package org.litesoft.GWT.client.pavsupport;

import org.litesoft.commonfoundation.base.*;

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 = Confirm.isNotNull( "View", pView );
        mPlaceChanger = Confirm.isNotNull( "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() {
    }
}