From 9675b86478e469e01795f5291f547a128cb12a47 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Fri, 24 Jan 2020 21:23:21 +0100
Subject: [PATCH] module/i3: window event: use 'app_id' for 'application', if
 available

We previously used the 'pid' property of the 'container' object in a
window event to lookup the application name under /proc/<pid>/comm.

In many cases, the application name is already available in the window
event itself, in the 'app_id' property.

Use this, if available, and fallback to the old PID method otherwise.

A quick experiment suggests 'app_id' is set for all Wayland native
applications, but not for X11 applications running under XWayland.
---
 modules/i3.c | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/modules/i3.c b/modules/i3.c
index 6f4299e..9eb0a0a 100644
--- a/modules/i3.c
+++ b/modules/i3.c
@@ -372,8 +372,26 @@ handle_window_event(int type, const struct json_object *json, void *_mod)
     ws->window.title = title != NULL ? strdup(title) : NULL;
     ws->window.id = json_object_get_int(id);
 
+    /*
+     * Sway only!
+     *
+     * Use 'app_id' for 'application' tag, if it exists.
+     *
+     * Otherwise, use 'pid' if it exists, and read application name
+     * from /proc/zpid>/comm
+     */
+
+    struct json_object *app_id;
+    if (json_object_object_get_ex(container, "app_id", &app_id) &&
+        json_object_get_string(app_id) != NULL)
+    {
+        free(ws->window.application);
+        ws->window.application = strdup(json_object_get_string(app_id));
+        LOG_DBG("application: \"%s\", via 'app_id'", ws->window.application);
+    }
+
     /* If PID has changed, update application name from /proc/<pid>/comm */
-    if (ws->window.pid != json_object_get_int(pid)) {
+    else if (ws->window.pid != json_object_get_int(pid)) {
         ws->window.pid = json_object_get_int(pid);
 
         char path[64];
@@ -398,6 +416,7 @@ handle_window_event(int type, const struct json_object *json, void *_mod)
         free(ws->window.application);
         ws->window.application = strdup(application);
         close(fd);
+        LOG_DBG("application: \"%s\", via 'pid'", ws->window.application);
     }
 
     m->dirty = true;