libcamera: controls: Use std::optional to handle invalid control values

Previously, ControlList::get<T>() would use default constructed objects to
indicate that a ControlList does not have the requested Control. This has
several disadvantages: 1) It requires types to be default constructible,
2) it does not differentiate between a default constructed object and an
object that happens to have the same state as a default constructed object.

std::optional<T> additionally stores the information if the object is valid
or not, and therefore is more expressive than a default constructed object.

Signed-off-by: Christian Rauch <Rauch.Christian@gmx.de>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

3 files changed, 17 insertions, 18 deletions

diff --git a/src/android/camera_capabilities.cpp b/src/android/camera_capabilities.cpp
index 6f197eb8..5304b2da 100644
--- a/src/android/camera_capabilities.cpp
+++ b/src/android/camera_capabilities.cpp
@@ -1042,7 +1042,7 @@ int CameraCapabilities::initializeStaticMetadata()
 	/* Sensor static metadata. */
 	std::array<int32_t, 2> pixelArraySize;
 	{
-		const Size &size = properties.get(properties::PixelArraySize);
+		const Size &size = properties.get(properties::PixelArraySize).value_or(Size{});
 		pixelArraySize[0] = size.width;
 		pixelArraySize[1] = size.height;
 		staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
@@ -1050,10 +1050,10 @@ int CameraCapabilities::initializeStaticMetadata()
 	}
 
 	if (properties.contains(properties::UnitCellSize)) {
-		const Size &cellSize = properties.get<Size>(properties::UnitCellSize);
+		const auto &cellSize = properties.get<Size>(properties::UnitCellSize);
 		std::array<float, 2> physicalSize{
-			cellSize.width * pixelArraySize[0] / 1e6f,
-			cellSize.height * pixelArraySize[1] / 1e6f
+			cellSize->width * pixelArraySize[0] / 1e6f,
+			cellSize->height * pixelArraySize[1] / 1e6f
 		};
 		staticMetadata_->addEntry(ANDROID_SENSOR_INFO_PHYSICAL_SIZE,
 					  physicalSize);
@@ -1061,7 +1061,7 @@ int CameraCapabilities::initializeStaticMetadata()
 
 	{
 		const Span<const Rectangle> &rects =
-			properties.get(properties::PixelArrayActiveAreas);
+			properties.get(properties::PixelArrayActiveAreas).value_or(Span<const Rectangle>{});
 		std::vector<int32_t> data{
 			static_cast<int32_t>(rects[0].x),
 			static_cast<int32_t>(rects[0].y),
@@ -1080,7 +1080,7 @@ int CameraCapabilities::initializeStaticMetadata()
 
 	/* Report the color filter arrangement if the camera reports it. */
 	if (properties.contains(properties::draft::ColorFilterArrangement)) {
-		uint8_t filterArr = properties.get(properties::draft::ColorFilterArrangement);
+		uint8_t filterArr = *properties.get(properties::draft::ColorFilterArrangement);
 		staticMetadata_->addEntry(ANDROID_SENSOR_INFO_COLOR_FILTER_ARRANGEMENT,
 					  filterArr);
 	}
diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index 8c039fb9..46621232 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -306,7 +306,7 @@ int CameraDevice::initialize(const CameraConfigData *cameraConfigData)
 	const ControlList &properties = camera_->properties();
 
