GStreamer: runtime check for controls that require GstPhotography.

Exposure, Flash, Focus and Locks controls were always initialized,
even when the GstPhotography interface was not available (on desktop
for example), causing some warnings and fooling the user in believing
that these features were available.
These controls are now lazily initialized and only when
GstPhotography is available.

The zoom control is not compile-checked anymore since it doesn't
actually require GstPhotography.

Change-Id: I5e8315d796dd920c9c29ccfa4155707f5f0fd7dc
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

src/plugins/gstreamer/camerabin/camerabin.pro

@@ -24,6 +24,7 @@ HEADERS += \
     $$PWD/camerabinrecorder.h \
     $$PWD/camerabincontainer.h \
     $$PWD/camerabinimagecapture.h \
+    $$PWD/camerabinzoom.h \
     $$PWD/camerabinimageprocessing.h \
     $$PWD/camerabinmetadata.h \
     $$PWD/camerabinvideoencoder.h \
@@ -43,6 +44,7 @@ SOURCES += \
     $$PWD/camerabincontainer.cpp \
     $$PWD/camerabinimagecapture.cpp \
     $$PWD/camerabinimageencoder.cpp \
+    $$PWD/camerabinzoom.cpp \
     $$PWD/camerabinimageprocessing.cpp \
     $$PWD/camerabinmetadata.cpp \
     $$PWD/camerabinrecorder.cpp \
@@ -71,15 +73,13 @@ config_gstreamer_photography {
         $$PWD/camerabinfocus.h \
         $$PWD/camerabinexposure.h \
         $$PWD/camerabinflash.h \
-        $$PWD/camerabinlocks.h \
-        $$PWD/camerabinzoom.h
+        $$PWD/camerabinlocks.h
 
     SOURCES += \
         $$PWD/camerabinexposure.cpp \
         $$PWD/camerabinflash.cpp \
         $$PWD/camerabinfocus.cpp \
-        $$PWD/camerabinlocks.cpp \
-        $$PWD/camerabinzoom.cpp
+        $$PWD/camerabinlocks.cpp
 
     LIBS += -lgstphotography-$$GST_VERSION
     DEFINES += GST_USE_UNSTABLE_API #prevents warnings because of unstable photography API

src/plugins/gstreamer/camerabin/camerabinsession.cpp

@@ -43,9 +43,9 @@
 #include "camerabinflash.h"
 #include "camerabinfocus.h"
 #include "camerabinlocks.h"
-#include "camerabinzoom.h"
 #endif
 
+#include "camerabinzoom.h"
 #include "camerabinimageprocessing.h"
 #include "camerabinviewfindersettings.h"
 
@@ -121,6 +121,12 @@ CameraBinSession::CameraBinSession(GstElementFactory *sourceFactory, QObject *pa
      m_videoInputFactory(0),
      m_viewfinder(0),
      m_viewfinderInterface(0),
+#ifdef HAVE_GST_PHOTOGRAPHY
+     m_cameraExposureControl(0),
+     m_cameraFlashControl(0),
+     m_cameraFocusControl(0),
+     m_cameraLocksControl(0),
+#endif
      m_cameraSrc(0),
      m_videoSrc(0),
      m_viewfinderElement(0),
@@ -157,14 +163,7 @@ CameraBinSession::CameraBinSession(GstElementFactory *sourceFactory, QObject *pa
     m_imageEncodeControl = new CameraBinImageEncoder(this);
     m_recorderControl = new CameraBinRecorder(this);
     m_mediaContainerControl = new CameraBinContainer(this);
-
-#ifdef HAVE_GST_PHOTOGRAPHY
-    m_cameraExposureControl = new CameraBinExposure(this);
-    m_cameraFlashControl = new CameraBinFlash(this);
-    m_cameraFocusControl = new CameraBinFocus(this);
-    m_cameraLocksControl = new CameraBinLocks(this);
     m_cameraZoomControl = new CameraBinZoom(this);
-#endif
     m_imageProcessingControl = new CameraBinImageProcessing(this);
     m_captureDestinationControl = new CameraBinCaptureDestination(this);
     m_captureBufferFormatControl = new CameraBinCaptureBufferFormat(this);
@@ -221,6 +220,34 @@ GstPhotography *CameraBinSession::photography()
 
     return 0;
 }
+
+CameraBinExposure *CameraBinSession::cameraExposureControl()
+{
+    if (!m_cameraExposureControl && photography())
+        m_cameraExposureControl = new CameraBinExposure(this);
+    return m_cameraExposureControl;
+}
+
+CameraBinFlash *CameraBinSession::cameraFlashControl()
+{
+    if (!m_cameraFlashControl && photography())
+        m_cameraFlashControl = new CameraBinFlash(this);
+    return m_cameraFlashControl;
+}
+
+CameraBinFocus *CameraBinSession::cameraFocusControl()
+{
+    if (!m_cameraFocusControl && photography())
+        m_cameraFocusControl = new CameraBinFocus(this);
+    return m_cameraFocusControl;
+}
+
+CameraBinLocks *CameraBinSession::cameraLocksControl()
+{
+    if (!m_cameraLocksControl && photography())
+        m_cameraLocksControl = new CameraBinLocks(this);
+    return m_cameraLocksControl;
+}
 #endif
 
 CameraBinSession::CameraRole CameraBinSession::cameraRole() const

src/plugins/gstreamer/camerabin/camerabinsession.h

@@ -121,13 +121,13 @@ public:
     CameraBinImageEncoder *imageEncodeControl() const { return m_imageEncodeControl; }
 
 #ifdef HAVE_GST_PHOTOGRAPHY
-    CameraBinExposure *cameraExposureControl() const  { return m_cameraExposureControl; }
-    CameraBinFlash *cameraFlashControl() const  { return m_cameraFlashControl; }
-    CameraBinFocus *cameraFocusControl() const  { return m_cameraFocusControl; }
-    CameraBinLocks *cameraLocksControl() const { return m_cameraLocksControl; }
-    CameraBinZoom *cameraZoomControl() const { return m_cameraZoomControl; }
+    CameraBinExposure *cameraExposureControl();
+    CameraBinFlash *cameraFlashControl();
+    CameraBinFocus *cameraFocusControl();
+    CameraBinLocks *cameraLocksControl();
 #endif
 
+    CameraBinZoom *cameraZoomControl() const { return m_cameraZoomControl; }
     CameraBinImageProcessing *imageProcessingControl() const { return m_imageProcessingControl; }
     CameraBinCaptureDestination *captureDestinationControl() const { return m_captureDestinationControl; }
     CameraBinCaptureBufferFormat *captureBufferFormatControl() const { return m_captureBufferFormatControl; }
@@ -238,9 +238,8 @@ private:
     CameraBinFlash *m_cameraFlashControl;
     CameraBinFocus *m_cameraFocusControl;
     CameraBinLocks *m_cameraLocksControl;
-    CameraBinZoom *m_cameraZoomControl;
 #endif
-
+    CameraBinZoom *m_cameraZoomControl;
     CameraBinImageProcessing *m_imageProcessingControl;
     CameraBinCaptureDestination *m_captureDestinationControl;
     CameraBinCaptureBufferFormat *m_captureBufferFormatControl;

src/plugins/gstreamer/camerabin/camerabinzoom.cpp

@@ -34,8 +34,6 @@
 #include "camerabinzoom.h"
 #include "camerabinsession.h"
 
-#include <gst/interfaces/photography.h>
-
 #define ZOOM_PROPERTY "zoom"
 #define MAX_ZOOM_PROPERTY "max-zoom"