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    
020    package org.crsh.console;
021    
022    import org.crsh.text.Style;
023    
024    import java.io.Closeable;
025    import java.io.IOException;
026    
027    /**
028     * The contract between the console and the underlying stream.
029     */
030    public 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    }