7 files changed, 150 insertions, 31 deletions
diff --git a/plugin/src/Caelestia/CMakeLists.txt b/plugin/src/Caelestia/CMakeLists.txt
index cc8e567..464ed98 100644
--- a/plugin/src/Caelestia/CMakeLists.txt
+++ b/plugin/src/Caelestia/CMakeLists.txt
@@ -11,6 +11,8 @@ qt_add_qml_module(caelestia
         filesystemmodel.hpp filesystemmodel.cpp
         qalculator.hpp qalculator.cpp
         beattracker.hpp beattracker.cpp
+        service.hpp service.cpp
+        serviceref.hpp serviceref.cpp
 )
 
 qt_query_qml_module(caelestia
diff --git a/plugin/src/Caelestia/beattracker.cpp b/plugin/src/Caelestia/beattracker.cpp
index 433ffab..aeca64b 100644
--- a/plugin/src/Caelestia/beattracker.cpp
+++ b/plugin/src/Caelestia/beattracker.cpp
@@ -1,5 +1,6 @@
 #include "beattracker.hpp"
 
+#include "service.hpp"
 #include <QAudioSource>
 #include <QDebug>
 #include <QIODevice>
@@ -10,13 +11,12 @@
 namespace caelestia {
 
 BeatTracker::BeatTracker(uint_t sampleRate, uint_t hopSize, QObject* parent)
-    : QObject(parent)
+    : Service(parent)
     , m_tempo(new_aubio_tempo("default", 1024, hopSize, sampleRate))
     , m_in(new_fvec(hopSize))
     , m_out(new_fvec(2))
     , m_hopSize(hopSize)
-    , m_bpm(120)
-    , m_refCount(0) {
+    , m_bpm(120) {
     QAudioFormat format;
     format.setSampleRate(static_cast<int>(sampleRate));
     format.setChannelCount(1);
@@ -39,25 +39,6 @@ smpl_t BeatTracker::bpm() const {
     return m_bpm;
 }
 
-int BeatTracker::refCount() const {
-    return m_refCount;
-}
-
-void BeatTracker::setRefCount(int refCount) {
-    if (m_refCount == refCount) {
-        return;
-    }
-
-    m_refCount = refCount;
-    emit refCountChanged();
-
-    if (m_refCount == 0) {
-        stop();
-    } else if (!m_device) {
-        start();
-    }
-}
-
 void BeatTracker::start() {
     m_device = m_source->start();
     connect(m_device, &QIODevice::readyRead, this, &BeatTracker::process);
diff --git a/plugin/src/Caelestia/beattracker.hpp b/plugin/src/Caelestia/beattracker.hpp
index fda0ddc..7c7fada 100644
--- a/plugin/src/Caelestia/beattracker.hpp
+++ b/plugin/src/Caelestia/beattracker.hpp
@@ -1,5 +1,6 @@
 #pragma once
 
+#include "service.hpp"
 #include <QAudioSource>
 #include <QIODevice>
 #include <QObject>
@@ -8,13 +9,12 @@
 
 namespace caelestia {
 
-class BeatTracker : public QObject {
+class BeatTracker : public Service {
     Q_OBJECT
     QML_ELEMENT
     QML_SINGLETON
 
     Q_PROPERTY(smpl_t bpm READ bpm NOTIFY bpmChanged)
-    Q_PROPERTY(int refCount READ refCount WRITE setRefCount NOTIFY refCountChanged)
 
 public:
     explicit BeatTracker(uint_t sampleRate = 44100, uint_t hopSize = 512, QObject* parent = nullptr);
@@ -22,12 +22,8 @@ public:
 
     [[nodiscard]] smpl_t bpm() const;
 
-    [[nodiscard]] int refCount() const;
-    void setRefCount(int refCount);
-
 signals:
     void bpmChanged();
-    void refCountChanged();
     void beat(smpl_t bpm);
 
 private:
@@ -40,10 +36,9 @@ private:
     uint_t m_hopSize;
 
     smpl_t m_bpm;
-    int m_refCount;
 
