Add simpler API to retrieve descriptor/characteristic for certain uuid

This new API is mostly syntactic sugar and reduces the amount of code
to be written by API users.

Change-Id: I51ff1ea706ac97199646d211e39e79c8140ee74b
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>

7 files changed, 86 insertions, 42 deletions

diff --git a/examples/bluetooth/heartlistener/heartrate.cpp b/examples/bluetooth/heartlistener/heartrate.cpp
index 996d8a79..f0f4230e 100644
--- a/examples/bluetooth/heartlistener/heartrate.cpp
+++ b/examples/bluetooth/heartlistener/heartrate.cpp
@@ -245,25 +245,21 @@ void HeartRate::serviceStateChanged(QLowEnergyService::ServiceState s)
     switch (s) {
     case QLowEnergyService::ServiceDiscovered:
     {
-        const QList<QLowEnergyCharacteristic> chars = m_service->characteristics();
-        for (int i = 0; i < chars.count(); i++) {
-            const QLowEnergyCharacteristic c = chars[i];
-            if (c.uuid() == QBluetoothUuid(QBluetoothUuid::HeartRateMeasurement)) {
-                const QList<QLowEnergyDescriptor> descriptors = c.descriptors();
-                //enable notification
-                for (int j = 0; j < descriptors.count(); j++) {
-                    const QLowEnergyDescriptor desc = descriptors[j];
-                    if (desc.type() == QBluetoothUuid::ClientCharacteristicConfiguration) {
-                        m_service->writeDescriptor(desc, QByteArray("0100"));
-                        setMessage("Measuring");
-                        m_notificationDesc = desc;
-                        m_start = QDateTime::currentDateTime();
-                        break;
-                    }
-                }
-                break;
-            }
+        const QLowEnergyCharacteristic hrChar = m_service->characteristic(
+                    QBluetoothUuid(QBluetoothUuid::HeartRateMeasurement));
+        if (!hrChar.isValid()) {
+            setMessage("HR Data not found.");
+            break;
+        }
+
+        const QLowEnergyDescriptor m_notificationDesc = hrChar.descriptor(
+                    QBluetoothUuid::ClientCharacteristicConfiguration);
+        if (m_notificationDesc.isValid()) {
+            m_service->writeDescriptor(m_notificationDesc, QByteArray("0100"));
+            setMessage("Measuring");
+            m_start = QDateTime::currentDateTime();
         }
+
         break;
     }
     default:
diff --git a/src/bluetooth/qlowenergycharacteristic.cpp b/src/bluetooth/qlowenergycharacteristic.cpp
index d1c1a14c..bba5b7a0 100644
--- a/src/bluetooth/qlowenergycharacteristic.cpp
+++ b/src/bluetooth/qlowenergycharacteristic.cpp
@@ -275,8 +275,33 @@ QLowEnergyHandle QLowEnergyCharacteristic::attributeHandle() const
     return data->handle;
 }
 
+
+/*!
+    Returns the descriptor with \a uuid; otherwise an invalid \c QLowEnergyDescriptor
+    instance.
+
+    \sa descriptors()
+*/
+QLowEnergyDescriptor QLowEnergyCharacteristic::descriptor(const QBluetoothUuid &uuid) const
+{
+    if (d_ptr.isNull() || !data)
+        return QLowEnergyDescriptor();
+
+    QList<QLowEnergyHandle> descriptorKeys = d_ptr->characteristicList[data->handle].
+                                                    descriptorList.keys();
+    foreach (const QLowEnergyHandle descHandle, descriptorKeys) {
+        if (uuid == d_ptr->characteristicList[data->handle].descriptorList[descHandle].uuid)
+            return QLowEnergyDescriptor(d_ptr, data->handle, descHandle);
+    }
+
+    return QLowEnergyDescriptor();
+}
+
 /*!
-    Returns the list of characteristic descriptors.
+    Returns the list of descriptors belonging to this characteristic; otherwise
+    an empty list.
+
+    \sa descriptor()
 */
 QList<QLowEnergyDescriptor> QLowEnergyCharacteristic::descriptors() const
 {
@@ -291,7 +316,7 @@ QList<QLowEnergyDescriptor> QLowEnergyCharacteristic::descriptors() const
 
     std::sort(descriptorKeys.begin(), descriptorKeys.end());
 
