//
// Fl_Help_View widget routines.
//
// Copyright 1997-2010 by Easy Software Products.
// Image support by Matthias Melcher, Copyright 2000-2009.
//
// Buffer management (HV_Edit_Buffer) and more by AlbrechtS and others.
// Copyright 2011-2019 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//
// Contents:
//
//   Fl_Help_View::add_block()       - Add a text block to the list.
//   Fl_Help_View::add_link()        - Add a new link to the list.
//   Fl_Help_View::add_target()      - Add a new target to the list.
//   Fl_Help_View::compare_targets() - Compare two targets.
//   Fl_Help_View::do_align()        - Compute the alignment for a line in
//                                     a block.
//   Fl_Help_View::draw()            - Draw the Fl_Help_View widget.
//   Fl_Help_View::format()          - Format the help text.
//   Fl_Help_View::format_table()    - Format a table...
//   Fl_Help_View::free_data()       - Free memory used for the document.
//   Fl_Help_View::get_align()       - Get an alignment attribute.
//   Fl_Help_View::get_attr()        - Get an attribute value from the string.
//   Fl_Help_View::get_color()       - Get an alignment attribute.
//   Fl_Help_View::handle()          - Handle events in the widget.
//   Fl_Help_View::Fl_Help_View()    - Build a Fl_Help_View widget.
//   Fl_Help_View::~Fl_Help_View()   - Destroy a Fl_Help_View widget.
//   Fl_Help_View::load()            - Load the specified file.
//   Fl_Help_View::resize()          - Resize the help widget.
//   Fl_Help_View::topline()         - Set the top line to the named target.
//   Fl_Help_View::topline()         - Set the top line by number.
//   Fl_Help_View::value()           - Set the help text directly.
//   scrollbar_callback()            - A callback for the scrollbar.
//

//
// Include necessary header files...
//

#include <FL/Fl_Help_View.H>
#include <FL/Fl_Shared_Image.H>
#include <FL/Fl_Window.H>
#include <FL/Fl_Pixmap.H>

#include <stdio.h>
#include <stdlib.h>
#include <FL/fl_utf8.h>
#include <FL/filename.H>        // fl_open_uri()
#include <FL/fl_string.h>       // fl_strdup()
#include "flstring.h"
#include <ctype.h>
#include <errno.h>
#include <math.h>

#define MAX_COLUMNS     200

//
// Typedef the C API sort function type the only way I know how...
//

extern "C"
{
  typedef int (*compare_func_t)(const void *, const void *);
}


//
// Local functions...
//

static int      quote_char(const char *);
static void     scrollbar_callback(Fl_Widget *s, void *);
static void     hscrollbar_callback(Fl_Widget *s, void *);

//
// global flag for image loading (see get_image).
//

static char initial_load = 0;

//
// Broken image...
//

static const char * const broken_xpm[] =
                {
                  "16 24 4 1",
                  "@ c #000000",
                  "  c #ffffff",
                  "+ c none",
                  "x c #ff0000",
                  // pixels
                  "@@@@@@@+++++++++",
                  "@    @++++++++++",
                  "@   @+++++++++++",
                  "@   @++@++++++++",
                  "@    @@+++++++++",
                  "@     @+++@+++++",
                  "@     @++@@++++@",
                  "@ xxx  @@  @++@@",
                  "@  xxx    xx@@ @",
                  "@   xxx  xxx   @",
                  "@    xxxxxx    @",
                  "@     xxxx     @",
                  "@    xxxxxx    @",
                  "@   xxx  xxx   @",
                  "@  xxx    xxx  @",
                  "@ xxx      xxx @",
                  "@              @",
                  "@              @",
                  "@              @",
                  "@              @",
                  "@              @",
                  "@              @",
                  "@              @",
                  "@@@@@@@@@@@@@@@@",
                  NULL
                };

static Fl_Pixmap broken_image(broken_xpm);

//
// Simple margin stack for Fl_Help_View::format()...
//

struct fl_margins {
  int depth_;
  int margins_[100];

  fl_margins() { clear();  }

  int clear() {
//    puts("fl_margins::clear()");

    depth_ = 0;
    return margins_[0] = 4;
  }

  int current() { return margins_[depth_]; }

  int pop() {
//    printf("fl_margins::pop(): depth_=%d, xx=%d\n", depth_,
//           depth_ > 0 ? margins_[depth_ - 1] : 4);

    if (depth_ > 0) {
      depth_ --;
      return margins_[depth_];
    } else return 4;
  }

  int push(int indent) {
    int xx;

    xx = margins_[depth_] + indent;

//    printf("fl_margins::push(indent=%d): depth_=%d, xx=%d\n", indent,
//           depth_ + 1, xx);

    if (depth_ < 99) {
      depth_ ++;
      margins_[depth_] = xx;
    }

    return xx;
  }
};

//
// All the stuff needed to implement text selection in Fl_Help_View
//

/* matt:
 * We are trying to keep binary compatibility with previous versions
 * of FLTK. This means that we are limited to adding static variables
 * only to not enlarge the Fl_Help_View class. Lucky for us, only one
 * text can be selected system wide, so we can remember the selection
 * in a single set of variables.
 *
 * Still to do:
 * - &word; style characters mess up our count inside a word boundary
 * - we can only select words, no individual characters
 * - no dragging of the selection into another widget
 * - selection must be cleared if another widget get focus!
 * - write a comment for every new function
 */

