base data structures

[fanfix.git] / src / jexer / backend / Backend.java

diff --git a/src/jexer/backend/Backend.java b/src/jexer/backend/Backend.java
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+/**
+ * Jexer - Java Text User Interface
+ *
+ * Version: $Id$
+ *
+ * Author: Kevin Lamonte, <a href="mailto:kevin.lamonte@gmail.com">kevin.lamonte@gmail.com</a>
+ *
+ * License: LGPLv3 or later
+ *
+ * Copyright: This module is licensed under the GNU Lesser General
+ * Public License Version 3.  Please see the file "COPYING" in this
+ * directory for more information about the GNU Lesser General Public
+ * License Version 3.
+ *
+ *     Copyright (C) 2015  Kevin Lamonte
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see
+ * http://www.gnu.org/licenses/, or write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ */
+package jexer.backend;
+
+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
+     */
+    public SessionInfo session;
+
+    /**
+     * The screen to draw on
+     */
+    public Screen screen;
+
+    /**
+     * Subclasses must provide an implementation that syncs the logical
+     * screen to the physical device.
+     */
+    abstract public void flushScreen();
+
+    /**
+     * Subclasses must provide an implementation to get keyboard, mouse, and
+     * screen resize events.
+     *
+     * @param timeout maximum amount of time to wait for an event
+     * @return events received, or an empty list if the timeout was reached
+     */
+    abstract public TInputEvent [] getEvents(int timeout);
+
+    /**
+     * Subclasses must provide an implementation that closes sockets,
+     * restores console, etc.
+     */
+    abstract public void shutdown();
+
+}
+