Fix fullscreen mode after switching workspace and back

* exwm-layout.el (exwm-layout--show): Always set an X window in
fullscreen mode the size in fullscreen.
(exwm-layout-unset-fullscreen): Leave the fullscreen mode first.

* exwm-layout.el (exwm-layout--fullscreen-p): New function telling
whether the current buffer is in fullscreen mode.
(exwm-layout-set-fullscreen, exwm-layout-unset-fullscreen)
(exwm-layout-toggle-fullscreen):
* exwm-manage.el (exwm-manage--manage-window)
(exwm-manage--on-ConfigureRequest):
* exwm-workspace.el (exwm-workspace-switch, exwm-workspace-swap)
(exwm-workspace-move):
* exwm.el (exwm-reset, exwm--on-ClientMessage): Use it.

4 files changed, 32 insertions, 20 deletions

diff --git a/exwm-layout.el b/exwm-layout.el
index 5a01f900323d..998556bc896f 100644
--- a/exwm-layout.el
+++ b/exwm-layout.el
@@ -69,6 +69,10 @@
          (buffer-local-value 'exwm-state (exwm--id->buffer id))
        exwm-state)))
 
+(defun exwm-layout--fullscreen-p ()
+  (when (derived-mode-p 'exwm-mode)
+    (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state)))
+
 (defun exwm-layout--show (id &optional window)
   "Show window ID exactly fit in the Emacs window WINDOW."
   (exwm--log "Show #x%x in %s" id window)
@@ -92,6 +96,16 @@
         (exwm--set-geometry (frame-parameter exwm--floating-frame
                                              'exwm-container)
                             frame-x frame-y frame-width frame-height))
+      (when (exwm-layout--fullscreen-p)
+        (with-slots ((x* x)
+                     (y* y)
+                     (width* width)
+                     (height* height))
+            (exwm-workspace--get-geometry exwm--frame)
+          (setq x x*
+                y y*
+                width width*
+                height height*)))
       (exwm--set-geometry id x y width height)
       (xcb:+request exwm--connection (make-instance 'xcb:MapWindow :window id))
       (exwm-layout--set-state id xcb:icccm:WM_STATE:NormalState)))
@@ -131,7 +145,7 @@
   "Make window ID fullscreen."
   (interactive)
   (unless (and (or id (derived-mode-p 'exwm-mode))
-               (not (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state)))
+               (not (exwm-layout--fullscreen-p)))
     (cl-return-from 'exwm-layout-set-fullscreen))
   (with-current-buffer (if id (exwm--id->buffer id) (window-buffer))
     ;; Expand the X window to fill the whole screen.
@@ -158,9 +172,11 @@
   "Restore window from fullscreen state."
   (interactive)
   (unless (and (or id (derived-mode-p 'exwm-mode))
-               (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
+               (exwm-layout--fullscreen-p))
     (cl-return-from 'exwm-layout-unset-fullscreen))
   (with-current-buffer (if id (exwm--id->buffer id) (window-buffer))
+    (setq exwm--ewmh-state
+          (delq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
     (if exwm--floating-frame
         (exwm-layout--show exwm--id (frame-root-window exwm--floating-frame))
       (xcb:+request exwm--connection
@@ -176,8 +192,6 @@
     (xcb:+request exwm--connection
         (make-instance 'xcb:ewmh:set-_NET_WM_STATE :window exwm--id :data []))
     (xcb:flush exwm--connection)
-    (setq exwm--ewmh-state
-          (delq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
     (call-interactively #'exwm-input-grab-keyboard)))
 
 ;;;###autoload
@@ -188,7 +202,7 @@
     (cl-return-from 'exwm-layout-toggle-fullscreen))
   (when id
     (with-current-buffer (exwm--id->buffer id)
-      (if (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state)
+      (if (exwm-layout--fullscreen-p)
           (exwm-reset)
         (exwm-layout-set-fullscreen id)))))
 