/*
The following functions are also used to draw stuff and should be replaced with
local copies that are much faster when merely counting:

fl_color(Fl_Color);
fl_rectf(int, int, int, int);
fl_push_clip(int, int, int, int);
fl_xyline(int, int, int);
fl_rect()
fl_line()
img->draw()
*/

// We don't put the offscreen buffer in the help view class because
// we'd need to include platform.H in the header...
static Fl_Offscreen fl_help_view_buffer;
int Fl_Help_View::selection_first = 0;
int Fl_Help_View::selection_last = 0;
int Fl_Help_View::selection_push_first = 0;
int Fl_Help_View::selection_push_last = 0;
int Fl_Help_View::selection_drag_first = 0;
int Fl_Help_View::selection_drag_last = 0;
int Fl_Help_View::selected = 0;
int Fl_Help_View::draw_mode = 0;
int Fl_Help_View::mouse_x = 0;
int Fl_Help_View::mouse_y = 0;
int Fl_Help_View::current_pos = 0;
Fl_Help_View *Fl_Help_View::current_view = 0L;
Fl_Color Fl_Help_View::hv_selection_color;
Fl_Color Fl_Help_View::hv_selection_text_color;

/*
 * This function must be optimized for speed!
 */
void Fl_Help_View::hv_draw(const char *t, int x, int y, int entity_extra_length)
{
  if (selected && current_view==this && current_pos<selection_last && current_pos>=selection_first) {
    Fl_Color c = fl_color();
    fl_color(hv_selection_color);
    int w = (int)fl_width(t);
    if (current_pos+(int)strlen(t)<selection_last)
      w += (int)fl_width(' ');
    fl_rectf(x, y+fl_descent()-fl_height(), w, fl_height());
    fl_color(hv_selection_text_color);
    fl_draw(t, x, y);
    fl_color(c);
  } else {
    fl_draw(t, x, y);
  }
  if (draw_mode) {
    int w = (int)fl_width(t);
    if (mouse_x>=x && mouse_x<x+w) {
      if (mouse_y>=y-fl_height()+fl_descent()&&mouse_y<=y+fl_descent()) {
        int f = (int) current_pos;
        int l = (int) (f+strlen(t)); // use 'quote_char' to calculate the true length of the HTML string
        if (draw_mode==1) {
          selection_push_first = f;
          selection_push_last = l;
        } else {
          selection_drag_first = f;
          selection_drag_last = l + entity_extra_length;
        }
      }
    }
  }
}

#define DEBUG_EDIT_BUFFER 0

#if (DEBUG_EDIT_BUFFER > 1)
#define DEBUG_FUNCTION(L,F) \
  printf("\n========\n  [%d] --- %s\n========\n", L, F); \
  fflush(stdout);
#else
#define DEBUG_FUNCTION(L,F)
#endif


/* ** Intentionally not Doxygen docs.
  HelpView Edit Buffer management class.
  <b>Internal use only.</b>

  This class is for internal use in this file. Its sole purpose is to
  allow buffer management to avoid buffer overflows in stack variables
  used to edit strings for formatting and drawing (STR #3275).

  This class will likely be superseded by an Fl_String or Fl_Buffer class
  in a later FLTK release (1.4.x).

  Note: The buffer allocation and extension size (chunk size) must be
  a power of 2, but this is deliberately never checked, because this
  class is only used here with default values. Using extension sizes
  that are not a power of 2 may result in unpredictable behavior.
*/

class HV_Edit_Buffer {

  int size_;                            // actually used text size w/o nul
  int allocated_;                       // allocated buffer size
  int extend_;                          // extend size (must be a power of 2)

  char *buf_;                           // internal buffer

public:

  HV_Edit_Buffer (int alloc = 1024, int ext = 1024);    // c'tor
  ~HV_Edit_Buffer ();                                   // d'tor

  char *c_str() { return buf_; }
  void clear();
  int size() { return size_; }
  void check(int size);
  const char *add(const char *text, int size = -1);
  void add(char c);
  void add(int ucs);

  int cmp(const char * str) { return !strcasecmp(buf_, str); }
  int width() { return (int)fl_width(buf_); }

  char & operator[] (int idx) { return buf_[idx]; }
  char operator[] (int idx) const { return buf_[idx]; }

#if (DEBUG_EDIT_BUFFER)
  void print(const char *text = "");
#endif
};

/*
  Edit buffer constructor.
*/
HV_Edit_Buffer::HV_Edit_Buffer(
        int     alloc,
        int     ext)
{
  alloc = (alloc + ext-1) & (~(ext-1)); // round to chunk size

  size_ = 0;
  allocated_ = alloc;
  extend_ = ext;
  buf_ = (char *)malloc(alloc);
}

/*
  Clears the edit buffer, but doesn't free the buffer.
*/
void HV_Edit_Buffer::clear()
{

  // DEBUG_FUNCTION(__LINE__,__FUNCTION__);

  size_ = 0;
  buf_[0] = '\0';
}

/*
  Adds text to the buffer.

