Introduce KeepAliveWhilePending to ScriptPromiseResolverWithContext.

Source/modules/webmidi/MIDIAccessInitializer.cpp

Index: Source/modules/webmidi/MIDIAccessInitializer.cpp
diff --git a/Source/modules/webmidi/MIDIAccessInitializer.cpp b/Source/modules/webmidi/MIDIAccessInitializer.cpp
index 8e75f96b64c3603d984b1c9cd61342d55109c5ed..9f03df9708cbd0e212858dac9a2329ab0884f49f 100644
--- a/Source/modules/webmidi/MIDIAccessInitializer.cpp
+++ b/Source/modules/webmidi/MIDIAccessInitializer.cpp
@@ -5,66 +5,72 @@
 #include "config.h"
 #include "modules/webmidi/MIDIAccessInitializer.h"
 
-#include "bindings/v8/ScriptFunction.h"
 #include "bindings/v8/ScriptPromise.h"
 #include "bindings/v8/ScriptPromiseResolverWithContext.h"
 #include "core/dom/DOMError.h"
 #include "core/dom/Document.h"
+#include "core/frame/Navigator.h"
 #include "modules/webmidi/MIDIAccess.h"
 #include "modules/webmidi/MIDIController.h"
 #include "modules/webmidi/MIDIOptions.h"
+#include "modules/webmidi/MIDIPort.h"
 
 namespace WebCore {
 
-class MIDIAccessInitializer::PostAction : public ScriptFunction {
-public:
-    static PassOwnPtr<MIDIAccessInitializer::PostAction> create(v8::Isolate* isolate, WeakPtr<MIDIAccessInitializer> owner, State state) { return adoptPtr(new PostAction(isolate, owner, state)); }
-
-private:
-    PostAction(v8::Isolate* isolate, WeakPtr<MIDIAccessInitializer> owner, State state): ScriptFunction(isolate), m_owner(owner), m_state(state) { }
-    virtual ScriptValue call(ScriptValue value) OVERRIDE
-    {
-        if (!m_owner.get())
-            return value;
-        m_owner->doPostAction(m_state);
-        return value;
-    }
-
-    WeakPtr<MIDIAccessInitializer> m_owner;
-    State m_state;
-};
+MIDIAccessInitializer::MIDIAccessInitializer(ScriptState* scriptState, const MIDIOptions& options)
+    : ScriptPromiseResolverWithContext(scriptState, ScriptPromiseResolverWithContext::KeepAliveWhilePending)
+    , m_options(options)
+    , m_sysexEnabled(false)
+{
+}
 
 MIDIAccessInitializer::~MIDIAccessInitializer()
 {
-    ASSERT(m_state != Requesting);
+    // It is safe to cancel a request which is already finished or canceld.
+    Document* document = toDocument(executionContext());
+    ASSERT(document);
+    MIDIController* controller = MIDIController::from(document->frame());
+    ASSERT(controller);

[Takashi Toyoshima, 2014/06/17 05:10:08]

On this ASSERT(), See a comment below.

[yhirano, 2014/06/17 08:28:06]

Done.

+    controller->cancelSysexPermissionRequest(this);
 }
 
-MIDIAccessInitializer::MIDIAccessInitializer(const MIDIOptions& options, MIDIAccess* access)
-    : m_state(Requesting)
-    , m_weakPtrFactory(this)
-    , m_options(options)
-    , m_sysexEnabled(false)
-    , m_access(access)
+ScriptPromise MIDIAccessInitializer::start()
 {
+    ScriptPromise promise = this->promise();
     m_accessor = MIDIAccessor::create(this);
+
+    if (!m_options.sysex) {
+        m_accessor->startSession();
+        return promise;
+    }
+    Document* document = toDocument(executionContext());
+    ASSERT(document);
+    MIDIController* controller = MIDIController::from(document->frame());
+    if (controller) {

[Takashi Toyoshima, 2014/06/17 05:10:08]

Here, we assume that MIDIController can be NULL, but we do not expect it in the
descriptor. It looks curious. Maybe we want to remove the previous ASSERT(). If
a blink embedder do not need to support sysex messages, the embedder may miss
MIDIController implementation.

[yhirano, 2014/06/17 08:28:06]

Done.

