bluetooth: Add characteristicvaluechanged event

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 fa4b8b6581ab760ffa7131cab4118991f958868c..16a629b7e33362b1c11a8f62d432a3c239f1c70f 100644
--- a/third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp
+++ b/third_party/WebKit/Source/modules/bluetooth/BluetoothGATTCharacteristic.cpp
@@ -10,6 +10,7 @@
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/DOMException.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/events/Event.h"
 #include "modules/bluetooth/BluetoothError.h"
 #include "modules/bluetooth/BluetoothSupplement.h"
 #include "modules/bluetooth/ConvertWebVectorToArrayBuffer.h"
@@ -37,6 +38,16 @@ BluetoothGATTCharacteristic* BluetoothGATTCharacteristic::take(ScriptPromiseReso
     return characteristic;
 }
 
+void BluetoothGATTCharacteristic::dispatchCharacteristicValueChanged(
+    const WebVector<uint8_t>& value)
+{
+    static_assert(sizeof(*value.data()) == 1, "uint8_t should be a single byte");

[palmer, 2015/10/19 19:23:33]

This doesn't necessarily mean what you think it means. See
http://en.cppreference.com/w/cpp/language/sizeof:

"""Depending on the computer architecture, a byte may consist of 8 or more bits,
the exact number being recorded in CHAR_BIT."""

[ortuno, 2015/10/19 20:09:18]

That assert is there to make sure that the byteLength of the vector's data is
equal to the number of elements or value.size(). This is because we pass
value.size() as byteLength to DOMArrayBuffer::create():

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

+
+    m_value = DOMArrayBuffer::create(value.data(), value.size());
+
+    dispatchEvent(Event::create(EventTypeNames::characteristicvaluechanged));
+}
+
 void BluetoothGATTCharacteristic::stop()
 {
     notifyCharacteristicObjectRemoved();
@@ -56,6 +67,27 @@ void BluetoothGATTCharacteristic::notifyCharacteristicObjectRemoved()
     }
 }
 
+const WTF::AtomicString& BluetoothGATTCharacteristic::interfaceName() const
+{
+    return EventTargetNames::BluetoothGATTCharacteristic;
+}
+
+ExecutionContext* BluetoothGATTCharacteristic::executionContext() const
+{
+    return ActiveDOMObject::executionContext();
+}
+
+bool BluetoothGATTCharacteristic::addEventListener(const AtomicString& eventType, PassRefPtrWillBeRawPtr<EventListener> listener, bool useCapture)
+{
+    // We will also need to unregister a characteristic once all the event
+    // listeners have been removed. See http://crbug.com/541390
+    if (eventType == EventTypeNames::characteristicvaluechanged) {
+        WebBluetooth* webbluetooth = BluetoothSupplement::fromExecutionContext(executionContext());
+        webbluetooth->registerCharacteristicObject(m_webCharacteristic->characteristicInstanceID, this);
+    }
+    return EventTarget::addEventListener(eventType, listener, useCapture);
+}
+
 ScriptPromise BluetoothGATTCharacteristic::readValue(ScriptState* scriptState)
 {
     WebBluetooth* webbluetooth = BluetoothSupplement::fromScriptState(scriptState);
@@ -109,6 +141,7 @@ ScriptPromise BluetoothGATTCharacteristic::stopNotifications(ScriptState* script
 
 DEFINE_TRACE(BluetoothGATTCharacteristic)
 {
+    RefCountedGarbageCollectedEventTargetWithInlineData<BluetoothGATTCharacteristic>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }