IO/CoreBluetooth - refactor the code a bit

... to simplify future code de-duplication. In this patch we:
- For simplicity move all C++ delegate classes into their
  own header. Since we have to hide Objective-C from C++ compiler
  (while compiling *.cpp files), these updated delegates
  have to use void * instead of Objective-C classes.
- Introduce a new RAII classes, that work with Objective-C
  instances but have a header that can be included into the
  *.cpp files, thus making it possible to share *_p.h files with
  all back-ends.

I'm also switching to a new naming convention, which will later
propagate to the pre-existing code - given files are already in
a sub-directory 'osx', having a prefix 'osxbt' in a name is
excessive. Now it's becoming 'bt' (include "osx/btsomething.h").
Later 'osx' dir is to be renamed into 'darwin', which is what
it is these days. Namespace OSXBluetooth is to become DarwinBluetooth.

Task-number: QTBUG-75348
Change-Id: Iebaeab7d0c5e672efebab8218debdec761353633
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

6 files changed, 474 insertions, 3 deletions

diff --git a/src/bluetooth/osx/btdelegates.cpp b/src/bluetooth/osx/btdelegates.cpp
new file mode 100644
index 00000000..c86516f9
--- /dev/null
+++ b/src/bluetooth/osx/btdelegates.cpp
@@ -0,0 +1,72 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtBluetooth module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "btdelegates_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace DarwinBluetooth {
+
+DeviceInquiryDelegate::~DeviceInquiryDelegate()
+{
+}
+
+PairingDelegate::~PairingDelegate()
+{
+}
+
+SDPInquiryDelegate::~SDPInquiryDelegate()
+{
+}
+
+ChannelDelegate::~ChannelDelegate()
+{
+}
+
+ConnectionMonitor::~ConnectionMonitor()
+{
+}
+
+SocketListener::~SocketListener()
+{
+}
+
+} // namespace DarwinBluetooth
+
+QT_END_NAMESPACE
diff --git a/src/bluetooth/osx/btdelegates_p.h b/src/bluetooth/osx/btdelegates_p.h
new file mode 100644
index 00000000..cb29b87e
--- /dev/null
+++ b/src/bluetooth/osx/btdelegates_p.h
@@ -0,0 +1,155 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtBluetooth module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef BTDELEGATES_P_H
+#define BTDELEGATES_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "qbluetoothdevicediscoveryagent.h"
+#include "qlowenergycontroller.h"
+#include "qbluetooth.h"
+
+#include <QtCore/qsharedpointer.h>
+#include <QtCore/qglobal.h>
+
+#if defined(Q_OS_MACOS) || defined(Q_OS_IOS)
+#include <IOKit/IOReturn.h>
+#endif
+
+#include <cstdint>
+
+QT_BEGIN_NAMESPACE
+
+class QLowEnergyServicePrivate;
+class QBluetoothAddress;
+class QByteArray;
+
+namespace DarwinBluetooth {
+
+#if defined(Q_OS_MACOS)
+
+class DeviceInquiryDelegate
+{
+public:
+    virtual ~DeviceInquiryDelegate();
+
+    virtual void inquiryFinished() = 0;
+    virtual void error(IOReturn error) = 0;
+    virtual void deviceFound(void *ioBluetoothDevice) = 0;
+};
+
+class PairingDelegate
+{
+public:
+    using BluetoothNumericValue = uint32_t;
+    using BluetoothPasskey = BluetoothNumericValue;
+
+    virtual ~PairingDelegate();
+
+    virtual void connecting(void *pair) = 0;
+    virtual void requestPIN(void *pair) = 0;
+    virtual void requestUserConfirmation(void *pair,
+                                         BluetoothNumericValue) = 0;
+    virtual void passkeyNotification(void *pair,
+                                     BluetoothPasskey passkey) = 0;
+    virtual void error(void *pair, IOReturn errorCode) = 0;
+    virtual void pairingFinished(void *pair) = 0;
+};
+
+class SDPInquiryDelegate {
+public:
+    virtual ~SDPInquiryDelegate();
+
+    virtual void SDPInquiryFinished(void *ioBluetoothDevice) = 0;
+    virtual void SDPInquiryError(void *ioBluetoothDevice, IOReturn errorCode) = 0;
+};
+
+// L2CAP and RFCOMM.
+class ChannelDelegate
+{
+public:
+    virtual ~ChannelDelegate();
+
+    virtual void setChannelError(IOReturn errorCode) = 0;
+    virtual void channelOpenComplete() = 0;
+    virtual void channelClosed() = 0;
+
+    virtual void readChannelData(void *data, std::size_t size) = 0;
+    virtual void writeComplete() = 0;
+};
+
+class ConnectionMonitor {
+public:
+    virtual ~ConnectionMonitor();
+
+    virtual void deviceConnected(const QBluetoothAddress &address) = 0;
+    virtual void deviceDisconnected(const QBluetoothAddress &address) = 0;
+};
+
+class SocketListener
+{
+public:
+    virtual ~SocketListener();
+
+    virtual void openNotifyRFCOMM(void *rfcommChannel) = 0;
+    virtual void openNotifyL2CAP(void *l2capChannel) = 0;
+};
+
+#else
+
+#error "This header is only for macOS (Bluetooth Classic only)"
+
+#endif // Q_OS_MACOS
+
+
+} // namespace DarwinBluetooth
+
+QT_END_NAMESPACE
+
+#endif // DARWINBTDELEGATES_P_H
diff --git a/src/bluetooth/osx/btraii.mm b/src/bluetooth/osx/btraii.mm
new file mode 100644
