1/*
2 * This file is part of "JTA - Telnet/SSH for the JAVA(tm) platform".
3 *
4 * (c) Matthias L. Jugel, Marcus Mei�ner 1996-2005. All Rights Reserved.
5 *
6 * Please visit http://javatelnet.org/ for updates and contact.
7 *
8 * --LICENSE NOTICE--
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version 2
12 * of the License, or (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 * --LICENSE NOTICE--
23 *
24 */
25
26package de.mud.terminal;
27
28import java.util.Arrays;
29
30/**
31 * Implementation of a Video Display Unit (VDU) buffer. This class contains all methods to
32 * manipulate the buffer that stores characters and their attributes as well as the regions
33 * displayed.
34 *
35 * @version $Id: VDUBuffer.java 503 2005-10-24 07:34:13Z marcus $
36 */
37public class VDUBuffer {
38
39  /** The current version id tag */
40  public final static String ID = "$Id: VDUBuffer.java 503 2005-10-24 07:34:13Z marcus $";
41
42  /** Enable debug messages. */
43  public final static int debug = 0;
44
45  public int height, width; /* rows and columns */
46  public boolean[] update; /* contains the lines that need update */
47  public char[][] charArray; /* contains the characters */
48  public int[][] charAttributes; /* contains character attrs */
49  public int bufSize;
50  public int maxBufSize; /* buffer sizes */
51  public int screenBase; /* the actual screen start */
52  public int windowBase; /* where the start displaying */
53  public int scrollMarker; /* marks the last line inserted */
54
55  private int topMargin; /* top scroll margin */
56  private int bottomMargin; /* bottom scroll margin */
57
58  // cursor variables
59  protected boolean showcursor = true;
60  protected int cursorX, cursorY;
61
62  /** Scroll up when inserting a line. */
63  public final static boolean SCROLL_UP = false;
64  /** Scroll down when inserting a line. */
65  public final static boolean SCROLL_DOWN = true;
66
67  /*
68   * Attributes bit-field usage:
69   *
70   * 8421 8421 8421 8421 8421 8421 8421 8421 |||| |||| |||| |||| |||| |||| |||| |||`- Bold |||| ||||
71   * |||| |||| |||| |||| |||| ||`-- Underline |||| |||| |||| |||| |||| |||| |||| |`--- Invert ||||
72   * |||| |||| |||| |||| |||| |||| `---- Low |||| |||| |||| |||| |||| |||| |||`------ Invisible ||||
73   * |||| |||| |||| ||`+-++++-+++------- Foreground Color |||| |||| |`++-++++-++------------------
74   * Background Color |||| |||| `----------------------------- Fullwidth character
75   * `+++-++++------------------------------- Reserved for future use
76   */
77
78  /** Make character normal. */
79  public final static int NORMAL = 0x00;
80  /** Make character bold. */
81  public final static int BOLD = 0x01;
82  /** Underline character. */
83  public final static int UNDERLINE = 0x02;
84  /** Invert character. */
85  public final static int INVERT = 0x04;
86  /** Lower intensity character. */
87  public final static int LOW = 0x08;
88  /** Invisible character. */
89  public final static int INVISIBLE = 0x10;
90  /** Unicode full-width character (CJK, et al.) */
91  public final static int FULLWIDTH = 0x8000000;
92
93  /** how much to left shift the foreground color */
94  public final static int COLOR_FG_SHIFT = 5;
95  /** how much to left shift the background color */
96  public final static int COLOR_BG_SHIFT = 14;
97  /** color mask */
98  public final static int COLOR = 0x7fffe0; /* 0000 0000 0111 1111 1111 1111 1110 0000 */
99  /** foreground color mask */
100  public final static int COLOR_FG = 0x3fe0; /* 0000 0000 0000 0000 0011 1111 1110 0000 */
101  /** background color mask */
102  public final static int COLOR_BG = 0x7fc000; /* 0000 0000 0111 1111 1100 0000 0000 0000 */
103
104  /**
105   * Create a new video display buffer with the passed width and height in characters.
