Provide a way to define GAP/GATT services for central roles

Some devices require the Generic Access (GAP) and Generic Attribute (GATT)
services to be defined. Otherwise they refuse a proper interaction.
This is done implicitly by Android and BlueZ. The reason why BlueZ does
not do this for QtBluetooth is because QtBluetooth sets up its own GATT
infrastructure.

Normally a QLEController in central role cannot do that via public API
as the QLEController::addService() function blocks on peripheral use
cases. This patch sets the profiles up.

In the future the feature really requires a better form of API
(beyond the above env variable) or should be enabled by default
but since we need this earlier than Qt 5.10 a more subtle
approach was chosen. For now the feature can
only be enabled if the QT_DEFAULT_CENTRAL_SERVICES was set.

Another limitation is that the characteristics of the added services
are completely static.

Task-number: QTBUG-61554
Change-Id: Id03bddb2e54cc4f0869838e13ddf281311ad3a26
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

1 files changed, 24 insertions, 13 deletions

diff --git a/src/bluetooth/qlowenergycontroller.cpp b/src/bluetooth/qlowenergycontroller.cpp
index 2337268d..053ca980 100644
--- a/src/bluetooth/qlowenergycontroller.cpp
+++ b/src/bluetooth/qlowenergycontroller.cpp
@@ -931,13 +931,24 @@ QLowEnergyService *QLowEnergyController::addService(const QLowEnergyServiceData
         return nullptr;
     }
 
+    Q_D(QLowEnergyController);
+    QLowEnergyService *newService = d->addServiceHelper(service);
+    if (newService)
+        newService->setParent(parent);
+
+    return newService;
+}
+
+QLowEnergyService *QLowEnergyControllerPrivate::addServiceHelper(
+                            const QLowEnergyServiceData &service)
+{
     // Spec says services "should" be grouped by uuid length (16-bit first, then 128-bit).
     // Since this is not mandatory, we ignore it here and let the caller take responsibility
     // for it.
 
     const auto servicePrivate = QSharedPointer<QLowEnergyServicePrivate>::create();
     servicePrivate->state = QLowEnergyService::LocalService;
-    servicePrivate->setController(d_ptr);
+    servicePrivate->setController(this);
     servicePrivate->uuid = service.uuid();
     servicePrivate->type = service.type() == QLowEnergyServiceData::ServiceTypePrimary
             ? QLowEnergyService::PrimaryService : QLowEnergyService::IncludedService;
@@ -947,13 +958,13 @@ QLowEnergyService *QLowEnergyController::addService(const QLowEnergyServiceData
     }
 
     // Spec v4.2, Vol 3, Part G, Section 3.
-    const QLowEnergyHandle oldLastHandle = d_ptr->lastLocalHandle;
-    servicePrivate->startHandle = ++d_ptr->lastLocalHandle; // Service declaration.
-    d_ptr->lastLocalHandle += servicePrivate->includedServices.count(); // Include declarations.
+    const QLowEnergyHandle oldLastHandle = this->lastLocalHandle;
+    servicePrivate->startHandle = ++this->lastLocalHandle; // Service declaration.
+    this->lastLocalHandle += servicePrivate->includedServices.count(); // Include declarations.
     foreach (const QLowEnergyCharacteristicData &cd, service.characteristics()) {
-        const QLowEnergyHandle declHandle = ++d_ptr->lastLocalHandle;
+        const QLowEnergyHandle declHandle = ++this->lastLocalHandle;
         QLowEnergyServicePrivate::CharData charData;
-        charData.valueHandle = ++d_ptr->lastLocalHandle;
+        charData.valueHandle = ++this->lastLocalHandle;
         charData.uuid = cd.uuid();
         charData.properties = cd.properties();
         charData.value = cd.value();
@@ -961,21 +972,21 @@ QLowEnergyService *QLowEnergyController::addService(const QLowEnergyServiceData
             QLowEnergyServicePrivate::DescData descData;
             descData.uuid = dd.uuid();
             descData.value = dd.value();
-            charData.descriptorList.insert(++d_ptr->lastLocalHandle, descData);
+            charData.descriptorList.insert(++this->lastLocalHandle, descData);
         }
         servicePrivate->characteristicList.insert(declHandle, charData);
     }
-    servicePrivate->endHandle = d_ptr->lastLocalHandle;
-    const bool handleOverflow = d_ptr->lastLocalHandle <= oldLastHandle;
+    servicePrivate->endHandle = this->lastLocalHandle;
+    const bool handleOverflow = this->lastLocalHandle <= oldLastHandle;
     if (handleOverflow) {
         qCWarning(QT_BT) << "Not enough attribute handles left to create this service";
-        d_ptr->lastLocalHandle = oldLastHandle;
+        this->lastLocalHandle = oldLastHandle;
         return nullptr;
     }
 
-    d_ptr->localServices.insert(servicePrivate->uuid, servicePrivate);
-    d_ptr->addToGenericAttributeList(service, servicePrivate->startHandle);
-    return new QLowEnergyService(servicePrivate, parent);
+    this->localServices.insert(servicePrivate->uuid, servicePrivate);
+    this->addToGenericAttributeList(service, servicePrivate->startHandle);
+    return new QLowEnergyService(servicePrivate);
 }
 
 /*!