[libcamera-devel] [PATCH 08/14] libcamera: bound_method: Support bindings to non-void methods
Niklas Söderlund
niklas.soderlund at ragnatech.se
Tue Jan 7 20:15:54 CET 2020
Hi Laurent,
Thanks for your work.
On 2020-01-04 07:09:41 +0200, Laurent Pinchart wrote:
> The bound method implementation is restricted to binding to void methods
> as return values are not supported. This complicates usage of bound
> methods, as non-void methods used a slots or Object::invokeMethod()
> targets need to be wrapped in a void method. Simplify this by supporting
> arbitrary return types and ignoring the return value.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
> ---
> include/libcamera/bound_method.h | 28 ++++++++++++------------
> include/libcamera/object.h | 6 +++---
> include/libcamera/signal.h | 37 +++++++++++++++++---------------
> src/libcamera/signal.cpp | 8 +++----
> 4 files changed, 41 insertions(+), 38 deletions(-)
>
> diff --git a/include/libcamera/bound_method.h b/include/libcamera/bound_method.h
> index d194cd4133bb..b50072ffc098 100644
> --- a/include/libcamera/bound_method.h
> +++ b/include/libcamera/bound_method.h
> @@ -79,7 +79,7 @@ public:
> std::tuple<typename std::remove_reference<Args>::type...> args_;
> };
>
> -template<typename... Args>
> +template<typename R, typename... Args>
> class BoundMethodArgs : public BoundMethodBase
> {
> public:
> @@ -107,19 +107,19 @@ public:
> virtual void invoke(Args... args) = 0;
> };
>
> -template<typename T, typename... Args>
> -class BoundMemberMethod : public BoundMethodArgs<Args...>
> +template<typename T, typename R, typename... Args>
> +class BoundMemberMethod : public BoundMethodArgs<R, Args...>
> {
> public:
> - using PackType = typename BoundMethodArgs<Args...>::PackType;
> + using PackType = typename BoundMethodArgs<R, Args...>::PackType;
>
> - BoundMemberMethod(T *obj, Object *object, void (T::*func)(Args...),
> + BoundMemberMethod(T *obj, Object *object, R (T::*func)(Args...),
> ConnectionType type = ConnectionTypeAuto)
> - : BoundMethodArgs<Args...>(obj, object, type), func_(func)
> + : BoundMethodArgs<R, Args...>(obj, object, type), func_(func)
> {
> }
>
> - bool match(void (T::*func)(Args...)) const { return func == func_; }
> + bool match(R (T::*func)(Args...)) const { return func == func_; }
>
> void activate(Args... args, bool deleteMethod = false) override
> {
> @@ -135,20 +135,20 @@ public:
> }
>
> private:
> - void (T::*func_)(Args...);
> + R (T::*func_)(Args...);
> };
>
> -template<typename... Args>
> -class BoundStaticMethod : public BoundMethodArgs<Args...>
> +template<typename R, typename... Args>
> +class BoundStaticMethod : public BoundMethodArgs<R, Args...>
> {
> public:
> - BoundStaticMethod(void (*func)(Args...))
> - : BoundMethodArgs<Args...>(nullptr, nullptr, ConnectionTypeAuto),
> + BoundStaticMethod(R (*func)(Args...))
> + : BoundMethodArgs<R, Args...>(nullptr, nullptr, ConnectionTypeAuto),
> func_(func)
> {
> }
>
> - bool match(void (*func)(Args...)) const { return func == func_; }
> + bool match(R (*func)(Args...)) const { return func == func_; }
>
> void activate(Args... args, bool deleteMethod = false) override
> {
> @@ -158,7 +158,7 @@ public:
> void invoke(Args...) override {}
>
> private:
> - void (*func_)(Args...);
> + R (*func_)(Args...);
> };
>
> } /* namespace libcamera */
> diff --git a/include/libcamera/object.h b/include/libcamera/object.h
> index c45165dec8ef..586c2cf6fc70 100644
> --- a/include/libcamera/object.h
> +++ b/include/libcamera/object.h
> @@ -29,13 +29,13 @@ public:
>
> void postMessage(std::unique_ptr<Message> msg);
>
> - template<typename T, typename... FuncArgs, typename... Args,
> + template<typename T, typename R, typename... FuncArgs, typename... Args,
> typename std::enable_if<std::is_base_of<Object, T>::value>::type * = nullptr>
> - void invokeMethod(void (T::*func)(FuncArgs...), ConnectionType type,
> + void invokeMethod(R (T::*func)(FuncArgs...), ConnectionType type,
> Args... args)
> {
> T *obj = static_cast<T *>(this);
> - auto *method = new BoundMemberMethod<T, FuncArgs...>(obj, this, func, type);
> + auto *method = new BoundMemberMethod<T, R, FuncArgs...>(obj, this, func, type);
> method->activate(args..., true);
> }
>
> diff --git a/include/libcamera/signal.h b/include/libcamera/signal.h
> index 57598335932c..7fbe5a2c528f 100644
> --- a/include/libcamera/signal.h
> +++ b/include/libcamera/signal.h
> @@ -54,27 +54,28 @@ public:
> }
>
> #ifndef __DOXYGEN__
> - template<typename T, typename std::enable_if<std::is_base_of<Object, T>::value>::type * = nullptr>
> - void connect(T *obj, void (T::*func)(Args...),
> + template<typename T, typename R, typename std::enable_if<std::is_base_of<Object, T>::value>::type * = nullptr>
> + void connect(T *obj, R (T::*func)(Args...),
> ConnectionType type = ConnectionTypeAuto)
> {
> Object *object = static_cast<Object *>(obj);
> object->connect(this);
> - slots_.push_back(new BoundMemberMethod<T, Args...>(obj, object, func, type));
> + slots_.push_back(new BoundMemberMethod<T, void, Args...>(obj, object, func, type));
> }
>
> - template<typename T, typename std::enable_if<!std::is_base_of<Object, T>::value>::type * = nullptr>
> + template<typename T, typename R, typename std::enable_if<!std::is_base_of<Object, T>::value>::type * = nullptr>
> #else
> - template<typename T>
> + template<typename T, typename R>
> #endif
> - void connect(T *obj, void (T::*func)(Args...))
