From e1d77e0124b6b2504c6740d432fae76639e0af25 Mon Sep 17 00:00:00 2001
From: John Maguire <john.maguire@gmail.com>
Date: Mon, 19 Mar 2012 19:36:52 +0100
Subject: [PATCH] Add support for QSharedPointer in Closure.

---
 ext/libclementine-common/core/closure.cpp |  3 ++
 ext/libclementine-common/core/closure.h   | 53 +++++++++++++++++++++++
 tests/closure_test.cpp                    | 27 ++++++++++++
 3 files changed, 83 insertions(+)

diff --git a/ext/libclementine-common/core/closure.cpp b/ext/libclementine-common/core/closure.cpp
index 0688903de..f8e51274d 100644
--- a/ext/libclementine-common/core/closure.cpp
+++ b/ext/libclementine-common/core/closure.cpp
@@ -50,6 +50,9 @@ Closure::Closure(QObject* sender,
   Connect(sender, signal);
 }
 
+Closure::~Closure() {
+}
+
 void Closure::Connect(QObject* sender, const char* signal) {
   bool success = connect(sender, signal, SLOT(Invoked()));
   Q_ASSERT(success);
diff --git a/ext/libclementine-common/core/closure.h b/ext/libclementine-common/core/closure.h
index 6f9c3626f..319155ba4 100644
--- a/ext/libclementine-common/core/closure.h
+++ b/ext/libclementine-common/core/closure.h
@@ -22,6 +22,7 @@
 
 #include <QMetaMethod>
 #include <QObject>
+#include <QSharedPointer>
 
 #include <boost/noncopyable.hpp>
 #include <boost/scoped_ptr.hpp>
@@ -62,6 +63,8 @@ class Closure : public QObject, boost::noncopyable {
   Closure(QObject* sender, const char* signal,
           std::tr1::function<void()> callback);
 
+  virtual ~Closure();
+
  private slots:
   void Invoked();
   void Cleanup();
@@ -78,6 +81,46 @@ class Closure : public QObject, boost::noncopyable {
   boost::scoped_ptr<const ClosureArgumentWrapper> val3_;
 };
 
+class SharedPointerWrapper {
+ public:
+  virtual ~SharedPointerWrapper() {}
+  virtual void* data() const = 0;
+};
+
+template<typename T>
+class SharedPointer : public SharedPointerWrapper {
+ public:
+  SharedPointer(QSharedPointer<T> ptr)
+      : ptr_(ptr) {
+  }
+  void* data() const {
+    return ptr_.data();
+  }
+ private:
+  QSharedPointer<T> ptr_;
+};
+
+// For use with a QSharedPointer as a sender.
+class SharedClosure : public Closure {
+  Q_OBJECT
+
+ public:
+  SharedClosure(SharedPointerWrapper* sender, const char* signal,
+                QObject* receiver, const char* slot,
+                const ClosureArgumentWrapper* val0 = 0,
+                const ClosureArgumentWrapper* val1 = 0,
+                const ClosureArgumentWrapper* val2 = 0,
+                const ClosureArgumentWrapper* val3 = 0)
+      : Closure(reinterpret_cast<QObject*>(sender->data()), signal,
+                receiver, slot,
+                val0, val1, val2, val3),
+        shared_sender_(sender) {
+  }
+
+ private:
+  boost::scoped_ptr<SharedPointerWrapper> shared_sender_;
+};
+
 #define C_ARG(type, data) new ClosureArgument<type>(data)
 
 Closure* NewClosure(
@@ -86,6 +129,16 @@ Closure* NewClosure(
     QObject* receiver,
     const char* slot);
 
+template <typename T>
+Closure* NewClosure(
+    QSharedPointer<T> sender,
+    const char* signal,
+    QObject* receiver,
+    const char* slot) {
+  Q_ASSERT(sender.data()->metaObject());  // Static check for something QObject-like.
+  return new SharedClosure(new SharedPointer<T>(sender), signal, receiver, slot);
+}
+
 template <typename T>
 Closure* NewClosure(
     QObject* sender,
diff --git a/tests/closure_test.cpp b/tests/closure_test.cpp
index 80e3bf8e7..2cb3abb1d 100644
--- a/tests/closure_test.cpp
+++ b/tests/closure_test.cpp
@@ -1,6 +1,8 @@
 #include "gtest/gtest.h"
 
 #include <QCoreApplication>
+#include <QPointer>
+#include <QSharedPointer>
 #include <QSignalSpy>
 
 #include "core/closure.h"
@@ -38,3 +40,28 @@ TEST_F(ClosureTest, ClosureDeletesSelf) {
   loop.exec();
   EXPECT_EQ(1, spy.count());
 }
+
+TEST_F(ClosureTest, ClosureDoesNotCrashWithSharedPointerSender) {
+  TestQObject receiver;
+  TestQObject* sender;
+  boost::scoped_ptr<QSignalSpy> spy;
+  QPointer<Closure> closure;
+  {
+    QSharedPointer<TestQObject> sender_shared(new TestQObject);
+    sender = sender_shared.data();
+    closure = QPointer<Closure>(NewClosure(
+        sender_shared, SIGNAL(Emitted()),
+        &receiver, SLOT(Invoke())));
+    spy.reset(new QSignalSpy(sender, SIGNAL(destroyed())));
+  }
+  EXPECT_EQ(0, receiver.invoked());
+  sender->Emit();
+  EXPECT_EQ(1, receiver.invoked());
+
+  EXPECT_EQ(0, spy->count());
+  QEventLoop loop;
+  QObject::connect(sender, SIGNAL(destroyed()), &loop, SLOT(quit()));
+  loop.exec();
+  EXPECT_EQ(1, spy->count());
+  EXPECT_TRUE(closure.isNull());
+}