Add support for kwin (wayland) (#1393)

CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.16...3.26)
+cmake_minimum_required(VERSION 3.21...3.26)
 
 project(advanced-scene-switcher VERSION 1.0.0)
 
@@ -415,6 +415,7 @@ else()
   set_target_properties(${LIB_NAME} PROPERTIES PREFIX "")
   set_target_properties(${LIB_NAME} PROPERTIES SOVERSION 1)
 
+  find_package(Qt6 REQUIRED COMPONENTS DBus)
   find_package(X11 REQUIRED COMPONENTS Xss)
   target_include_directories(${LIB_NAME} PRIVATE "${X11_INCLUDE_DIR}"
                                                  "${X11_Xss_INCLUDE_PATH}")
@@ -446,7 +447,8 @@ else()
     )
   endif()
   target_include_directories(${LIB_NAME} PRIVATE "${PROC_INCLUDE_DIR}")
-  target_sources(${LIB_NAME} PRIVATE lib/linux/advanced-scene-switcher-nix.cpp)
+  target_sources(${LIB_NAME} PRIVATE lib/linux/advanced-scene-switcher-nix.cpp
+                                     lib/linux/kwin-helpers.cpp)
 
   # Don't include irrelevant folders into sources archive
   list(APPEND CPACK_SOURCE_IGNORE_FILES "\\.deps/.*")

lib/linux/advanced-scene-switcher-nix.cpp

@@ -32,6 +32,7 @@
 #endif
 #include <fstream>
 #include <sstream>
+#include "kwin-helpers.h"
 
 namespace advss {
 
@@ -44,6 +45,10 @@ static XScreenSaverAllocInfoFunc allocSSFunc = nullptr;
 static XScreenSaverQueryInfoFunc querySSFunc = nullptr;
 bool canGetIdleTime = false;
 
+static bool KWin = false;
+static FocusNotifier notifier;
+static QString KWinScriptObjectPath;
+
 static QLibrary *libprocps = nullptr;
 #ifdef PROCPS_AVAILABLE
 typedef PROCTAB *(*openproc_func)(int flags);
@@ -275,6 +280,11 @@ int getActiveWindow(Window *&window)
 
 void GetCurrentWindowTitle(std::string &title)
 {
+	if (KWin) {
+		title = FocusNotifier::getActiveWindowTitle();
+		return;
+	}
+
 	Window *data = 0;
 	if (getActiveWindow(data) != Success || !data) {
 		return;
@@ -286,6 +296,7 @@ void GetCurrentWindowTitle(std::string &title)
 
 	auto name = getWindowName(data[0]);
 	XFree(data);
+
 	if (name.empty()) {
 		return;
 	}
@@ -412,6 +423,10 @@ void GetProcessList(QStringList &processes)
 
 long getForegroundProcessPid()
 {
+	if (KWin) {
+		return FocusNotifier::getActiveWindowPID();
+	}
+
 	Window *window;
 	if (getActiveWindow(window) != Success || !window || !*window) {
 		return -1;
@@ -437,6 +452,7 @@ long getForegroundProcessPid()
 
 	pid = *((long *)prop);
 	XFree(prop);
+
 	return pid;
 }
 
@@ -562,6 +578,17 @@ void PlatformInit()
 		return;
 	}
 
+	KWin = isKWinAvailable();
+	if (!(KWin && startKWinScript(KWinScriptObjectPath) &&
+	      registerKWinDBusListener(&notifier))) {
+		// something bad happened while trying to initialize
+		// the KWin script/dbus so disable it
+		KWin = false;
+		blog(LOG_INFO, "not using KWin compat");
+	} else {
+		blog(LOG_INFO, "using KWin compat");
+	}
+
 	initXss();
 	initProcps();
 	initProc2();
@@ -583,6 +610,8 @@ void PlatformCleanup()
 	cleanupHelper(libproc2);
 	cleanupDisplay();
 	XSetErrorHandler(NULL);
+	if (KWin && !KWinScriptObjectPath.isEmpty())
+		stopKWinScript(KWinScriptObjectPath);
 }
 