diff --git a/exwm-manage.el b/exwm-manage.el
index 94aefd8c555f..b5c3f58dfdde 100644
--- a/exwm-manage.el
+++ b/exwm-manage.el
@@ -109,6 +109,7 @@ You can still make the X windows floating afterwards."
 (declare-function exwm-floating--unset-floating "exwm-floating.el" (id))
 (declare-function exwm-input-grab-keyboard "exwm-input.el")
 (declare-function exwm-input-set-local-simulation-keys "exwm-input.el")
+(declare-function exwm-layout--fullscreen-p "exwm-layout.el" ())
 (declare-function exwm-layout--iconic-state-p "exwm-layout.el" (&optional id))
 (declare-function exwm-workspace--count "exwm-workspace.el" ())
 (declare-function exwm-workspace--position "exwm-workspace.el" (frame))
@@ -318,7 +319,7 @@ You can still make the X windows floating afterwards."
       (exwm-manage--update-ewmh-state id)
       (with-current-buffer (exwm--id->buffer id)
         (when (or (plist-get exwm--configurations 'fullscreen)
-                  (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
+                  (exwm-layout--fullscreen-p))
           (setq exwm--ewmh-state (delq xcb:Atom:_NET_WM_STATE_FULLSCREEN
                                        exwm--ewmh-state))
           (exwm-layout-set-fullscreen id))
@@ -533,7 +534,7 @@ border-width: %d; sibling: #x%x; stack-mode: %d"
                  border-width sibling stack-mode)
       (if (and (setq buffer (exwm--id->buffer window))
                (with-current-buffer buffer
-                 (or (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state)
+                 (or (exwm-layout--fullscreen-p)
                      ;; Make sure it's a floating X window wanting to resize
                      ;; itself.
                      (or (not exwm--floating-frame)
@@ -559,7 +560,7 @@ border-width: %d; sibling: #x%x; stack-mode: %d"
           ;; Send client message for managed windows
           (with-current-buffer buffer
             (setq edges
-                  (if (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state)
+                  (if (exwm-layout--fullscreen-p)
                       (with-slots (x y width height)
                           (exwm-workspace--get-geometry exwm--frame)
                         (list x y width height))
diff --git a/exwm-workspace.el b/exwm-workspace.el
index 0651b575d8b4..deb6a653575a 100644
--- a/exwm-workspace.el
+++ b/exwm-workspace.el
@@ -128,6 +128,7 @@ Please manually run the hook `exwm-workspace-list-change-hook' afterwards.")
 (defvar exwm-manage--desktop)
 (declare-function exwm--exit "exwm.el")
 (declare-function exwm-input--on-buffer-list-update "exwm-input.el" ())
+(declare-function exwm-layout--fullscreen-p "exwm-layout.el" ())
 (declare-function exwm-layout--hide "exwm-layout.el" (id))
 (declare-function exwm-layout--other-buffer-predicate "exwm-layout.el"
                   (buffer))
@@ -504,7 +505,7 @@ for internal use only."
      ((null current-prefix-arg)
       (unless (and (eq major-mode 'exwm-mode)
                    ;; The prompt is invisible in fullscreen mode.
-                   (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
+                   (exwm-layout--fullscreen-p))
         (let ((exwm-workspace--prompt-add-allowed t)
               (exwm-workspace--prompt-delete-allowed t))
           (exwm-workspace--prompt-for-workspace "Switch to [+/-]: "))))
@@ -631,7 +632,7 @@ Passing a workspace frame as the first option is for internal use only."
   (interactive
    (unless (and (eq major-mode 'exwm-mode)
                 ;; The prompt is invisible in fullscreen mode.
-                (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
+                (exwm-layout--fullscreen-p))
      (let (w1 w2)
        (let ((exwm-workspace--prompt-add-allowed t)
              (exwm-workspace--prompt-delete-allowed t))
@@ -671,7 +672,7 @@ before it."
     ((null current-prefix-arg)
      (unless (and (eq major-mode 'exwm-mode)
                   ;; The prompt is invisible in fullscreen mode.
-                  (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state))
+                  (exwm-layout--fullscreen-p))
        (list exwm-workspace--current
              (exwm-workspace--position
               (exwm-workspace--prompt-for-workspace "Move workspace to: ")))))
diff --git a/exwm.el b/exwm.el
index ed251f30adfc..0387426ffc68 100644
--- a/exwm.el
+++ b/exwm.el
@@ -110,7 +110,7 @@
   (interactive)
   (with-current-buffer (window-buffer)
     (when (eq major-mode 'exwm-mode)
-      (when (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN exwm--ewmh-state)
+      (when (exwm-layout--fullscreen-p)
         (exwm-layout-unset-fullscreen))
       ;; Force refresh
       (exwm-layout--refresh)
@@ -484,8 +484,7 @@
               exwm--connection
               (make-instance 'xcb:ewmh:set-_NET_WM_STATE
                              :window id
-                             :data (vector
-                                    xcb:Atom:_NET_WM_STATE_FULLSCREEN)))
+                             :data (vector xcb:Atom:_NET_WM_STATE_FULLSCREEN)))
           (xcb:flush exwm--connection))
         (when buffer                    ;ensure it's managed
           (with-current-buffer buffer
@@ -493,17 +492,14 @@
             (when (or (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN props)
                       (memq xcb:Atom:_NET_WM_STATE_ABOVE props))
               (cond ((= action xcb:ewmh:_NET_WM_STATE_ADD)
-                     (unless (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN
-                                   exwm--ewmh-state)
+                     (unless (exwm-layout--fullscreen-p)
                        (exwm-layout-set-fullscreen id))
                      (push xcb:Atom:_NET_WM_STATE_FULLSCREEN props-new))
                     ((= action xcb:ewmh:_NET_WM_STATE_REMOVE)
-                     (when (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN
-                                 exwm--ewmh-state)
+                     (when (exwm-layout--fullscreen-p)
                        (exwm-layout-unset-fullscreen id)))
                     ((= action xcb:ewmh:_NET_WM_STATE_TOGGLE)
-                     (if (memq xcb:Atom:_NET_WM_STATE_FULLSCREEN
-                               exwm--ewmh-state)
+                     (if (exwm-layout--fullscreen-p)
                          (exwm-layout-unset-fullscreen id)
                        (exwm-layout-set-fullscreen id)
                        (push xcb:Atom:_NET_WM_STATE_FULLSCREEN props-new)))))