106   *
107   * @param width
108   *          the length of the character lines
109   * @param height
110   *          the amount of lines on the screen
111   */
112  public VDUBuffer(int width, int height) {
113    // set the display screen size
114    setScreenSize(width, height, false);
115  }
116
117  /**
118   * Create a standard video display buffer with 80 columns and 24 lines.
119   */
120  public VDUBuffer() {
121    this(80, 24);
122  }
123
124  /**
125   * Put a character on the screen with normal font and outline. The character previously on that
126   * position will be overwritten. You need to call redraw() to update the screen.
127   *
128   * @param c
129   *          x-coordinate (column)
130   * @param l
131   *          y-coordinate (line)
132   * @param ch
133   *          the character to show on the screen
134   * @see #insertChar
135   * @see #deleteChar
136   * @see #redraw
137   */
138  public void putChar(int c, int l, char ch) {
139    putChar(c, l, ch, NORMAL);
140  }
141
142  /**
143   * Put a character on the screen with specific font and outline. The character previously on that
144   * position will be overwritten. You need to call redraw() to update the screen.
145   *
146   * @param c
147   *          x-coordinate (column)
148   * @param l
149   *          y-coordinate (line)
150   * @param ch
151   *          the character to show on the screen
152   * @param attributes
153   *          the character attributes
154   * @see #BOLD
155   * @see #UNDERLINE
156   * @see #INVERT
157   * @see #INVISIBLE
158   * @see #NORMAL
159   * @see #LOW
160   * @see #insertChar
161   * @see #deleteChar
162   * @see #redraw
163   */
164
165  public void putChar(int c, int l, char ch, int attributes) {
166    charArray[screenBase + l][c] = ch;
167    charAttributes[screenBase + l][c] = attributes;
168    if (l < height) {
169      update[l + 1] = true;
170    }
171  }
172
173  /**
174   * Get the character at the specified position.
175   *
176   * @param c
177   *          x-coordinate (column)
178   * @param l
179   *          y-coordinate (line)
180   * @see #putChar
181   */
182  public char getChar(int c, int l) {
183    return charArray[screenBase + l][c];
184  }
185
186  /**
187   * Get the attributes for the specified position.
188   *
189   * @param c
190   *          x-coordinate (column)
191   * @param l
192   *          y-coordinate (line)
193   * @see #putChar
194   */
195  public int getAttributes(int c, int l) {
196    return charAttributes[screenBase + l][c];
197  }
198
199  /**
200   * Insert a character at a specific position on the screen. All character right to from this
201   * position will be moved one to the right. You need to call redraw() to update the screen.
202   *
203   * @param c
204   *          x-coordinate (column)
205   * @param l
206   *          y-coordinate (line)
207   * @param ch
208   *          the character to insert
209   * @param attributes
210   *          the character attributes
211   * @see #BOLD
212   * @see #UNDERLINE
213   * @see #INVERT
214   * @see #INVISIBLE
215   * @see #NORMAL
216   * @see #LOW
217   * @see #putChar
218   * @see #deleteChar
219   * @see #redraw
220   */
221  public void insertChar(int c, int l, char ch, int attributes) {
222    System.arraycopy(charArray[screenBase + l], c, charArray[screenBase + l], c + 1, width - c - 1);
223    System.arraycopy(charAttributes[screenBase + l], c, charAttributes[screenBase + l], c + 1,
224        width - c - 1);
225    putChar(c, l, ch, attributes);
226  }
227
228  /**
229   * Delete a character at a given position on the screen. All characters right to the position will
230   * be moved one to the left. You need to call redraw() to update the screen.
231   *
232   * @param c
233   *          x-coordinate (column)
234   * @param l
235   *          y-coordinate (line)
236   * @see #putChar
237   * @see #insertChar
238   * @see #redraw
239   */
240  public void deleteChar(int c, int l) {
241    if (c < width - 1) {
242      System.arraycopy(charArray[screenBase + l], c + 1, charArray[screenBase + l], c, width - c
243          - 1);
244      System.arraycopy(charAttributes[screenBase + l], c + 1, charAttributes[screenBase + l], c,
245          width - c - 1);
246    }
247    putChar(width - 1, l, (char) 0);
248  }
249
250  /**
251   * Put a String at a specific position. Any characters previously on that position will be
252   * overwritten. You need to call redraw() for screen update.
