bluetooth: Update BluetoothCharacteristic.value on readValue

third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp

Index: third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp
diff --git a/third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp b/third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp
index 23250910ad7f10a724d3c1e995096e85b6832766..b95ffe58e885ffbbdf4fed422c0b3acd56b4f280 100644
--- a/third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp
+++ b/third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp
@@ -13,7 +13,6 @@
 #include "modules/bluetooth/BluetoothCharacteristicProperties.h"
 #include "modules/bluetooth/BluetoothError.h"
 #include "modules/bluetooth/BluetoothSupplement.h"
-#include "modules/bluetooth/ConvertWebVectorToArrayBuffer.h"
 #include "public/platform/modules/bluetooth/WebBluetooth.h"
 
 namespace blink {
@@ -39,12 +38,18 @@ BluetoothGATTCharacteristic* BluetoothGATTCharacteristic::take(ScriptPromiseReso
     return characteristic;
 }
 
-void BluetoothGATTCharacteristic::dispatchCharacteristicValueChanged(
+void BluetoothGATTCharacteristic::setValue(
     const WebVector<uint8_t>& value)
 {
     static_assert(sizeof(*value.data()) == 1, "uint8_t should be a single byte");
 
     m_value = DOMArrayBuffer::create(value.data(), value.size());
+}
+
+void BluetoothGATTCharacteristic::dispatchCharacteristicValueChanged(
+    const WebVector<uint8_t>& value)
+{
+    setValue(value);
 
     dispatchEvent(Event::create(EventTypeNames::characteristicvaluechanged));
 }
@@ -89,13 +94,39 @@ bool BluetoothGATTCharacteristic::addEventListenerInternal(const AtomicString& e
     return EventTarget::addEventListenerInternal(eventType, listener, options);
 }
 
+
+class ReadValueCallback : public WebBluetoothReadValueCallbacks {
+public:
+    ReadValueCallback(BluetoothGATTCharacteristic* characteristic, ScriptPromiseResolver* resolver) : m_webCharacteristic(characteristic), m_resolver(resolver) {}
+
+    void onSuccess(const WebVector<uint8_t>& value) override
+    {
+        if (!m_resolver->executionContext() || m_resolver->executionContext()->activeDOMObjectsAreStopped())
+            return;
+
+        m_webCharacteristic->setValue(value);
+        m_resolver->resolve(m_webCharacteristic->value());
+    }
+
+    void onError(const WebBluetoothError& e) override
+    {
+        if (!m_resolver->executionContext() || m_resolver->executionContext()->activeDOMObjectsAreStopped())
+            return;
+        m_resolver->reject(BluetoothError::take(m_resolver, e));
+    }
+
+private:
+    Persistent<BluetoothGATTCharacteristic> m_webCharacteristic;

[ortuno, 2016/01/13 21:14:09]

Talked to jyasskin about this. We don't need to keep an object alive longer than
necessary so we should use WeakPersistent instead. That would mean you need to
add a null check before resolving the promise:

RefPtr<DOMArrayBuffer> domBuffer = ConvertWebVectorToArrayBuffer(value);
if (m_webCharacteristic != nullptr) {
    m_webCharacteristic->setValue(domBuffer);
}
m_resolver->resolve(domBuffer);

+    Persistent<ScriptPromiseResolver> m_resolver;
+};
+
 ScriptPromise BluetoothGATTCharacteristic::readValue(ScriptState* scriptState)
 {
     WebBluetooth* webbluetooth = BluetoothSupplement::fromScriptState(scriptState);
 
     ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
-    webbluetooth->readValue(m_webCharacteristic->characteristicInstanceID, new CallbackPromiseAdapter<ConvertWebVectorToArrayBuffer, BluetoothError>(resolver));
+    webbluetooth->readValue(m_webCharacteristic->characteristicInstanceID, new ReadValueCallback(this, resolver));
 
     return promise;
 }