# AbstractForm.java

    /*
     * Copyright 2011 Marc Grue.
     *
     * Licensed  under the  Apache License,  Version 2.0  (the "License");
     * you may not use  this file  except in  compliance with the License.
     * You may obtain a copy of the License at
     *
     *   http://www.apache.org/licenses/LICENSE-2.0
     *
     * Unless required by applicable law or agreed to in writing, software
     * distributed  under the  License is distributed on an "AS IS" BASIS,
     * WITHOUT  WARRANTIES OR CONDITIONS  OF ANY KIND, either  express  or
     * implied.
     *
     * See the License for the specific language governing permissions and
     * limitations under the License.
     */
    package org.qi4j.sample.dcicargo.sample_b.infrastructure.wicket.form;

    import org.apache.wicket.ajax.AjaxRequestTarget;
    import org.apache.wicket.markup.html.form.Button;
    import org.apache.wicket.markup.html.form.CheckBox;
    import org.apache.wicket.markup.html.form.FormComponent;
    import org.apache.wicket.markup.html.form.RadioChoice;
    import org.apache.wicket.markup.html.form.StatelessForm;
    import org.apache.wicket.util.visit.IVisit;
    import org.apache.wicket.util.visit.IVisitor;

    /**
     * AbstractForm
     *
     * Base class for forms.
     */
    public abstract class AbstractForm<T> extends StatelessForm<T>
    {
        public AbstractForm( String id )
        {
            super( id );
        }

        public AbstractForm()
        {
            super( "form" );
        }

        public void focusFirstError( final AjaxRequestTarget target )
        {
            visitFormComponents( new IVisitor<FormComponent<?>, Void>()
            {
                public void component( FormComponent<?> fc, IVisit<Void> visit )
                {
                    if( isOtherComponent( fc ) || fc.isValid() )
                    {
                        return;
                    }

                    target.focusComponent( fc );
                    visit.stop();
                }
            } );
        }

        private boolean isOtherComponent( FormComponent<?> fc )
        {
            return fc instanceof Button || fc instanceof CheckBox || fc instanceof RadioChoice;
        }
    }