kwin: add support for determining active window's monitor name

include/KwinWorkaround.hpp

@@ -6,9 +6,11 @@ namespace gsr {
     struct ActiveKwinWindow {
         std::string title = "Game";
         bool fullscreen = false;
+        std::string monitorName = "";
     };
 
     void start_kwin_helper_thread();
     std::string get_current_kwin_window_title();
     bool get_current_kwin_window_fullscreen();
+    std::string get_current_kwin_window_monitor_name();
 }

src/KwinWorkaround.cpp

@@ -27,6 +27,7 @@ namespace gsr {
         char buffer[4096];
         const std::string prefix_title = "Active window title set to: ";
         const std::string prefix_fullscreen = "Active window fullscreen state set to: ";
+        const std::string prefix_monitor = "Active window monitor name set to: ";
 
         std::string line;
         while (fgets(buffer, sizeof(buffer), pipe) != nullptr) {
@@ -43,6 +44,9 @@ namespace gsr {
             } else if ((pos = line.find(prefix_fullscreen)) != std::string::npos) {
                 std::string fullscreen = line.substr(pos + prefix_fullscreen.length());
                 active_kwin_window.fullscreen = fullscreen == "1";
+            } else if ((pos = line.find(prefix_monitor)) != std::string::npos) {
+                std::string monitorName = line.substr(pos + prefix_monitor.length());
+                active_kwin_window.monitorName = std::move(monitorName);
             }
         }
 
@@ -57,6 +61,10 @@ namespace gsr {
         return active_kwin_window.fullscreen;
     }
 
+    std::string get_current_kwin_window_monitor_name() {
+        return active_kwin_window.monitorName;
+    }
+
     void start_kwin_helper_thread() {
         if (kwin_helper_thread_started) {
             return;

tools/gsr-kwin-helper/gsrkwinhelper.js

@@ -1,10 +1,10 @@
 const DAEMON_DBUS_NAME = "com.dec05eba.gpu_screen_recorder";
 
-function dbusSendUpdateActiveWindow(title, isFullscreen) {
+function dbusSendUpdateActiveWindow(title, isFullscreen, monitorName) {
     callDBus(
         DAEMON_DBUS_NAME, "/", DAEMON_DBUS_NAME,
         "updateActiveWindow",
-        title, isFullscreen,
+        title, isFullscreen, monitorName,
     );
 }
 
@@ -13,15 +13,18 @@ let prevEmitActiveWindowUpdate = null;
 
 let prevCaption = null;
 let prevFullScreen = null;
+let prevMonitorName = null;
 
 function emitActiveWindowUpdate(window) {
     if (workspace.activeWindow === window) {
         let caption = window.caption || "";
         let fullScreen = window.fullScreen || false;
-        if (caption !== prevCaption || fullScreen !== prevFullScreen) {
+        let monitorName = window.output?.name || "";
-            dbusSendUpdateActiveWindow(caption, fullScreen);
+        if (caption !== prevCaption || fullScreen !== prevFullScreen || monitorName !== prevMonitorName) {
+            dbusSendUpdateActiveWindow(caption, fullScreen, monitorName);
             prevCaption = caption;
             prevFullScreen = fullScreen;
+            prevMonitorName = monitorName;
         }
     }
 }
@@ -32,10 +35,12 @@ function subscribeToWindow(window) {
         if (prevWindow !== null) {
             prevWindow.captionChanged.disconnect(prevEmitActiveWindowUpdate);
             prevWindow.fullScreenChanged.disconnect(prevEmitActiveWindowUpdate);
+            prevWindow.outputChanged.disconnect(prevEmitActiveWindowUpdate);
         }
         let emitActiveWindowUpdateBound = emitActiveWindowUpdate.bind(null, window);
         window.captionChanged.connect(emitActiveWindowUpdateBound);
         window.fullScreenChanged.connect(emitActiveWindowUpdateBound);
+        window.outputChanged.connect(emitActiveWindowUpdateBound);
         prevWindow = window;
         prevEmitActiveWindowUpdate = emitActiveWindowUpdateBound;
     }

tools/gsr-kwin-helper/main.cpp

@@ -11,6 +11,7 @@ static const char* INTROSPECTION_XML =
     "    <method name='updateActiveWindow'>\n"
     "      <arg type='s' name='title' direction='in'/>\n"
     "      <arg type='b' name='fullscreen' direction='in'/>\n"
+    "      <arg type='s' name='monitorName' direction='in'/>\n"
     "    </method>\n"
     "  </interface>\n"
     "  <interface name='org.freedesktop.DBus.Introspectable'>\n"
@@ -25,6 +26,7 @@ class GsrKwinHelper {
 public:
     std::string active_window_title;
     bool active_window_fullscreen;
+    std::string active_window_monitor_name;
     DBusConnection* connection = nullptr;
     DBusError err;
 
@@ -114,6 +116,7 @@ public:
         DBusMessageIter args;
         DBusBasicValue title;
         DBusBasicValue fullscreen;
+        DBusBasicValue monitorName;
 
         if (!dbus_message_iter_init(msg, &args)) {
             send_error_reply(msg, "No arguments provided");
@@ -138,6 +141,18 @@ public:
         }
 
         dbus_message_iter_get_basic(&args, &fullscreen);
+
+        if (!dbus_message_iter_next(&args)) {
+            send_error_reply(msg, "Not enough arguments provided");
+            return;
+        }
+
+        if (dbus_message_iter_get_arg_type(&args) != DBUS_TYPE_STRING) {
+            send_error_reply(msg, "Expected string argument");
+            return;
+        }
+
+        dbus_message_iter_get_basic(&args, &monitorName);
         
         if (title.str) {
             if (active_window_title != title.str) {
@@ -156,6 +171,17 @@ public:
             std::cout.flush();
         }
 
+        if (monitorName.str) {
+            if (active_window_monitor_name != monitorName.str) {
+                active_window_monitor_name = monitorName.str;
+                std::cout << "Active window monitor name set to: " << active_window_monitor_name << "\n";
+                std::cout.flush();
+            }
+        } else {
+            send_error_reply(msg, "Failed to read string");
+            return;
+        }
+
         send_success_reply(msg);
     }