index 00000000..a1bf2a8d
--- /dev/null
+++ b/src/bluetooth/osx/btraii.mm
@@ -0,0 +1,110 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtBluetooth module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "btraii_p.h"
+
+#include <qdebug.h>
+
+#include <Foundation/Foundation.h>
+
+#include <utility>
+
+QT_BEGIN_NAMESPACE
+
+namespace DarwinBluetooth {
+
+StrongReference::StrongReference(void *object, RetainPolicy policy)
+    : objCInstance(object)
+{
+    if (policy == RetainPolicy::doInitialRetain)
+        objCInstance = [getAs<NSObject>() retain];
+}
+
+StrongReference::StrongReference(const StrongReference &other)
+{
+    objCInstance = [other.getAs<NSObject>() retain];
+}
+
+StrongReference::StrongReference(StrongReference &&other)
+{
+    std::swap(objCInstance, other.objCInstance);
+}
+
+StrongReference::~StrongReference()
+{
+    [getAs<NSObject>() release];
+}
+
+StrongReference &StrongReference::operator = (const StrongReference &other) noexcept
+{
+    if (this != &other) {
+        [getAs<NSObject>() release];
+        objCInstance = [other.getAs<NSObject>() retain];
+    }
+
+    return *this;
+}
+
+StrongReference &StrongReference::operator = (StrongReference &&other) noexcept
+{
+    swap(other);
+    return *this;
+}
+
+void StrongReference::reset()
+{
+    [getAs<NSObject>() release];
+    objCInstance = nullptr;
+}
+
+void StrongReference::reset(void *obj, RetainPolicy policy)
+{
+    [getAs<NSObject>() release];
+    objCInstance = obj;
+
+    if (policy == RetainPolicy::doInitialRetain) {
+        auto newInstance = static_cast<NSObject *>(obj);
+        Q_ASSERT(newInstance);
+        objCInstance = [newInstance retain];
+    }
+}
+
+} // namespace DarwinBluetooth
+
+QT_END_NAMESPACE
diff --git a/src/bluetooth/osx/btraii_p.h b/src/bluetooth/osx/btraii_p.h
new file mode 100644
index 00000000..b64defb6
--- /dev/null
+++ b/src/bluetooth/osx/btraii_p.h
@@ -0,0 +1,131 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtBluetooth module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef BTRAII_P_H
+#define BTRAII_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qglobal.h>
+
+#include <utility>
+
+QT_BEGIN_NAMESPACE
+
+namespace DarwinBluetooth {
+
+enum class RetainPolicy
+{
+    noInitialRetain,
+    doInitialRetain
+};
+
+// The class StrongReference and its descendant ScopedGuard
+// are RAII classes dealing with raw pointers to NSObject class
+// and its descendants (and thus hiding Objective-C's retain/
+// release semantics). The header itself is meant to be included
+// into *.cpp files so it's a pure C++ code without any Objective-C
+// syntax. Thus it's a bit clunky - the type information is 'erased'
+// and has to be enforced by the code using these smart pointers.
+// That's because these types are Objective-C classes - thus require
+// Objective-C compiler to work. Member-function template 'getAs' is
+// a convenience shortcut giving the desired pointer type in
+// Objective-C++ files (*.mm).
+
+// TODO: on top of these classes I can build ObjCStrongReference (it's
+// now inside osxbtutils_p.h, a template class that does have type
+// information needed but works only in Objective-C++ environment.
+class StrongReference
+{
+public:
+    StrongReference() = default;
+    StrongReference(void *object, RetainPolicy policy);
+    StrongReference(const StrongReference &other);
+    StrongReference(StrongReference &&other);
+
+    ~StrongReference();
+
+    StrongReference &operator = (const StrongReference &other) noexcept;
+    StrongReference &operator = (StrongReference &&other) noexcept;
+
+    void swap(StrongReference &other) noexcept
+    {
+        std::swap(objCInstance, other.objCInstance);
+    }
+
+    void reset();
+    void reset(void *newInstance, RetainPolicy policy);
+
+    template<class ObjCType>
+    ObjCType *getAs() const
+    {
+        return static_cast<ObjCType *>(objCInstance);
+    }
+
+private:
+    void *objCInstance = nullptr;
+};
+
+class ScopedPointer final : public StrongReference
+{
+public:
+    ScopedPointer() = default;
+    ScopedPointer(void *instance, RetainPolicy policy)
+        : StrongReference(instance, policy)
+    {
+    }
+
+private:
+    Q_DISABLE_COPY_MOVE(ScopedPointer)
+};
+
+} // namespace DarwinBluetooth
+
+QT_END_NAMESPACE
+
+#endif // BTRAII_P_H
diff --git a/src/bluetooth/osx/osxbt.pri b/src/bluetooth/osx/osxbt.pri
index b7ac0535..ae6111ee 100644
--- a/src/bluetooth/osx/osxbt.pri
+++ b/src/bluetooth/osx/osxbt.pri
@@ -21,7 +21,9 @@ CONFIG(osx) {
                        osx/osxbluetooth_p.h \
                        osx/osxbtcentralmanager_p.h \
                        osx/osxbtnotifier_p.h \
-                       osx/osxbtperipheralmanager_p.h
+                       osx/osxbtperipheralmanager_p.h \
+                       osx/btraii_p.h \
+                       osx/btdelegates_p.h
 
