Web MIDI: implement MIDIAccessPromise

Source/modules/webmidi/MIDIAccessPromise.cpp

+/*
+ * Copyright (C) 2013 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "modules/webmidi/MIDIAccessPromise.h"
+
+#include "core/dom/DOMError.h"
+#include "modules/webmidi/MIDIAccess.h"
+#include "modules/webmidi/MIDIErrorCallback.h"
+#include "modules/webmidi/MIDISuccessCallback.h"
+
+namespace WebCore {
+
+PassRefPtr<MIDIAccessPromise> MIDIAccessPromise::create(ScriptExecutionContext* context, const Dictionary& options)
+{
+    RefPtr<MIDIAccessPromise> midiAccessPromise(adoptRef(new MIDIAccessPromise(context, options)));
+    midiAccessPromise->suspendIfNeeded();
+    return midiAccessPromise.release();
+}
+
+MIDIAccessPromise::MIDIAccessPromise(ScriptExecutionContext* context, const Dictionary& options)
+    : ActiveDOMObject(context)
+    , m_context(context)
+    , m_state(Pending)
+    , m_options(adoptPtr(new MIDIOptions(options)))
+    , m_access(MIDIAccess::create(m_context, this))
+{
+    ScriptWrappable::init(this);
+}
+
+MIDIAccessPromise::~MIDIAccessPromise()
+{
+    stop();
+}
+
+void MIDIAccessPromise::fulfill()
+{
+    if (m_state == Pending) {
+        if (m_successCallback) {
+            m_state = Invoked;
+            m_successCallback->handleEvent(m_access.release().leakRef(), m_options->sysexEnabled);
+            m_options.clear();
+        } else {
+            m_state = Accepted;
+        }
+    }
+    m_successCallback.clear();
+    m_errorCallback.clear();
+}
+
+void MIDIAccessPromise::reject(DOMError* error)
+{
+    if (m_state == Pending) {
+        if (m_errorCallback) {
+            m_state = Invoked;
+            m_errorCallback->handleEvent(error);
+        } else {
+            m_state = Rejected;
+            m_error = adoptRef(error);
+        }
+    }
+    m_successCallback.clear();
+    m_errorCallback.clear();
+}
+
+void MIDIAccessPromise::then(PassRefPtr<MIDISuccessCallback> successCallback, PassRefPtr<MIDIErrorCallback> errorCallback)
+{
+    switch (m_state) {
+    case Accepted:
+        successCallback->handleEvent(m_access.release().leakRef(), m_options->sysexEnabled);
+        m_options.clear();
+        m_state = Invoked;
+        break;
+    case Rejected:
+        errorCallback->handleEvent(m_error.release().leakRef());
+        m_state = Invoked;
+        break;
+    case Pending:
+        m_successCallback = successCallback;
+        m_errorCallback = errorCallback;
+        break;
+    case Invoked:
+        break;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+}
+
+} // namespace WebCore