199 lines
		
	
	
	
		
			7.7 KiB
		
	
	
	
		
			EmacsLisp
		
	
	
	
	
	
			
		
		
	
	
			199 lines
		
	
	
	
		
			7.7 KiB
		
	
	
	
		
			EmacsLisp
		
	
	
	
	
	
| ;;; exwm-background.el --- X Background Module for EXWM  -*- lexical-binding: t -*-
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| 
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| ;; Copyright (C) 2022-2024 Free Software Foundation, Inc.
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| 
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| ;; Author: Steven Allen <steven@stebalien.com>
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| 
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| ;; This file is part of GNU Emacs.
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| 
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| ;; GNU Emacs is free software: you can redistribute it and/or modify
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| ;; it under the terms of the GNU General Public License as published by
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| ;; the Free Software Foundation, either version 3 of the License, or
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| ;; (at your option) any later version.
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| 
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| ;; GNU Emacs is distributed in the hope that it will be useful,
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| ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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| ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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| ;; GNU General Public License for more details.
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| 
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| ;; You should have received a copy of the GNU General Public License
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| ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
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| 
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| ;;; Commentary:
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| 
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| ;; This module adds X background color setting support to EXWM.
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| 
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| ;; To use this module, load and enable it as follows:
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| ;;   (require 'exwm-background)
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| ;;   (exwm-background-enable)
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| ;;
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| ;; By default, this will apply the theme's background color. However, that
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| ;; color can be customized via the `exwm-background-color' setting.
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| 
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| ;;; Code:
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| 
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| (require 'exwm-core)
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| 
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| (defcustom exwm-background-color nil
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|   "Background color for Xorg."
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|   :type '(choice
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|           (color :tag "Background Color")
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|           (const :tag "Default" nil))
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|   :group 'exwm
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|   :initialize #'custom-initialize-default
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|   :set (lambda (symbol value)
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|          (set-default-toplevel-value symbol value)
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|          (exwm-background--update)))
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| 
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| (defconst exwm-background--properties '("_XROOTPMAP_ID" "_XSETROOT_ID" "ESETROOT_PMAP_ID")
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|   "The background properties to set.
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| We can't need to set these so that compositing window managers can correctly display the background
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| color.")
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| 
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| (defvar exwm-background--connection nil
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|   "The X connection used for setting the background.
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| We use a separate connection as other background-setting tools may kill this connection when they
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| replace it.")
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| 
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| (defvar exwm-background--pixmap nil
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|   "Cached background pixmap.")
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| 
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| (defvar exwm-background--atoms nil
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|   "Cached background atoms.")
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| 
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| (defun exwm-background--update (&rest _)
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|   "Update the EXWM background."
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| 
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|   ;; Always reconnect as any tool that sets the background may have disconnected us (to force X to
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|   ;; free resources).
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|   (exwm-background--connect)
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| 
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|   (let ((gc (xcb:generate-id exwm-background--connection))
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|         (color (exwm--color->pixel (or exwm-background-color
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|                                        (face-background 'default)))))
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|     ;; Fill the pixmap.
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|     (xcb:+request exwm-background--connection
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|         (make-instance 'xcb:CreateGC
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|                        :cid gc :drawable exwm-background--pixmap
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|                        :value-mask (logior xcb:GC:Foreground
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|                                            xcb:GC:GraphicsExposures)
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|                        :foreground color
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|                        :graphics-exposures 0))
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| 
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|     (xcb:+request exwm-background--connection
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|         (make-instance 'xcb:PolyFillRectangle
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|                        :gc gc :drawable exwm-background--pixmap
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|                        :rectangles
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|                        (list
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|                         (make-instance
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|                          'xcb:RECTANGLE
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|                          :x 0 :y 0 :width 1 :height 1))))
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|     (xcb:+request exwm-background--connection (make-instance 'xcb:FreeGC :gc gc)))
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| 
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|   ;; Reapply it to force an update (also clobber anyone else who may have set it).
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|   (xcb:+request exwm-background--connection
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|       (make-instance 'xcb:ChangeWindowAttributes
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|                      :window exwm--root
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|                      :value-mask xcb:CW:BackPixmap
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|                      :background-pixmap exwm-background--pixmap))
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| 
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|   (let (old)
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|     ;; Collect old pixmaps so we can kill other background clients (all the background setting tools
