master 32a6d52d43: Move selection delayed message to a better location

[Po Lu]

branch: master
commit 32a6d52d43b4c3452687a11b01dfb51ba111fee2
Author: Po Lu <luangruo@yahoo.com>
Commit: Po Lu <luangruo@yahoo.com>

    Move selection delayed message to a better location
    
    * lisp/term/x-win.el (gui-backend-get-selection): Remove
    `with-delayed-message' here.
    * src/xselect.c (x_display_selection_waiting_message)
    (x_cancel_atimer): New functions.
    (x_get_foreign_selection): Add an atimer that displays the
    message after a while.
---
 lisp/term/x-win.el |  5 ++---
 src/xselect.c      | 41 +++++++++++++++++++++++++++++++++++------
 2 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/lisp/term/x-win.el b/lisp/term/x-win.el
index 6e083499df..32675a07b1 100644
--- a/lisp/term/x-win.el
+++ b/lisp/term/x-win.el
@@ -1366,9 +1366,8 @@ This returns an error if any Emacs frames are X frames."
 (cl-defmethod gui-backend-get-selection (selection-symbol target-type
                                          &context (window-system x)
                                          &optional time-stamp terminal)
-  (with-delayed-message (1 "Waiting for selection")
-    (x-get-selection-internal selection-symbol target-type
-                              time-stamp terminal)))
+  (x-get-selection-internal selection-symbol target-type
+                            time-stamp terminal))
 
 ;; Initiate drag and drop
 (add-hook 'after-make-frame-functions 'x-dnd-init-frame)
diff --git a/src/xselect.c b/src/xselect.c
index fcf0ee944e..d90916c6b6 100644
--- a/src/xselect.c
+++ b/src/xselect.c
@@ -36,6 +36,7 @@ along with GNU Emacs.  If not, see 
<https://www.gnu.org/licenses/>.  */
 #include "termhooks.h"
 #include "keyboard.h"
 #include "pdumper.h"
+#include "atimer.h"
 
 #include <X11/Xproto.h>
 
@@ -1198,6 +1199,20 @@ x_handle_property_notify (const XPropertyEvent *event)
     }
 }
 
+static void
+x_display_selection_waiting_message (struct atimer *timer)
+{
+  Lisp_Object val;
+
+  val = build_string ("Waiting for reply from selection owner...");
+  message3_nolog (val);
+}
+
+static void
+x_cancel_atimer (void *atimer)
+{
+  cancel_atimer (atimer);
+}
 
 
 /* Variables for communication with x_handle_selection_notify.  */
@@ -1223,9 +1238,14 @@ x_get_foreign_selection (Lisp_Object selection_symbol, 
Lisp_Object target_type,
   Atom type_atom = (CONSP (target_type)
                    ? symbol_to_x_atom (dpyinfo, XCAR (target_type))
                    : symbol_to_x_atom (dpyinfo, target_type));
+  struct atimer *delayed_message;
+  struct timespec message_interval;
+  specpdl_ref count;
+
+  count = SPECPDL_INDEX ();
 
   if (!FRAME_LIVE_P (f))
-    return Qnil;
+    return unbind_to (count, Qnil);
 
   if (! NILP (time_stamp))
     CONS_TO_INTEGER (time_stamp, Time, requestor_time);
@@ -1257,6 +1277,12 @@ x_get_foreign_selection (Lisp_Object selection_symbol, 
Lisp_Object target_type,
 
   unblock_input ();
 
+  message_interval = make_timespec (1, 0);
+  delayed_message = start_atimer (ATIMER_RELATIVE, message_interval,
+                                 x_display_selection_waiting_message,
+                                 NULL);
+  record_unwind_protect_ptr (x_cancel_atimer, delayed_message);
+
   /* This allows quits.  Also, don't wait forever.  */
   intmax_t timeout = max (0, x_selection_timeout);
   intmax_t secs = timeout / 1000;
@@ -1288,13 +1314,16 @@ x_get_foreign_selection (Lisp_Object selection_symbol, 
Lisp_Object target_type,
   if (NILP (XCAR (reading_selection_reply)))
     error ("Timed out waiting for reply from selection owner");
   if (EQ (XCAR (reading_selection_reply), Qlambda))
-    return Qnil;
+    return unbind_to (count, Qnil);
 
   /* Otherwise, the selection is waiting for us on the requested property.  */
-  return
-    x_get_window_property_as_lisp_data (dpyinfo, requestor_window,
-                                       target_property, target_type,
-                                       selection_atom, false);
+  return unbind_to (count,
+                   x_get_window_property_as_lisp_data (dpyinfo,
+                                                       requestor_window,
+                                                       target_property,
+                                                       target_type,
+                                                       selection_atom,
+                                                       false));
 }
 
 /* Subroutines of x_get_window_property_as_lisp_data */