  \param[in]    text    text to be added
  \param[in]    size    text size, default: -1 => strlen(text)
  \returns      new input text pointer, i.e. points beyond inserted text
*/
const char *HV_Edit_Buffer::add(const char *text, int size) {

  if (size < 0) size = (int)strlen(text);
  if (!size) return text;

  check(size);

#if (DEBUG_EDIT_BUFFER > 1)
  printf("HV_Edit_Buffer::add(text,%d), allocated=%d, size=%d\n",
         size, allocated_, size_+size);
  fflush(stdout);
#endif

  memcpy(buf_+size_, text, size);
  size_ += size;
  buf_[size_] = '\0';

  return (text + size);

} // add(const char *text, int size)

/*
  Adds one byte (character) to the buffer.

  \note It is possible to add partial UTF-8 sequences.

  \param[in]    c       byte (char) to be added
*/
void HV_Edit_Buffer::add(char c) {

  check(1);

#if (DEBUG_EDIT_BUFFER > 1)
  printf("HV_Edit_Buffer::add(char = '%c'), allocated=%d, size=%d\n",
         c, allocated_, size_+1);
  fflush(stdout);
#endif

  buf_[size_++] = c;
  buf_[size_] = '\0';

} // add(char c)

/*
  Adds one Unicode character (int) to the buffer.

  The Unicode character \p ucs is converted to UTF-8 and appended to
  the buffer.

  \param[in]    ucs     Unicode character (code point) to be added
*/
void HV_Edit_Buffer::add(int ucs) {

  int len;
  char cbuf[6];

  len = fl_utf8encode((unsigned int)ucs, cbuf);
  if (len < 1) len = 1;
  add(cbuf,len);

} // add(int ucs)

/*
  Checks needed buffer size and reallocates the buffer if necessary.

  Tests if the given string \p size can be added to the string buffer.
  An additional nul byte is also considered in the calculation.

  \p size must be >= 0.

  If the requested \p size doesn't fit in the allocated buffer size,
  the buffer is extended.

  \param[in]    size    requested text size to be added (w/o trailing nul)
*/
void HV_Edit_Buffer::check(int size) {

  if (size_ + size + 1 <= allocated_) return;

  int new_size = (allocated_ + size + extend_) & (~(extend_-1)); // round to chunk size

  buf_ = (char *)realloc(buf_, new_size);

#if (DEBUG_EDIT_BUFFER)
  printf("HV_Edit_Buffer::check(%d), allocated: %d ->%d\n",
         size, allocated_, new_size);
  fflush(stdout);
#endif

  allocated_ = new_size;

} // HV_Edit_Buffer::check()


/*
  The destructor frees the edit buffer.
*/
HV_Edit_Buffer::~HV_Edit_Buffer() {

  if (buf_) {
#if (DEBUG_EDIT_BUFFER)
    printf("~HV_Edit_Buffer(): size = %d, allocated = %d\n",
      size_, allocated_);
    fflush(stdout);
#endif
    free(buf_);
  }
} // ~HV_Edit_Buffer()


/*
  Prints the edit buffer (Debug only).
*/
#if (DEBUG_EDIT_BUFFER)
void HV_Edit_Buffer::print(const char *text) {
  printf("HV_Edit_Buffer::print(%s), allocated=%d, size=%d\n",
         text, allocated_, size_);
  printf("    \"%s\"\n", buf_ && size_ ? buf_ : "");
  fflush(stdout);
} // print()
#endif

/** Adds a text block to the list. */
Fl_Help_Block *                                 // O - Pointer to new block
Fl_Help_View::add_block(const char   *s,        // I - Pointer to start of block text
                        int           xx,       // I - X position of block
                        int           yy,       // I - Y position of block
                        int           ww,       // I - Right margin of block
                        int           hh,       // I - Height of block
                        unsigned char border)   // I - Draw border?
{
  Fl_Help_Block *temp;                          // New block


  // printf("add_block(s = %p, xx = %d, yy = %d, ww = %d, hh = %d, border = %d)\n",
  //        s, xx, yy, ww, hh, border);

  if (nblocks_ >= ablocks_)
  {
    ablocks_ += 16;

    if (ablocks_ == 16)
      blocks_ = (Fl_Help_Block *)malloc(sizeof(Fl_Help_Block) * ablocks_);
    else
      blocks_ = (Fl_Help_Block *)realloc(blocks_, sizeof(Fl_Help_Block) * ablocks_);
  }

  temp = blocks_ + nblocks_;
  memset(temp, 0, sizeof(Fl_Help_Block));
  temp->start   = s;
  temp->end     = s;
  temp->x       = xx;
  temp->y       = yy;
  temp->w       = ww;
  temp->h       = hh;
  temp->border  = border;
  temp->bgcolor = bgcolor_;
  nblocks_ ++;

  return (temp);
}


/** Adds a new link to the list. */
void Fl_Help_View::add_link(const char *n,      // I - Name of link
                      int        xx,    // I - X position of link
                      int        yy,    // I - Y position of link
                      int        ww,    // I - Width of link text
                      int        hh)    // I - Height of link text
{
  Fl_Help_Link  *temp;                  // New link
  char          *target;                // Pointer to target name


  if (nlinks_ >= alinks_)
  {
    alinks_ += 16;

