[libcamera-devel] [PATCH 08/14] libcamera: bound_method: Support bindings to non-void methods
Laurent Pinchart
laurent.pinchart at ideasonboard.com
Sat Jan 4 06:09:41 CET 2020
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>
---
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
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