253   *
254   * @param c
255   *          x-coordinate (column)
256   * @param l
257   *          y-coordinate (line)
258   * @param s
259   *          the string to be shown on the screen
260   * @see #BOLD
261   * @see #UNDERLINE
262   * @see #INVERT
263   * @see #INVISIBLE
264   * @see #NORMAL
265   * @see #LOW
266   * @see #putChar
267   * @see #insertLine
268   * @see #deleteLine
269   * @see #redraw
270   */
271  public void putString(int c, int l, String s) {
272    putString(c, l, s, NORMAL);
273  }
274
275  /**
276   * Put a String at a specific position giving all characters the same attributes. Any characters
277   * previously on that position will be overwritten. You need to call redraw() to update the
278   * screen.
279   *
280   * @param c
281   *          x-coordinate (column)
282   * @param l
283   *          y-coordinate (line)
284   * @param s
285   *          the string to be shown on the screen
286   * @param attributes
287   *          character attributes
288   * @see #BOLD
289   * @see #UNDERLINE
290   * @see #INVERT
291   * @see #INVISIBLE
292   * @see #NORMAL
293   * @see #LOW
294   * @see #putChar
295   * @see #insertLine
296   * @see #deleteLine
297   * @see #redraw
298   */
299  public void putString(int c, int l, String s, int attributes) {
300    for (int i = 0; i < s.length() && c + i < width; i++) {
301      putChar(c + i, l, s.charAt(i), attributes);
302    }
303  }
304
305  /**
306   * Insert a blank line at a specific position. The current line and all previous lines are
307   * scrolled one line up. The top line is lost. You need to call redraw() to update the screen.
308   *
309   * @param l
310   *          the y-coordinate to insert the line
311   * @see #deleteLine
312   * @see #redraw
313   */
314  public void insertLine(int l) {
315    insertLine(l, 1, SCROLL_UP);
316  }
317
318  /**
319   * Insert blank lines at a specific position. You need to call redraw() to update the screen
320   *
321   * @param l
322   *          the y-coordinate to insert the line
323   * @param n
324   *          amount of lines to be inserted
325   * @see #deleteLine
326   * @see #redraw
327   */
328  public void insertLine(int l, int n) {
329    insertLine(l, n, SCROLL_UP);
330  }
331
332  /**
333   * Insert a blank line at a specific position. Scroll text according to the argument. You need to
334   * call redraw() to update the screen
335   *
336   * @param l
337   *          the y-coordinate to insert the line
338   * @param scrollDown
339   *          scroll down
340   * @see #deleteLine
341   * @see #SCROLL_UP
342   * @see #SCROLL_DOWN
343   * @see #redraw
344   */
345  public void insertLine(int l, boolean scrollDown) {
346    insertLine(l, 1, scrollDown);
347  }
348
349  /**
350   * Insert blank lines at a specific position. The current line and all previous lines are scrolled
351   * one line up. The top line is lost. You need to call redraw() to update the screen.
