keyd-application-mapper: Add proper wayland support

Replace hacky Sway and Hypr application detection logic with a generic
wayland implementation that works for wlroots based compositors.
This also provides the scaffolding for adding Gnome/KDE support
in the future should they decide to implement the requisite
protocols.

scripts/keyd-application-mapper

@@ -3,6 +3,8 @@
 import subprocess
 import argparse
 import select
+import socket
+import struct
 import os
 import shutil
 import re
@@ -101,99 +103,87 @@ def new_interruptible_generator(monfd, genfn):
         if monfd in r:
             yield genfn()
 
-class SwayMonitor():
-    def __init__(self, on_window_change):
-        assert_env('SWAYSOCK')
 
-        self.on_window_change = on_window_change
+# Just enough wayland wire protocol to listen for interesting events.
+#
+# Sadly most of the useful protocols haven't been standardized,
+# so this only works for wlroots based compositors :(.
 
-    def init(self):
-        pass
+class Wayland():
+    def __init__(self, interface_name):
+        path = os.getenv("WAYLAND_DISPLAY")
+        if path == None:
+            raise Exception("WAYLAND_DISPLAY not set (is wayland running?)")
 
-    def run(self):
-        import json
-        import subprocess
+        if path[0] != '/':
+            path = os.getenv("XDG_RUNTIME_DIR") + "/" + path
 
-        last_cls = ''
-        last_title = ''
+        self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+        self.sock.connect(path)
+        self._bind_interface(interface_name)
 
-        swayproc = subprocess.Popen(
-            ['swaymsg',
-                '--type',
-                'subscribe',
-                '--monitor',
-                '--raw',
-                '["window"]'], stdout=subprocess.PIPE)
+    def send_msg(self, object_id, opcode, payload):
+        opcode |= (len(payload)+8) << 16
 
-        for line in new_interruptible_generator(swayproc.stdout.fileno(), swayproc.stdout.readline):
-            if line == None:
-                self.on_window_change(last_cls, last_title)
-                continue
+        self.sock.sendall(struct.pack(b'II', object_id, opcode))
+        self.sock.sendall(payload)
 
-            data = json.loads(line)
+    def recv_msg(self):
+        (object_id, evcode) = struct.unpack('II', self.sock.recv(8))
 
-            title = ''
-            cls = ''
+        size = evcode >> 16
+        evcode = evcode & 0xFFFF
 
-            try:
-                if data['container']['focused'] == True:
-                    props = data['container']['window_properties']
+        data = self.sock.recv(size-8)
 
-                    cls = props['class']
-                    title = props['title']
-            except:
-                try:
-                    title = ''
-                    cls = data['container']['app_id']
-                except:
-                    pass
+        return (object_id, evcode, data)
 
-            if title == '' and cls == '':
-                continue
+    def read_string(self, b):
+        return b[4:4+struct.unpack('I', b[:4])[0]-1].decode('utf8')
+
+    # Will bind the requested interface to object id 4
+    def _bind_interface(self, name):
+        # bind the registry object to id 2
+        self.send_msg(1, 1, b'\x02\x00\x00\x00')
+        # solicit a sync message to bookend the registry events
+        self.send_msg(1, 0, b'\x03\x00\x00\x00')
+        while True:
+            (obj, event, payload) = self.recv_msg()
+            if obj == 2 and event == 0:  # registry.global event
+                wl_name = struct.unpack('I', payload[0:4])[0]
 
-            if last_cls != cls or last_title != title:
-                last_cls = cls
-                last_title = title
+                wl_interface = self.read_string(payload[4:])
 
-                self.on_window_change(cls, title)
+                if wl_interface == name:
+                    self.send_msg(2, 0, payload+b'\x04\x00\x00\x00')
+                    return
 
-class HyprMonitor():
-    def __init__(self, on_window_change):
-        assert_env('HYPRLAND_INSTANCE_SIGNATURE')
+            if obj == 3:  # sync message
+                raise Exception(f"Could not find interface {name}")
 
+
+class Wlroots():
+    def __init__(self, on_window_change):
+        self.wl = Wayland('zwlr_foreign_toplevel_manager_v1')
         self.on_window_change = on_window_change
 
     def init(self):
         pass
 
     def run(self):
-        import socket
-
-        last_cls = ''
-        last_title = ''
-
-        s = "/tmp/hypr/" + str(os.getenv('HYPRLAND_INSTANCE_SIGNATURE')) + "/.socket2.sock"
-
-        client = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-        client.connect(s)
-
+        windows = {}
         while True:
-            data = client.recv(4096)
-            msg = data.decode('utf-8')
-            tmp = msg.split('>>')
-            if tmp[0] == 'activewindow' and len(tmp) > 1:
-                cls, title = tmp[1].split(',')
-
-                if title == '' and cls == '':
-                    continue
-
-                if last_cls != cls or last_title != title:
-                    last_cls = cls
-                    last_title = title
-
-                    self.on_window_change(cls, title)
-
-        client.close()
+            (obj, event, payload) = self.wl.recv_msg()
+            if obj == 4 and event == 0:
+                windows[struct.unpack('I', payload)[0]] = {}
+
+            if obj in windows:
+                if event == 0:
+                    windows[obj]['title'] = self.wl.read_string(payload)
+                if event == 1:
+                    windows[obj]['appid'] = self.wl.read_string(payload)
+                if event == 4 and payload[0] > 0 and payload[4] == 2:
+                    self.on_window_change(windows[obj]['appid'], windows[obj]['title'])
 
 class XMonitor():
     def __init__(self, on_window_change):
@@ -411,8 +401,7 @@ class GnomeMonitor():
 
 def get_monitor(on_window_change):
     monitors = [
-        ('Sway', SwayMonitor),
-        ('Hyprland', HyprMonitor),
+        ('wlroots', Wlroots),
         ('Gnome', GnomeMonitor),
         ('X', XMonitor),
     ]