// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.GWT.forms.client.nonpublic;

import org.litesoft.GWT.client.widgets.nonpublic.*;
import org.litesoft.ui.def.nonpublic.support.*;

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

public class VerticalSubFormRowCarrier implements SubFormRowCarrier {
    private AbstractSizeableVerticalRegularPanel mRowContainer;
    private Widget mEmptyFiller = null;

    public VerticalSubFormRowCarrier( AbstractSizeableVerticalRegularPanel pRowContainer ) {
        mRowContainer = pRowContainer;
        addEmptyEntry();
    }

    public void dispose() {
        if ( mRowContainer != null ) {
            mRowContainer.clear();
            mRowContainer = null;
        }
        mEmptyFiller = null;
    }

    public void clear() {
        mRowContainer.clear();
        addEmptyEntry();
    }

    public void remove( Widget pWidget ) {
        if ( mRowContainer.remove( pWidget ) ) {
            if ( mRowContainer.getWidgetCount() == 0 ) {
                addEmptyEntry();
            }
        }
    }

    public void insert( Widget pWidget, int pBeforeIndex ) {
        mRowContainer.insert( pWidget, pBeforeIndex );
        if ( mEmptyFiller != null ) {
            mRowContainer.remove( mEmptyFiller );
            mEmptyFiller = null;
        }
    }

    public void membershipChangesComplete() {
        mRowContainer.relayoutFromHereDown();
    }

    public FormAttributeAdapter createTabAttributeAdapter( FormInstanceComponentHandler pComponentHandler,
                                                           AttributeMetaData pTabAttributeMetaData, Widget pWidget ) {
        return null;
    }

    private void addEmptyEntry() {
        mRowContainer.add( mEmptyFiller = new Label( " " ) );
    }
}