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|     ;; seem to do this).
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|     (dolist (atom exwm-background--atoms)
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|       (when-let* ((reply (xcb:+request-unchecked+reply exwm-background--connection
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|                              (make-instance 'xcb:GetProperty
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|                                             :delete 0
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|                                             :window exwm--root
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|                                             :property atom
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|                                             :type xcb:Atom:PIXMAP
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|                                             :long-offset 0
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|                                             :long-length 1)))
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|                   (value (vconcat (slot-value reply 'value)))
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|                   ((length= value 4))
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|                   (pixmap (funcall (if xcb:lsb #'xcb:-unpack-u4-lsb #'xcb:-unpack-u4)
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|                                    value 0))
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|                   ((not (or (= pixmap exwm-background--pixmap)
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|                             (member pixmap old)))))
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|         (push pixmap old)))
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| 
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|     ;; Change the background.
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|     (dolist (atom exwm-background--atoms)
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|       (xcb:+request exwm-background--connection
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|           (make-instance 'xcb:ChangeProperty
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|                          :window exwm--root
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|                          :property atom
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|                          :type xcb:Atom:PIXMAP
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|                          :format 32
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|                          :mode xcb:PropMode:Replace
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|                          :data-len 1
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|                          :data
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|                          (funcall (if xcb:lsb
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|                                       #'xcb:-pack-u4-lsb
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|                                     #'xcb:-pack-u4)
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|                                   exwm-background--pixmap))))
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| 
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|     ;; Kill the old background clients.
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|     (dolist (pixmap old)
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|       (xcb:+request exwm-background--connection
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|           (make-instance 'xcb:KillClient :resource pixmap))))
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| 
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|   (xcb:flush exwm-background--connection))
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| 
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| (defun exwm-background--connected-p ()
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|   (and exwm-background--connection
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|        (process-live-p (slot-value exwm-background--connection 'process))))
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| 
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| (defun exwm-background--connect ()
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|   (unless (exwm-background--connected-p)
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|     (setq exwm-background--connection (xcb:connect))
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|     ;;prevent query message on exit
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|     (set-process-query-on-exit-flag (slot-value exwm-background--connection 'process) nil)
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| 
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|     ;; Intern the background property atoms.
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|     (setq exwm-background--atoms
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|           (mapcar
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|            (lambda (prop) (exwm--intern-atom prop exwm-background--connection))
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|            exwm-background--properties))
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| 
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|     ;; Create the pixmap.
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|     (setq exwm-background--pixmap (xcb:generate-id exwm-background--connection))
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|     (xcb:+request exwm-background--connection
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|         (make-instance 'xcb:CreatePixmap
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|                        :depth
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|                        (slot-value
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|                         (xcb:+request-unchecked+reply exwm-background--connection
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|                             (make-instance 'xcb:GetGeometry :drawable exwm--root))
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|                         'depth)
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|                        :pid exwm-background--pixmap
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|                        :drawable exwm--root
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|                        :width 1 :height 1))))
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| 
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| (defun exwm-background--init ()
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|   "Initialize background module."
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|   (exwm--log)
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|   (add-hook 'enable-theme-functions 'exwm-background--update)
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|   (add-hook 'disable-theme-functions 'exwm-background--update)
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|   (exwm-background--update))
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| 
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| (defun exwm-background--exit ()
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|   "Uninitialize the background module."
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|   (exwm--log)
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|   (remove-hook 'enable-theme-functions 'exwm-background--update)
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|   (remove-hook 'disable-theme-functions 'exwm-background--update)
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|   (when (and exwm-background--connection
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|              (slot-value exwm-background--connection 'connected))
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|     (xcb:disconnect exwm-background--connection))
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|   (setq exwm-background--pixmap nil
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|         exwm-background--connection nil
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|         exwm-background--atoms nil))
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| 
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| (defun exwm-background-enable ()
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|   "Enable background support for EXWM."
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|   (exwm--log)
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|   (add-hook 'exwm-init-hook #'exwm-background--init)
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|   (add-hook 'exwm-exit-hook #'exwm-background--exit))
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| 
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| (provide 'exwm-background)
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| 
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| ;;; exwm-background.el ends here
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