+        controller->requestSysexPermission(this);
+    } else {
+        reject(DOMError::create("SecurityError"));
+    }
+    return promise;
 }
 
 void MIDIAccessInitializer::didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version)
 {

[Takashi Toyoshima, 2014/06/17 05:10:08]

How about addding an ASSERT() to check |m_accessor| is valid.
It will be useful in the future to detect a error for switching client
implementations currently done in MIDIAccess constructor.

[yhirano, 2014/06/17 08:28:06]

Done.

-    m_access->didAddInputPort(id, manufacturer, name, version);
+    m_portDescriptors.append(PortDescriptor(id, manufacturer, name, MIDIPort::MIDIPortTypeInput, version));
 }
 
 void MIDIAccessInitializer::didAddOutputPort(const String& id, const String& manufacturer, const String& name, const String& version)
 {

[Takashi Toyoshima, 2014/06/17 05:10:08]

ditto

[yhirano, 2014/06/17 08:28:06]

Done.

-    m_access->didAddOutputPort(id, manufacturer, name, version);
+    m_portDescriptors.append(PortDescriptor(id, manufacturer, name, MIDIPort::MIDIPortTypeOutput, version));
 }
 
 void MIDIAccessInitializer::didStartSession(bool success, const String& error, const String& message)
 {

[Takashi Toyoshima, 2014/06/17 05:10:08]

ditto

[yhirano, 2014/06/17 08:28:06]

Done.

-    if (success)
-        m_resolver->resolve(m_access);
-    else
-        m_resolver->reject(DOMError::create(error, message));
+    if (success) {
+        resolve(MIDIAccess::create(m_accessor.release(), m_sysexEnabled, m_portDescriptors, executionContext()));
+    } else {
+        reject(DOMError::create(error, message));
+    }
 }
 
 void MIDIAccessInitializer::setSysexEnabled(bool enable)
@@ -73,71 +79,17 @@ void MIDIAccessInitializer::setSysexEnabled(bool enable)
     if (enable)
         m_accessor->startSession();
     else
-        m_resolver->reject(DOMError::create("SecurityError"));
+        reject(DOMError::create("SecurityError"));
 }
 
 SecurityOrigin* MIDIAccessInitializer::securityOrigin() const
 {
-    return m_access->executionContext()->securityOrigin();
-}
-
-void MIDIAccessInitializer::cancel()
-{
-    if (m_state != Requesting)
-        return;
-    m_accessor.clear();
-    m_weakPtrFactory.revokeAll();
-    Document* document = toDocument(executionContext());
-    ASSERT(document);
-    MIDIController* controller = MIDIController::from(document->frame());
-    ASSERT(controller);
-    controller->cancelSysexPermissionRequest(this);
-    m_state = Stopped;
+    return executionContext()->securityOrigin();
 }
 
 ExecutionContext* MIDIAccessInitializer::executionContext() const
 {
-    return m_access->executionContext();
-}
-
-void MIDIAccessInitializer::permissionDenied()
-{
-    ASSERT(isMainThread());
-    m_resolver->reject(DOMError::create("SecurityError"));
-}
-
-ScriptPromise MIDIAccessInitializer::initialize(ScriptState* scriptState)
-{
-    m_resolver = ScriptPromiseResolverWithContext::create(scriptState);
-    ScriptPromise promise = m_resolver->promise();
-    promise.then(PostAction::create(scriptState->isolate(), m_weakPtrFactory.createWeakPtr(), Resolved),
-        PostAction::create(scriptState->isolate(), m_weakPtrFactory.createWeakPtr(), Stopped));
-
-    if (!m_options.sysex) {
-        m_accessor->startSession();
-        return promise;
-    }
-    Document* document = toDocument(executionContext());
-    ASSERT(document);
-    MIDIController* controller = MIDIController::from(document->frame());
-    if (controller) {
-        controller->requestSysexPermission(this);
-    } else {
-        m_resolver->reject(DOMError::create("SecurityError"));
-    }
-    return promise;
-}
-
-void MIDIAccessInitializer::doPostAction(State state)
-{
-    ASSERT(m_state == Requesting);
-    ASSERT(state == Resolved || state == Stopped);
-    if (state == Resolved) {
-        m_access->initialize(m_accessor.release(), m_sysexEnabled);
-    }
-    m_accessor.clear();
-    m_weakPtrFactory.revokeAll();
-    m_state = state;
+    return scriptState()->executionContext();
 }
 
 } // namespace WebCore