Implement customFocusPoint in camerabin backend.

Send a regions-of-interest event containing a rectangle surrounding the
focus point to the camera source when the camera's focusPointMode
is QCameraFocus::CustomFocusPoint.  Reset the regions-of-interest if the
focusPointMode changes to any other value.

[ChangeLog][GStreamer] Implement customFocusPoint in camerabin backend.

Change-Id: If75405733b18d476dff5467abae3f08271caf06a
Reviewed-by: Yoann Lopes <yoann.lopes@digia.com>

src/plugins/gstreamer/camerabin/camerabinfocus.cpp

@@ -54,10 +54,16 @@ QT_BEGIN_NAMESPACE
 CameraBinFocus::CameraBinFocus(CameraBinSession *session)
     :QCameraFocusControl(session),
      m_session(session),
+     m_cameraState(QCamera::UnloadedState),
      m_focusMode(QCameraFocus::AutoFocus),
+     m_focusPointMode(QCameraFocus::FocusPointAuto),
      m_focusStatus(QCamera::Unlocked),
-     m_focusZoneStatus(QCameraFocusZone::Selected)
+     m_focusZoneStatus(QCameraFocusZone::Selected),
+     m_focusPoint(0.5, 0.5),
+     m_focusRect(0, 0, 0.3, 0.3)
 {
+    m_focusRect.moveCenter(m_focusPoint);
+
     gst_photography_set_focus_mode(m_session->photography(), GST_PHOTOGRAPHY_FOCUS_MODE_AUTO);
 
     connect(m_session, SIGNAL(stateChanged(QCamera::State)),
@@ -122,32 +128,61 @@ bool CameraBinFocus::isFocusModeSupported(QCameraFocus::FocusModes mode) const
 
 QCameraFocus::FocusPointMode CameraBinFocus::focusPointMode() const
 {
-    return QCameraFocus::FocusPointAuto;
+    return m_focusPointMode;
 }
 
 void CameraBinFocus::setFocusPointMode(QCameraFocus::FocusPointMode mode)
 {
     Q_UNUSED(mode);
+    if (m_focusPointMode != mode
+            && (mode == QCameraFocus::FocusPointAuto || mode == QCameraFocus::FocusPointCustom)) {
+        m_focusPointMode = mode;
+
+        if (m_focusPointMode == QCameraFocus::FocusPointAuto)
+            resetFocusPoint();
+
+        emit focusPointModeChanged(m_focusPointMode);
+
+    }
 }
 
 bool CameraBinFocus::isFocusPointModeSupported(QCameraFocus::FocusPointMode mode) const
 {
-    return mode == QCameraFocus::FocusPointAuto;
+    return mode == QCameraFocus::FocusPointAuto || mode == QCameraFocus::FocusPointCustom;
 }
 
 QPointF CameraBinFocus::customFocusPoint() const
 {
-    return QPointF(0.5, 0.5);
+    return m_focusPoint;
 }
 
 void CameraBinFocus::setCustomFocusPoint(const QPointF &point)
 {
-    Q_UNUSED(point);
+    if (m_focusPoint != point) {
+        m_focusPoint = point;
+
+        // Bound the focus point so the focus rect remains entirely within the unit square.
+        m_focusPoint.setX(qBound(m_focusRect.width() / 2, m_focusPoint.x(), 1 - m_focusRect.width() / 2));
+        m_focusPoint.setY(qBound(m_focusRect.height() / 2, m_focusPoint.y(), 1 - m_focusRect.height() / 2));
+
+        if (m_focusPointMode == QCameraFocus::FocusPointCustom) {
+            const QRectF focusRect = m_focusRect;
+            m_focusRect.moveCenter(m_focusPoint);
+
+            updateRegionOfInterest(m_focusRect, 1);
+
+            if (focusRect != m_focusRect) {
+                emit focusZonesChanged();
+            }
+        }
+
+        emit customFocusPointChanged(m_focusPoint);
+    }
 }
 
 QCameraFocusZoneList CameraBinFocus::focusZones() const
 {
-    return QCameraFocusZoneList() << QCameraFocusZone(QRectF(0.35, 0.35, 0.3, 0.3), m_focusZoneStatus);
+    return QCameraFocusZoneList() << QCameraFocusZone(m_focusRect, m_focusZoneStatus);
 }
 
 
@@ -213,8 +248,29 @@ void CameraBinFocus::_q_setFocusStatus(QCamera::LockStatus status, QCamera::Lock
 
 void CameraBinFocus::_q_handleCameraStateChange(QCamera::State state)
 {
-    if (state != QCamera::ActiveState)
+    m_cameraState = state;
+    if (state == QCamera::ActiveState) {
+        if (GstPad *pad = gst_element_get_static_pad(m_session->cameraSource(), "vfsrc")) {
+            if (GstCaps *caps = gst_pad_get_negotiated_caps(pad)) {
+                if (GstStructure *structure = gst_caps_get_structure(caps, 0)) {
+                    int width = 0;
+                    int height = 0;
+                    gst_structure_get_int(structure, "width", &width);
+                    gst_structure_get_int(structure, "height", &height);
+                    setViewfinderResolution(QSize(width, height));
+                }
+                gst_caps_unref(caps);
+            }
+            gst_object_unref(GST_OBJECT(pad));
+        }
+        if (m_focusPointMode == QCameraFocus::FocusPointCustom) {
+                updateRegionOfInterest(m_focusRect, 1);
+        }
+    } else {
         _q_setFocusStatus(QCamera::Unlocked, QCamera::LockLost);
+
+        resetFocusPoint();
+    }
 }
 
 void CameraBinFocus::_q_startFocusing()
@@ -229,4 +285,70 @@ void CameraBinFocus::_q_stopFocusing()
     _q_setFocusStatus(QCamera::Unlocked, QCamera::UserRequest);
 }
 