352   *
353   * @param l
354   *          the y-coordinate to insert the line
355   * @param n
356   *          number of lines to be inserted
357   * @param scrollDown
358   *          scroll down
359   * @see #deleteLine
360   * @see #SCROLL_UP
361   * @see #SCROLL_DOWN
362   * @see #redraw
363   */
364  public synchronized void insertLine(int l, int n, boolean scrollDown) {
365    char cbuf[][] = null;
366    int abuf[][] = null;
367    int offset = 0;
368    int oldBase = screenBase;
369
370    int newScreenBase = screenBase;
371    int newWindowBase = windowBase;
372    int newBufSize = bufSize;
373
374    if (l > bottomMargin) {
375      return;
376    }
377    int top =
378        (l < topMargin ? 0 : (l > bottomMargin ? (bottomMargin + 1 < height ? bottomMargin + 1
379            : height - 1) : topMargin));
380    int bottom =
381        (l > bottomMargin ? height - 1 : (l < topMargin ? (topMargin > 0 ? topMargin - 1 : 0)
382            : bottomMargin));
383
384    // System.out.println("l is "+l+", top is "+top+", bottom is "+bottom+", bottomargin is "+bottomMargin+", topMargin is "+topMargin);
385
386    if (scrollDown) {
387      if (n > (bottom - top)) {
388        n = (bottom - top);
389      }
390      int size = bottom - l - (n - 1);
391      if (size < 0) {
392        size = 0;
393      }
394      cbuf = new char[size][];
395      abuf = new int[size][];
396
397      System.arraycopy(charArray, oldBase + l, cbuf, 0, bottom - l - (n - 1));
398      System.arraycopy(charAttributes, oldBase + l, abuf, 0, bottom - l - (n - 1));
399      System.arraycopy(cbuf, 0, charArray, oldBase + l + n, bottom - l - (n - 1));
400      System.arraycopy(abuf, 0, charAttributes, oldBase + l + n, bottom - l - (n - 1));
401      cbuf = charArray;
402      abuf = charAttributes;
403    } else {
404      try {
405        if (n > (bottom - top) + 1) {
406          n = (bottom - top) + 1;
407        }
408        if (bufSize < maxBufSize) {
409          if (bufSize + n > maxBufSize) {
410            offset = n - (maxBufSize - bufSize);
411            scrollMarker += offset;
412            newBufSize = maxBufSize;
413            newScreenBase = maxBufSize - height - 1;
414            newWindowBase = screenBase;
415          } else {
416            scrollMarker += n;
417            newScreenBase += n;
418            newWindowBase += n;
419            newBufSize += n;
420          }
421
422          cbuf = new char[newBufSize][];
423          abuf = new int[newBufSize][];
424        } else {
425          offset = n;
426          cbuf = charArray;
427          abuf = charAttributes;
428        }
429        // copy anything from the top of the buffer (+offset) to the new top
430        // up to the screenBase.
431        if (oldBase > 0) {
432          System.arraycopy(charArray, offset, cbuf, 0, oldBase - offset);
433          System.arraycopy(charAttributes, offset, abuf, 0, oldBase - offset);
434        }
435        // copy anything from the top of the screen (screenBase) up to the
436        // topMargin to the new screen
437        if (top > 0) {
438          System.arraycopy(charArray, oldBase, cbuf, newScreenBase, top);
439          System.arraycopy(charAttributes, oldBase, abuf, newScreenBase, top);
440        }
441        // copy anything from the topMargin up to the amount of lines inserted
442        // to the gap left over between scrollback buffer and screenBase
443        if (oldBase >= 0) {
444          System.arraycopy(charArray, oldBase + top, cbuf, oldBase - offset, n);
445          System.arraycopy(charAttributes, oldBase + top, abuf, oldBase - offset, n);
446        }
447        // copy anything from topMargin + n up to the line linserted to the
448        // topMargin
449        System
450            .arraycopy(charArray, oldBase + top + n, cbuf, newScreenBase + top, l - top - (n - 1));
451        System.arraycopy(charAttributes, oldBase + top + n, abuf, newScreenBase + top, l - top
452            - (n - 1));
453        //
454        // copy the all lines next to the inserted to the new buffer
455        if (l < height - 1) {
456          System.arraycopy(charArray, oldBase + l + 1, cbuf, newScreenBase + l + 1, (height - 1)
457              - l);
458          System.arraycopy(charAttributes, oldBase + l + 1, abuf, newScreenBase + l + 1,
459              (height - 1) - l);
460        }
461      } catch (ArrayIndexOutOfBoundsException e) {
462        // this should not happen anymore, but I will leave the code
463        // here in case something happens anyway. That code above is