> + void connect(T *obj, R (T::*func)(Args...))
> {
> - slots_.push_back(new BoundMemberMethod<T, Args...>(obj, nullptr, func));
> + slots_.push_back(new BoundMemberMethod<T, R, Args...>(obj, nullptr, func));
> }
>
> - void connect(void (*func)(Args...))
> + template<typename R>
> + void connect(R (*func)(Args...))
> {
> - slots_.push_back(new BoundStaticMethod<Args...>(func));
> + slots_.push_back(new BoundStaticMethod<R, Args...>(func));
> }
>
> void disconnect()
> @@ -90,11 +91,12 @@ public:
> SignalBase::disconnect(obj);
> }
>
> - template<typename T>
> - void disconnect(T *obj, void (T::*func)(Args...))
> + template<typename T, typename R>
> + void disconnect(T *obj, R (T::*func)(Args...))
> {
> for (auto iter = slots_.begin(); iter != slots_.end(); ) {
> - BoundMethodArgs<Args...> *slot = static_cast<BoundMethodArgs<Args...> *>(*iter);
> + BoundMethodArgs<R, Args...> *slot =
> + static_cast<BoundMethodArgs<R, Args...> *>(*iter);
> /*
> * If the object matches the slot, the slot is
> * guaranteed to be a member slot, so we can safely
> @@ -102,7 +104,7 @@ public:
> * func.
> */
> if (slot->match(obj) &&
> - static_cast<BoundMemberMethod<T, Args...> *>(slot)->match(func)) {
> + static_cast<BoundMemberMethod<T, R, Args...> *>(slot)->match(func)) {
> iter = slots_.erase(iter);
> delete slot;
> } else {
> @@ -111,12 +113,13 @@ public:
> }
> }
>
> - void disconnect(void (*func)(Args...))
> + template<typename R>
> + void disconnect(R (*func)(Args...))
> {
> for (auto iter = slots_.begin(); iter != slots_.end(); ) {
> - BoundMethodArgs<Args...> *slot = *iter;
> + BoundMethodArgs<R, Args...> *slot = *iter;
> if (slot->match(nullptr) &&
> - static_cast<BoundStaticMethod<Args...> *>(slot)->match(func)) {
> + static_cast<BoundStaticMethod<R, Args...> *>(slot)->match(func)) {
> iter = slots_.erase(iter);
> delete slot;
> } else {
> @@ -133,7 +136,7 @@ public:
> */
> std::vector<BoundMethodBase *> slots{ slots_.begin(), slots_.end() };
> for (BoundMethodBase *slot : slots)
> - static_cast<BoundMethodArgs<Args...> *>(slot)->activate(args...);
> + static_cast<BoundMethodArgs<void, Args...> *>(slot)->activate(args...);
> }
> };
>
> diff --git a/src/libcamera/signal.cpp b/src/libcamera/signal.cpp
> index 6ee348acc8d4..190033317c72 100644
> --- a/src/libcamera/signal.cpp
> +++ b/src/libcamera/signal.cpp
> @@ -54,7 +54,7 @@ namespace libcamera {
> */
>
> /**
> - * \fn Signal::connect(T *object, void(T::*func)(Args...))
> + * \fn Signal::connect(T *object, R (T::*func)(Args...))
> * \brief Connect the signal to a member function slot
> * \param[in] object The slot object pointer
> * \param[in] func The slot member function
> @@ -66,7 +66,7 @@ namespace libcamera {
> */
>
> /**
> - * \fn Signal::connect(void(*func)(Args...))
> + * \fn Signal::connect(R (*func)(Args...))
> * \brief Connect the signal to a static function slot
> * \param[in] func The slot static function
> */
> @@ -83,14 +83,14 @@ namespace libcamera {
> */
>
> /**
> - * \fn Signal::disconnect(T *object, void(T::*func)(Args...))
> + * \fn Signal::disconnect(T *object, R (T::*func)(Args...))
> * \brief Disconnect the signal from the \a object slot member function \a func
> * \param[in] object The object pointer whose slots to disconnect
> * \param[in] func The slot member function to disconnect
> */
>
> /**
> - * \fn Signal::disconnect(void(*func)(Args...))
> + * \fn Signal::disconnect(R (*func)(Args...))
> * \brief Disconnect the signal from the slot static function \a func
> * \param[in] func The slot static function to disconnect
> */
> --
> Regards,
>
> Laurent Pinchart
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel at lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
--
Regards,
Niklas Söderlund
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