-    void start();
-    void stop();
+    void start() override;
+    void stop() override;
     void process();
     void handleStateChanged(QtAudio::State state) const;
 };
diff --git a/plugin/src/Caelestia/service.cpp b/plugin/src/Caelestia/service.cpp
new file mode 100644
index 0000000..9c13421
--- /dev/null
+++ b/plugin/src/Caelestia/service.cpp
@@ -0,0 +1,39 @@
+#include "service.hpp"
+
+#include <QDebug>
+#include <QObject>
+
+namespace caelestia {
+
+Service::Service(QObject* parent)
+    : QObject(parent)
+    , m_refCount(0) {}
+
+int Service::refCount() const {
+    return m_refCount;
+}
+
+void Service::ref() {
+    if (m_refCount == 0) {
+        start();
+    }
+
+    m_refCount++;
+    emit refCountChanged();
+}
+
+void Service::unref() {
+    if (m_refCount == 0) {
+        qWarning() << "ServiceRef::unref: attempted to unref service with no active refs";
+        return;
+    }
+
+    m_refCount--;
+    emit refCountChanged();
+
+    if (m_refCount == 0) {
+        stop();
+    }
+}
+
+} // namespace caelestia
diff --git a/plugin/src/Caelestia/service.hpp b/plugin/src/Caelestia/service.hpp
new file mode 100644
index 0000000..861d715
--- /dev/null
+++ b/plugin/src/Caelestia/service.hpp
@@ -0,0 +1,30 @@
+#pragma once
+
+#include <QObject>
+
+namespace caelestia {
+
+class Service : public QObject {
+    Q_OBJECT
+
+    Q_PROPERTY(int refCount READ refCount NOTIFY refCountChanged)
+
+public:
+    explicit Service(QObject* parent = nullptr);
+
+    [[nodiscard]] int refCount() const;
+
+    void ref();
+    void unref();
+
+signals:
+    void refCountChanged();
+
+private:
+    int m_refCount;
+
+    virtual void start() = 0;
+    virtual void stop() = 0;
+};
+
+} // namespace caelestia
diff --git a/plugin/src/Caelestia/serviceref.cpp b/plugin/src/Caelestia/serviceref.cpp
new file mode 100644
index 0000000..ebda663
--- /dev/null
+++ b/plugin/src/Caelestia/serviceref.cpp
@@ -0,0 +1,43 @@
+#include "serviceref.hpp"
+#include "service.hpp"
+
+#include <QObject>
+
+namespace caelestia {
+
+ServiceRef::ServiceRef(Service* service, QObject* parent)
+    : QObject(parent)
+    , m_service(service) {
+    if (m_service) {
+        m_service->ref();
+    }
+}
+
+ServiceRef::~ServiceRef() {
+    if (m_service) {
+        m_service->unref();
+    }
+}
+
+Service* ServiceRef::service() const {
+    return m_service;
+}
+
+void ServiceRef::setService(Service* service) {
+    if (m_service == service) {
+        return;
+    }
+
+    if (m_service) {
+        m_service->unref();
+    }
+
+    m_service = service;
+    emit serviceChanged();
+
+    if (m_service) {
+        m_service->ref();
+    }
+}
+
+} // namespace caelestia
diff --git a/plugin/src/Caelestia/serviceref.hpp b/plugin/src/Caelestia/serviceref.hpp
new file mode 100644
index 0000000..fb48a47
--- /dev/null
+++ b/plugin/src/Caelestia/serviceref.hpp
@@ -0,0 +1,29 @@
+#pragma once
+
+#include "service.hpp"
+#include <QObject>
+#include <qqmlintegration.h>
+
+namespace caelestia {
+
+class ServiceRef : public QObject {
+    Q_OBJECT
+    QML_ELEMENT
+
+    Q_PROPERTY(Service* service READ service WRITE setService NOTIFY serviceChanged)
+
+public:
+    explicit ServiceRef(Service* service = nullptr, QObject* parent = nullptr);
+    ~ServiceRef();
+
+    [[nodiscard]] Service* service() const;
+    void setService(Service* service);
+
+signals:
+    void serviceChanged();
+
+private:
+    Service* m_service;
+};
+
+} // namespace caelestia