feat: log the window properties gamescope checks before counting a window as focusable

tools/linuxfs/overlay/usr/local/bin/droiddeck-xwindows

@@ -2,7 +2,10 @@
 # The top-level windows of one Xwayland server, one line each, for the session log: what gamescope
 # had to pick focus from. Each line has the window, whether it is mapped, override-redirect, its
 # geometry, the app id it carries (STEAM_GAME, which gamescope focuses by), its WM_STATE, pid and
-# class. Windows that are neither mapped nor tagged with an app id are left out - wine keeps many
+# class. Then whatever is set of what else gamescope weighs before it counts a mapped window as
+# focusable: an InputOnly class, _NET_WM_WINDOW_OPACITY (0 is never focusable), STEAM_OVERLAY,
+# GAMESCOPE_EXTERNAL_OVERLAY, STEAM_INPUT_FOCUS and _NET_WM_STATE (skip taskbar and pager without
+# fullscreen is left out of the focusable list the client reads). Windows that are neither mapped nor tagged with an app id are left out - wine keeps many
 # hidden ones. The rootfs has xprop but no xwininfo, so this speaks the X protocol itself.
 #
 #   droiddeck-xwindows :1
@@ -65,7 +68,13 @@ class X:
 
     def attributes(self, win):
         r = self.request(struct.pack("<BxHI", 3, 2, win))
-        return (r[26], r[27]) if r else None
+        return (r[26], r[27], struct.unpack_from("<H", r, 12)[0]) if r else None
+
+    def atom_name(self, atom):
+        r = self.request(struct.pack("<BxHI", 17, 2, atom))
+        if not r:
+            return str(atom)
+        return r[32:32 + struct.unpack_from("<H", r, 8)[0]].decode(errors="replace")
 
     def geometry(self, win):
         r = self.request(struct.pack("<BxHI", 14, 2, win))
@@ -91,7 +100,9 @@ def main():
     except OSError as e:
         print("==   %s: %s" % (display, e))
         return
-    atoms = {name: x.atom(name) for name in ("STEAM_GAME", "WM_STATE", "_NET_WM_PID", "WM_CLASS")}
+    atoms = {name: x.atom(name) for name in (
+        "STEAM_GAME", "WM_STATE", "_NET_WM_PID", "WM_CLASS", "_NET_WM_WINDOW_OPACITY", "STEAM_OVERLAY",
+        "GAMESCOPE_EXTERNAL_OVERLAY", "STEAM_INPUT_FOCUS", "_NET_WM_STATE")}
     for win in x.children(x.root):
         attrs = x.attributes(win)
         if not attrs:
@@ -103,6 +114,19 @@ def main():
         state = x.prop(win, atoms["WM_STATE"])
         pid = x.prop(win, atoms["_NET_WM_PID"])
         cls = x.prop(win, atoms["WM_CLASS"])
+        extra = []
+        if attrs[2] == 2:
+            extra.append("InputOnly")
+        for label, name in (("opacity", "_NET_WM_WINDOW_OPACITY"), ("overlay", "STEAM_OVERLAY"),
+                            ("external-overlay", "GAMESCOPE_EXTERNAL_OVERLAY"),
+                            ("input-focus", "STEAM_INPUT_FOCUS")):
+            value = x.prop(win, atoms[name])
+            if value:
+                extra.append("%s 0x%x" % (label, value[0]) if label == "opacity" else "%s %d" % (label, value[0]))
+        net_state = x.prop(win, atoms["_NET_WM_STATE"])
+        if net_state:
+            extra.append("net-state " + ",".join(
+                x.atom_name(a).replace("_NET_WM_STATE_", "") for a in net_state))
         print("==   %s window 0x%x: %s%s %s app %s state %s pid %s class %s" % (
             display, win, MAP_STATE[attrs[0]] if attrs[0] < 3 else attrs[0],
             " override-redirect" if attrs[1] else "",
@@ -111,7 +135,7 @@ def main():
             WM_STATES.get(state[0], state[0]) if state else "-",
             pid[0] if pid else "-",
             cls.split(b"\0")[-2].decode(errors="replace") if cls and b"\0" in cls else "-",
-        ))
+        ) + "".join(" " + e for e in extra))
 
 
 main()