ViewWithUiHandlers.java

/*
 * Copyright 2011 ArcBees Inc.
 *
 * 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 com.gwtplatform.mvp.client;

import java.util.logging.Logger;

/**
 * Base class for a {@link View} that implements the {@link HasUiHandlers}
 * interface. You should always call {@link #setUiHandlers(UiHandlers)} from your
 * presenter's constructor.
 * <p/>
 * <b>Important!</b> Never call {@link #getUiHandlers()} inside your constructor
 * since the {@link UiHandlers} are not yet set.
 *
 * @param <C> Your {@link UiHandlers} interface type.
 */
public abstract class ViewWithUiHandlers<C extends UiHandlers> extends ViewImpl
        implements HasUiHandlers<C> {

    private static final Logger logger = Logger.getLogger(ViewWithUiHandlers.class.getName());
    private C uiHandlers;

    /**
     * Access the {@link UiHandlers} associated with this {@link View}.
     * <p/>
     * <b>Important!</b> Never call {@link #getUiHandlers()} inside your constructor
     * since the {@link UiHandlers} are not yet set.
     *
     * @return The {@link UiHandlers}, or {@code null} if they are not yet set.
     */
    protected C getUiHandlers() {
        if (uiHandlers == null) {
            logger.severe("uiHandlers are not set. You should call " +
                    "setUiHandlers() from your presenter's constructor to make " +
                    "the UiHandlers instance available.");
        }
        return uiHandlers;
    }

    @Override
    public void setUiHandlers(final C uiHandlers) {
        this.uiHandlers = uiHandlers;
    }
}