Implement WebBluetooth getDescriptor[s]

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

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "modules/bluetooth/BluetoothRemoteGATTDescriptor.h"
+
+#include "bindings/core/v8/CallbackPromiseAdapter.h"
+#include "bindings/core/v8/ScriptPromise.h"
+#include "bindings/core/v8/ScriptPromiseResolver.h"
+#include "core/dom/DOMDataView.h"
+#include "core/dom/DOMException.h"
+#include "core/dom/ExceptionCode.h"
+#include "core/events/Event.h"
+#include "core/inspector/ConsoleMessage.h"
+#include "modules/bluetooth/BluetoothError.h"
+#include "modules/bluetooth/BluetoothRemoteGATTService.h"
+#include "modules/bluetooth/BluetoothSupplement.h"
+#include "public/platform/modules/bluetooth/WebBluetooth.h"
+#include <memory>
+
+namespace blink {
+
+namespace {
+
+// TODO dft move to some utility!
+
+const char kGATTServerDisconnected[] =
+    "GATT Server disconnected while performing a GATT operation.";
+const char kGATTServerNotConnected[] =
+    "GATT Server is disconnected. Cannot perform GATT operations.";
+
+DOMDataView* ConvertWebVectorToDataView(const WebVector<uint8_t>& webVector) {
+  static_assert(sizeof(*webVector.data()) == 1,
+                "uint8_t should be a single byte");
+  DOMArrayBuffer* domBuffer =
+      DOMArrayBuffer::create(webVector.data(), webVector.size());
+  return DOMDataView::create(domBuffer, 0, webVector.size());
+}
+
+}  // anonymous namespace
+
+BluetoothRemoteGATTDescriptor::BluetoothRemoteGATTDescriptor(
+    ExecutionContext* context,
+    std::unique_ptr<WebBluetoothRemoteGATTDescriptorInit> webDescriptor,
+    BluetoothRemoteGATTService* service)
+    : ActiveDOMObject(context),
+      m_webDescriptor(std::move(webDescriptor)),
+      m_service(service),
+      m_stopped(false) {
+  // See example in Source/platform/heap/ThreadState.h
+  ThreadState::current()->registerPreFinalizer(this);
+}
+
+BluetoothRemoteGATTDescriptor* BluetoothRemoteGATTDescriptor::take(
+    ScriptPromiseResolver* resolver,
+    std::unique_ptr<WebBluetoothRemoteGATTDescriptorInit> webDescriptor,
+    BluetoothRemoteGATTService* service) {
+  if (!webDescriptor) {
+    return nullptr;
+  }
+  BluetoothRemoteGATTDescriptor* descriptor = new BluetoothRemoteGATTDescriptor(
+      resolver->getExecutionContext(), std::move(webDescriptor), service);
+  // See note in ActiveDOMObject about suspendIfNeeded.
+  descriptor->suspendIfNeeded();
+  return descriptor;
+}
+
+void BluetoothRemoteGATTDescriptor::setValue(DOMDataView* domDataView) {
+  m_value = domDataView;
+}
+
+void BluetoothRemoteGATTDescriptor::dispatchDescriptorValueChanged(
+    const WebVector<uint8_t>& value) {
+  this->setValue(ConvertWebVectorToDataView(value));
+  dispatchEvent(Event::create(EventTypeNames::descriptorvaluechanged));
+}
+
+void BluetoothRemoteGATTDescriptor::contextDestroyed() {
+  notifyDescriptorObjectRemoved();
+}
+
+void BluetoothRemoteGATTDescriptor::dispose() {
+  notifyDescriptorObjectRemoved();
+}
+
+void BluetoothRemoteGATTDescriptor::notifyDescriptorObjectRemoved() {
+  if (!m_stopped) {
+    m_stopped = true;
+    WebBluetooth* webbluetooth = BluetoothSupplement::fromExecutionContext(
+        ActiveDOMObject::getExecutionContext());
+    webbluetooth->descriptorObjectRemoved(m_webDescriptor->descriptorInstanceID,
+                                          this);
+  }
+}
+
+const WTF::AtomicString& BluetoothRemoteGATTDescriptor::interfaceName() const {
+  return EventTargetNames::BluetoothRemoteGATTDescriptor;
+}
+
+ExecutionContext* BluetoothRemoteGATTDescriptor::getExecutionContext() const {
+  return ActiveDOMObject::getExecutionContext();
+}
+
+void BluetoothRemoteGATTDescriptor::addedEventListener(
+    const AtomicString& eventType,
+    RegisteredEventListener& registeredListener) {
+  EventTargetWithInlineData::addedEventListener(eventType, registeredListener);
+  // We will also need to unregister a descriptor once all the event
+  // listeners have been removed. See http://crbug.com/541390
+  if (eventType == EventTypeNames::descriptorvaluechanged) {
+    WebBluetooth* webbluetooth =
+        BluetoothSupplement::fromExecutionContext(getExecutionContext());
+    webbluetooth->registerDescriptorObject(
+        m_webDescriptor->descriptorInstanceID, this);
+  }
+}
+
+// TODO dft -- can we move out into a utility
+class ReadValueCallback : public WebBluetoothReadValueCallbacks {
+ public:
+  ReadValueCallback(BluetoothRemoteGATTDescriptor* descriptor,
+                    ScriptPromiseResolver* resolver)
+      : m_descriptor(descriptor), m_resolver(resolver) {
+    // We always check that the device is connected before constructing this
+    // object.