    if (alinks_ == 16)
      links_ = (Fl_Help_Link *)malloc(sizeof(Fl_Help_Link) * alinks_);
    else
      links_ = (Fl_Help_Link *)realloc(links_, sizeof(Fl_Help_Link) * alinks_);
  }

  temp = links_ + nlinks_;

  temp->x       = xx;
  temp->y       = yy;
  temp->w       = xx + ww;
  temp->h       = yy + hh;

  strlcpy(temp->filename, n, sizeof(temp->filename));

  if ((target = strrchr(temp->filename, '#')) != NULL)
  {
    *target++ = '\0';
    strlcpy(temp->name, target, sizeof(temp->name));
  }
  else
    temp->name[0] = '\0';

  nlinks_ ++;
}


/** Adds a new target to the list. */
void Fl_Help_View::add_target(const char *n,    // I - Name of target
                              int        yy)    // I - Y position of target
{
  Fl_Help_Target        *temp;                  // New target


  if (ntargets_ >= atargets_)
  {
    atargets_ += 16;

    if (atargets_ == 16)
      targets_ = (Fl_Help_Target *)malloc(sizeof(Fl_Help_Target) * atargets_);
    else
      targets_ = (Fl_Help_Target *)realloc(targets_, sizeof(Fl_Help_Target) * atargets_);
  }

  temp = targets_ + ntargets_;

  temp->y = yy;
  strlcpy(temp->name, n, sizeof(temp->name));

  ntargets_ ++;
}

/** Compares two targets.*/
int                                                     // O - Result of comparison
Fl_Help_View::compare_targets(const Fl_Help_Target *t0, // I - First target
                             const Fl_Help_Target *t1)  // I - Second target
{
  return (strcasecmp(t0->name, t1->name));
}

/** Computes the alignment for a line in a block.*/
int                                             // O - New line
Fl_Help_View::do_align(Fl_Help_Block *block,    // I - Block to add to
                      int          line,        // I - Current line
                      int          xx,          // I - Current X position
                      int          a,           // I - Current alignment
                      int          &l)          // IO - Starting link
{
  int   offset;                                 // Alignment offset


  switch (a)
  {
    case RIGHT :        // Right align
        offset = block->w - xx;
        break;
    case CENTER :       // Center
        offset = (block->w - xx) / 2;
        break;
    default :           // Left align
        offset = 0;
        break;
  }

  block->line[line] = block->x + offset;

  if (line < 31)
    line ++;

  while (l < nlinks_)
  {
    links_[l].x += offset;
    links_[l].w += offset;
    l ++;
  }

  return (line);
}

/** Draws the Fl_Help_View widget. */
void
Fl_Help_View::draw()
{
  int                   i;              // Looping var
  const Fl_Help_Block   *block;         // Pointer to current block
  const char            *ptr,           // Pointer to text in block
                        *attrs;         // Pointer to start of element attributes
  HV_Edit_Buffer        buf;            // Text buffer
  char                  attr[1024];     // Attribute buffer
  int                   xx, yy, ww, hh; // Current positions and sizes
  int                   line;           // Current line
  Fl_Font               font;
  Fl_Fontsize           fsize;          // Current font and size
  Fl_Color              fcolor;         // current font color
  int                   head, pre,      // Flags for text
                        needspace;      // Do we need whitespace?
  Fl_Boxtype            b = box() ? box() : FL_DOWN_BOX;
                                        // Box to draw...
  int                   underline,      // Underline text?
                        xtra_ww;        // Extra width for underlined space between words

  DEBUG_FUNCTION(__LINE__,__FUNCTION__);

  // Draw the scrollbar(s) and box first...
  ww = w();
  hh = h();
  i  = 0;

  draw_box(b, x(), y(), ww, hh, bgcolor_);

  if ( hscrollbar_.visible() || scrollbar_.visible() ) {
    int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
    int hor_vis = hscrollbar_.visible();
    int ver_vis = scrollbar_.visible();
    // Scrollbar corner
    int scorn_x = x() + ww - (ver_vis?scrollsize:0) - Fl::box_dw(b) + Fl::box_dx(b);
    int scorn_y = y() + hh - (hor_vis?scrollsize:0) - Fl::box_dh(b) + Fl::box_dy(b);
    if ( hor_vis ) {
      if ( hscrollbar_.h() != scrollsize ) {            // scrollsize changed?
        hscrollbar_.resize(x(), scorn_y, scorn_x - x(), scrollsize);
        init_sizes();
      }
      draw_child(hscrollbar_);
      hh -= scrollsize;
    }
    if ( ver_vis ) {
      if ( scrollbar_.w() != scrollsize ) {             // scrollsize changed?
        scrollbar_.resize(scorn_x, y(), scrollsize, scorn_y - y());
        init_sizes();
      }
      draw_child(scrollbar_);
      ww -= scrollsize;
    }
    if ( hor_vis && ver_vis ) {
      // Both scrollbars visible? Draw little gray box in corner
      fl_color(FL_GRAY);
      fl_rectf(scorn_x, scorn_y, scrollsize, scrollsize);
    }
  }

  if (!value_)
    return;

  if (current_view == this && selected) {
    hv_selection_color      = FL_SELECTION_COLOR;
    hv_selection_text_color = fl_contrast(textcolor_, FL_SELECTION_COLOR);
  }
  current_pos = 0;