464        // so complex I always have a hard time understanding what
465        // I did, even though there are comments
466        System.err.println("*** Error while scrolling up:");
467        System.err.println("--- BEGIN STACK TRACE ---");
468        e.printStackTrace();
469        System.err.println("--- END STACK TRACE ---");
470        System.err.println("bufSize=" + bufSize + ", maxBufSize=" + maxBufSize);
471        System.err.println("top=" + top + ", bottom=" + bottom);
472        System.err.println("n=" + n + ", l=" + l);
473        System.err.println("screenBase=" + screenBase + ", windowBase=" + windowBase);
474        System.err.println("newScreenBase=" + newScreenBase + ", newWindowBase=" + newWindowBase);
475        System.err.println("oldBase=" + oldBase);
476        System.err.println("size.width=" + width + ", size.height=" + height);
477        System.err.println("abuf.length=" + abuf.length + ", cbuf.length=" + cbuf.length);
478        System.err.println("*** done dumping debug information");
479      }
480    }
481
482    // this is a little helper to mark the scrolling
483    scrollMarker -= n;
484
485    for (int i = 0; i < n; i++) {
486      cbuf[(newScreenBase + l) + (scrollDown ? i : -i)] = new char[width];
487      Arrays.fill(cbuf[(newScreenBase + l) + (scrollDown ? i : -i)], ' ');
488      abuf[(newScreenBase + l) + (scrollDown ? i : -i)] = new int[width];
489    }
490
491    charArray = cbuf;
492    charAttributes = abuf;
493    screenBase = newScreenBase;
494    windowBase = newWindowBase;
495    bufSize = newBufSize;
496
497    if (scrollDown) {
498      markLine(l, bottom - l + 1);
499    } else {
500      markLine(top, l - top + 1);
501    }
502
503    display.updateScrollBar();
504  }
505
506  /**
507   * Delete a line at a specific position. Subsequent lines will be scrolled up to fill the space
508   * and a blank line is inserted at the end of the screen.
509   *
510   * @param l
511   *          the y-coordinate to insert the line
512   * @see #deleteLine
513   */
514  public void deleteLine(int l) {
515    int bottom = (l > bottomMargin ? height - 1 : (l < topMargin ? topMargin : bottomMargin + 1));
516    int numRows = bottom - l - 1;
517
518    char[] discardedChars = charArray[screenBase + l];
519    int[] discardedAttributes = charAttributes[screenBase + l];
520
521    if (numRows > 0) {
522      System.arraycopy(charArray, screenBase + l + 1, charArray, screenBase + l, numRows);
523      System.arraycopy(charAttributes, screenBase + l + 1, charAttributes, screenBase + l, numRows);
524    }
525
526    int newBottomRow = screenBase + bottom - 1;
527    charArray[newBottomRow] = discardedChars;
528    charAttributes[newBottomRow] = discardedAttributes;
529    Arrays.fill(charArray[newBottomRow], ' ');
530    Arrays.fill(charAttributes[newBottomRow], 0);
531
532    markLine(l, bottom - l);
533  }
534
535  /**
536   * Delete a rectangular portion of the screen. You need to call redraw() to update the screen.
537   *
538   * @param c
539   *          x-coordinate (column)
540   * @param l
541   *          y-coordinate (row)
542   * @param w
543   *          with of the area in characters
544   * @param h
545   *          height of the area in characters
546   * @param curAttr
547   *          attribute to fill
548   * @see #deleteChar
549   * @see #deleteLine
550   * @see #redraw
551   */
552  public void deleteArea(int c, int l, int w, int h, int curAttr) {
553    int endColumn = c + w;
554    int targetRow = screenBase + l;
555    for (int i = 0; i < h && l + i < height; i++) {
556      Arrays.fill(charAttributes[targetRow], c, endColumn, curAttr);
557      Arrays.fill(charArray[targetRow], c, endColumn, ' ');
558      targetRow++;
559    }
560    markLine(l, h);
561  }
562
563  /**
564   * Delete a rectangular portion of the screen. You need to call redraw() to update the screen.
565   *
566   * @param c
567   *          x-coordinate (column)
568   * @param l
569   *          y-coordinate (row)
570   * @param w
571   *          with of the area in characters
572   * @param h
573   *          height of the area in characters
574   * @see #deleteChar
575   * @see #deleteLine
576   * @see #redraw
577   */
578  public void deleteArea(int c, int l, int w, int h) {
579    deleteArea(c, l, w, h, 0);
580  }
581
582  /**
583   * Sets whether the cursor is visible or not.
584   *
585   * @param doshow
586   */
587  public void showCursor(boolean doshow) {
588    showcursor = doshow;
589  }
590
591  /**
592   * Check whether the cursor is currently visible.
