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      1 /*
      2  * Copyright (c) 2002-2007, Marc Prud'hommeaux. All rights reserved.
      3  *
      4  * This software is distributable under the BSD license. See the terms of the
      5  * BSD license in the documentation provided with this software.
      6  */
      7 package jline;
      8 
      9 /**
     10  * A CursorBuffer is a holder for a {@link StringBuffer} that also contains the
     11  * current cursor position.
     12  *
     13  * @author <a href="mailto:mwp1 (at) cornell.edu">Marc Prud'hommeaux</a>
     14  */
     15 public class CursorBuffer {
     16     public int cursor = 0;
     17 
     18     StringBuffer buffer = new StringBuffer();
     19 
     20     private boolean overtyping = false;
     21 
     22     public int length() {
     23         return buffer.length();
     24     }
     25 
     26     public char current() {
     27         if (cursor <= 0) {
     28             return 0;
     29         }
     30 
     31         return buffer.charAt(cursor - 1);
     32     }
     33 
     34     public boolean clearBuffer() {
     35         if (buffer.length() == 0) {
     36             return false;
     37         }
     38 
     39         buffer.delete(0, buffer.length());
     40         cursor = 0;
     41         return true;
     42     }
     43 
     44     /**
     45      * Write the specific character into the buffer, setting the cursor position
     46      * ahead one. The text may overwrite or insert based on the current setting
     47      * of isOvertyping().
     48      *
     49      * @param c
     50      *            the character to insert
     51      */
     52     public void write(final char c) {
     53         buffer.insert(cursor++, c);
     54         if (isOvertyping() && cursor < buffer.length()) {
     55             buffer.deleteCharAt(cursor);
     56         }
     57     }
     58 
     59     /**
     60      * Insert the specified {@link String} into the buffer, setting the cursor
     61      * to the end of the insertion point.
     62      *
     63      * @param str
     64      *            the String to insert. Must not be null.
     65      */
     66     public void write(final String str) {
     67         if (buffer.length() == 0) {
     68             buffer.append(str);
     69         } else {
     70             buffer.insert(cursor, str);
     71         }
     72 
     73         cursor += str.length();
     74 
     75         if (isOvertyping() && cursor < buffer.length()) {
     76             buffer.delete(cursor, (cursor + str.length()));
     77         }
     78     }
     79 
     80     public String toString() {
     81         return buffer.toString();
     82     }
     83 
     84     public boolean isOvertyping() {
     85         return overtyping;
     86     }
     87 
     88     public void setOvertyping(boolean b) {
     89         overtyping = b;
     90     }
     91 
     92 	public StringBuffer getBuffer() {
     93 		return buffer;
     94 	}
     95 
     96 	public void setBuffer(StringBuffer buffer) {
     97 		buffer.setLength(0);
     98 		buffer.append(this.buffer.toString());
     99 
    100 		this.buffer = buffer;
    101 	}
    102 
    103 
    104 }
    105