  // Clip the drawing to the inside of the box...
  fl_push_clip(x() + Fl::box_dx(b), y() + Fl::box_dy(b),
               ww - Fl::box_dw(b), hh - Fl::box_dh(b));
  fl_color(textcolor_);

  // Draw all visible blocks...
  for (i = 0, block = blocks_; i < nblocks_; i ++, block ++)
    if ((block->y + block->h) >= topline_ && block->y < (topline_ + h()))
    {
      line      = 0;
      xx        = block->line[line];
      yy        = block->y - topline_;
      hh        = 0;
      pre       = 0;
      head      = 0;
      needspace = 0;
      underline = 0;

      initfont(font, fsize, fcolor);
      // byte length difference between html entity (encoded by &...;) and
      // UTF-8 encoding of same character
      int entity_extra_length = 0;
      for (ptr = block->start, buf.clear(); ptr < block->end;)
      {
        if ((*ptr == '<' || isspace((*ptr)&255)) && buf.size() > 0)
        {
          if (!head && !pre)
          {
            // Check width...
            ww = buf.width();

            if (needspace && xx > block->x)
              xx += (int)fl_width(' ');

            if ((xx + ww) > block->w)
            {
              if (line < 31)
                line ++;
              xx = block->line[line];
              yy += hh;
              hh = 0;
            }

            hv_draw(buf.c_str(), xx + x() - leftline_, yy + y(), entity_extra_length);
            buf.clear();
            entity_extra_length = 0;
            if (underline) {
              xtra_ww = isspace((*ptr)&255)?(int)fl_width(' '):0;
              fl_xyline(xx + x() - leftline_, yy + y() + 1,
                        xx + x() - leftline_ + ww + xtra_ww);
            }
            current_pos = (int) (ptr-value_);

            xx += ww;
            if ((fsize + 2) > hh)
              hh = fsize + 2;

            needspace = 0;
          }
          else if (pre)
          {
            while (isspace((*ptr)&255))
            {
              if (*ptr == '\n')
              {
                hv_draw(buf.c_str(), xx + x() - leftline_, yy + y());
                if (underline) fl_xyline(xx + x() - leftline_, yy + y() + 1,
                                         xx + x() - leftline_ + buf.width());
                buf.clear();
                current_pos = (int) (ptr-value_);
                if (line < 31)
                  line ++;
                xx = block->line[line];
                yy += hh;
                hh = fsize + 2;
              }
              else if (*ptr == '\t')
              {
                // Do tabs every 8 columns...
                buf.add(' '); // add at least one space
                while (buf.size() & 7)
                  buf.add(' ');
              }
              else {
                buf.add(' ');
              }
              if ((fsize + 2) > hh)
                hh = fsize + 2;

              ptr ++;
            }

            if (buf.size() > 0)
            {
              hv_draw(buf.c_str(), xx + x() - leftline_, yy + y());
              ww = buf.width();
              buf.clear();
              if (underline) fl_xyline(xx + x() - leftline_, yy + y() + 1,
                                       xx + x() - leftline_ + ww);
              xx += ww;
              current_pos = (int) (ptr-value_);
            }

            needspace = 0;
          }
          else
          {
            buf.clear();

            while (isspace((*ptr)&255))
              ptr ++;
            current_pos = (int) (ptr-value_);
          }
        }

        if (*ptr == '<')
        {
          ptr ++;

          if (strncmp(ptr, "!--", 3) == 0)
          {
            // Comment...
            ptr += 3;
            if ((ptr = strstr(ptr, "-->")) != NULL)
            {
              ptr += 3;
              continue;
            }
            else
              break;
          }

          while (*ptr && *ptr != '>' && !isspace((*ptr)&255))
            buf.add(*ptr++);

          attrs = ptr;
          while (*ptr && *ptr != '>')
            ptr ++;

          if (*ptr == '>')
            ptr ++;

          // end of command reached, set the supposed start of printed eord here
          current_pos = (int) (ptr-value_);
          if (buf.cmp("HEAD"))
            head = 1;
          else if (buf.cmp("BR"))
          {
            if (line < 31)
              line ++;
            xx = block->line[line];
            yy += hh;
            hh = 0;
          }
          else if (buf.cmp("HR"))
          {
            fl_line(block->x + x(), yy + y(), block->w + x(),
                    yy + y());

            if (line < 31)
              line ++;
            xx = block->line[line];
            yy += 2 * fsize;//hh;
            hh = 0;
          }
          else if (buf.cmp("CENTER") ||
                   buf.cmp("P") ||
                   buf.cmp("H1") ||
                   buf.cmp("H2") ||
                   buf.cmp("H3") ||
                   buf.cmp("H4") ||
                   buf.cmp("H5") ||
                   buf.cmp("H6") ||
                   buf.cmp("UL") ||
                   buf.cmp("OL") ||
                   buf.cmp("DL") ||
                   buf.cmp("LI") ||
                   buf.cmp("DD") ||
                   buf.cmp("DT") ||
                   buf.cmp("PRE"))
          {
            if (tolower(buf[0]) == 'h')
            {
              font  = FL_HELVETICA_BOLD;
              fsize = textsize_ + '7' - buf[1];
            }
            else if (buf.cmp("DT"))
            {
              font  = textfont_ | FL_ITALIC;
              fsize = textsize_;
            }
            else if (buf.cmp("PRE"))
            {
              font  = FL_COURIER;
              fsize = textsize_;
              pre   = 1;
            }

