Handle alternate actions for Motif drop targets

* src/xterm.c (xm_side_effect_from_action): Handle
`XdndActionAsk'.
(xm_operations_from_actions): New function.
(xm_send_top_level_leave_message, x_dnd_cleanup_drag_and_drop)
(x_dnd_update_state, handle_one_xevent, x_connection_closed):
Use those actions when building a side effect.
(x_dnd_begin_drag_and_drop): Keep track of the set of
alternative drag-and-drop actions.

1 files changed, 58 insertions, 33 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 9826f2fbd85..d949439d188 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -1119,6 +1119,14 @@ static Atom x_dnd_action;
    in `x_dnd_action' upon completion of a drop.  */
 static Atom x_dnd_wanted_action;
 
+/* The set of optional actions available to a Motif drop target
+   computed at the start of the drag-and-drop operation.  */
+static uint8_t x_dnd_motif_operations;
+
+/* The preferred optional action out of that set.  Only takes effect
+   if `x_dnd_action' is XdndAsk.  */
+static uint8_t x_dnd_first_motif_operation;
+
 /* Array of selection targets available to the drop target.  */
 static Atom *x_dnd_targets = NULL;
 
@@ -1405,10 +1413,34 @@ xm_side_effect_from_action (struct x_display_info *dpyinfo, Atom action)
     return XM_DRAG_MOVE;
   else if (action == dpyinfo->Xatom_XdndActionLink)
     return XM_DRAG_LINK;
+  else if (action == dpyinfo->Xatom_XdndActionAsk)
+    return x_dnd_first_motif_operation;
 
   return XM_DRAG_NOOP;
 }
 
+static uint8_t
+xm_operations_from_actions (struct x_display_info *dpyinfo,
+                            Atom *ask_actions, int n_ask_actions)
+{
+  int i;
+  uint8_t flags;
+
+  flags = 0;
+
+  for (i = 0; i < n_ask_actions; ++i)
+    {
+      if (ask_actions[i] == dpyinfo->Xatom_XdndActionCopy)
+        flags |= XM_DRAG_COPY;
+      else if (ask_actions[i] == dpyinfo->Xatom_XdndActionMove)
+        flags |= XM_DRAG_MOVE;
+      else if (ask_actions[i] == dpyinfo->Xatom_XdndActionLink)
+        flags |= XM_DRAG_LINK;
+    }
+
+  return flags;
+}
+
 static int
 xm_read_targets_table_header (uint8_t *bytes, ptrdiff_t length,
                               xm_targets_table_header *header_return,
@@ -2038,7 +2070,7 @@ xm_send_top_level_leave_message (struct x_display_info *dpyinfo, Window source,
       mmsg.byteorder = XM_BYTE_ORDER_CUR_FIRST;
       mmsg.side_effects = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                            x_dnd_wanted_action),
-                                               XM_DROP_SITE_NONE, XM_DRAG_NOOP,
+                                               XM_DROP_SITE_NONE, x_dnd_motif_operations,
                                                XM_DROP_ACTION_DROP_CANCEL);
       mmsg.timestamp = dmsg->timestamp;
       mmsg.x = 65535;
@@ -3904,9 +3936,7 @@ x_dnd_cleanup_drag_and_drop (void *frame)
           dmsg.side_effects
             = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
                                                                x_dnd_wanted_action),
-                                   XM_DROP_SITE_VALID,
-                                   xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
-                                                               x_dnd_wanted_action),
+                                   XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                    XM_DROP_ACTION_DROP_CANCEL);
           dmsg.x = 0;
           dmsg.y = 0;
@@ -10361,8 +10391,21 @@ x_dnd_begin_drag_and_drop (struct frame *f, Time time, Atom xaction,
   else
     x_dnd_selection_timestamp = XFIXNUM (ltimestamp);
 