593   *
594   * @return visibility
595   */
596  public boolean isCursorVisible() {
597    return showcursor;
598  }
599
600  /**
601   * Puts the cursor at the specified position.
602   *
603   * @param c
604   *          column
605   * @param l
606   *          line
607   */
608  public void setCursorPosition(int c, int l) {
609    cursorX = c;
610    cursorY = l;
611  }
612
613  /**
614   * Get the current column of the cursor position.
615   */
616  public int getCursorColumn() {
617    return cursorX;
618  }
619
620  /**
621   * Get the current line of the cursor position.
622   */
623  public int getCursorRow() {
624    return cursorY;
625  }
626
627  /**
628   * Set the current window base. This allows to view the scrollback buffer.
629   *
630   * @param line
631   *          the line where the screen window starts
632   * @see #setBufferSize
633   * @see #getBufferSize
634   */
635  public void setWindowBase(int line) {
636    if (line > screenBase) {
637      line = screenBase;
638    } else if (line < 0) {
639      line = 0;
640    }
641    windowBase = line;
642    update[0] = true;
643    redraw();
644  }
645
646  /**
647   * Get the current window base.
648   *
649   * @see #setWindowBase
650   */
651  public int getWindowBase() {
652    return windowBase;
653  }
654
655  /**
656   * Set the scroll margins simultaneously. If they're out of bounds, trim them.
657   *
658   * @param l1
659   *          line that is the top
660   * @param l2
661   *          line that is the bottom
662   */
663  public void setMargins(int l1, int l2) {
664    if (l1 > l2) {
665      return;
666    }
667
668    if (l1 < 0) {
669      l1 = 0;
670    }
671    if (l2 >= height) {
672      l2 = height - 1;
673    }
674
675    topMargin = l1;
676    bottomMargin = l2;
677  }
678
679  /**
680   * Set the top scroll margin for the screen. If the current bottom margin is smaller it will
681   * become the top margin and the line will become the bottom margin.
682   *
683   * @param l
684   *          line that is the margin
685   */
686  public void setTopMargin(int l) {
687    if (l > bottomMargin) {
688      topMargin = bottomMargin;
689      bottomMargin = l;
690    } else {
691      topMargin = l;
692    }
693    if (topMargin < 0) {
694      topMargin = 0;
695    }
696    if (bottomMargin >= height) {
697      bottomMargin = height - 1;
698    }
699  }
700
701  /**
702   * Get the top scroll margin.
703   */
704  public int getTopMargin() {
705    return topMargin;
706  }
707
708  /**
709   * Set the bottom scroll margin for the screen. If the current top margin is bigger it will become
710   * the bottom margin and the line will become the top margin.
711   *
712   * @param l
713   *          line that is the margin
714   */
715  public void setBottomMargin(int l) {
716    if (l < topMargin) {
717      bottomMargin = topMargin;
718      topMargin = l;
719    } else {
720      bottomMargin = l;
721    }
722    if (topMargin < 0) {
723      topMargin = 0;
724    }
725    if (bottomMargin >= height) {
726      bottomMargin = height - 1;
727    }
728  }
729
730  /**
731   * Get the bottom scroll margin.
732   */
733  public int getBottomMargin() {
734    return bottomMargin;
735  }
736
737  /**
738   * Set scrollback buffer size.
739   *
740   * @param amount
741   *          new size of the buffer
742   */
743  public void setBufferSize(int amount) {
744    if (amount < height) {
745      amount = height;
746    }
747    if (amount < maxBufSize) {
748      char cbuf[][] = new char[amount][width];
749      int abuf[][] = new int[amount][width];
750      int copyStart = bufSize - amount < 0 ? 0 : bufSize - amount;
751      int copyCount = bufSize - amount < 0 ? bufSize : amount;
752      if (charArray != null) {
753        System.arraycopy(charArray, copyStart, cbuf, 0, copyCount);
754      }
755      if (charAttributes != null) {
756        System.arraycopy(charAttributes, copyStart, abuf, 0, copyCount);
757      }
758      charArray = cbuf;
759      charAttributes = abuf;
760      bufSize = copyCount;
761      screenBase = bufSize - height;
762      windowBase = screenBase;
763    }
764    maxBufSize = amount;
765
766    update[0] = true;
767    redraw();
768  }
769
770  /**
771   * Retrieve current scrollback buffer size.
