package org.litesoft.GWT.client.view;

import java.util.*;

import org.litesoft.core.util.*;
import org.litesoft.security.*;
import org.litesoft.uispecification.*;

import com.google.gwt.user.client.*;

/**
 * Controls which screen is showing. Coordinates w/ the GWT {@link History}
 * mechanism.
 */
public abstract class AbstractViewManager implements ViewManager
{
    protected final ViewAccessControlManager mAccessControlManager;
    private final Map<String, ViewDef> mScreenDefs = new HashMap<String, ViewDef>();
    private final Map<String, ViewFactory> mViewFactories = new HashMap<String, ViewFactory>();

    AbstractViewManager( ViewAccessControlManager pAccessControlManager, ViewFactory... pFactories )
    {
        UtilsCommon.assertNotNull( "AccessControlManager", mAccessControlManager = pAccessControlManager );
        add( pFactories );
    }

    public ViewFactory getViewFactory( ViewDef pDef )
    {
        if ( pDef == null )
        {
            return null;
        }
        return mAccessControlManager.allowAccessTo( pDef ) ? mViewFactories.get( pDef.getFragmentID() ) : ViewFactory.NO_ACCESS;
    }

    protected ViewDef getViewDef( String pViewDefId )
    {
        ViewDef zDef = mScreenDefs.get( pViewDefId );
        return mAccessControlManager.allowAccessTo( zDef ) ? zDef : null;
    }

    /**
     * Use this to add a navigable screen.
     *
     * @param pFactories
     */
    public void add( ViewFactory... pFactories )
    {
        if ( pFactories != null )
        {
            for ( ViewFactory zFactory : pFactories )
            {
                if ( zFactory != null )
                {
                    ViewDef zDef = zFactory.getViewDef();
                    mViewFactories.put( zDef.getFragmentID(), zFactory );
                    mScreenDefs.put( zDef.getFragmentID(), zDef );
                }
            }
        }
    }

    /**
     * Use this to add placeholder(e.g. for displaying a disabled button).
     *
     * @param pViewDefs
     */
    public void add( ViewDef... pViewDefs )
    {
        if ( pViewDefs != null )
        {
            for ( ViewDef zDef : pViewDefs )
            {
                if ( zDef != null )
                {
                    mScreenDefs.put( zDef.getFragmentID(), zDef );
                }
            }
        }
    }
}