Add support for standard function callbacks in NewClosure (including C++11 lambdas).

ext/libclementine-common/core/closure.cpp

@@ -30,6 +30,18 @@ ClosureBase::ClosureBase(ObjectHelper* helper)
 ClosureBase::~ClosureBase() {
 }
 
+CallbackClosure::CallbackClosure(
+    QObject* sender,
+    const char* signal,
+    std::function<void()> callback)
+  : ClosureBase(new ObjectHelper(sender, signal, this)),
+    callback_(callback) {
+}
+
+void CallbackClosure::Invoke() {
+  callback_();
+}
+
 ObjectHelper* ClosureBase::helper() const {
   return helper_;
 }
@@ -52,6 +64,14 @@ void Unpack(QList<QGenericArgument>*) {}
 
 }  // namespace _detail
 
+_detail::ClosureBase* NewClosure(
+    QObject* sender,
+    const char* signal,
+    std::function<void()> callback) {
+  return new _detail::CallbackClosure(
+      sender, signal, callback);
+}
+
 void DoAfter(QObject* receiver, const char* slot, int msec) {
   QTimer::singleShot(msec, receiver, slot);
 }

ext/libclementine-common/core/closure.h

@@ -150,6 +150,19 @@ class SharedClosure : public Closure<Args...> {
   QSharedPointer<T> data_;
 };
 
+class CallbackClosure : public ClosureBase {
+ public:
+  CallbackClosure(
+      QObject* sender,
+      const char* signal,
+      std::function<void()> callback);
+
+  virtual void Invoke();
+
+ private:
+  std::function<void()> callback_;
+};
+
 }  // namespace _detail
 
 template <typename... Args>
@@ -175,6 +188,11 @@ _detail::ClosureBase* NewClosure(
       sender, signal, receiver, slot, args...);
 }
 
+_detail::ClosureBase* NewClosure(
+    QObject* sender,
+    const char* signal,
+    std::function<void()> callback);
+
 
 void DoAfter(QObject* receiver, const char* slot, int msec);
 void DoInAMinuteOrSo(QObject* receiver, const char* slot);

tests/closure_test.cpp

@@ -62,3 +62,14 @@ TEST(ClosureTest, ClosureDoesNotCrashWithSharedPointerSender) {
   ASSERT_EQ(1, spy->count());
   EXPECT_TRUE(closure.isNull());
 }
+
+TEST(ClosureTest, ClosureCallsLambda) {
+  TestQObject sender;
+  bool called = false;
+  _detail::ClosureBase* closure = NewClosure(
+      &sender, SIGNAL(Emitted()),
+      [&called] () { called = true; });
+  EXPECT_FALSE(called);
+  sender.Emit();
+  EXPECT_TRUE(called);
+}