+    CHECK(m_descriptor->gatt()->connected());
+    m_descriptor->gatt()->AddToActiveAlgorithms(m_resolver.get());
+  }
+
+  void onSuccess(const WebVector<uint8_t>& value) override {
+    if (!m_resolver->getExecutionContext() ||
+        m_resolver->getExecutionContext()->activeDOMObjectsAreStopped())
+      return;
+
+    if (!m_descriptor->gatt()->RemoveFromActiveAlgorithms(m_resolver.get())) {
+      m_resolver->reject(
+          DOMException::create(NetworkError, kGATTServerDisconnected));
+      return;
+    }
+
+    DOMDataView* domDataView = ConvertWebVectorToDataView(value);
+    if (m_descriptor)
+      m_descriptor->setValue(domDataView);
+
+    m_resolver->resolve(domDataView);
+  }
+
+  void onError(
+      int32_t
+          error /* Corresponds to WebBluetoothResult in web_bluetooth.mojom */)
+      override {
+    if (!m_resolver->getExecutionContext() ||
+        m_resolver->getExecutionContext()->activeDOMObjectsAreStopped())
+      return;
+
+    if (!m_descriptor->gatt()->RemoveFromActiveAlgorithms(m_resolver.get())) {
+      m_resolver->reject(
+          DOMException::create(NetworkError, kGATTServerDisconnected));
+      return;
+    }
+
+    m_resolver->reject(BluetoothError::take(m_resolver, error));
+  }
+
+ private:
+  WeakPersistent<BluetoothRemoteGATTDescriptor> m_descriptor;
+  Persistent<ScriptPromiseResolver> m_resolver;
+};
+
+ScriptPromise BluetoothRemoteGATTDescriptor::readValue(
+    ScriptState* scriptState) {
+  if (!gatt()->connected()) {
+    return ScriptPromise::rejectWithDOMException(
+        scriptState,
+        DOMException::create(NetworkError, kGATTServerNotConnected));
+  }
+
+  WebBluetooth* webbluetooth =
+      BluetoothSupplement::fromScriptState(scriptState);
+
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+  ScriptPromise promise = resolver->promise();
+
+  webbluetooth->descriptorReadValue(m_webDescriptor->descriptorInstanceID,
+                                    new ReadValueCallback(this, resolver));
+  return promise;
+}
+
+class WriteValueCallback : public WebBluetoothWriteValueCallbacks {
+ public:
+  WriteValueCallback(BluetoothRemoteGATTDescriptor* descriptor,
+                     ScriptPromiseResolver* resolver)
+      : m_webDescriptor(descriptor), m_resolver(resolver) {}
+
+  void onSuccess(const WebVector<uint8_t>& value) override {
+    if (!m_resolver->getExecutionContext() ||
+        m_resolver->getExecutionContext()->activeDOMObjectsAreStopped())
+      return;
+
+    if (m_webDescriptor) {
+      m_webDescriptor->setValue(ConvertWebVectorToDataView(value));
+    }
+    m_resolver->resolve();
+  }
+
+  void onError(
+      int32_t
+          error /* Corresponds to WebBluetoothResult in web_bluetooth.mojom */)
+      override {
+    if (!m_resolver->getExecutionContext() ||
+        m_resolver->getExecutionContext()->activeDOMObjectsAreStopped())
+      return;
+    m_resolver->reject(BluetoothError::take(m_resolver, error));
+  }
+
+ private:
+  WeakPersistent<BluetoothRemoteGATTDescriptor> m_webDescriptor;
+  Persistent<ScriptPromiseResolver> m_resolver;
+};
+
+ScriptPromise BluetoothRemoteGATTDescriptor::writeValue(
+    ScriptState* scriptState,
+    const DOMArrayPiece& value) {
+  WebBluetooth* webbluetooth =
+      BluetoothSupplement::fromScriptState(scriptState);
+
+  // Partial implementation of writeValue algorithm:
+  // https://webbluetoothchrome.github.io/web-bluetooth/#dom-bluetoothgattdescriptor-writevalue
+
+  // If bytes is more than 512 bytes long (the maximum length of an attribute
+  // value, per Long Attribute Values) return a promise rejected with an
+  // InvalidModificationError and abort.
+  if (value.byteLength() > 512) {
+    return ScriptPromise::rejectWithDOMException(
+        scriptState, DOMException::create(InvalidModificationError,
+                                          "Value can't exceed 512 bytes."));
+  }
+
+  // Let valueVector be a copy of the bytes held by value.
+  WebVector<uint8_t> valueVector(value.bytes(), value.byteLength());
+
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+
+  ScriptPromise promise = resolver->promise();
+  webbluetooth->descriptorWriteValue(m_webDescriptor->descriptorInstanceID,
+                                     valueVector,
+                                     new WriteValueCallback(this, resolver));
+
+  return promise;
+}
+
+DEFINE_TRACE(BluetoothRemoteGATTDescriptor) {
+  visitor->trace(m_service);
+  visitor->trace(m_characteristic);
+  visitor->trace(m_value);
+  EventTargetWithInlineData::trace(visitor);
+  ActiveDOMObject::trace(visitor);
+}
+
+}  // namespace blink