            if (buf.cmp("LI"))
            {
              // draw bullet (&bull;) Unicode: U+2022, UTF-8 (hex): e2 80 a2
              unsigned char bullet[4] = { 0xe2, 0x80, 0xa2, 0x00 };
              hv_draw((char *)bullet, xx - fsize + x() - leftline_, yy + y());
            }

            pushfont(font, fsize);
            buf.clear();
          }
          else if (buf.cmp("A") &&
                   get_attr(attrs, "HREF", attr, sizeof(attr)) != NULL)
          {
            fl_color(linkcolor_);
            underline = 1;
          }
          else if (buf.cmp("/A"))
          {
            fl_color(textcolor_);
            underline = 0;
          }
          else if (buf.cmp("FONT"))
          {
            if (get_attr(attrs, "COLOR", attr, sizeof(attr)) != NULL) {
              textcolor_ = get_color(attr, textcolor_);
            }

            if (get_attr(attrs, "FACE", attr, sizeof(attr)) != NULL) {
              if (!strncasecmp(attr, "helvetica", 9) ||
                  !strncasecmp(attr, "arial", 5) ||
                  !strncasecmp(attr, "sans", 4)) font = FL_HELVETICA;
              else if (!strncasecmp(attr, "times", 5) ||
                       !strncasecmp(attr, "serif", 5)) font = FL_TIMES;
              else if (!strncasecmp(attr, "symbol", 6)) font = FL_SYMBOL;
              else font = FL_COURIER;
            }

            if (get_attr(attrs, "SIZE", attr, sizeof(attr)) != NULL) {
              if (isdigit(attr[0] & 255)) {
                // Absolute size
                fsize = (int)(textsize_ * pow(1.2, atof(attr) - 3.0));
              } else {
                // Relative size
                fsize = (int)(fsize * pow(1.2, atof(attr) - 3.0));
              }
            }

            pushfont(font, fsize);
          }
          else if (buf.cmp("/FONT"))
          {
            popfont(font, fsize, textcolor_);
          }
          else if (buf.cmp("U"))
            underline = 1;
          else if (buf.cmp("/U"))
            underline = 0;
          else if (buf.cmp("B") ||
                   buf.cmp("STRONG"))
            pushfont(font |= FL_BOLD, fsize);
          else if (buf.cmp("TD") ||
                   buf.cmp("TH"))
          {
            int tx, ty, tw, th;

            if (tolower(buf[1]) == 'h')
              pushfont(font |= FL_BOLD, fsize);
            else
              pushfont(font = textfont_, fsize);

            tx = block->x - 4 - leftline_;
            ty = block->y - topline_ - fsize - 3;
            tw = block->w - block->x + 7;
            th = block->h + fsize - 5;

            if (tx < 0)
            {
              tw += tx;
              tx  = 0;
            }

            if (ty < 0)
            {
              th += ty;
              ty  = 0;
            }

            tx += x();
            ty += y();

            if (block->bgcolor != bgcolor_)
            {
              fl_color(block->bgcolor);
              fl_rectf(tx, ty, tw, th);
              fl_color(textcolor_);
            }

            if (block->border)
              fl_rect(tx, ty, tw, th);
          }
          else if (buf.cmp("I") ||
                   buf.cmp("EM"))
            pushfont(font |= FL_ITALIC, fsize);
          else if (buf.cmp("CODE") ||
                   buf.cmp("TT"))
            pushfont(font = FL_COURIER, fsize);
          else if (buf.cmp("KBD"))
            pushfont(font = FL_COURIER_BOLD, fsize);
          else if (buf.cmp("VAR"))
            pushfont(font = FL_COURIER_ITALIC, fsize);
          else if (buf.cmp("/HEAD"))
            head = 0;
          else if (buf.cmp("/H1") ||
                   buf.cmp("/H2") ||
                   buf.cmp("/H3") ||
                   buf.cmp("/H4") ||
                   buf.cmp("/H5") ||
                   buf.cmp("/H6") ||
                   buf.cmp("/B") ||
                   buf.cmp("/STRONG") ||
                   buf.cmp("/I") ||
                   buf.cmp("/EM") ||
                   buf.cmp("/CODE") ||
                   buf.cmp("/TT") ||
                   buf.cmp("/KBD") ||
                   buf.cmp("/VAR"))
            popfont(font, fsize, fcolor);
          else if (buf.cmp("/PRE"))
          {
            popfont(font, fsize, fcolor);
            pre = 0;
          }
          else if (buf.cmp("IMG"))
          {
            Fl_Shared_Image *img = 0;
            int         width, height;
            char        wattr[8], hattr[8];


            get_attr(attrs, "WIDTH", wattr, sizeof(wattr));
            get_attr(attrs, "HEIGHT", hattr, sizeof(hattr));
            width  = get_length(wattr);
            height = get_length(hattr);

