libcamera: camera: Pre-process AeEnable control

Handle the AeEnable under the hood in the Camera class, such that
AeEnable activates ExposureTimeMode and AnalogueGain together. This
allows applications the convenience of setting auto/manual mode of all
of the AE-related controls, as well as protecting applications against a
nasty behavior change if an aperture control is added in the future.
This also moves common handling code out of the IPA.

While we also want to inject AeEnable in Camera::controls() so that IPAs
don't have to report it, it is technically difficult at the moment as
ControlInfoMaps are not easily modifiable.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Stefan Klug <stefan.klug@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/camera.cpp

@@ -19,6 +19,7 @@
 #include <libcamera/base/thread.h>
 
 #include <libcamera/color_space.h>
+#include <libcamera/control_ids.h>
 #include <libcamera/framebuffer_allocator.h>
 #include <libcamera/request.h>
 #include <libcamera/stream.h>
@@ -1325,6 +1326,25 @@ int Camera::queueRequest(Request *request)
 		}
 	}
 
+	/* Pre-process AeEnable. */
+	ControlList &controls = request->controls();
+	const auto &aeEnable = controls.get(controls::AeEnable);
+	if (aeEnable) {
+		if (_d()->controlInfo_.count(controls::AnalogueGainMode.id()) &&
+		    !controls.contains(controls::AnalogueGainMode.id())) {
+			controls.set(controls::AnalogueGainMode,
+				     *aeEnable ? controls::AnalogueGainModeAuto
+					       : controls::AnalogueGainModeManual);
+		}
+
+		if (_d()->controlInfo_.count(controls::ExposureTimeMode.id()) &&
+		    !controls.contains(controls::ExposureTimeMode.id())) {
+			controls.set(controls::ExposureTimeMode,
+				     *aeEnable ? controls::ExposureTimeModeAuto
+					       : controls::ExposureTimeModeManual);
+		}
+	}
+
 	d->pipe_->invokeMethod(&PipelineHandler::queueRequest,
 			       ConnectionTypeQueued, request);