 } // namespace advss

lib/linux/kwin-helpers.cpp

@@ -0,0 +1,166 @@
+#include "kwin-helpers.h"
+
+#include "log-helper.hpp"
+
+#include <QDir>
+#include <QFile>
+#include <QFileDevice>
+#include <QTextStream>
+#include <QtDBus/QDBusConnectionInterface>
+#include <QtDBus/QDBusInterface>
+#include <QtDBus/QDBusReply>
+
+namespace advss {
+
+int FocusNotifier::activePID = -1;
+std::string FocusNotifier::activeTitle = {};
+
+int FocusNotifier::getActiveWindowPID()
+{
+	return activePID;
+}
+
+std::string FocusNotifier::getActiveWindowTitle()
+{
+	return activeTitle;
+}
+
+void FocusNotifier::focusChanged(const int pid)
+{
+	activePID = pid;
+}
+
+void FocusNotifier::focusTitle(const QString &title)
+{
+	activeTitle = title.toStdString();
+}
+
+bool isKWinAvailable()
+{
+	const QDBusConnectionInterface *interface =
+		QDBusConnection::sessionBus().interface();
+	if (!interface)
+		return false;
+
+	const QStringList services =
+		interface->registeredServiceNames().value();
+	return services.contains("org.kde.KWin");
+}
+
+bool startKWinScript(QString &scriptObjectPath)
+{
+	const QString scriptPath =
+		"/tmp/AdvancedSceneSwitcher/KWinFocusNotifier.js";
+
+	const QString script =
+		R"(workspace.windowActivated.connect(function(client) {
+if (!client) return;
+if (!client.pid) return;
+if (!client.caption) return;
+
+callDBus(
+    "com.github.AdvancedSceneSwitcher",
+	"/com/github/AdvancedSceneSwitcher",
+	"com.github.AdvancedSceneSwitcher",
+	"focusChanged",
+	client.pid
+);
+callDBus(
+    "com.github.AdvancedSceneSwitcher",
+	"/com/github/AdvancedSceneSwitcher",
+	"com.github.AdvancedSceneSwitcher",
+	"focusTitle",
+	client.caption
+);
+}))";
+
+	if (const QDir dir; !dir.mkpath(QFileInfo(scriptPath).absolutePath())) {
+		blog(LOG_ERROR, "error creating /tmp/AdvancedSceneSwitcher");
+		return false;
+	}
+
+	QFile scriptFile(scriptPath);
+	if (!scriptFile.open(QIODevice::WriteOnly | QIODevice::Text)) {
+		blog(LOG_ERROR,
+		     "error opening KWinFocusNotifier.js for writing");
+		return false;
+	}
+
+	scriptFile.setPermissions(QFileDevice::ReadOwner |
+				  QFileDevice::WriteOwner);
+	QTextStream outputStream(&scriptFile);
+	outputStream << script;
+	scriptFile.close();
+
+	const QDBusConnection bus = QDBusConnection::sessionBus();
+
+	QDBusInterface scriptingIface("org.kde.KWin", "/Scripting",
+				      "org.kde.kwin.Scripting", bus);
+	if (!scriptingIface.isValid()) {
+		return false;
+	}
+
+	const QDBusReply<bool> scriptRunningReply =
+		scriptingIface.call("isScriptLoaded", scriptPath);
+	if (scriptRunningReply.isValid() && scriptRunningReply.value()) {
+		// script already registered and running, don't do it again
+		// this will leave the script running since we do not have
+		// a valid script id anymore, but at the very least this prevents
+		// it from running multiple times
+		return true;
+	}
+
+	const QDBusReply<int> scriptIdReply =
+		scriptingIface.call("loadScript", scriptPath);
+	if (!scriptIdReply.isValid()) {
+		return false;
+	}
+
+	const int scriptId = scriptIdReply.value();
+	scriptObjectPath =
+		QString("/Scripting/Script%1").arg(QString::number(scriptId));
+
+	QDBusInterface scriptRunner("org.kde.KWin", scriptObjectPath,
+				    "org.kde.kwin.Script", bus);
+	if (!scriptRunner.isValid()) {
+		return false;
+	}
+
+	const QDBusReply<void> runReply = scriptRunner.call("run");
+	return runReply.isValid();
+}
+
+bool stopKWinScript(const QString &scriptObjectPath)
+{
+	QDBusInterface scriptRunner("org.kde.KWin", scriptObjectPath,
+				    "org.kde.kwin.Script",
+				    QDBusConnection::sessionBus());
+	if (!scriptRunner.isValid()) {
+		return false;
+	}
+	const QDBusReply<void> stopReply = scriptRunner.call("stop");
+	return stopReply.isValid();
+}
+
+bool registerKWinDBusListener(FocusNotifier *notifier)
+{
+	static const QString serviceName = "com.github.AdvancedSceneSwitcher";
+	static const QString objectPath = "/com/github/AdvancedSceneSwitcher";
+	auto bus = QDBusConnection::sessionBus();
+
+	if (bus.objectRegisteredAt(objectPath)) {
+		// already registered?
+		return true;
+	}
+
+	if (!bus.registerService(serviceName)) {
+		return false;
+	}
+
+	if (!bus.registerObject(objectPath, notifier,
+				QDBusConnection::ExportAllSlots)) {
+		return false;
+	}
+	return true;
+}
+} // namespace advss

lib/linux/kwin-helpers.h

@@ -0,0 +1,33 @@
+#pragma once
+
+#include <QObject>
+#include <QString>
+#include <string>
+
+namespace advss {
+
+class FocusNotifier final : public QObject {
+	Q_OBJECT
+	Q_CLASSINFO("D-Bus Interface", "com.github.AdvancedSceneSwitcher")
+
+	static int activePID;
+	static std::string activeTitle;
+
+public:
+	using QObject::QObject;
+
+	static int getActiveWindowPID();
+	static std::string getActiveWindowTitle();
+
+public slots:
+	void focusChanged(const int pid);
+	void focusTitle(const QString &title);
+};
+
+bool isKWinAvailable();
+bool startKWinScript(QString &scriptObjectPath);
+bool stopKWinScript(const QString &scriptObjectPath);
+bool registerKWinDBusListener(FocusNotifier *notifier);
+void printDBusError();
+
+} // namespace advss