Add basic RandR support

This implementation is analogous to that in i3-wm, which requires external
tools to properly configure RandR first.

1 files changed, 131 insertions, 0 deletions

diff --git a/exwm-randr.el b/exwm-randr.el
new file mode 100644
index 000000000000..c9ad1ce6ae7b
--- /dev/null
+++ b/exwm-randr.el
@@ -0,0 +1,131 @@
+;;; exwm-randr.el --- RandR Module for EXWM  -*- lexical-binding: t -*-
+
+;; Copyright (C) 2015 Chris Feng
+
+;; Author: Chris Feng <chris.w.feng@gmail.com>
+;; Keywords: unix
+
+;; This file is not part of GNU Emacs.
+
+;; 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 <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This module adds RandR support for EXWM. Currently it requires external
+;; tools such as xrandr(1) to properly configure RandR first. This dependency
+;; may be removed in the future, but more work is needed before that.
+
+;; To use this module, first set `exwm-randr-workspace-output-plist':
+;;   (setq exwm-randr-workspace-output-plist '(0 "VGA1"))
+;; Then configure RandR with 'xrandr':
+;;   $ xrandr --output VGA1 --left-of LVDS1 --auto
+;; With above lines, workspace 0 should be assigned to the output named "VGA1",
+;; staying at the left of other workspaces on the output "LVDS1".
+
+;; Todo:
+;; + Update EWMH hints.
+
+;; References:
+;; + RandR (http://www.x.org/archive/X11R7.7/doc/randrproto/randrproto.txt)
+
+;;; Code:
+
+(require 'xcb-randr)
+
+(defvar exwm-randr-workspace-output-plist nil)
+
+(defun exwm-randr--refresh ()
+  "Refresh workspaces according to the updated RandR info."
+  (let (output-plist default-geometry)
+    ;; Query all outputs
+    (with-slots (config-timestamp outputs)
+        (xcb:+request-unchecked+reply exwm--connection
+            (make-instance 'xcb:randr:GetScreenResources
+                           :window exwm--root))
+      (dolist (output outputs)
+        (with-slots (crtc connection name)
+            (xcb:+request-unchecked+reply exwm--connection
+                (make-instance 'xcb:randr:GetOutputInfo
+                               :output output
+                               :config-timestamp config-timestamp))
+          (setq name                    ;UTF-8 encoded
+                (decode-coding-string (apply 'unibyte-string name) 'utf-8))
+          (if (or (/= connection xcb:randr:Connection:Connected)
+                  (= 0 crtc))           ;FIXME
+              (plist-put output-plist name nil)
+            (with-slots (x y width height)
+                (xcb:+request-unchecked+reply exwm--connection
+                    (make-instance 'xcb:randr:GetCrtcInfo
+                                   :crtc crtc
+                                   :config-timestamp config-timestamp))
+              (setq output-plist (plist-put output-plist name
+                                            (vector x y width height)))
+              (unless default-geometry ;assume the first output as primary
+                (setq default-geometry (vector x y width height))))))))
+    (cl-assert (<= 2 (length output-plist)))
+    (dotimes (i exwm-workspace-number)
+      (let* ((output (plist-get exwm-randr-workspace-output-plist i))
+             (geometry (lax-plist-get output-plist output))
+             (frame (elt exwm-workspace--list i)))
+        (unless geometry
+          (setq geometry default-geometry
+                output nil))
+        (set-frame-parameter frame 'exwm-randr-output output)
+        (xcb:+request exwm--connection
+            (make-instance 'xcb:ConfigureWindow
+                           :window (frame-parameter frame 'exwm-outer-id)
+                           :value-mask (logior xcb:ConfigWindow:X
+                                               xcb:ConfigWindow:Y
+                                               xcb:ConfigWindow:Width
+                                               xcb:ConfigWindow:Height)
+                           :x (elt geometry 0) :y (elt geometry 1)
+                           :width (elt geometry 2) :height (elt geometry 3)))))
+    (xcb:flush exwm--connection)))
+
+(defun exwm-randr--init ()
+  "Initialize RandR extension and EXWM RandR module."
+  (if (= 0 (slot-value (xcb:get-extension-data exwm--connection 'xcb:randr)
+                       'present))
+      (error "[EXWM] RandR extension is not supported by the server")
+    (with-slots (major-version minor-version)
+        (xcb:+request-unchecked+reply exwm--connection
+            (make-instance 'xcb:randr:QueryVersion
+                           :major-version 1 :minor-version 2))
+      (if (or (/= major-version 1) (< minor-version 2))
+          (error "[EXWM] The server only support RandR version up to %d.%d"
+                 major-version minor-version)
+        (exwm-randr--refresh)
+        (xcb:+event exwm--connection 'xcb:randr:ScreenChangeNotify
+                    (lambda (data synthetic)
+                      (exwm-randr--refresh)))
+        ;; (xcb:+event exwm--connection 'xcb:randr:Notify
+        ;;             (lambda (data synthetic)
+        ;;               (exwm-randr--refresh)))
+        (xcb:+request exwm--connection
+            (make-instance 'xcb:randr:SelectInput
+                           :window exwm--root
+                           :enable xcb:randr:NotifyMask:ScreenChange
+                           ;; :enable (logior
+                           ;;          xcb:randr:NotifyMask:ScreenChange
+                           ;;          xcb:randr:NotifyMask:OutputChange
+                           ;;          xcb:randr:NotifyMask:OutputProperty
+                           ;;          xcb:randr:NotifyMask:CrtcChange)
+                           ))
+        (xcb:flush exwm--connection)))))
+
+
+
+(provide 'exwm-randr)
+
+;;; exwm-randr.el ends here