            if (get_attr(attrs, "SRC", attr, sizeof(attr))) {
              img = get_image(attr, width, height);
              if (!width) width = img->w();
              if (!height) height = img->h();
            }

            if (!width || !height) {
              if (get_attr(attrs, "ALT", attr, sizeof(attr)) == NULL) {
                strcpy(attr, "IMG");
              }
            }

            ww = width;

            if (needspace && xx > block->x)
              xx += (int)fl_width(' ');

            if ((xx + ww) > block->w)
            {
              if (line < 31)
                line ++;

              xx = block->line[line];
              yy += hh;
              hh = 0;
            }

            if (img) {
              img->draw(xx + x() - leftline_,
                        yy + y() - fl_height() + fl_descent() + 2);
            }

            xx += ww;
            if ((height + 2) > hh)
              hh = height + 2;

            needspace = 0;
          }
          buf.clear();
        }
        else if (*ptr == '\n' && pre)
        {
          hv_draw(buf.c_str(), xx + x() - leftline_, yy + y());
          buf.clear();

          if (line < 31)
            line ++;
          xx = block->line[line];
          yy += hh;
          hh = fsize + 2;
          needspace = 0;

          ptr ++;
          current_pos = (int) (ptr-value_);
        }
        else if (isspace((*ptr)&255))
        {
          if (pre)
          {
            if (*ptr == ' ')
              buf.add(' ');
            else
            {
              // Do tabs every 8 columns...
              buf.add(' '); // at least one space
              while (buf.size() & 7)
                buf.add(' ');
            }
          }

          ptr ++;
          if (!pre) current_pos = (int) (ptr-value_);
          needspace = 1;
        }
        else if (*ptr == '&') // process html entity
        {
          ptr ++;

          int qch = quote_char(ptr);

          if (qch < 0)
            buf.add('&');
          else {
            int utf8l = buf.size();
            buf.add(qch);
            utf8l = buf.size() - utf8l; // length of added UTF-8 text
            const char *oldptr = ptr;
            ptr = strchr(ptr, ';') + 1;
            entity_extra_length += ptr - (oldptr-1) - utf8l; // extra length between html entity and UTF-8
          }

          if ((fsize + 2) > hh)
            hh = fsize + 2;
        }
        else
        {
          buf.add(*ptr++);

          if ((fsize + 2) > hh)
            hh = fsize + 2;
        }
      }

      if (buf.size() > 0 && !pre && !head)
      {
        ww = buf.width();

        if (needspace && xx > block->x)
          xx += (int)fl_width(' ');

        if ((xx + ww) > block->w)
        {
          if (line < 31)
            line ++;
          xx = block->line[line];
          yy += hh;
          hh = 0;
        }
      }

      if (buf.size() > 0 && !head)
      {
        hv_draw(buf.c_str(), xx + x() - leftline_, yy + y());
        if (underline) fl_xyline(xx + x() - leftline_, yy + y() + 1,
                                 xx + x() - leftline_ + ww);
        current_pos = (int) (ptr-value_);
      }
    }

  fl_pop_clip();
} // draw()


/** Finds the specified string \p s at starting position \p p.

  The argument \p p and the return value are offsets in Fl_Help_View::value(),
  counting from 0. If \p p is out of range, 0 is used.

  The string comparison is simple but honors some special cases:
  - the specified string \p s must be in UTF-8 encoding
  - HTML tags in value() are filtered (not compared as such, they never match)
  - HTML entities like '\&lt;' or '\&x#20ac;' are converted to Unicode (UTF-8)
  - ASCII characters (7-bit, \< 0x80) are compared case insensitive
  - every newline (LF, '\\n') in value() is treated like a single space
  - all other strings are compared as-is (byte by byte)

  \todo complex HTML entities for Unicode code points \> 0x80 are currently treated
    like one byte (not character!) and do not (yet) match correctly ("<" matches "&lt;"
    but "€" doesn't match "&euro;", and "ü" doesn't match "&uuml;")

  \param[in]  s   search string in UTF-8 encoding
  \param[in]  p   starting position for search (0,...), Default = 0

  \return the matching position or -1 if not found
*/
int                                             // O - Matching position or -1 if not found
Fl_Help_View::find(const char *s,               // I - String to find
                   int        p)                // I - Starting position
{
  int           i,                              // Looping var
                c;                              // Current character
  Fl_Help_Block *b;                             // Current block
  const char    *bp,                            // Block matching pointer
                *bs,                            // Start of current comparison
                *sp;                            // Search string pointer

  DEBUG_FUNCTION(__LINE__,__FUNCTION__);

  // Range check input and value...
  if (!s || !value_) return -1;

  if (p < 0 || p >= (int)strlen(value_)) p = 0;

