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 * in the documentation and/or other materials provided with the
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#include "config.h"
#include "InjectedScriptManager.h"

#include "DOMWindow.h"
#include "InjectedScript.h"
#include "InjectedScriptHost.h"
#include "ScriptValue.h"
#include "V8Binding.h"
#include "V8BindingState.h"
#include "V8DOMWindow.h"
#include "V8HiddenPropertyName.h"
#include "V8InjectedScriptHost.h"
#include "V8Proxy.h"
#include <wtf/RefPtr.h>

namespace WebCore {

static void WeakReferenceCallback(v8::Persistent<v8::Value> object, void* parameter)
{
    InjectedScriptHost* nativeObject = static_cast<InjectedScriptHost*>(parameter);
    nativeObject->deref();
    object.Dispose();
}

static v8::Local<v8::Object> createInjectedScriptHostV8Wrapper(InjectedScriptHost* host)
{
    v8::Local<v8::Function> function = V8InjectedScriptHost::GetTemplate()->GetFunction();
    if (function.IsEmpty()) {
        // Return if allocation failed.
        return v8::Local<v8::Object>();
    }
    v8::Local<v8::Object> instance = SafeAllocation::newInstance(function);
    if (instance.IsEmpty()) {
        // Avoid setting the wrapper if allocation failed.
        return v8::Local<v8::Object>();
    }
    V8DOMWrapper::setDOMWrapper(instance, &V8InjectedScriptHost::info, host);
    // Create a weak reference to the v8 wrapper of InspectorBackend to deref
    // InspectorBackend when the wrapper is garbage collected.
    host->ref();
    v8::Persistent<v8::Object> weakHandle = v8::Persistent<v8::Object>::New(instance);
    weakHandle.MakeWeak(host, &WeakReferenceCallback);
    return instance;
}

ScriptObject InjectedScriptManager::createInjectedScript(const String& scriptSource, ScriptState* inspectedScriptState, long id)
{
    v8::HandleScope scope;

    v8::Local<v8::Context> inspectedContext = inspectedScriptState->context();
    v8::Context::Scope contextScope(inspectedContext);

    // Call custom code to create InjectedScripHost wrapper specific for the context
    // instead of calling toV8() that would create the
    // wrapper in the current context.
    // FIXME: make it possible to use generic bindings factory for InjectedScriptHost.
    v8::Local<v8::Object> scriptHostWrapper = createInjectedScriptHostV8Wrapper(m_injectedScriptHost.get());
    if (scriptHostWrapper.IsEmpty())
        return ScriptObject();

    v8::Local<v8::Object> windowGlobal = inspectedContext->Global();

    // Inject javascript into the context. The compiled script is supposed to evaluate into
    // a single anonymous function(it's anonymous to avoid cluttering the global object with
    // inspector's stuff) the function is called a few lines below with InjectedScriptHost wrapper,
    // injected script id and explicit reference to the inspected global object. The function is expected
    // to create and configure InjectedScript instance that is going to be used by the inspector.
    v8::Local<v8::Script> script = v8::Script::Compile(v8String(scriptSource));
    v8::Local<v8::Value> v = script->Run();
    ASSERT(!v.IsEmpty());
    ASSERT(v->IsFunction());

    v8::Handle<v8::Value> args[] = {
      scriptHostWrapper,
      windowGlobal,
      v8::Number::New(id),
    };
    v8::Local<v8::Value> injectedScriptValue = v8::Function::Cast(*v)->Call(windowGlobal, 3, args);
    v8::Local<v8::Object> injectedScript(v8::Object::Cast(*injectedScriptValue));
    return ScriptObject(inspectedScriptState, injectedScript);
}

void InjectedScriptManager::discardInjectedScript(ScriptState* inspectedScriptState)
{
    v8::HandleScope handleScope;
    v8::Local<v8::Context> context = inspectedScriptState->context();
    v8::Context::Scope contextScope(context);

    v8::Local<v8::Object> global = context->Global();
    // Skip proxy object. The proxy object will survive page navigation while we need
    // an object whose lifetime consides with that of the inspected context.
    global = v8::Local<v8::Object>::Cast(global->GetPrototype());

    v8::Handle<v8::String> key = V8HiddenPropertyName::devtoolsInjectedScript();
    global->DeleteHiddenValue(key);
}

InjectedScript InjectedScriptManager::injectedScriptFor(ScriptState* inspectedScriptState)
{
    v8::HandleScope handleScope;
    v8::Local<v8::Context> context = inspectedScriptState->context();
    v8::Context::Scope contextScope(context);

    v8::Local<v8::Object> global = context->Global();
    // Skip proxy object. The proxy object will survive page navigation while we need
    // an object whose lifetime consides with that of the inspected context.
    global = v8::Local<v8::Object>::Cast(global->GetPrototype());

    v8::Handle<v8::String> key = V8HiddenPropertyName::devtoolsInjectedScript();
    v8::Local<v8::Value> val = global->GetHiddenValue(key);
    if (!val.IsEmpty() && val->IsObject())
        return InjectedScript(ScriptObject(inspectedScriptState, v8::Local<v8::Object>::Cast(val)));

    if (!canAccessInspectedWindow(inspectedScriptState))
        return InjectedScript();

    pair<long, ScriptObject> injectedScript = injectScript(injectedScriptSource(), inspectedScriptState);
    InjectedScript result(injectedScript.second);
    m_idToInjectedScript.set(injectedScript.first, result);
    global->SetHiddenValue(key, injectedScript.second.v8Object());
    return result;
}

bool InjectedScriptManager::canAccessInspectedWindow(ScriptState* scriptState)
{
    v8::HandleScope handleScope;
    v8::Local<v8::Context> context = scriptState->context();
    v8::Local<v8::Object> global = context->Global();
    if (global.IsEmpty())
        return false;
    v8::Handle<v8::Object> holder = V8DOMWrapper::lookupDOMWrapper(V8DOMWindow::GetTemplate(), global);
    if (holder.IsEmpty())
        return false;
    Frame* frame = V8DOMWindow::toNative(holder)->frame();

    v8::Context::Scope contextScope(context);
    return V8BindingSecurity::canAccessFrame(V8BindingState::Only(), frame, false);
}

} // namespace WebCore