772   *
773   * @see #setBufferSize
774   */
775  public int getBufferSize() {
776    return bufSize;
777  }
778
779  /**
780   * Retrieve maximum buffer Size.
781   *
782   * @see #getBufferSize
783   */
784  public int getMaxBufferSize() {
785    return maxBufSize;
786  }
787
788  /**
789   * Change the size of the screen. This will include adjustment of the scrollback buffer.
790   *
791   * @param w
792   *          of the screen
793   * @param h
794   *          of the screen
795   */
796  @SuppressWarnings("unused")
797  public void setScreenSize(int w, int h, boolean broadcast) {
798    char cbuf[][];
799    int abuf[][];
800    int maxSize = bufSize;
801
802    if (w < 1 || h < 1) {
803      return;
804    }
805
806    if (debug > 0) {
807      System.err.println("VDU: screen size [" + w + "," + h + "]");
808    }
809
810    if (h > maxBufSize) {
811      maxBufSize = h;
812    }
813
814    if (h > bufSize) {
815      bufSize = h;
816      screenBase = 0;
817      windowBase = 0;
818    }
819
820    if (windowBase + h >= bufSize) {
821      windowBase = bufSize - h;
822    }
823
824    if (screenBase + h >= bufSize) {
825      screenBase = bufSize - h;
826    }
827
828    cbuf = new char[bufSize][w];
829    abuf = new int[bufSize][w];
830
831    for (int i = 0; i < bufSize; i++) {
832      Arrays.fill(cbuf[i], ' ');
833    }
834
835    if (bufSize < maxSize) {
836      maxSize = bufSize;
837    }
838
839    int rowLength;
840    if (charArray != null && charAttributes != null) {
841      for (int i = 0; i < maxSize && charArray[i] != null; i++) {
842        rowLength = charArray[i].length;
843        System.arraycopy(charArray[i], 0, cbuf[i], 0, w < rowLength ? w : rowLength);
844        System.arraycopy(charAttributes[i], 0, abuf[i], 0, w < rowLength ? w : rowLength);
845      }
846    }
847
848    int C = getCursorColumn();
849    if (C < 0) {
850      C = 0;
851    } else if (C >= width) {
852      C = width - 1;
853    }
854
855    int R = getCursorRow();
856    if (R < 0) {
857      R = 0;
858    } else if (R >= height) {
859      R = height - 1;
860    }
861
862    setCursorPosition(C, R);
863
864    charArray = cbuf;
865    charAttributes = abuf;
866    width = w;
867    height = h;
868    topMargin = 0;
869    bottomMargin = h - 1;
870    update = new boolean[h + 1];
871    update[0] = true;
872    /*
873     * FIXME: ??? if(resizeStrategy == RESIZE_FONT) setBounds(getBounds());
874     */
875  }
876
877  /**
878   * Get amount of rows on the screen.
879   */
880  public int getRows() {
881    return height;
882  }
883
884  /**
885   * Get amount of columns on the screen.
886   */
887  public int getColumns() {
888    return width;
889  }
890
891  /**
892   * Mark lines to be updated with redraw().
893   *
894   * @param l
895   *          starting line
896   * @param n
897   *          amount of lines to be updated
898   * @see #redraw
899   */
900  public void markLine(int l, int n) {
901    for (int i = 0; (i < n) && (l + i < height); i++) {
902      update[l + i + 1] = true;
903    }
904  }
905
906  // private static int checkBounds(int value, int lower, int upper) {
907  // if (value < lower)
908  // return lower;
909  // else if (value > upper)
910  // return upper;
911  // else
912  // return value;
913  // }
914
915  /** a generic display that should redraw on demand */
916  protected VDUDisplay display;
917
918  public void setDisplay(VDUDisplay display) {
919    this.display = display;
920  }
921
922  /**
923   * Trigger a redraw on the display.
924   */
925  protected void redraw() {
926    if (display != null) {
927      display.redraw();
928    }
929  }
930}
931