Wt

#include <Wt/WApplication>

#include <Wt/WContainerWidget>

#include <Wt/WPushButton>

#include <Wt/WLineEdit>

#include <iostream>

#include <boost/thread.hpp>

using namespace Wt;

using namespace boost;

using namespace std;

class ExampleWidget;

class CometTestApplication : public WApplication

{

public:

  CometTestApplication(const WEnvironment& env);

    ExampleWidget *t;

};

class ExampleWidget : public WLineEdit

{

    boost::thread updater;

public:

    void startBigWork()

    {

       wApp->enableUpdates(true); // enable server-push temporarily

       updater = boost::thread(boost::bind(&ExampleWidget::doWork, this, WApplication::instance(), text()));

    }

    ExampleWidget()

    {

       keyWentUp().connect(SLOT(this, ExampleWidget::startBigWork));

    }

    void doWork(WApplication *app, const WString s)

    {

      WApplication::UpdateLock uiLock = app->getUpdateLock(); // RAII lock

      cout << endl << s << endl;

      setText(s + " " + s);

      cout << endl << text() << endl;

      // if using server push, push now the changes to the client

      app->triggerUpdate();

      app->enableUpdates(false); // disable server-push again

   }

};

CometTestApplication::CometTestApplication(const WEnvironment& env)

  : WApplication(env)

{

    t = new ExampleWidget();

    root()->addWidget(t);

}

WApplication *createApplication(const WEnvironment& env)

{

  return new CometTestApplication(env);

}

int main(int argc, char **argv)

{

  return WRun(argc, argv, &createApplication);

}