Support replacing and being replaced by other window managers

* exwm.el (exwm--on-SelectionClear, exwm--init-icccm-ewmh)
(exwm--exit-icccm-ewmh, exwm--wmsn-acquire, exwm--wmsn-release):
Get the window manager selection; die when it is cleared.
This commit is contained in:
Adrián Medraño Calvo 2018-03-06 00:00:00 +00:00
parent 350950abfc
commit 7aae6efdcd
2 changed files with 103 additions and 3 deletions

View file

@ -37,6 +37,15 @@
(defvar exwm--connection nil "X connection.")
(defvar exwm--wmsn-window nil
"An X window owning the WM_S0 selection.")
(defvar exwm--wmsn-acquire-timeout 3
"Number of seconds to wait for other window managers to release the selection.")
(defvar exwm--wmsn-replace 'ask
"Replace existing window manager.")
(defvar exwm--guide-window nil
"An X window separating workspaces and X windows.")

97
exwm.el
View file

@ -529,12 +529,26 @@
(bury-buffer)))))
(t (exwm--log "Unhandled client message: %s" obj)))))
(defun exwm--on-SelectionClear (data _synthetic)
"Handle SelectionClear events."
(exwm--log "SelectionClear")
(let ((obj (make-instance 'xcb:SelectionClear))
owner selection)
(xcb:unmarshal obj data)
(setq owner (slot-value obj 'owner)
selection (slot-value obj 'selection))
(when (and (eq owner exwm--wmsn-window)
(eq selection xcb:Atom:WM_S0))
(exwm-exit))))
(defun exwm--init-icccm-ewmh ()
"Initialize ICCCM/EWMH support."
;; Handle PropertyNotify event
(xcb:+event exwm--connection 'xcb:PropertyNotify #'exwm--on-PropertyNotify)
;; Handle relevant client messages
(xcb:+event exwm--connection 'xcb:ClientMessage #'exwm--on-ClientMessage)
;; Handle SelectionClear
(xcb:+event exwm--connection 'xcb:SelectionClear #'exwm--on-SelectionClear)
;; Set _NET_SUPPORTED
(xcb:+request exwm--connection
(make-instance 'xcb:ewmh:set-_NET_SUPPORTED
@ -667,6 +681,81 @@
:data [0 0]))
(xcb:flush exwm--connection))
(defun exwm--wmsn-acquire (replace)
"Acquire the WM_Sn selection.
REPLACE specifies what to do in case there already is a window
manager. If t, replace it, if nil, abort and if `ask'."
(with-slots (owner)
(xcb:+request-unchecked+reply exwm--connection
(make-instance 'xcb:GetSelectionOwner
:selection xcb:Atom:WM_S0))
(when (/= owner xcb:Window:None)
(when (eq replace 'ask)
(setq replace (yes-or-no-p "Replace existing window manager?")))
(when (not replace)
(error "Other window manager detected")))
(let ((new-owner (xcb:generate-id exwm--connection)))
(xcb:+request exwm--connection
(make-instance 'xcb:CreateWindow
:depth 0
:wid new-owner
:parent exwm--root
:x -1
:y -1
:width 1
:height 1
:border-width 0
:class xcb:WindowClass:CopyFromParent
:visual 0
:value-mask 0
:override-redirect 0))
(xcb:+request exwm--connection
(make-instance 'xcb:ewmh:set-_NET_WM_NAME
:window new-owner :data "EXWM selection owner"))
(xcb:+request-checked+request-check exwm--connection
(make-instance 'xcb:SetSelectionOwner
:selection xcb:Atom:WM_S0
:owner new-owner
:time xcb:Time:CurrentTime))
(with-slots (owner)
(xcb:+request-unchecked+reply exwm--connection
(make-instance 'xcb:GetSelectionOwner
:selection xcb:Atom:WM_S0))
(unless (eq owner new-owner)
(error "Could not acquire ownership of WM selection")))
;; Wait for the other window manager to terminate.
(when (/= owner xcb:Window:None)
(let (reply)
(cl-dotimes (i 10) ;exwm--wmsn-acquire-timeout)
(setq reply (xcb:+request-unchecked+reply exwm--connection
(make-instance 'xcb:GetGeometry :drawable owner)))
(when (not reply)
(cl-return))
(message "Waiting for other window manager to quit... %ds" i)
(sleep-for 1))
(when reply
(error "Other window manager did not release selection in time"))))
;; announce
(let* ((cmd (make-instance 'xcb:ClientMessageData
:data32 (vector xcb:Time:CurrentTime
xcb:Atom:WM_S0
new-owner
0
0)))
(cm (make-instance 'xcb:ClientMessage
:window exwm--root
:format 32
:type xcb:Atom:MANAGER
:data cmd))
(se (make-instance 'xcb:SendEvent
:propagate 0
:destination exwm--root
:event-mask xcb:EventMask:NoEvent
:event (xcb:marshal cm exwm--connection))))
(xcb:+request exwm--connection se))
(setq exwm--wmsn-window new-owner))))
;;;###autoload
(defun exwm-init (&optional frame)
"Initialize EXWM."
@ -689,6 +778,11 @@
(slot-value (car (slot-value
(xcb:get-setup exwm--connection) 'roots))
'root))
;; Initialize ICCCM/EWMH support
(xcb:icccm:init exwm--connection t)
(xcb:ewmh:init exwm--connection t)
;; Try to register window manager selection.
(exwm--wmsn-acquire 'ask)
(when (xcb:+request-checked+request-check exwm--connection
(make-instance 'xcb:ChangeWindowAttributes
:window exwm--root :value-mask xcb:CW:EventMask
@ -697,9 +791,6 @@
;; Disable some features not working well with EXWM
(setq use-dialog-box nil
confirm-kill-emacs #'exwm--confirm-kill-emacs)
;; Initialize ICCCM/EWMH support
(xcb:icccm:init exwm--connection t)
(xcb:ewmh:init exwm--connection t)
(exwm--lock)
(exwm--init-icccm-ewmh)
(exwm-layout--init)