wayland/toplevel_management: add ToplevelManager.activeToplevel

If the signal was fired slightly before the scheduled time, it would
schedule itself again a couple ms in the future.

src/core/clock.cpp

@@ -8,7 +8,7 @@
 #include "util.hpp"
 
 SystemClock::SystemClock(QObject* parent): QObject(parent) {
-	QObject::connect(&this->timer, &QTimer::timeout, this, &SystemClock::update);
+	QObject::connect(&this->timer, &QTimer::timeout, this, &SystemClock::onTimeout);
 	this->update();
 }
 
@@ -30,41 +30,63 @@ void SystemClock::setPrecision(SystemClock::Enum precision) {
 	this->update();
 }
 
+void SystemClock::onTimeout() {
+	this->setTime(this->nextTime);
+	this->schedule(this->nextTime);
+}
+
 void SystemClock::update() {
-	auto time = QTime::currentTime();
-
 	if (this->mEnabled) {
-		auto secondPrecision = this->mPrecision >= SystemClock::Seconds;
-		auto secondChanged = this->setSeconds(secondPrecision ? time.second() : 0);
-
-		auto minutePrecision = this->mPrecision >= SystemClock::Minutes;
-		auto minuteChanged = this->setMinutes(minutePrecision ? time.minute() : 0);
-
-		auto hourPrecision = this->mPrecision >= SystemClock::Hours;
-		auto hourChanged = this->setHours(hourPrecision ? time.hour() : 0);
-
-		DropEmitter::call(secondChanged, minuteChanged, hourChanged);
-
-		auto nextTime = QTime(
-		    hourPrecision ? time.hour() : 0,
-		    minutePrecision ? time.minute() : 0,
-		    secondPrecision ? time.second() : 0
-		);
-
-		if (secondPrecision) nextTime = nextTime.addSecs(1);
-		else if (minutePrecision) nextTime = nextTime.addSecs(60);
-		else if (hourPrecision) nextTime = nextTime.addSecs(3600);
-
-		auto delay = time.msecsTo(nextTime);
-		// day rollover
-		if (delay < 0) delay += 86400000;
-
-		this->timer.start(delay);
+		this->setTime(QTime::currentTime());
+		this->schedule(QTime::currentTime());
 	} else {
 		this->timer.stop();
 	}
 }
 
+void SystemClock::setTime(QTime time) {
+	auto secondPrecision = this->mPrecision >= SystemClock::Seconds;
+	auto secondChanged = this->setSeconds(secondPrecision ? time.second() : 0);
+
+	auto minutePrecision = this->mPrecision >= SystemClock::Minutes;
+	auto minuteChanged = this->setMinutes(minutePrecision ? time.minute() : 0);
+
+	auto hourPrecision = this->mPrecision >= SystemClock::Hours;
+	auto hourChanged = this->setHours(hourPrecision ? time.hour() : 0);
+
+	DropEmitter::call(secondChanged, minuteChanged, hourChanged);
+}
+
+void SystemClock::schedule(QTime floor) {
+	auto secondPrecision = this->mPrecision >= SystemClock::Seconds;
+	auto minutePrecision = this->mPrecision >= SystemClock::Minutes;
+	auto hourPrecision = this->mPrecision >= SystemClock::Hours;
+
+setnext:
+	auto nextTime = QTime(
+	    hourPrecision ? floor.hour() : 0,
+	    minutePrecision ? floor.minute() : 0,
+	    secondPrecision ? floor.second() : 0
+	);
+
+	if (secondPrecision) nextTime = nextTime.addSecs(1);
+	else if (minutePrecision) nextTime = nextTime.addSecs(60);
+	else if (hourPrecision) nextTime = nextTime.addSecs(3600);
+
+	auto delay = QTime::currentTime().msecsTo(nextTime);
+
+	// If off by more than 2 hours we likely wrapped around midnight.
+	if (delay < -7200000) delay += 86400000;
+	else if (delay < 0) {
+		// Otherwise its just the timer being unstable.
+		floor = QTime::currentTime();
+		goto setnext;
+	}
+
+	this->timer.start(delay);
+	this->nextTime = nextTime;
+}
+
 DEFINE_MEMBER_GETSET(SystemClock, hours, setHours);
 DEFINE_MEMBER_GETSET(SystemClock, minutes, setMinutes);
 DEFINE_MEMBER_GETSET(SystemClock, seconds, setSeconds);

src/core/clock.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <qdatetime.h>
 #include <qobject.h>
 #include <qqmlintegration.h>
 #include <qtimer.h>
@@ -49,7 +50,7 @@ signals:
 	void secondsChanged();
 
 private slots:
-	void update();
+	void onTimeout();
 
 private:
 	bool mEnabled = true;
@@ -58,6 +59,11 @@ private:
 	quint32 mMinutes = 0;
 	quint32 mSeconds = 0;
 	QTimer timer;
+	QTime nextTime;
+
+	void update();
+	void setTime(QTime time);
+	void schedule(QTime floor);
 
