libcamera: Add signal/slot communication mechanism

Introduce a Signal class that allows connecting event sources (signals)
to event listeners (slots) without adding any boilerplate code usually
associated with the observer or listener design patterns.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index 78562299..3ec86e75 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -6,6 +6,7 @@ libcamera_sources = files([
     'media_device.cpp',
     'media_object.cpp',
     'pipeline_handler.cpp',
+    'signal.cpp',
 ])
 
 libcamera_headers = files([