package org.litesoft.GWT.client.pavsupport;

import org.litesoft.core.typeutils.*;

import com.google.gwt.place.shared.*;
import com.google.gwt.user.client.ui.*;

/**
 * Simple Activity implementation that is always willing to stop, and does
 * nothing onStop and onCancel.
 */
public abstract class AbstractActivity<View extends AbstractView> implements Activity, AbstractPresenter
{
    protected final View mView;
    protected final PlaceChanger mPlaceChanger;

    public AbstractActivity( View pView, PlaceChanger pPlaceChanger )
    {
        mView = Objects.assertNotNull( "View", pView );
        mPlaceChanger = Objects.assertNotNull( "PlaceChanger", pPlaceChanger );
    }

    @SuppressWarnings("unchecked") @Override
    public final void start( AcceptsOneWidget pPanel )
    {
        start();
        mView.setPresenter( this );
        pPanel.setWidget( mView );
    }

    @Override
    public Place getWhere()
    {
        return mPlaceChanger.getWhere();
    }

    @Override
    public void goBack()
    {
        mPlaceChanger.goBack();
    }

    @Override
    public PlaceChanger.GoToPlace goForwardTo( Place pNewPlace )
    {
        return mPlaceChanger.goForwardTo( pNewPlace );
    }

    abstract protected void start();

    @Override
    public String mayStop()
    {
        return null;
    }

    @Override
    public void onCancel()
    {
    }

    @Override
    public void onStop()
    {
    }
}