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author | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2021-08-27 04:05:33 +0300 |
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committer | Laurent Pinchart <laurent.pinchart@ideasonboard.com> | 2021-09-02 01:16:45 +0300 |
commit | 58720e1dc98186e79ef4e758a851b58df562f7b4 (patch) | |
tree | 00c8b9701e937dd1d7a47937bf1792cd623ef834 /src | |
parent | c4e2b00d51f150632b203f81866604168d2ac1ff (diff) |
libcamera: base: signal: Support connecting signals to functors
It can be useful to connect a signal to a functor, and in particular a
lambda function, while still operating in the context of a receiver
object (to support both object-based disconnection and queued
connections to Object instances).
Add a BoundMethodFunctor class to bind a functor, and a corresponding
Signal::connect() function. There is no corresponding disconnect()
function, as a lambda passed to connect() can't be later passed to
disconnect(). Disconnection typically uses disconnect(T *object), which
will cover the vast majority of use cases.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Diffstat (limited to 'src')
-rw-r--r-- | src/libcamera/base/signal.cpp | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/libcamera/base/signal.cpp b/src/libcamera/base/signal.cpp index adcfa796..9c2319c5 100644 --- a/src/libcamera/base/signal.cpp +++ b/src/libcamera/base/signal.cpp @@ -122,6 +122,30 @@ SignalBase::SlotList SignalBase::slots() */ /** + * \fn Signal::connect(T *object, Func func) + * \brief Connect the signal to a function object slot + * \param[in] object The slot object pointer + * \param[in] func The function object + * + * If the typename T inherits from Object, the signal will be automatically + * disconnected from the \a func slot of \a object when \a object is destroyed. + * Otherwise the caller shall disconnect signals manually before destroying \a + * object. + * + * The function object is typically a lambda function, but may be any object + * that satisfies the FunctionObject named requirements. The types of the + * function object arguments shall match the types of the signal arguments. + * + * No matching disconnect() function exist, as it wouldn't be possible to pass + * to a disconnect() function the same lambda that was passed to connect(). The + * connection created by this function can not be removed selectively if the + * signal is connected to multiple slots of the same receiver, but may be + * otherwise be removed using the disconnect(T *object) function. + * + * \context This function is \threadsafe. + */ + +/** * \fn Signal::connect(R (*func)(Args...)) * \brief Connect the signal to a static function slot * \param[in] func The slot static function |