Expose availability from the backend to C++ and QML.

The availabilityError property was static based on the service, but it
can change at run time, so add the plumbing to allow the backend to
report it itself.

Also make sure that both QML and C++ expose the availability.

The radio tuner and data controls previously had properties (but no
signals) for availability - these have been removed.

Change-Id: I9240cf93e2a51b14cd38642f9312ae3c75f05361
Reviewed-by: Ling Hu <ling.hu@nokia.com>

src/imports/multimedia/qdeclarativecamera_p.h

@@ -84,6 +84,8 @@ class QDeclarativeCamera : public QObject, public QDeclarativeParserStatus
     Q_PROPERTY(LockStatus lockStatus READ lockStatus NOTIFY lockStatusChanged)
     Q_PROPERTY(QString errorString READ errorString NOTIFY errorChanged)
 
+    Q_PROPERTY(Availability availability READ availability NOTIFY availabilityChanged)
+
     Q_PROPERTY(qreal opticalZoom READ opticalZoom WRITE setOpticalZoom NOTIFY opticalZoomChanged)
     Q_PROPERTY(qreal maximumOpticalZoom READ maximumOpticalZoom NOTIFY maximumOpticalZoomChanged)
     Q_PROPERTY(qreal digitalZoom READ digitalZoom WRITE setDigitalZoom NOTIFY digitalZoomChanged)
@@ -109,6 +111,8 @@ class QDeclarativeCamera : public QObject, public QDeclarativeParserStatus
     Q_ENUMS(FocusMode)
     Q_ENUMS(FocusPointMode)
     Q_ENUMS(FocusAreaStatus)
+    Q_ENUMS(Availability)
+
 public:
     enum CaptureMode {
         CaptureStillImage = QCamera::CaptureStillImage,
@@ -193,6 +197,12 @@ public:
         FocusAreaFocused = QCameraFocusZone::Focused
     };
 
+    enum Availability {
+        Available = QtMultimedia::NoError,
+        Busy = QtMultimedia::BusyError,
+        Unavailable = QtMultimedia::ServiceMissingError,
+        ResourceMissing = QtMultimedia::ResourceError
+    };
 
     QDeclarativeCamera(QObject *parent = 0);
     ~QDeclarativeCamera();
@@ -220,6 +230,8 @@ public:
     qreal opticalZoom() const;
     qreal digitalZoom() const;
 
+    Availability availability() const;
+
 public Q_SLOTS:
     void setCaptureMode(CaptureMode mode);
 
@@ -250,9 +262,12 @@ Q_SIGNALS:
 
     void mediaObjectChanged();
 
+    void availabilityChanged(Availability availability);
+
 private Q_SLOTS:
     void _q_updateState(QCamera::State);
     void _q_error(int, const QString &);
+    void _q_availabilityChanged(QtMultimedia::AvailabilityError);
 
 protected:
     void classBegin();