+  x_dnd_motif_operations
+    = xm_side_effect_from_action (FRAME_DISPLAY_INFO (f), xaction);
+
+  x_dnd_first_motif_operation = XM_DRAG_NOOP;
+
   if (n_ask_actions)
     {
+      x_dnd_motif_operations
+        = xm_operations_from_actions (FRAME_DISPLAY_INFO (f),
+                                      ask_action_list,
+                                      n_ask_actions);
+      x_dnd_first_motif_operation
+        = xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
+                                      ask_action_list[0]);
+
       ask_actions = NULL;
       end = 0;
       count = SPECPDL_INDEX ();
@@ -10609,9 +10652,7 @@ x_dnd_begin_drag_and_drop (struct frame *f, Time time, Atom xaction,
                       dmsg.side_effects
                         = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
                                                                            x_dnd_wanted_action),
-                                               XM_DROP_SITE_VALID,
-                                               xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
-                                                                           x_dnd_wanted_action),
+                                               XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                                XM_DROP_ACTION_DROP_CANCEL);
                       dmsg.x = 0;
                       dmsg.y = 0;
@@ -10683,9 +10724,7 @@ x_dnd_begin_drag_and_drop (struct frame *f, Time time, Atom xaction,
                       dmsg.side_effects
                         = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
                                                                            x_dnd_wanted_action),
-                                               XM_DROP_SITE_VALID,
-                                               xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
-                                                                           x_dnd_wanted_action),
+                                               XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                                XM_DROP_ACTION_DROP_CANCEL);
                       dmsg.x = 0;
                       dmsg.y = 0;
@@ -14643,9 +14682,7 @@ x_dnd_update_state (struct x_display_info *dpyinfo, Time timestamp)
           dmsg.side_effects
             = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                x_dnd_wanted_action),
-                                   XM_DROP_SITE_VALID,
-                                   xm_side_effect_from_action (dpyinfo,
-                                                               x_dnd_wanted_action),
+                                   XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                    (!x_dnd_xm_use_help
                                     ? XM_DROP_ACTION_DROP
                                     : XM_DROP_ACTION_DROP_HELP));
@@ -14677,9 +14714,7 @@ x_dnd_update_state (struct x_display_info *dpyinfo, Time timestamp)
           dsmsg.side_effects
             = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                x_dnd_wanted_action),
-                                   XM_DROP_SITE_VALID,
-                                   xm_side_effect_from_action (dpyinfo,
-                                                               x_dnd_wanted_action),
+                                   XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                    XM_DROP_ACTION_DROP_CANCEL);
           dsmsg.x = 0;
           dsmsg.y = 0;
@@ -16579,7 +16614,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                     dmsg.byteorder = XM_BYTE_ORDER_CUR_FIRST;
                     dmsg.side_effects = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                                          x_dnd_wanted_action),
-                                                             XM_DROP_SITE_NONE, XM_DRAG_NOOP,
+                                                             XM_DROP_SITE_NONE, x_dnd_motif_operations,
                                                              XM_DROP_ACTION_DROP_CANCEL);
                     dmsg.timestamp = event->xmotion.time;
                     dmsg.x = event->xmotion.x_root;
@@ -16648,9 +16683,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                 dmsg.byteorder = XM_BYTE_ORDER_CUR_FIRST;
                 dmsg.side_effects = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                                      x_dnd_wanted_action),
-                                                         XM_DROP_SITE_VALID,
-                                                         xm_side_effect_from_action (dpyinfo,
-                                                                                     x_dnd_wanted_action),
+                                                         XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                                          (!x_dnd_xm_use_help
                                                           ? XM_DROP_ACTION_DROP
                                                           : XM_DROP_ACTION_DROP_HELP));
@@ -17182,9 +17215,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                                 dmsg.side_effects
                                   = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                                      x_dnd_wanted_action),
-                                                         XM_DROP_SITE_VALID,
-                                                         xm_side_effect_from_action (dpyinfo,
-                                                                                     x_dnd_wanted_action),
+                                                         XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                                          (!x_dnd_xm_use_help
                                                           ? XM_DROP_ACTION_DROP
                                                           : XM_DROP_ACTION_DROP_HELP));
@@ -18204,7 +18235,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                           dmsg.side_effects
                             = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                                x_dnd_wanted_action),
-                                                   XM_DROP_SITE_NONE, XM_DRAG_NOOP,
+                                                   XM_DROP_SITE_NONE, x_dnd_motif_operations,
                                                    XM_DROP_ACTION_DROP_CANCEL);
                           dmsg.timestamp = xev->time;
                           dmsg.x = lrint (xev->root_x);
@@ -18287,9 +18318,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                       dmsg.side_effects
                         = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                            x_dnd_wanted_action),
-                                               XM_DROP_SITE_VALID,
-                                               xm_side_effect_from_action (dpyinfo,
-                                                                           x_dnd_wanted_action),
+                                               XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                                (!x_dnd_xm_use_help
                                                 ? XM_DROP_ACTION_DROP
                                                 : XM_DROP_ACTION_DROP_HELP));
@@ -18480,9 +18509,7 @@ handle_one_xevent (struct x_display_info *dpyinfo,
                                       dmsg.side_effects
                                         = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (dpyinfo,
                                                                                            x_dnd_wanted_action),
-                                                               XM_DROP_SITE_VALID,
-                                                               xm_side_effect_from_action (dpyinfo,
-                                                                                           x_dnd_wanted_action),
+                                                               XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                                                (!x_dnd_xm_use_help
                                                                 ? XM_DROP_ACTION_DROP
                                                                 : XM_DROP_ACTION_DROP_HELP));
@@ -21311,9 +21338,7 @@ x_connection_closed (Display *dpy, const char *error_message, bool ioerror)
               dmsg.side_effects
                 = XM_DRAG_SIDE_EFFECT (xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
                                                                    x_dnd_wanted_action),
-                                       XM_DROP_SITE_VALID,
-                                       xm_side_effect_from_action (FRAME_DISPLAY_INFO (f),
-                                                                   x_dnd_wanted_action),
+                                       XM_DROP_SITE_VALID, x_dnd_motif_operations,
                                        XM_DROP_ACTION_DROP_CANCEL);
               dmsg.x = 0;
               dmsg.y = 0;