WebKit merge 41660:41709 (WebKit side)....

third_party/WebKit/WebCore/bindings/v8/V8AbstractEventListener.cpp

+/*
+ * Copyright (C) 2006, 2007, 2008, 2009 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 "V8AbstractEventListener.h"
+
+#include "Document.h"
+#include "Event.h"
+#include "Frame.h"
+#include "Tokenizer.h"
+#include "V8Binding.h"
+
+namespace WebCore {
+
+V8AbstractEventListener::V8AbstractEventListener(Frame* frame, bool isInline)
+    : m_isInline(isInline)
+    , m_frame(frame)
+    , m_lineNumber(0)
+    , m_columnNumber(0)
+{
+    if (!m_frame)
+        return;
+
+    // Get the position in the source if any.
+    if (m_isInline && m_frame->document()->tokenizer()) {
+        m_lineNumber = m_frame->document()->tokenizer()->lineNumber();
+        m_columnNumber = m_frame->document()->tokenizer()->columnNumber();
+    }
+}
+
+void V8AbstractEventListener::invokeEventHandler(v8::Handle<v8::Context> context, Event* event, v8::Handle<v8::Value> jsEvent, bool isWindowEvent)
+{
+    // For compatibility, we store the event object as a property on the window called "event".  Because this is the global namespace, we save away any
+    // existing "event" property, and then restore it after executing the javascript handler.
+    v8::Local<v8::String> eventSymbol = v8::String::NewSymbol("event");
+    v8::Local<v8::Value> returnValue;
+
+    {
+        // Catch exceptions thrown in the event handler so they do not propagate to javascript code that caused the event to fire.
+        // Setting and getting the 'event' property on the global object can throw exceptions as well (for instance if accessors that
+        // throw exceptions are defined for 'event' using __defineGetter__ and __defineSetter__ on the global object).
+        v8::TryCatch tryCatch;
+        tryCatch.SetVerbose(true);
+
+        // Save the old 'event' property so we can restore it later.
+        v8::Local<v8::Value> savedEvent = context->Global()->Get(eventSymbol);
+        tryCatch.Reset();
+
+        // Make the event available in the window object.
+        //
+        // FIXME: This does not work as it does with jsc bindings if the window.event property is already set. We need to make sure that property
+        // access is intercepted correctly.
+        context->Global()->Set(eventSymbol, jsEvent);
+        tryCatch.Reset();
+
+        // Call the event handler.
+        returnValue = callListenerFunction(jsEvent, event, isWindowEvent);
+        tryCatch.Reset();
+
+        // Restore the old event. This must be done for all exit paths through this method.
+        if (savedEvent.IsEmpty())
+            context->Global()->Set(eventSymbol, v8::Undefined());
+        else
+            context->Global()->Set(eventSymbol, savedEvent);
+        tryCatch.Reset();
+    }
+
+    ASSERT(!V8Proxy::HandleOutOfMemory() || returnValue.IsEmpty());
+
+    if (returnValue.IsEmpty())
+        return;
+
+    if (!returnValue->IsNull() && !returnValue->IsUndefined() && event->storesResultAsString())
+        event->storeResult(toWebCoreString(returnValue));
+
+    // Prevent default action if the return value is false;
+    // FIXME: Add example, and reference to bug entry.
+    if (m_isInline && returnValue->IsBoolean() && !returnValue->BooleanValue())
+        event->preventDefault();
+}
+
+void V8AbstractEventListener::handleEvent(Event* event, bool isWindowEvent)
+{
+    // EventListener could be disconnected from the frame.
+    if (disconnected())
+        return;
+
+    // The callback function on XMLHttpRequest can clear the event listener and destroys 'this' object. Keep a local reference to it.
+    // See issue 889829.
+    RefPtr<V8AbstractEventListener> protect(this);
+
+    v8::HandleScope handleScope;
+
+    v8::Handle<v8::Context> context = V8Proxy::GetContext(m_frame);
+    if (context.IsEmpty())
+        return;
+
+    // m_frame can removed by the callback function, protect it until the callback function returns.
+    RefPtr<Frame> protectFrame(m_frame);
+
+    // Enter the V8 context in which to perform the event handling.
+    v8::Context::Scope scope(context);
+
+    // Get the V8 wrapper for the event object.
+    v8::Handle<v8::Value> jsEvent = V8Proxy::EventToV8Object(event);
+
+    invokeEventHandler(context, event, jsEvent, isWindowEvent);
+
+    Document::updateDocumentsRendering();
+}
+
+void V8AbstractEventListener::disposeListenerObject()
+{
+    if (!m_listener.IsEmpty()) {
+#ifndef NDEBUG
+        V8Proxy::UnregisterGlobalHandle(this, m_listener);
+#endif
+        m_listener.Dispose();
+        m_listener.Clear();
+    }
+}
+
+v8::Local<v8::Object> V8AbstractEventListener::getReceiverObject(Event* event, bool isWindowEvent)
+{
+    if (!m_listener.IsEmpty() && !m_listener->IsFunction())
+        return v8::Local<v8::Object>::New(m_listener);
+
+    if (isWindowEvent)
+        return v8::Context::GetCurrent()->Global();
+
+    EventTarget* target = event->currentTarget();
+    v8::Handle<v8::Value> value = V8Proxy::EventTargetToV8Object(target);
+    if (value.IsEmpty())
+        return v8::Local<v8::Object>();
+    return v8::Local<v8::Object>::New(v8::Handle<v8::Object>::Cast(value));
+}
+
+} // namespace WebCore