bopomofo))
	(set-fontset-font t charset spec)))
    (set-fontset-font t 'hangul (font-spec :name "Noto Serif CJK KR"))))
(add-to-list 'after-make-frame-functions #'spw/set-fontset-fonts)

(defvar spw/tiling-wm-p nil
  "Have we had at least one frame managed by a tiling window manager?")

(defun spw/disable-mouse-autoselect-window (orig-fun &rest args)
  (let (mouse-autoselect-window)
    (apply orig-fun args)))

;; 'emacsclient --spw/update-environment' supplies us with I3SOCK, so if we
;; see that variable we know there is at least one frame under i3 or swaywm,
;; and so we want to set `focus-follows-mouse' to t.  As we can't do that
;; frame-locally, once it's set it's set.  (I used to set
;; `mouse-autoselect-window' to t too, but it often caused unwanted focus
;; changes, and it makes the tool and menu bars much fiddlier to use.)
;;
;; On the other hand, ideally functions like `spw/save-buffer-for-later'
;; decide whether to open a new frame or a new tab frame-locally, so we used
;; to temporarily set DISPLAY to (frame-parameter (selected-frame) 'display)
;; and then call wmctrl(1) to get the name of the window manager for that
;; frame, and stored it in a frame parameter.  But that works only for X11,
;; not Wayland.  So for now we just set a boolean `spw/tiling-wm-p' to which
;; functions like `spw/save-buffer-for-later' can respond.
(defun spw/detect-tiling-wm (frame)
  (unless (or spw/tiling-wm-p
	      (not (setq spw/tiling-wm-p
			 (or (getenv "I3SOCK") (getenv "SWAYSOCK")))))
    (setq focus-follows-mouse t
	  ;; mouse-autoselect-window t
	  desktop-restore-forces-onscreen nil)
    ;; Disable `mouse-autoselect-window' during `display-buffer', to avoid
    ;; surprise focus changes -- some code that calls `display-buffer' does
    ;; not expect `mouse-autoselect-window' to be on.  E.g. `magit-status' can
    ;; leave focus in the wrong window without this.
    ;; (advice-add 'display-buffer
    ;; 		:around #'spw/disable-mouse-autoselect-window)
    )
  ;; If X or Sway, we know we have a usable primary selection, so we used to
  ;; turn off additionally copying to the clipboard.  However, we do want to
  ;; be able to yank from the clipboard.  See also NEWS.24.
  ;; (setq select-enable-clipboard
  ;; 	(not (or spw/tiling-wm-p (eq (framep frame) 'x))))
  )
(add-to-list 'after-make-frame-functions #'spw/detect-tiling-wm)