TolaStateManager.java

/*
 * Copyright (c) 2008 TouK.pl
 *
 * 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 pl.touk.tola.gwt.client.state;

import com.extjs.gxt.ui.client.state.Provider;
import com.extjs.gxt.ui.client.state.StateManager;

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

import java.util.Date;


/**
 * @author Łukasz Kucharski - lkc@touk.pl
 */
public final class TolaStateManager extends StateManager {
    private static TolaStateManager INSTANCE;

    private TolaStateManager() {
    }

    public static TolaStateManager get() {
        if (INSTANCE == null) {
            INSTANCE = initialize();
        }

        return INSTANCE;
    }

    /**
     * Bug fix for gxt-2.x com.extjs.gxt.ui.client.state.Provider.getInteger()
     * That method will throw NPE if value property for given name don't exist.
     * @param name
     * @return
     */
    @Override
    public int getInteger(String name) {
        if (get(name) == null) {
            return -1;
        }

        return super.getInteger(name);
    }

    /**
     * Z powodu dziwnej implementacji statne providera i managera w GXT nie można pobierać ani przechowywać
     * ujemnych wartości.
     *
     * @param name         of the value to extract from state provder
     * @param defaultValue value to return when state provider return -1 (meaning no cookie has been found)
     * @return integer value of saved cookie or default value if cookie has not been found
     */
    public int getInteger(String name, int defaultValue) {
        int value = getInteger(name);

        return (value == -1) ? defaultValue : value;
    }

    private static TolaStateManager initialize() {
        INSTANCE = new TolaStateManager();

        Provider provider = new TolaCookieProvider();
        INSTANCE.setProvider(provider);

        return INSTANCE;
    }

    static class TolaCookieProvider extends Provider {
        protected Date defaultExpires = new Date(System.currentTimeMillis() +
                (1000L * 60 * 60 * 24 * 7 * 12));

        protected void clearKey(String name) {
            Cookies.removeCookie(name);
        }

        protected String getValue(String name) {
            return Cookies.getCookie(name);
        }

        protected void setValue(String name, String value) {
            Cookies.setCookie(name, value, defaultExpires);
        }
    }
}