/*
 * Jexer - Java Text User Interface
 *
 * The MIT License (MIT)
 *
 * Copyright (C) 2016 Kevin Lamonte
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * @author Kevin Lamonte [kevin.lamonte@gmail.com]
 * @version 1
 */
package jexer.backend;

import java.util.List;

import jexer.event.TInputEvent;
import jexer.io.Screen;
import jexer.session.SessionInfo;

/**
 * This abstract class provides a screen, keyboard, and mouse to
 * TApplication.  It also exposes session information as gleaned from lower
 * levels of the communication stack.
 */
public abstract class Backend {

    /**
     * The session information.
     */
    protected SessionInfo sessionInfo;

    /**
     * Getter for sessionInfo.
     *
     * @return the SessionInfo
     */
    public final SessionInfo getSessionInfo() {
        return sessionInfo;
    }

    /**
     * The screen to draw on.
     */
    protected Screen screen;

    /**
     * Getter for screen.
     *
     * @return the Screen
     */
    public final Screen getScreen() {
        return screen;
    }

    /**
     * Subclasses must provide an implementation that syncs the logical
     * screen to the physical device.
     */
    public abstract void flushScreen();

    /**
     * Subclasses must provide an implementation to get keyboard, mouse, and
     * screen resize events.
     *
     * @param queue list to append new events to
     */
    public abstract void getEvents(List<TInputEvent> queue);

    /**
     * Subclasses must provide an implementation that closes sockets,
     * restores console, etc.
     */
    public abstract void shutdown();

}