     OBJECTIVE_SOURCES += osx/osxbtutility.mm \
                          osx/osxbtdevicepair.mm \
@@ -36,7 +38,9 @@ CONFIG(osx) {
                          osx/osxbtobexsession.mm \
                          osx/osxbtledeviceinquiry.mm \
                          osx/osxbtcentralmanager.mm \
-                         osx/osxbtperipheralmanager.mm
+                         osx/osxbtperipheralmanager.mm \
+                         osx/btraii.mm
+    SOURCES += osx/btdelegates.cpp
 } else {
     PRIVATE_HEADERS += osx/osxbtutility_p.h \
                        osx/osxbtledeviceinquiry_p.h \
diff --git a/src/bluetooth/osx/osxbtnotifier_p.h b/src/bluetooth/osx/osxbtnotifier_p.h
index dca6c268..397214d0 100644
--- a/src/bluetooth/osx/osxbtnotifier_p.h
+++ b/src/bluetooth/osx/osxbtnotifier_p.h
@@ -96,7 +96,6 @@ Q_SIGNALS:
     void CBManagerError(QLowEnergyController::Error error);
     void CBManagerError(const QBluetoothUuid &serviceUuid, QLowEnergyController::Error error);
     void CBManagerError(const QBluetoothUuid &serviceUuid, QLowEnergyService::ServiceError error);
-
 };
 
 }