Pull demo into jar

[nikiroo-utils.git] / src / jexer / session / TTYSessionInfo.java

/**
 * Jexer - Java Text User Interface
 *
 * License: LGPLv3 or later
 *
 * 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
 *
 * @author Kevin Lamonte [kevin.lamonte@gmail.com]
 * @version 1
 */
package jexer.session;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;
import java.util.Date;
import java.util.StringTokenizer;

/**
 * TTYSessionInfo queries environment variables and the tty window size for
 * the session information.  The username is taken from
 * getpwuid(geteuid()).pw_name, language is taken from LANG, and text window
 * size from ioctl(TIOCGWINSIZ).
 */
public final class TTYSessionInfo implements SessionInfo {

    /**
     * User name.
     */
    private String username = "";

    /**
     * Language.
     */
    private String language = "";

    /**
     * Text window width.  Default is 80x24 (same as VT100-ish terminals).
     */
    private int windowWidth = 80;

    /**
     * Text window height.  Default is 80x24 (same as VT100-ish terminals).
     */
    private int windowHeight = 24;

    /**
     * Time at which the window size was refreshed.
     */
    private Date lastQueryWindowTime;

    /**
     * Username getter.
     *
     * @return the username
     */
    public String getUsername() {
        return this.username;
    }

    /**
     * Username setter.
     *
     * @param username the value
     */
    public void setUsername(final String username) {
        this.username = username;
    }

    /**
     * Language getter.
     *
     * @return the language
     */
    public String getLanguage() {
        return this.language;
    }

    /**
     * Language setter.
     *
     * @param language the value
     */
    public void setLanguage(final String language) {
        this.language = language;
    }

    /**
     * Call 'stty size' to obtain the tty window size.  windowWidth and
     * windowHeight are set automatically.
     */
    private void sttyWindowSize() {
        String [] cmd = {
            "/bin/sh", "-c", "stty size < /dev/tty"
        };
        try {
            Process process = Runtime.getRuntime().exec(cmd);
            BufferedReader in = new BufferedReader(
                new InputStreamReader(process.getInputStream(), "UTF-8"));
            String line = in.readLine();
            if ((line != null) && (line.length() > 0)) {
                StringTokenizer tokenizer = new StringTokenizer(line);
                windowHeight = Integer.parseInt(tokenizer.nextToken());
                windowWidth = Integer.parseInt(tokenizer.nextToken());
            }
            while (true) {
                BufferedReader err = new BufferedReader(
                        new InputStreamReader(process.getErrorStream(),
                            "UTF-8"));
                line = err.readLine();
                if ((line != null) && (line.length() > 0)) {
                    System.err.println("Error output from stty: " + line);
                }
                try {
                    process.waitFor();
                    break;
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
            int rc = process.exitValue();
            if (rc != 0) {
                System.err.println("stty returned error code: " + rc);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * Text window width getter.
     *
     * @return the window width
     */
    public int getWindowWidth() {
        if (System.getProperty("os.name").startsWith("Windows")) {
            // Always use 80x25 for Windows (same as DOS)
            return 80;
        }
        return windowWidth;
    }

    /**
     * Text window height getter.
     *
     * @return the window height
     */
    public int getWindowHeight() {
        if (System.getProperty("os.name").startsWith("Windows")) {
            // Always use 80x25 for Windows (same as DOS)
            return 25;
        }
        return windowHeight;
    }

    /**
     * Re-query the text window size.
     */
    public void queryWindowSize() {
        if (lastQueryWindowTime == null) {
            lastQueryWindowTime = new Date();
        } else {
            Date now = new Date();
            if (now.getTime() - lastQueryWindowTime.getTime() < 3000) {
                // Don't re-spawn stty, it's been too soon.
                return;
            }
        }
        if (System.getProperty("os.name").startsWith("Linux")
            || System.getProperty("os.name").startsWith("Mac OS X")
            || System.getProperty("os.name").startsWith("SunOS")
            || System.getProperty("os.name").startsWith("FreeBSD")
        ) {
            // Use stty to get the window size
            sttyWindowSize();
        }
    }

    /**
     * Public constructor.
     */
    public TTYSessionInfo() {
        // Populate lang and user from the environment
        username = System.getProperty("user.name");
        language = System.getProperty("user.language");
        queryWindowSize();
    }
}