third_party/WebKit/Source/bindings/core/v8/V8EventListener.cpp

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#include "bindings/core/v8/V8EventListener.h"

#include "bindings/core/v8/ScriptController.h"
#include "bindings/core/v8/V8Binding.h"
#include "core/dom/Document.h"
#include "core/events/Event.h"
#include "core/frame/LocalFrame.h"

namespace blink {

V8EventListener::V8EventListener(bool isAttribute, ScriptState* scriptState)
    : V8AbstractEventListener(isAttribute,
                              scriptState->world(),
                              scriptState->isolate()) {}

v8::Local<v8::Function> V8EventListener::getListenerFunction(
    ScriptState* scriptState) {
  v8::Local<v8::Object> listener =
      getListenerObject(scriptState->getExecutionContext());

  // Has the listener been disposed?
  if (listener.IsEmpty())
    return v8::Local<v8::Function>();

  if (listener->IsFunction())
    return v8::Local<v8::Function>::Cast(listener);

  // The EventHandler callback function type (used for event handler
  // attributes in HTML) has [TreatNonObjectAsNull], which implies that
  // non-function objects should be treated as no-op functions that return
  // undefined.
  if (isAttribute())
    return v8::Local<v8::Function>();

  if (listener->IsObject()) {
    // Check that no exceptions were thrown when getting the
    // handleEvent property and that the value is a function.
    v8::Local<v8::Value> property;
    if (listener
            ->Get(scriptState->context(),
                  v8AtomicString(isolate(), "handleEvent"))
            .ToLocal(&property) &&
        property->IsFunction())
      return v8::Local<v8::Function>::Cast(property);
  }

  return v8::Local<v8::Function>();
}

v8::Local<v8::Value> V8EventListener::callListenerFunction(
    ScriptState* scriptState,
    v8::Local<v8::Value> jsEvent,
    Event* event) {
  ASSERT(!jsEvent.IsEmpty());
  v8::Local<v8::Function> handlerFunction = getListenerFunction(scriptState);
  v8::Local<v8::Object> receiver = getReceiverObject(scriptState, event);
  if (handlerFunction.IsEmpty() || receiver.IsEmpty())
    return v8::Local<v8::Value>();

  if (!scriptState->getExecutionContext()->isDocument())
    return v8::Local<v8::Value>();

  LocalFrame* frame = toDocument(scriptState->getExecutionContext())->frame();
  if (!frame)
    return v8::Local<v8::Value>();

  // TODO(jochen): Consider moving this check into canExecuteScripts. http://crbug.com/608641
  if (scriptState->world().isMainWorld() &&
      !frame->script().canExecuteScripts(AboutToExecuteScript))
    return v8::Local<v8::Value>();

  v8::Local<v8::Value> parameters[1] = {jsEvent};
  v8::Local<v8::Value> result;
  if (!V8ScriptRunner::callFunction(handlerFunction, frame->document(),
                                    receiver, WTF_ARRAY_LENGTH(parameters),
                                    parameters, scriptState->isolate())
           .ToLocal(&result))
    return v8::Local<v8::Value>();
  return result;
}

}  // namespace blink