Dart bindings for WebKit

Source/WebCore/bindings/dart/DartEventListener.cpp

+/*
+ * Copyright (C) 2011 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 "DartEventListener.h"
+
+#include "DartController.h"
+#include "DartEvent.h"
+#include "DartIsolateState.h"
+#include "DartUtilities.h"
+#include "ScriptExecutionContext.h"
+
+namespace WebCore {
+
+DartEventListener::DartEventListener(Dart_Isolate isolate, Dart_Handle listener)
+    : EventListener(JSEventListenerType)
+    , m_listener(0)
+{
+    setListenerObject(isolate, listener);
+}
+
+DartEventListener::~DartEventListener()
+{
+    disposeListenerObject();
+}
+
+PassRefPtr<DartEventListener> DartEventListener::createOrFetch(Dart_Handle listener)
+{
+    ASSERT(Dart_IsClosure(listener));
+    DartEventListener* nativeListener = reinterpret_cast<DartEventListener*>(Dart_ClosureSmrck(listener));
+    if (nativeListener)
+        return nativeListener;
+    return adoptRef(new DartEventListener(Dart_CurrentIsolate(), listener));
+}
+
+void DartEventListener::handleEvent(ScriptExecutionContext* context, Event* event)
+{
+    // Don't reenter Dart if execution was terminated in this instance of Dart.
+    // FIXME: we probably need isDartExecutionForbidden.
+    if (context->isJSExecutionForbidden())
+        return;
+
+    // FIXME: Validate that this isolate hasn't been shutdown.
+    DartIsolateState::push(m_isolate);
+    ASSERT(event);
+
+    // The callback function on XMLHttpRequest can clear the event listener and destroys 'this' object. Keep a local reference to it.
+    // See issue 889829.
+    RefPtr<DartEventListener> protect(this);
+
+    {
+      DartApiScope scope;
+
+      // Get the Dart wrapper for the event object.
+      Dart_Handle dartEvent = toDartValue(event);
+      ASSERT(dartEvent);
+
+      invokeEventHandler(context, event, dartEvent);
+    }
+    DartIsolateState::pop();
+}
+
+void DartEventListener::invokeEventHandler(ScriptExecutionContext* context, Event* event, Dart_Handle dartEvent)
+{
+    if (!dartEvent)
+        return;
+
+    // FIXME: consider if DateExtension manipulations are necessary and if yes (most probably),
+    // factor out common logic. For example by introducing EventProcessScope RAII to manage DateExtension.
+    Dart_Handle result = callListenerFunction(context, dartEvent, event);
+    if (Dart_IsError(result)) {
+        DartUtilities::reportProblem(context, result);
+        return;
+    }
+
+    if (Dart_IsString(result)) {
+        if (event->storesResultAsString())
+            event->storeResult(DartUtilities::dartStringToString(result));
+    }
+}
+
+Dart_Handle DartEventListener::callListenerFunction(ScriptExecutionContext* context, Dart_Handle dartEvent, Event* event)
+{
+    if (!m_listener)
+        return Dart_Error("No listener to call");
+
+    DartController* dartController = DartController::retrieve(context);
+    if (!dartController)
+        return Dart_Error("Internal error: failed to fetch Dart controller");
+
+    Dart_Handle parameters[1] = { dartEvent };
+    Dart_Handle result = dartController->callFunction(m_listener, 1, parameters);
+    if (Dart_IsError(result))
+        DartUtilities::reportProblem(context, result);
+    return result;
+}
+
+void DartEventListener::setListenerObject(Dart_Isolate isolate, Dart_Handle listener)
+{
+    disposeListenerObject();
+    ASSERT(Dart_IsClosure(listener));
+    m_isolate = isolate;
+    // FIXME: Validate isolate.
+    ASSERT(m_isolate);
+    // NOTE: DartEventListener destructor will clean wild smrck so
+    // Dart wrapper never keeps the pointer to destroyed object.
+    ASSERT(!Dart_ClosureSmrck(listener));
+    Dart_ClosureSetSmrck(listener, reinterpret_cast<int64_t>(this));
+
+    m_listener = Dart_NewPersistentHandle(listener);
+}
+
+void DartEventListener::disposeListenerObject()
+{
+    if (!m_listener)
+        return;
+
+    DartIsolateState::push(m_isolate);
+
+    {
+        DartApiScope scope;
+
+        ASSERT(this == reinterpret_cast<DartEventListener*>(Dart_ClosureSmrck(m_listener)));
+
+        // DartEventListener is going to be disposed, remove a pointer to it from Dart wrapper.
+        Dart_ClosureSetSmrck(m_listener, 0);
+
+        // FIXME: implement persistent handles tracking a la V8GCController::unregisterGlobalHandle.
+        Dart_DeletePersistentHandle(m_listener);
+        m_listener = 0;
+    }
+
+    // FIXME: We probably should ref count the isolate and
+    // shutdown if this is the last one.  This can happen if the
+    // isolate sets a listener on another frame and its original
+    // frame is closed.
+    DartIsolateState::pop();
+}
+
+}