Implement notifications when the available cameras change for macOS

Listen to AVCaptureDeviceWas(Dis)ConnectedNotification notifications
and refresh our video device list if we get one of them.

Change-Id: Idf79e88e06422d74ab61cb82676c4b82fd1fb387
Reviewed-by: Doris Verria <doris.verria@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 23 insertions, 11 deletions

diff --git a/examples/multimediawidgets/camera/camera.cpp b/examples/multimediawidgets/camera/camera.cpp
index 196b8ba84..385608bbc 100644
--- a/examples/multimediawidgets/camera/camera.cpp
+++ b/examples/multimediawidgets/camera/camera.cpp
@@ -73,18 +73,10 @@ Camera::Camera() : ui(new Ui::Camera)
 
     //Camera devices:
 
-    QActionGroup *videoDevicesGroup = new QActionGroup(this);
+    videoDevicesGroup = new QActionGroup(this);
     videoDevicesGroup->setExclusive(true);
-    const QList<QCameraInfo> availableCameras = QMediaDeviceManager::videoInputs();
-    for (const QCameraInfo &cameraInfo : availableCameras) {
-        QAction *videoDeviceAction = new QAction(cameraInfo.description(), videoDevicesGroup);
-        videoDeviceAction->setCheckable(true);
-        videoDeviceAction->setData(QVariant::fromValue(cameraInfo));
-        if (cameraInfo == QMediaDeviceManager::defaultVideoInput())
-            videoDeviceAction->setChecked(true);
-
-        ui->menuDevices->addAction(videoDeviceAction);
-    }
+    updateCameras();
+    connect(QMediaDeviceManager::instance(), &QMediaDeviceManager::videoInputsChanged, this, &Camera::updateCameras);
 
     connect(videoDevicesGroup, &QActionGroup::triggered, this, &Camera::updateCameraDevice);
     connect(ui->captureWidget, &QTabWidget::currentChanged, this, &Camera::updateCaptureMode);
@@ -433,3 +425,18 @@ void Camera::closeEvent(QCloseEvent *event)
         event->accept();
     }
 }
+
+void Camera::updateCameras()
+{
+    ui->menuDevices->clear();
+    const QList<QCameraInfo> availableCameras = QMediaDeviceManager::videoInputs();
+    for (const QCameraInfo &cameraInfo : availableCameras) {
+        QAction *videoDeviceAction = new QAction(cameraInfo.description(), videoDevicesGroup);
+        videoDeviceAction->setCheckable(true);
+        videoDeviceAction->setData(QVariant::fromValue(cameraInfo));
+        if (cameraInfo == QMediaDeviceManager::defaultVideoInput())
+            videoDeviceAction->setChecked(true);
+
+        ui->menuDevices->addAction(videoDeviceAction);
+    }
+}
diff --git a/examples/multimediawidgets/camera/camera.h b/examples/multimediawidgets/camera/camera.h
index bdef8b8f8..d45923cc4 100644
--- a/examples/multimediawidgets/camera/camera.h
+++ b/examples/multimediawidgets/camera/camera.h
@@ -60,6 +60,7 @@
 
 QT_BEGIN_NAMESPACE
 namespace Ui { class Camera; }
+class QActionGroup;
 QT_END_NAMESPACE
 
 class Camera : public QMainWindow
@@ -109,6 +110,8 @@ private slots:
     void readyForCapture(bool ready);
     void imageSaved(int id, const QString &fileName);
 
+    void updateCameras();
+
 protected:
     void keyPressEvent(QKeyEvent *event) override;
     void keyReleaseEvent(QKeyEvent *event) override;
@@ -117,6 +120,8 @@ protected:
 private:
     Ui::Camera *ui;
 
+    QActionGroup *videoDevicesGroup  = nullptr;
+
     QScopedPointer<QCamera> m_camera;
     QCameraImageCapture *m_imageCapture;
     QScopedPointer<QMediaRecorder> m_mediaRecorder;