Add abstract control class.
Partial implementation of tagged_partial_metadata. A control
is a value that can be changed.
Implements supported/get/set of parent class, abstracting
into simpler supported/get/set methods for children to implement.
BUG: 30140438
Change-Id: Iaba6fc2f54f6a8786c5ca379972ee1da9604c7a3
TEST: unit tests pass
diff --git a/modules/camera/3_4/metadata/control.h b/modules/camera/3_4/metadata/control.h
new file mode 100644
index 0000000..db19b1d
--- /dev/null
+++ b/modules/camera/3_4/metadata/control.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef V4L2_CAMERA_HAL_METADATA_CONTROL_H_
+#define V4L2_CAMERA_HAL_METADATA_CONTROL_H_
+
+#include <vector>
+
+#include <system/camera_metadata.h>
+
+#include "../common.h"
+#include "tagged_partial_metadata.h"
+
+namespace v4l2_camera_hal {
+
+// A Control is a PartialMetadata with values that can be gotten/set.
+template <typename T>
+class Control : public TaggedPartialMetadata {
+ public:
+ Control(int32_t control_tag, std::vector<int32_t> static_tags = {});
+
+ // Child classes still need to implement PopulateStaticFields.
+ virtual int PopulateDynamicFields(
+ android::CameraMetadata* metadata) const override;
+ virtual bool SupportsRequestValues(
+ const android::CameraMetadata& metadata) const override;
+ virtual int SetRequestValues(
+ const android::CameraMetadata& metadata) override;
+
+ protected:
+ // Simpler access to tag.
+ inline int32_t ControlTag() const { return ControlTags()[0]; }
+
+ // Get/Set the control value. Return non-0 on failure.
+ virtual int GetValue(T* value) const = 0;
+ virtual int SetValue(const T& value) = 0;
+ // Helper to check if val is supported by this control.
+ virtual bool IsSupported(const T& val) const = 0;
+
+ DISALLOW_COPY_AND_ASSIGN(Control);
+};
+
+// -----------------------------------------------------------------------------
+
+template <typename T>
+Control<T>::Control(int32_t control_tag, std::vector<int32_t> static_tags)
+ // Controls use the same tag for setting the control
+ // and getting the dynamic value.
+ : TaggedPartialMetadata(static_tags, {control_tag}, {control_tag}) {
+ HAL_LOG_ENTER();
+}
+
+template <typename T>
+int Control<T>::PopulateDynamicFields(android::CameraMetadata* metadata) const {
+ HAL_LOG_ENTER();
+
+ // Populate the current setting.
+ T value;
+ int res = GetValue(&value);
+ if (res) {
+ return res;
+ }
+ return UpdateMetadata(metadata, ControlTag(), value);
+}
+
+template <typename T>
+bool Control<T>::SupportsRequestValues(
+ const android::CameraMetadata& metadata) const {
+ HAL_LOG_ENTER();
+ if (metadata.isEmpty()) {
+ // Implicitly supported.
+ return true;
+ }
+
+ // Check that the requested setting is in the supported options.
+ T requested;
+ int res = SingleTagValue(metadata, ControlTag(), &requested);
+ if (res == -ENOENT) {
+ // Nothing requested of this control, that's fine.
+ return true;
+ } else if (res) {
+ HAL_LOGE("Failure while searching for request value for tag %d",
+ ControlTag());
+ return false;
+ }
+ return IsSupported(requested);
+}
+
+template <typename T>
+int Control<T>::SetRequestValues(const android::CameraMetadata& metadata) {
+ HAL_LOG_ENTER();
+ if (metadata.isEmpty()) {
+ // No changes necessary.
+ return 0;
+ }
+
+ // Get the requested value.
+ T requested;
+ int res = SingleTagValue(metadata, ControlTag(), &requested);
+ if (res == -ENOENT) {
+ // Nothing requested of this control, nothing to do.
+ return 0;
+ } else if (res) {
+ HAL_LOGE("Failure while searching for request value for tag %d",
+ ControlTag());
+ return res;
+ }
+
+ return SetValue(requested);
+}
+
+} // namespace v4l2_camera_hal
+
+#endif // V4L2_CAMERA_HAL_METADATA_CONTROL_H_