[libcamera-devel] [PATCH 07/12] libcamera: deviceenumerator: add factory for DeviceEnumerators

[Niklas Söderlund]

Provide a factory for DeviceEnumerator objects. Depending on which
libraries are available there will be different ways to enumerate
information in the system. This factory hides this from the rest of the
library.

Currently udev enumeration is the only supported implementation, a sysfs
implementation is another method that surely will be added in the
future.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/libcamera/deviceenumerator.cpp       | 17 +++++++++++++++++
 src/libcamera/include/deviceenumerator.h |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/src/libcamera/deviceenumerator.cpp b/src/libcamera/deviceenumerator.cpp
index f4c40bf0376ab453..6d675fc78af8e586 100644
--- a/src/libcamera/deviceenumerator.cpp
+++ b/src/libcamera/deviceenumerator.cpp
@@ -138,6 +138,23 @@ bool DeviceMatch::matchEntities(const std::vector<std::string> &entities) const
  * Enumerator Base
  */
 
+DeviceEnumerator *DeviceEnumerator::create()
+{
+	DeviceEnumerator *enumerator;
+
+	/* TODO: add compile time checks to only try udev enumerator if libudev is available */
+	enumerator = new DeviceEnumeratorUdev();
+	if (!enumerator->init())
+		return enumerator;
+
+	/* NOTE: Either udev is not available or initialization of it
+	 * failed, use/fallback on sysfs enumerator */
+
+	/* TODO: add a sysfs based enumerator */
+
+	return NULL;
+}
+
 DeviceEnumerator::~DeviceEnumerator()
 {
 	for (DeviceInfo *dev : devices_) {
diff --git a/src/libcamera/include/deviceenumerator.h b/src/libcamera/include/deviceenumerator.h
index 2c7ff3f336ba127d..6aa6e59d4a8a9729 100644
--- a/src/libcamera/include/deviceenumerator.h
+++ b/src/libcamera/include/deviceenumerator.h
@@ -59,6 +59,8 @@ private:
 class DeviceEnumerator
 {
 public:
+	static DeviceEnumerator *create();
+
 	virtual ~DeviceEnumerator();
 
 	virtual int init() = 0;
-- 
2.20.1