rpc: allow handling of nvim_ui_try_resize at the pager

This makes external UI behave consistenly with TUI w.r.t resizes.
Which will be needed anyway as TUI will use the external UI protocol
soon.

1 files changed, 37 insertions, 0 deletions

diff --git a/src/nvim/event/multiqueue.c b/src/nvim/event/multiqueue.c
index ef9f3f1870..a1b75f66a5 100644
--- a/src/nvim/event/multiqueue.c
+++ b/src/nvim/event/multiqueue.c
@@ -78,6 +78,13 @@ struct multiqueue {
   size_t size;
 };
 
+typedef struct {
+  Event event;
+  bool fired;
+  int refcount;
+} SplitEvent;
+
+
 #ifdef INCLUDE_GENERATED_DECLARATIONS
 # include "event/multiqueue.c.generated.h"
 #endif
@@ -245,3 +252,33 @@ static MultiQueueItem *multiqueue_node_data(QUEUE *q)
 {
   return QUEUE_DATA(q, MultiQueueItem, node);
 }
+
+/// Allow an event to be processed by multiple child queues to the main queue
+///
+/// The handler will be fired once by the _first_ queue that processes the
+/// event. Later processing will do nothing (just memory cleanup).
+///
+/// @param ev the event
+/// @param num number of queues that the split event will be put on
+/// @return an Event that is safe to put onto `num` queues
+Event event_split(Event ev, int num)
+{
+  SplitEvent *data = xmalloc(sizeof(*data));
+  data->event = ev;
+  data->fired = false;
+  data->refcount = num;
+  return event_create(split_event, 1, data);
+}
+static void split_event(void ** argv)
+{
+  SplitEvent *data = argv[0];
+  if (!data->fired) {
+    data->fired = true;
+    if (data->event.handler) {
+      data->event.handler(data->event.argv);
+    }
+  }
+  if ((--data->refcount) == 0) {
+    xfree(data);
+  }
+}