-    foreach (QLowEnergyHandle descHandle, descriptorKeys) {
+    foreach (const QLowEnergyHandle descHandle, descriptorKeys) {
         QLowEnergyDescriptor descriptor(d_ptr, data->handle, descHandle);
         result.append(descriptor);
     }
diff --git a/src/bluetooth/qlowenergycharacteristic.h b/src/bluetooth/qlowenergycharacteristic.h
index 51cb70e6..5ed3dc55 100644
--- a/src/bluetooth/qlowenergycharacteristic.h
+++ b/src/bluetooth/qlowenergycharacteristic.h
@@ -87,7 +87,7 @@ public:
     QLowEnergyCharacteristic::PropertyTypes properties() const;
     QLowEnergyHandle handle() const;
 
-    // TODO: Simplify obtaining descriptor (e.g. via uuid)
+    QLowEnergyDescriptor descriptor(const QBluetoothUuid &uuid) const;
     QList<QLowEnergyDescriptor> descriptors() const;
 
     bool isValid() const;
diff --git a/src/bluetooth/qlowenergyservice.cpp b/src/bluetooth/qlowenergyservice.cpp
index 30fe5733..401468f4 100644
--- a/src/bluetooth/qlowenergyservice.cpp
+++ b/src/bluetooth/qlowenergyservice.cpp
@@ -93,12 +93,35 @@ QLowEnergyService::ServiceState QLowEnergyService::state() const
     return d_ptr->state;
 }
 
-
 QLowEnergyService::ServiceType QLowEnergyService::type() const
 {
     return d_ptr->type;
 }
 
+/*!
+    Returns the matching characteristic for \a uuid; otherwise an invalid
+    characteristic.
+
+    \sa characteristics()
+*/
+QLowEnergyCharacteristic QLowEnergyService::characteristic(const QBluetoothUuid &uuid) const
+{
+    foreach (const QLowEnergyHandle handle, d_ptr->characteristicList.keys()) {
+        if (d_ptr->characteristicList[handle].uuid == uuid)
+            return QLowEnergyCharacteristic(d_ptr, handle);
+    }
+
+    return QLowEnergyCharacteristic();
+}
+
+/*!
+    Returns all characteristics associated with this \c QLowEnergyService instance.
+
+    The returned list will be empty if this service instance is invalid,
+    \l discoverDetails() was not yet called or there are no known characteristics.
+
+    \sa characteristic(), state(), discoverDetails
+*/
 
 QList<QLowEnergyCharacteristic> QLowEnergyService::characteristics() const
 {
diff --git a/src/bluetooth/qlowenergyservice.h b/src/bluetooth/qlowenergyservice.h
index 1250e3a7..fcaf9496 100644
--- a/src/bluetooth/qlowenergyservice.h
+++ b/src/bluetooth/qlowenergyservice.h
@@ -79,7 +79,7 @@ public:
     QLowEnergyService::ServiceType type() const;
     QLowEnergyService::ServiceState state() const;
 
-    // TODO: Simplify obtaining characteristic (e.g. via uuid)
+    QLowEnergyCharacteristic characteristic(const QBluetoothUuid &uuid) const;
     QList<QLowEnergyCharacteristic> characteristics() const;
     QBluetoothUuid serviceUuid() const;
     QString serviceName() const;
diff --git a/tests/auto/qlowenergycharacteristic/tst_qlowenergycharacteristic.cpp b/tests/auto/qlowenergycharacteristic/tst_qlowenergycharacteristic.cpp
index 27c32db9..c6c408b6 100644
--- a/tests/auto/qlowenergycharacteristic/tst_qlowenergycharacteristic.cpp
+++ b/tests/auto/qlowenergycharacteristic/tst_qlowenergycharacteristic.cpp
@@ -188,6 +188,12 @@ void tst_QLowEnergyCharacteristic::tst_constructionDefault()
     QVERIFY(characteristic.handle() == 0);
     QCOMPARE(characteristic.name(), QString());
     QCOMPARE(characteristic.descriptors().count(), 0);
+    QCOMPARE(characteristic.descriptor(QBluetoothUuid()),
+             QLowEnergyDescriptor());
+    QCOMPARE(characteristic.descriptor(QBluetoothUuid(QBluetoothUuid::ClientCharacteristicConfiguration)),
+             QLowEnergyDescriptor());
+    QCOMPARE(characteristic.descriptor(QBluetoothUuid::ClientCharacteristicConfiguration),
+             QLowEnergyDescriptor());
     QCOMPARE(characteristic.properties(), QLowEnergyCharacteristic::Unknown);
 
