eolus.client.EntityManager.java Source code

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Here is the source code for eolus.client.EntityManager.java

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/*
 * Copyright 2010 Konstantinos Tsakalozos
 *
 * Licensed under the EUPL, Version 1.1 or  as soon they will be
 * approved by the European Commission - subsequent versions of the EUPL (the Licence);
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 *
 * http://ec.europa.eu/idabc/eupl
 *
 * Unless required by applicable law or agreed to in  writing, software
 * distributed under the Licence is distributed on an AS IS basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and limitations under the Licence.
 */

package eolus.client;

import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.Widget;

/**
 * @author kristian 
 */

/**
 * 
 * This class simulates an entity manager on the client side of a GWT project by 
 * writting data (with the persist() method) in a hidden div tag on the html page.
 * The data can later be retrieved with the get method. The object types that can
 * be stored are: String
 */
public class EntityManager {

    private static FlexTable em = null;

    public static void init() {
        RootPanel root = RootPanel.get("EntityManager");
        root.setVisible(false);
        if ("".equals(root.getElement().getInnerHTML())) {
            em = new FlexTable();
            root.add(em);
        }
    }

    public static void persist(String name, Object o) {
        /*
        //protupo gia tin dimiourgia kwdika pou na apothikeuei antikeimena tupou "Antikeimeno".
        //analogi diadikasia prepei na ulopoithei kai stin sinartisi get
            
            
        if(o instanceof Antikeimeno) {
           Antikeimeno antik = (Antikeimeno) o; 
           int rows = em.getRowCount();
           int i=0;
           for(i=0 ; i<rows ; i++)
        if( em.getText(i, 0).equals(name) )
           break;
           em.setText(i, 0, name);
           em.setWidget(i, 1, antik);
        }
         */

        if (o instanceof String) {
            Label l = new Label((String) o);
            int rows = em.getRowCount();
            int i = 0;
            for (i = 0; i < rows; i++)
                if (em.getText(i, 0).equals(name))
                    break;
            em.setText(i, 0, name);
            em.setWidget(i, 1, l);
        }
    }

    public static Object get(String name) {
        int rows = em.getRowCount();
        int i = 0;
        for (; i < rows; i++)
            if (em.getText(i, 0).equals(name))
                break;
        if (i == rows)
            return null;
        Widget w = em.getWidget(i, 1);
        if (w instanceof Label) {
            Label l = (Label) w;
            return l.getText();
        }
        return null;
    }

    public static void remove(String name) {
        int rows = em.getRowCount();
        int i = 0;
        for (; i < rows; i++)
            if (em.getText(i, 0).equals(name))
                break;
        if (i != rows)
            em.removeRow(i);
    }

    public static void clear() {
        em.removeAllRows();
    }
}