 	if (properties.contains(properties::Location)) {
-		int32_t location = properties.get(properties::Location);
+		int32_t location = *properties.get(properties::Location);
 		switch (location) {
 		case properties::CameraLocationFront:
 			facing_ = CAMERA_FACING_FRONT;
@@ -356,7 +356,7 @@ int CameraDevice::initialize(const CameraConfigData *cameraConfigData)
 	 * metadata.
 	 */
 	if (properties.contains(properties::Rotation)) {
-		int rotation = properties.get(properties::Rotation);
+		int rotation = *properties.get(properties::Rotation);
 		orientation_ = (360 - rotation) % 360;
 		if (cameraConfigData && cameraConfigData->rotation != -1 &&
 		    orientation_ != cameraConfigData->rotation) {
@@ -1181,7 +1181,8 @@ void CameraDevice::requestComplete(Request *request)
 	 * as soon as possible, earlier than request completion time.
 	 */
 	uint64_t sensorTimestamp = static_cast<uint64_t>(request->metadata()
-							 .get(controls::SensorTimestamp));
+								 .get(controls::SensorTimestamp)
+								 .value_or(0));
 	notifyShutter(descriptor->frameNumber_, sensorTimestamp);
 
 	LOG(HAL, Debug) << "Request " << request->cookie() << " completed with "
@@ -1560,29 +1561,28 @@ CameraDevice::getResultMetadata(const Camera3RequestDescriptor &descriptor) cons
 				 rolling_shutter_skew);
 
 	/* Add metadata tags reported by libcamera. */
-	const int64_t timestamp = metadata.get(controls::SensorTimestamp);
+	const int64_t timestamp = metadata.get(controls::SensorTimestamp).value_or(0);
 	resultMetadata->addEntry(ANDROID_SENSOR_TIMESTAMP, timestamp);
 
 	if (metadata.contains(controls::draft::PipelineDepth)) {
-		uint8_t pipeline_depth =
-			metadata.get<int32_t>(controls::draft::PipelineDepth);
+		uint8_t pipeline_depth = *metadata.get<int32_t>(controls::draft::PipelineDepth);
 		resultMetadata->addEntry(ANDROID_REQUEST_PIPELINE_DEPTH,
 					 pipeline_depth);
 	}
 
 	if (metadata.contains(controls::ExposureTime)) {
-		int64_t exposure = metadata.get(controls::ExposureTime) * 1000ULL;
+		int64_t exposure = *metadata.get(controls::ExposureTime) * 1000ULL;
 		resultMetadata->addEntry(ANDROID_SENSOR_EXPOSURE_TIME, exposure);
 	}
 
 	if (metadata.contains(controls::FrameDuration)) {
-		int64_t duration = metadata.get(controls::FrameDuration) * 1000;
+		int64_t duration = *metadata.get(controls::FrameDuration) * 1000;
 		resultMetadata->addEntry(ANDROID_SENSOR_FRAME_DURATION,
 					 duration);
 	}
 
 	if (metadata.contains(controls::ScalerCrop)) {
-		Rectangle crop = metadata.get(controls::ScalerCrop);
+		Rectangle crop = *metadata.get(controls::ScalerCrop);
 		int32_t cropRect[] = {
 			crop.x, crop.y, static_cast<int32_t>(crop.width),
 			static_cast<int32_t>(crop.height),
@@ -1591,8 +1591,7 @@ CameraDevice::getResultMetadata(const Camera3RequestDescriptor &descriptor) cons
 	}
 
 	if (metadata.contains(controls::draft::TestPatternMode)) {
-		const int32_t testPatternMode =
-			metadata.get(controls::draft::TestPatternMode);
+		const int32_t testPatternMode = *metadata.get(controls::draft::TestPatternMode);
 		resultMetadata->addEntry(ANDROID_SENSOR_TEST_PATTERN_MODE,
 					 testPatternMode);
 	}
diff --git a/src/android/camera_hal_manager.cpp b/src/android/camera_hal_manager.cpp
index 5f7bfe26..0bffe96f 100644
--- a/src/android/camera_hal_manager.cpp
+++ b/src/android/camera_hal_manager.cpp
@@ -232,7 +232,7 @@ int32_t CameraHalManager::cameraLocation(const Camera *cam)
 	if (!properties.contains(properties::Location))
 		return -1;
 
-	return properties.get(properties::Location);
+	return *properties.get(properties::Location);
 }
 
 CameraDevice *CameraHalManager::cameraDeviceFromHalId(unsigned int id)