     QLowEnergyCharacteristic copyConstructed(characteristic);
@@ -244,6 +250,10 @@ void tst_QLowEnergyCharacteristic::tst_assignCompare()
     const QList<QLowEnergyCharacteristic> chars = globalService->characteristics();
     QVERIFY(!chars.isEmpty());
     for (int i = 0; i < chars.count(); i++) {
+        const QLowEnergyCharacteristic specific =
+                globalService->characteristic(chars[i].uuid());
+        QVERIFY(specific.isValid());
+        QCOMPARE(specific, chars[i]);
         if (chars[i].descriptors().count() > 0) {
             indexWithDescriptor = i;
             break;
@@ -290,6 +300,9 @@ void tst_QLowEnergyCharacteristic::tst_assignCompare()
         QCOMPARE(target.descriptors()[i].handle(), ref.handle());
         QCOMPARE(target.descriptors()[i].uuid(), ref.uuid());
         QCOMPARE(target.descriptors()[i].value(), ref.value());
+
+        const QLowEnergyDescriptor ref2 = chars[indexWithDescriptor].descriptor(ref.uuid());
+        QCOMPARE(ref, ref2);
     }
 
     // test copy constructor
diff --git a/tests/auto/qlowenergycontroller/tst_qlowenergycontroller.cpp b/tests/auto/qlowenergycontroller/tst_qlowenergycontroller.cpp
index 1fa8b9bf..bb7bd720 100644
--- a/tests/auto/qlowenergycontroller/tst_qlowenergycontroller.cpp
+++ b/tests/auto/qlowenergycontroller/tst_qlowenergycontroller.cpp
@@ -1648,17 +1648,10 @@ void tst_QLowEnergyController::tst_writeDescriptor()
     // http://processors.wiki.ti.com/index.php/SensorTag_User_Guide
 
     // 1. Find temperature data characteristic
-    const QList<QLowEnergyCharacteristic> chars = service->characteristics();
-    QLowEnergyCharacteristic tempData, tempConfig;
-    foreach (const QLowEnergyCharacteristic &c, chars) {
-        if (c.uuid() ==
-                QBluetoothUuid(QStringLiteral("f000aa01-0451-4000-b000-000000000000"))) {
-            tempData = c;
-        } else if (c.uuid() ==
-                   QBluetoothUuid(QStringLiteral("f000aa02-0451-4000-b000-000000000000"))) {
-            tempConfig = c;
-        }
-    }
+    const QLowEnergyCharacteristic tempData = service->characteristic(
+                QBluetoothUuid(QStringLiteral("f000aa01-0451-4000-b000-000000000000")));
+    const QLowEnergyCharacteristic tempConfig = service->characteristic(
+                QBluetoothUuid(QStringLiteral("f000aa02-0451-4000-b000-000000000000")));
 
     if (!tempData.isValid()) {
         delete service;
@@ -1667,14 +1660,8 @@ void tst_QLowEnergyController::tst_writeDescriptor()
     }
 
     // 2. Find temperature data notification descriptor
-    const QList<QLowEnergyDescriptor> descs = tempData.descriptors();
-    QLowEnergyDescriptor notification;
-    foreach (const QLowEnergyDescriptor &d, descs) {
-        if (d.type() == QBluetoothUuid::ClientCharacteristicConfiguration) {
-            notification = d;
-            break;
-        }
-    }
+    const QLowEnergyDescriptor notification = tempData.descriptor(
+                QBluetoothUuid(QBluetoothUuid::ClientCharacteristicConfiguration));
 
     if (!notification.isValid()) {
         delete service;