wayland/shortcuts-inhibit: merge multiple inhibitors on same surface

Author: bbedward

src/wayland/shortcuts_inhibit/inhibitor.cpp

@@ -18,7 +18,15 @@ ShortcutsInhibitor::ShortcutsInhibitor() {
 	});
 }
 
-ShortcutsInhibitor::~ShortcutsInhibitor() { delete this->inhibitor; }
+ShortcutsInhibitor::~ShortcutsInhibitor() {
+	if (!this->inhibitor) return;
+
+	auto* manager = impl::ShortcutsInhibitManager::instance();
+	if (!manager) return;
+
+	QObject::disconnect(this->inhibitor, nullptr, this, nullptr);
+	manager->unrefShortcutsInhibitor(this->inhibitor);
+}
 
 QObject* ShortcutsInhibitor::window() const { return this->bWindowObject; }
 
@@ -140,7 +148,7 @@ void ShortcutsInhibitor::onWaylandSurfaceCreated() {
 
 	if (this->inhibitor) {
 		QObject::disconnect(this->inhibitor, nullptr, this, nullptr);
-		delete this->inhibitor;
+		manager->unrefShortcutsInhibitor(this->inhibitor);
 		this->inhibitor = nullptr;
 	}
 	this->inhibitor = manager->createShortcutsInhibitor(this->mWaylandWindow);
@@ -156,13 +164,17 @@ void ShortcutsInhibitor::onWaylandSurfaceCreated() {
 }
 
 void ShortcutsInhibitor::onWaylandSurfaceDestroyed() {
-	if (this->inhibitor) {
-		QObject::disconnect(this->inhibitor, nullptr, this, nullptr);
-		auto wasActive = this->inhibitor->isActive();
-		delete this->inhibitor;
-		this->inhibitor = nullptr;
-		if (wasActive) { emit this->activeChanged(); }
-	}
+	if (!this->inhibitor) return;
+
+	auto* manager = impl::ShortcutsInhibitManager::instance();
+	if (!manager) return;
+
+	QObject::disconnect(this->inhibitor, nullptr, this, nullptr);
+	auto wasActive = this->inhibitor->isActive();
+	manager->unrefShortcutsInhibitor(this->inhibitor);
+	this->inhibitor = nullptr;
+
+	if (wasActive) { emit this->activeChanged(); }
 }
 
 } // namespace qs::wayland::shortcuts_inhibit

src/wayland/shortcuts_inhibit/inhibitor.hpp

@@ -32,15 +32,12 @@ class ShortcutsInhibitor: public QObject {
 	///
   /// Must be set to a non null value to enable the inhibitor.
 	Q_PROPERTY(QObject* window READ window WRITE setWindow NOTIFY windowChanged);
-	/// Whether the inhibitor is currently active. The inhibitor is active when the compositor
-	/// has granted the request and shortcuts are being inhibited.
+	/// Whether the inhibitor is currently active. The inhibitor is only active when the
+	/// associated window has keyboard focus and the compositor has granted the request.
 	///
 	/// The compositor may deactivate the inhibitor if the user requests normal shortcuts to be restored.
 	/// When inactive, there is no way to programmatically reactivate it - the user must do so through
 	/// compositor-specific mechanisms.
-	///
-	/// Note that if the surface loses focus or is destroyed, the inhibitor becomes irrelevant and this
-	/// property will become false, but no inactive event is sent by the compositor in those cases.
 	Q_PROPERTY(bool active READ isActive NOTIFY activeChanged);
 	// clang-format on
 

src/wayland/shortcuts_inhibit/proto.cpp

@@ -40,26 +40,46 @@ ShortcutsInhibitManager::createShortcutsInhibitor(QtWaylandClient::QWaylandWindo
 	auto* wlSurface = surface->surface();
 
 	if (this->inhibitors.contains(wlSurface)) {
-		qCWarning(logShortcutsInhibit)
-		    << "An inhibitor already exists for surface, skipping creation." << wlSurface;
-		return nullptr;
+		auto* inhibitor = this->inhibitors.value(wlSurface);
+		this->refCounts[inhibitor]++;
+		qCDebug(logShortcutsInhibit) << "Reusing existing inhibitor" << inhibitor << "for surface"
+		                             << wlSurface << "- refcount:" << this->refCounts[inhibitor];
+		return inhibitor;
 	}
 
 	auto* inhibitor =
 	    new ShortcutsInhibitor(this->inhibit_shortcuts(wlSurface, inputDevice->object()), wlSurface);
 	this->inhibitors.insert(wlSurface, inhibitor);
+	this->refCounts.insert(inhibitor, 1);
 	qCDebug(logShortcutsInhibit) << "Created inhibitor" << inhibitor << "for surface" << wlSurface;
 	return inhibitor;
 }
 
-void ShortcutsInhibitManager::destroyShortcutsInhibitor(ShortcutsInhibitor* inhibitor) {
-	if (inhibitor) { this->inhibitors.remove(inhibitor->surface()); }
+void ShortcutsInhibitManager::refShortcutsInhibitor(ShortcutsInhibitor* inhibitor) {
+	if (inhibitor && this->refCounts.contains(inhibitor)) {
+		this->refCounts[inhibitor]++;
+		qCDebug(logShortcutsInhibit) << "Incremented refcount for inhibitor" << inhibitor
+		                             << "- refcount:" << this->refCounts[inhibitor];
+	}
+}
+
+void ShortcutsInhibitManager::unrefShortcutsInhibitor(ShortcutsInhibitor* inhibitor) {
+	if (!inhibitor || !this->refCounts.contains(inhibitor)) return;
+
+	this->refCounts[inhibitor]--;
+	qCDebug(logShortcutsInhibit) << "Decremented refcount for inhibitor" << inhibitor
+	                             << "- refcount:" << this->refCounts[inhibitor];
+
+	if (this->refCounts[inhibitor] <= 0) {
+		qCDebug(logShortcutsInhibit) << "Refcount reached 0, destroying inhibitor" << inhibitor;
+		this->inhibitors.remove(inhibitor->surface());
+		this->refCounts.remove(inhibitor);
+		delete inhibitor;
+	}
 }
 
 ShortcutsInhibitor::~ShortcutsInhibitor() {
 	qCDebug(logShortcutsInhibit) << "Destroying inhibitor" << this << "for surface" << this->mSurface;
-	auto* manager = ShortcutsInhibitManager::instance();
-	if (manager) { manager->destroyShortcutsInhibitor(this); }
 	if (this->isInitialized()) this->destroy();
 }
 

src/wayland/shortcuts_inhibit/proto.hpp

@@ -18,12 +18,14 @@ class ShortcutsInhibitManager
 	explicit ShortcutsInhibitManager();
 
 	ShortcutsInhibitor* createShortcutsInhibitor(QtWaylandClient::QWaylandWindow* surface);
-	void destroyShortcutsInhibitor(ShortcutsInhibitor* inhibitor);
+	void refShortcutsInhibitor(ShortcutsInhibitor* inhibitor);
+	void unrefShortcutsInhibitor(ShortcutsInhibitor* inhibitor);
 
 	static ShortcutsInhibitManager* instance();
 
 private:
 	QHash<wl_surface*, ShortcutsInhibitor*> inhibitors;
+	QHash<ShortcutsInhibitor*, int> refCounts;
 };
 
 class ShortcutsInhibitor