+void CameraBinFocus::setViewfinderResolution(const QSize &resolution)
+{
+    if (resolution != m_viewfinderResolution) {
+        m_viewfinderResolution = resolution;
+        if (!resolution.isEmpty()) {
+            const QPointF center = m_focusRect.center();
+            m_focusRect.setWidth(m_focusRect.height() * resolution.height() / resolution.width());
+            m_focusRect.moveCenter(center);
+        }
+    }
+}
+
+void CameraBinFocus::resetFocusPoint()
+{
+    const QRectF focusRect = m_focusRect;
+    m_focusPoint = QPointF(0.5, 0.5);
+    m_focusRect.moveCenter(m_focusPoint);
+
+    updateRegionOfInterest(QRectF(0, 0, 0, 0), 0);
+
+    if (focusRect != m_focusRect) {
+        emit customFocusPointChanged(m_focusPoint);
+        emit focusZonesChanged();
+    }
+}
+
+void CameraBinFocus::updateRegionOfInterest(const QRectF &focusRect, int priority)
+{
+    if (m_cameraState != QCamera::ActiveState)
+        return;
+
+    GstElement * const cameraSource = m_session->cameraSource();
+    if (!cameraSource)
+        return;
+
+    GstStructure *region = gst_structure_new(
+                "region",
+                "region-x"        , G_TYPE_UINT , uint(m_viewfinderResolution.width()  * focusRect.x()),
+                "region-y"        , G_TYPE_UINT,  uint(m_viewfinderResolution.height() * focusRect.y()),
+                "region-w"        , G_TYPE_UINT , uint(m_viewfinderResolution.width()  * focusRect.width()),
+                "region-h"        , G_TYPE_UINT,  uint(m_viewfinderResolution.height() * focusRect.height()),
+                "region-priority" , G_TYPE_UINT,  priority,
+                NULL);
+
+    GValue regionValue = G_VALUE_INIT;
+    g_value_init(&regionValue, GST_TYPE_STRUCTURE);
+    gst_value_set_structure(&regionValue, region);
+    gst_structure_free(region);
+
+    GValue regions = G_VALUE_INIT;
+    g_value_init(&regions, GST_TYPE_LIST);
+    gst_value_list_append_value(&regions, &regionValue);
+    g_value_unset(&regionValue);
+
+    GstStructure *regionsOfInterest = gst_structure_new(
+                "regions-of-interest",
+                "frame-width"     , G_TYPE_UINT , m_viewfinderResolution.width(),
+                "frame-height"    , G_TYPE_UINT,  m_viewfinderResolution.height(),
+                NULL);
+    gst_structure_set_value(regionsOfInterest, "regions", &regions);
+    g_value_unset(&regions);
+
+    GstEvent *event = gst_event_new_custom(GST_EVENT_CUSTOM_UPSTREAM, regionsOfInterest);
+    gst_element_send_event(cameraSource, event);
+}
+
 QT_END_NAMESPACE

src/plugins/gstreamer/camerabin/camerabinfocus.h

@@ -82,15 +82,25 @@ public Q_SLOTS:
     void _q_startFocusing();
     void _q_stopFocusing();
 
+    void setViewfinderResolution(const QSize &resolution);
+
 private Q_SLOTS:
     void _q_setFocusStatus(QCamera::LockStatus status, QCamera::LockChangeReason reason);
     void _q_handleCameraStateChange(QCamera::State state);
 
 private:
+    void resetFocusPoint();
+    void updateRegionOfInterest(const QRectF &focusRect, int priority);
+
     CameraBinSession *m_session;
+    QCamera::State m_cameraState;
     QCameraFocus::FocusModes m_focusMode;
+    QCameraFocus::FocusPointMode m_focusPointMode;
     QCamera::LockStatus m_focusStatus;
     QCameraFocusZone::FocusZoneStatus m_focusZoneStatus;
+    QPointF m_focusPoint;
+    QRectF m_focusRect;
+    QSize m_viewfinderResolution;
 };
 
 QT_END_NAMESPACE

src/plugins/gstreamer/camerabin/camerabinsession.h

@@ -103,6 +103,7 @@ public:
     GstPhotography *photography();
 #endif
     GstElement *cameraBin() { return m_camerabin; }
+    GstElement *cameraSource() { return m_videoSrc; }
     QGstreamerBusHelper *bus() { return m_busHelper; }
 
     CameraRole cameraRole() const;

src/plugins/gstreamer/camerabin/camerabinviewfindersettings.cpp

@@ -89,6 +89,7 @@ void CameraBinViewfinderSettings::setViewfinderParameter(ViewfinderParameter par
     switch (parameter) {
     case Resolution:
         m_resolution = value.toSize();
+        break;
     case PixelAspectRatio:
     case MinimumFrameRate:
     case MaximumFrameRate: