[Spice-devel] [PATCH vdagent v2 2/2] retrieve _NET_WM_NAME using GDK

[Jakub Janků]

String returned by gdk_x11_screen_get_window_manager_name()
is never NULL. If the name cannot be retrieved, "unknown" is returned.
Change in logging behavior:
If debug flag is specified, _NET_WM_NAME is always logged
(either the actual name or "unknown").
---
 src/vdagent/x11-priv.h |  2 +-
 src/vdagent/x11.c      | 75 ++++++++++----------------------------------------
 2 files changed, 15 insertions(+), 62 deletions(-)

diff --git a/src/vdagent/x11-priv.h b/src/vdagent/x11-priv.h
index 677a44d..a7f9f14 100644
--- a/src/vdagent/x11-priv.h
+++ b/src/vdagent/x11-priv.h
@@ -87,7 +87,7 @@ struct vdagent_x11 {
     Window root_window[MAX_SCREENS];
     Window selection_window;
     struct udscs_connection *vdagentd;
-    char *net_wm_name;
+    const char *net_wm_name;
     int debug;
     int fd;
     int screen_count;
diff --git a/src/vdagent/x11.c b/src/vdagent/x11.c
index 6e47ea1..736d1ea 100644
--- a/src/vdagent/x11.c
+++ b/src/vdagent/x11.c
@@ -32,6 +32,10 @@
    pending writes are flushed. */
 
 #include <glib.h>
+#include <gdk/gdk.h>
+#ifdef GDK_WINDOWING_X11
+#include <gdk/gdkx.h>
+#endif
 #include <stdlib.h>
 #include <limits.h>
 #include <string.h>
@@ -113,64 +117,14 @@ int vdagent_x11_restore_error_handler(struct vdagent_x11 *x11)
 
 static void vdagent_x11_get_wm_name(struct vdagent_x11 *x11)
 {
-    Atom type_ret;
-    int format_ret;
-    unsigned long len, remain;
-    unsigned char *data = NULL;
-    Window sup_window = None;
-
-    /* XGetWindowProperty can throw a BadWindow error. One way we can trigger
-       this is when the display-manager (ie gdm) has set, and not cleared the
-       _NET_SUPPORTING_WM_CHECK property, and the window manager running in
-       the user session has not yet updated it to point to its window, so its
-       pointing to a nonexistent window. */
-    vdagent_x11_set_error_handler(x11, vdagent_x11_ignore_bad_window_handler);
-
-    /* Get the window manager SUPPORTING_WM_CHECK window */
-    if (XGetWindowProperty(x11->display, x11->root_window[0],
-            XInternAtom(x11->display, "_NET_SUPPORTING_WM_CHECK", False), 0,
-            LONG_MAX, False, XA_WINDOW, &type_ret, &format_ret, &len,
-            &remain, &data) == Success) {
-        if (type_ret == XA_WINDOW)
-            sup_window = *((Window *)data);
-        XFree(data);
-    }
-    if (sup_window == None &&
-        XGetWindowProperty(x11->display, x11->root_window[0],
-            XInternAtom(x11->display, "_WIN_SUPPORTING_WM_CHECK", False), 0,
-            LONG_MAX, False, XA_CARDINAL, &type_ret, &format_ret, &len,
-            &remain, &data) == Success) {
-        if (type_ret == XA_CARDINAL)
-            sup_window = *((Window *)data);
-        XFree(data);
-    }
-    /* So that we can get the net_wm_name */
-    if (sup_window != None) {
-        Atom utf8 = XInternAtom(x11->display, "UTF8_STRING", False);
-        if (XGetWindowProperty(x11->display, sup_window,
-                XInternAtom(x11->display, "_NET_WM_NAME", False), 0,
-                LONG_MAX, False, utf8, &type_ret, &format_ret, &len,
-                &remain, &data) == Success) {
-            if (type_ret == utf8) {
-                x11->net_wm_name =
-                    g_strndup((char *)data, (format_ret / 8) * len);
-            }
-            XFree(data);
-        }
-        if (x11->net_wm_name == NULL &&
-            XGetWindowProperty(x11->display, sup_window,
-                XInternAtom(x11->display, "_NET_WM_NAME", False), 0,
-                LONG_MAX, False, XA_STRING, &type_ret, &format_ret, &len,
-                &remain, &data) == Success) {
-            if (type_ret == XA_STRING) {
-                x11->net_wm_name =
-                    g_strndup((char *)data, (format_ret / 8) * len);
-            }
-            XFree(data);
-        }
-    }
-
-    vdagent_x11_restore_error_handler(x11);
+#ifdef GDK_WINDOWING_X11
+    GdkDisplay *display = gdk_display_get_default();
+    if (GDK_IS_X11_DISPLAY(display))
+        x11->net_wm_name = gdk_x11_screen_get_window_manager_name(
+            gdk_display_get_default_screen(display));
+    else
+#endif
+    x11->net_wm_name = "unknown";
 }
 
 struct vdagent_x11 *vdagent_x11_create(struct udscs_connection *vdagentd,
@@ -279,11 +233,11 @@ struct vdagent_x11 *vdagent_x11_create(struct udscs_connection *vdagentd,
        sometimes we need to wait a bit for it to show up. */
     i = 10;
     vdagent_x11_get_wm_name(x11);
-    while (x11->net_wm_name == NULL && --i > 0) {
+    while (!strcmp(x11->net_wm_name, "unknown") && --i > 0) {
         usleep(100000);
         vdagent_x11_get_wm_name(x11);
     }
-    if (x11->debug && x11->net_wm_name)
+    if (x11->debug)
         syslog(LOG_DEBUG, "net_wm_name: \"%s\", has icons: %d",
                x11->net_wm_name, vdagent_x11_has_icons_on_desktop(x11));
 
@@ -308,7 +262,6 @@ void vdagent_x11_destroy(struct vdagent_x11 *x11, int vdagentd_disconnected)
     }
 
     XCloseDisplay(x11->display);
-    g_free(x11->net_wm_name);
     free(x11->randr.failed_conf);
     free(x11);
 }
-- 
2.13.6