Disconnect QAudioInput from QCaptureMediaSession in destructor

The expected behavior of elements connected to the capture session
is to disconnect automatically when deleted.
This patch adds this behavior to the QAudioInput object.
Additionally, this patch enables automatic handover of QAudioInput
between two capture session.

Pick-to: 6.2
Change-Id: If9e3b4ad1bf4c8abf117dc67367716ebc759c1c1
Reviewed-by: André de la Rocha <andre.rocha@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

4 files changed, 31 insertions, 4 deletions

diff --git a/src/multimedia/audio/qaudioinput.cpp b/src/multimedia/audio/qaudioinput.cpp
index 1d0d68f0f..8472ceb6c 100644
--- a/src/multimedia/audio/qaudioinput.cpp
+++ b/src/multimedia/audio/qaudioinput.cpp
@@ -43,6 +43,8 @@
 #include <private/qplatformaudioinput_p.h>
 #include <private/qplatformmediaintegration_p.h>
 
+#include <utility>
+
 /*!
     \qmltype AudioInput
     \instantiates QAudioInput
@@ -99,6 +101,7 @@ QAudioInput::QAudioInput(const QAudioDevice &device, QObject *parent)
 
 QAudioInput::~QAudioInput()
 {
+    setDisconnectFunction({});
     delete d;
 }
 
@@ -197,4 +200,18 @@ void QAudioInput::setDevice(const QAudioDevice &device)
     d->setAudioDevice(dev);
     emit deviceChanged();
 }
+
+/*!
+    \internal
+*/
+void QAudioInput::setDisconnectFunction(std::function<void()> disconnectFunction)
+{
+    if (d->disconnectFunction) {
+        auto df = d->disconnectFunction;
+        d->disconnectFunction = {};
+        df();
+    }
+    d->disconnectFunction = std::move(disconnectFunction);
+}
+
 #include "moc_qaudioinput.cpp"
diff --git a/src/multimedia/audio/qaudioinput.h b/src/multimedia/audio/qaudioinput.h
index 10c3ae1c9..3b3154fb5 100644
--- a/src/multimedia/audio/qaudioinput.h
+++ b/src/multimedia/audio/qaudioinput.h
@@ -75,9 +75,10 @@ Q_SIGNALS:
     void volumeChanged(float volume);
     void mutedChanged(bool muted);
 
-public:
-    QPlatformAudioInput *handle() const { return d; }
 private:
+    QPlatformAudioInput *handle() const { return d; }
+    void setDisconnectFunction(std::function<void()> disconnectFunction);
+    friend class QMediaCaptureSession;
     Q_DISABLE_COPY(QAudioInput)
     QPlatformAudioInput *d = nullptr;
 };
diff --git a/src/multimedia/platform/qplatformaudioinput_p.h b/src/multimedia/platform/qplatformaudioinput_p.h
index c4e4334b3..c1e3c1ecc 100644
--- a/src/multimedia/platform/qplatformaudioinput_p.h
+++ b/src/multimedia/platform/qplatformaudioinput_p.h
@@ -71,6 +71,7 @@ public:
     QAudioDevice device;
     float volume = 1.;
     bool muted = false;
+    std::function<void()> disconnectFunction;
 };
 
 QT_END_NAMESPACE
diff --git a/src/multimedia/recording/qmediacapturesession.cpp b/src/multimedia/recording/qmediacapturesession.cpp
index 55b223d90..c83a43153 100644
--- a/src/multimedia/recording/qmediacapturesession.cpp
+++ b/src/multimedia/recording/qmediacapturesession.cpp
@@ -174,6 +174,7 @@ QMediaCaptureSession::~QMediaCaptureSession()
     }
     if (d_ptr->imageCapture)
         d_ptr->imageCapture->setCaptureSession(nullptr);
+    setAudioInput(nullptr);
     d_ptr->setVideoSink(nullptr);
     delete d_ptr->captureSession;
     delete d_ptr;
@@ -199,10 +200,17 @@ QAudioInput *QMediaCaptureSession::audioInput() const
 */
 void QMediaCaptureSession::setAudioInput(QAudioInput *input)
 {
-    if (d_ptr->audioInput == input)
+    QAudioInput *oldInput = d_ptr->audioInput;
+    if (oldInput == input)
         return;
     d_ptr->audioInput = input;
-    d_ptr->captureSession->setAudioInput(input ? input->handle() : nullptr);
+    d_ptr->captureSession->setAudioInput(nullptr);
+    if (oldInput)
+        oldInput->setDisconnectFunction({});
+    if (input) {
+        input->setDisconnectFunction([this](){ setAudioInput(nullptr); });
+        d_ptr->captureSession->setAudioInput(input->handle());
+    }
     emit audioInputChanged();
 }