/* 
 * Copyright 2011 Vaadin Ltd.
 * 
 * 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.vaadin.terminal;

import java.io.Serializable;

import com.vaadin.Application;

/**
 * This interface must be implemented by classes wishing to provide Application
 * resources.
 * <p>
 * <code>ApplicationResource</code> are a set of named resources (pictures,
 * sounds, etc) associated with some specific application. Having named
 * application resources provides a convenient method for having inter-theme
 * common resources for an application.
 * </p>
 * 
 * @author Vaadin Ltd.
 * @since 3.0
 */
public interface ApplicationResource extends Resource, Serializable {

    /**
     * Default cache time.
     */
    public static final long DEFAULT_CACHETIME = 1000 * 60 * 60 * 24;

    /**
     * Gets resource as stream.
     */
    public DownloadStream getStream();

    /**
     * Gets the application of the resource.
     */
    public Application getApplication();

    /**
     * Gets the virtual filename for this resource.
     * 
     * @return the file name associated to this resource.
     */
    public String getFilename();

    /**
     * Gets the length of cache expiration time.
     * 
     * <p>
     * This gives the adapter the possibility cache streams sent to the client.
     * The caching may be made in adapter or at the client if the client
     * supports caching. Default is <code>DEFAULT_CACHETIME</code>.
     * </p>
     * 
     * @return Cache time in milliseconds
     */
    public long getCacheTime();

    /**
     * Gets the size of the download buffer used for this resource.
     * 
     * <p>
     * If the buffer size is 0, the buffer size is decided by the terminal
     * adapter. The default value is 0.
     * </p>
     * 
     * @return int the size of the buffer in bytes.
     */
    public int getBufferSize();

}