001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.console;
021
022import org.crsh.text.Style;
023
024import java.io.Closeable;
025import java.io.IOException;
026
027/**
028 * The contract between the console and the underlying stream.
029 */
030public interface ConsoleDriver extends Closeable {
031
032  /**
033   * Returns the term width in chars. When the value is not positive it means the value could not be determined.
034   *
035   * @return the term width
036   */
037  int getWidth();
038
039  /**
040   * Returns the term height in chars. When the value is not positive it means the value could not be determined.
041   *
042   * @return the term height
043   */
044  int getHeight();
045
046  /**
047   * Retrieves the value of a property specified by this TermIO
048   *
049   * @param name the name of the property
050   * @return value of the property
051   */
052  String getProperty(String name);
053
054  /**
055   * Take control of the alternate buffer. When the alternate buffer is already used
056   * nothing happens. The buffer switch should occur when then {@link #flush()} method
057   * is invoked.
058   *
059   * @return true if the alternate buffer is shown
060   */
061  boolean takeAlternateBuffer() throws IOException;
062
063  /**
064   * Release control of the alternate buffer. When the normal buffer is already used
065   * nothing happens. The buffer switch should occur when then {@link #flush()} method
066   * is invoked.
067   *
068   * @return true if the usual buffer is shown
069   */
070  boolean releaseAlternateBuffer() throws IOException;
071
072  /**
073   * Flush output.
074   *
075   * @throws java.io.IOException any io exception
076   */
077  void flush() throws IOException;
078
079  /**
080   * Write a string.
081   *
082   * @param s the string to write
083   * @throws java.io.IOException any io exception
084   */
085  void write(CharSequence s) throws IOException;
086
087  /**
088   * Write a char.
089   *
090   * @param c the char to write
091   * @throws java.io.IOException any io exception
092   */
093  void write(int c) throws IOException;
094
095  /**
096   * Write a style.
097   *
098   * @param d the data to write
099   * @throws java.io.IOException any io exception
100   */
101  void write(Style d) throws IOException;
102
103  /**
104   * Delete the char under the cursor.
105   *
106   * @throws java.io.IOException any io exception
107   */
108  void writeDel() throws IOException;
109
110  /**
111   * Write a CRLF.
112   *
113   * @throws java.io.IOException any io exception
114   */
115  void writeCRLF() throws IOException;
116
117  /**
118   * Clear screen.
119   *
120   * @throws java.io.IOException any io exception
121   */
122  void cls() throws IOException;
123
124  /**
125   * Move the cursor right.
126   *
127   * @param c the char skipped over
128   * @return true if the cursor moved.
129   * @throws java.io.IOException any io exception
130   */
131  boolean moveRight(char c) throws IOException;
132
133  /**
134   * Move the cursor left.
135   *
136   * @return true if the cursor moved
137   * @throws java.io.IOException any io exception
138   */
139  boolean moveLeft() throws IOException;
140
141}