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 string.
089   *
090   * @param s the string to write
091   * @param start the index of the first char
092   * @param end the index of the last char
093   * @throws java.io.IOException any io exception
094   */
095  void write(CharSequence s, int start, int end) throws IOException;
096
097  /**
098   * Write a char.
099   *
100   * @param c the char to write
101   * @throws java.io.IOException any io exception
102   */
103  void write(char c) throws IOException;
104
105  /**
106   * Write a style.
107   *
108   * @param d the data to write
109   * @throws java.io.IOException any io exception
110   */
111  void write(Style d) throws IOException;
112
113  /**
114   * Delete the char under the cursor.
115   *
116   * @throws java.io.IOException any io exception
117   */
118  void writeDel() throws IOException;
119
120  /**
121   * Write a CRLF.
122   *
123   * @throws java.io.IOException any io exception
124   */
125  void writeCRLF() throws IOException;
126
127  /**
128   * Clear screen.
129   *
130   * @throws java.io.IOException any io exception
131   */
132  void cls() throws IOException;
133
134  /**
135   * Move the cursor right.
136   *
137   * @param c the char skipped over
138   * @return true if the cursor moved.
139   * @throws java.io.IOException any io exception
140   */
141  boolean moveRight(char c) throws IOException;
142
143  /**
144   * Move the cursor left.
145   *
146   * @return true if the cursor moved
147   * @throws java.io.IOException any io exception
148   */
149  boolean moveLeft() throws IOException;
150
151}