 	DECLARE_PRIVATE_MEMBER(SystemClock, hours, setHours, mHours, hoursChanged);
 	DECLARE_PRIVATE_MEMBER(SystemClock, minutes, setMinutes, mMinutes, minutesChanged);

src/wayland/toplevel_management/qml.cpp

@@ -3,6 +3,7 @@
 #include <qobject.h>
 #include <qtmetamacros.h>
 
+#include "../../core/util.hpp"
 #include "../../core/model.hpp"
 #include "../../core/proxywindow.hpp"
 #include "../../core/qmlscreen.hpp"
@@ -132,22 +133,49 @@ ObjectModel<Toplevel>* ToplevelManager::toplevels() { return &this->mToplevels;
 
 void ToplevelManager::onToplevelReady(impl::ToplevelHandle* handle) {
 	auto* toplevel = new Toplevel(handle, this);
+
+	// clang-format off
 	QObject::connect(toplevel, &Toplevel::closed, this, &ToplevelManager::onToplevelClosed);
+	QObject::connect(toplevel, &Toplevel::activatedChanged, this, &ToplevelManager::onToplevelActiveChanged);
+	// clang-format on
+
+	if (toplevel->activated()) this->setActiveToplevel(toplevel);
 	this->mToplevels.insertObject(toplevel);
 }
 
+void ToplevelManager::onToplevelActiveChanged() {
+	auto* toplevel = qobject_cast<Toplevel*>(this->sender());
+	if (toplevel->activated()) this->setActiveToplevel(toplevel);
+}
+
 void ToplevelManager::onToplevelClosed() {
 	auto* toplevel = qobject_cast<Toplevel*>(this->sender());
+	if (toplevel == this->mActiveToplevel) this->setActiveToplevel(nullptr);
 	this->mToplevels.removeObject(toplevel);
 }
 
+DEFINE_MEMBER_GETSET(ToplevelManager, activeToplevel, setActiveToplevel);
+
 ToplevelManager* ToplevelManager::instance() {
 	static auto* instance = new ToplevelManager(); // NOLINT
 	return instance;
 }
 
+ToplevelManagerQml::ToplevelManagerQml(QObject* parent): QObject(parent) {
+	QObject::connect(
+	    ToplevelManager::instance(),
+	    &ToplevelManager::activeToplevelChanged,
+	    this,
+	    &ToplevelManagerQml::activeToplevelChanged
+	);
+}
+
 ObjectModel<Toplevel>* ToplevelManagerQml::toplevels() {
 	return ToplevelManager::instance()->toplevels();
 }
 
+Toplevel* ToplevelManagerQml::activeToplevel() {
+	return ToplevelManager::instance()->activeToplevel();
+}
+
 } // namespace qs::wayland::toplevel_management

src/wayland/toplevel_management/qml.hpp

@@ -7,6 +7,7 @@
 #include "../../core/model.hpp"
 #include "../../core/proxywindow.hpp"
 #include "../../core/qmlscreen.hpp"
+#include "../../core/util.hpp"
 
 namespace qs::wayland::toplevel_management {
 
@@ -111,14 +112,27 @@ public:
 
 	static ToplevelManager* instance();
 
+signals:
+	void activeToplevelChanged();
+
 private slots:
 	void onToplevelReady(impl::ToplevelHandle* handle);
+	void onToplevelActiveChanged();
 	void onToplevelClosed();
 
 private:
 	explicit ToplevelManager();
 
 	ObjectModel<Toplevel> mToplevels {this};
+	Toplevel* mActiveToplevel = nullptr;
+
+	DECLARE_PRIVATE_MEMBER(
+	    ToplevelManager,
+	    activeToplevel,
+	    setActiveToplevel,
+	    mActiveToplevel,
+	    activeToplevelChanged
+	);
 };
 
 ///! Exposes a list of Toplevels.
@@ -127,14 +141,24 @@ private:
 /// wayland protocol.
 class ToplevelManagerQml: public QObject {
 	Q_OBJECT;
+	/// All toplevel windows exposed by the compositor.
 	Q_PROPERTY(ObjectModel<Toplevel>* toplevels READ toplevels CONSTANT);
+	/// Active toplevel or null.
+	///
+	/// > [!INFO] If multiple are active, this will be the most recently activated one.
+	/// > Usually compositors will not report more than one toplevel as active at a time.
+	Q_PROPERTY(Toplevel* activeToplevel READ activeToplevel NOTIFY activeToplevelChanged);
 	QML_NAMED_ELEMENT(ToplevelManager);
 	QML_SINGLETON;
 
 public:
-	explicit ToplevelManagerQml(QObject* parent = nullptr): QObject(parent) {}
+	explicit ToplevelManagerQml(QObject* parent = nullptr);
 
 	[[nodiscard]] static ObjectModel<Toplevel>* toplevels();
+	[[nodiscard]] static Toplevel* activeToplevel();
+
+signals:
+	void activeToplevelChanged();
 };
 
 } // namespace qs::wayland::toplevel_management