add "render" callback on output

kiwmi/include/desktop/output.h

@@ -26,6 +26,7 @@ struct kiwmi_output {
     int damaged;
 
     struct {
+        struct wl_signal render;
         struct wl_signal destroy;
         struct wl_signal resize;
         struct wl_signal usable_area_change;

kiwmi/kiwmi/desktop/output.c

@@ -230,6 +230,8 @@ output_frame_notify(struct wl_listener *listener, void *data)
         wl_signal_emit(&view->events.post_render, &rdata);
     }
 
+    wl_signal_emit(&output->events.render, output);
+
     render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_TOP], &rdata);
     render_layer(&output->layers[ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY], &rdata);
 
@@ -372,6 +374,7 @@ new_output_notify(struct wl_listener *listener, void *data)
     wl_signal_init(&output->events.destroy);
     wl_signal_init(&output->events.resize);
     wl_signal_init(&output->events.usable_area_change);
+    wl_signal_init(&output->events.render);
 
     wl_signal_emit(&desktop->events.new_output, output);
 }

kiwmi/kiwmi/luak/kiwmi_output.c

@@ -299,6 +299,32 @@ kiwmi_output_on_resize_notify(struct wl_listener *listener, void *data)
     }
 }
 
+static void
+kiwmi_output_on_render_notify(struct wl_listener *listener, void *data)
+{
+    struct kiwmi_lua_callback *lc = wl_container_of(listener, lc, listener);
+    struct kiwmi_server *server   = lc->server;
+    lua_State *L                  = server->lua->L;
+    struct kiwmi_output *output   = data;
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
+
+    lua_pushcfunction(L, luaK_kiwmi_output_new);
+    lua_pushlightuserdata(L, server->lua);
+    lua_pushlightuserdata(L, output);
+
+    if (lua_pcall(L, 2, 1, 0)) {
+        wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
+        lua_pop(L, 1);
+        return;
+    }
+
+    if (lua_pcall(L, 1, 0, 0)) {
+        wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
+        lua_pop(L, 1);
+    }
+}
+
 static void
 kiwmi_output_on_usable_area_change_notify(
     struct wl_listener *listener,
@@ -403,6 +429,37 @@ l_kiwmi_output_on_resize(lua_State *L)
     return 0;
 }
 
+static int
+l_kiwmi_output_on_render(lua_State *L)
+{
+    struct kiwmi_object *obj =
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_output");
+    luaL_checktype(L, 2, LUA_TFUNCTION);
+
+    if (!obj->valid) {
+        return luaL_error(L, "kiwmi_output no longer valid");
+    }
+
+    struct kiwmi_output *output   = obj->object;
+    struct kiwmi_desktop *desktop = output->desktop;
+    struct kiwmi_server *server   = wl_container_of(desktop, server, desktop);
+
+    lua_pushcfunction(L, luaK_kiwmi_lua_callback_new);
+    lua_pushlightuserdata(L, server);
+    lua_pushvalue(L, 2);
+    lua_pushlightuserdata(L, kiwmi_output_on_render_notify);
+    lua_pushlightuserdata(L, &output->events.render);
+    lua_pushlightuserdata(L, obj);
+
+    if (lua_pcall(L, 5, 0, 0)) {
+        wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
+        return 0;
+    }
+
+    return 0;
+}
+
+
 static int
 l_kiwmi_output_on_usable_area_change(lua_State *L)
 {
@@ -437,6 +494,7 @@ static const luaL_Reg kiwmi_output_events[] = {
     {"destroy", l_kiwmi_output_on_destroy},
     {"resize", l_kiwmi_output_on_resize},
     {"usable_area_change", l_kiwmi_output_on_usable_area_change},
+    {"render", l_kiwmi_output_on_render},
     {NULL, NULL},
 };