  // Look for the string...
  for (i = nblocks_, b = blocks_; i > 0; i--, b++) {
    if (b->end < (value_ + p))
      continue;

    if (b->start < (value_ + p)) bp = value_ + p;
    else bp = b->start;

    for (sp = s, bs = bp; *sp && *bp && bp < b->end; bp++) {
      if (*bp == '<') {
        // skip to end of element...
        while (*bp && bp < b->end && *bp != '>') bp++;
        // no match, so reset to start of search...
        sp = s;
        bs = bp + 1;
        continue;
      } else if (*bp == '&') {
        // decode HTML entity...
        if ((c = quote_char(bp + 1)) < 0) c = '&';      // *FIXME* UTF-8, see below
        else bp = strchr(bp + 1, ';') + 1;
      } else c = *bp;

      if (c == '\n') c = ' '; // treat newline as a single space

      // *FIXME* *UTF-8* (A.S. 02/14/2016)
      // At this point c may be an arbitrary Unicode Code Point corresponding
      // to a quoted character (see above), i.e. it _can_ be a multi byte
      // UTF-8 sequence and must be compared with the corresponding
      // multi byte string in (*sp)...
      // For instance: "&euro;" == 0x20ac -> 0xe2 0x82 0xac (UTF-8: 3 bytes).
      // Hint: use fl_utf8encode() [see below]

      if (c > 0x20 && c < 0x80 && tolower(*sp) == tolower(c)) sp++;
      else if (*sp == c) sp++;
      else { // No match, so reset to start of search...
        sp = s;
        bp = bs;
        bs++;
      }
    }

    if (!*sp) { // Found a match!
      topline(b->y - b->h);
      return int(bs - value_);
    }
  }

  // No match!
  return (-1);
}

/** Formats the help text. */
void Fl_Help_View::format() {
  int           i;              // Looping var
  int           done;           // Are we done yet?
  Fl_Help_Block *block,         // Current block
                *cell;          // Current table cell
  int           cells[MAX_COLUMNS],
                                // Cells in the current row...
                row;            // Current table row (block number)
  const char    *ptr,           // Pointer into block
                *start,         // Pointer to start of element
                *attrs;         // Pointer to start of element attributes
  HV_Edit_Buffer buf;           // Text buffer
  char          attr[1024],     // Attribute buffer
                wattr[1024],    // Width attribute buffer
                hattr[1024],    // Height attribute buffer
                linkdest[1024]; // Link destination
  int           xx, yy, ww, hh; // Size of current text fragment
  int           line;           // Current line in block
  int           links;          // Links for current line
  Fl_Font       font;
  Fl_Fontsize   fsize;          // Current font and size
  Fl_Color      fcolor;         // Current font color
  unsigned char border;         // Draw border?
  int           talign,         // Current alignment
                newalign,       // New alignment
                head,           // In the <HEAD> section?
                pre,            // <PRE> text?
                needspace;      // Do we need whitespace?
  int           table_width,    // Width of table
                table_offset;   // Offset of table
  int           column,         // Current table column number
                columns[MAX_COLUMNS];
                                // Column widths
  Fl_Color      tc, rc;         // Table/row background color
  Fl_Boxtype    b = box() ? box() : FL_DOWN_BOX;
                                // Box to draw...
  fl_margins    margins;        // Left margin stack...

  DEBUG_FUNCTION(__LINE__,__FUNCTION__);

  // Reset document width...
  int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
  hsize_ = w() - scrollsize - Fl::box_dw(b);

  done = 0;
  while (!done)
  {
    // Reset state variables...
    done       = 1;
    nblocks_   = 0;
    nlinks_    = 0;
    ntargets_  = 0;
    size_      = 0;
    bgcolor_   = color();
    textcolor_ = textcolor();
    linkcolor_ = fl_contrast(FL_BLUE, color());

    tc = rc = bgcolor_;

    strcpy(title_, "Untitled");

    if (!value_)
      return;

    // Setup for formatting...
    initfont(font, fsize, fcolor);

    line         = 0;
    links        = 0;
    xx           = margins.clear();
    yy           = fsize + 2;
    ww           = 0;
    column       = 0;
    border       = 0;
    hh           = 0;
    block        = add_block(value_, xx, yy, hsize_, 0);
    row          = 0;
    head         = 0;
    pre          = 0;
    talign       = LEFT;
    newalign     = LEFT;
    needspace    = 0;
    linkdest[0]  = '\0';
    table_offset = 0;

    // Html text character loop
    for (ptr = value_, buf.clear(); *ptr;)
    {
      // End of word?
      if ((*ptr == '<' || isspace((*ptr)&255)) && buf.size() > 0)
      {
        // Get width of word parsed so far...
        ww = buf.width();

        if (!head && !pre)
        {
          // Check width...
          if (ww > hsize_) {
            hsize_ = ww;
            done   = 0;
            break;
          }

          if (needspace && xx > block->x)
            ww += (int)fl_width(' ');

  //        printf("line = %d, xx = %d, ww = %d, block->x = %d, block->w = %d\n",
  //           line, xx, ww, block->x, block->w);

          if ((xx + ww) > block->w)
          {
            line     = do_align(block, line, xx, newalign, links);
            xx       = block->x;
            yy       += hh;
            block->h += hh;
            hh       = 0;
          }

          if (linkdest[0])
            add_link(linkdest, xx, yy - fsize, ww, fsize);

          xx += ww;
          if ((fsize + 2) > hh)
            hh = fsize + 2;

          needspace = 0;
        }
        else if (pre)
        {
          // Add a link as needed...
          if (linkdest[0])
            add_link(linkdest, xx, yy - hh, ww, hh);

          xx += ww;
          if ((fsize + 2) > hh)
            hh = fsize + 2;

          // Handle preformatted text...
          while (isspace((*ptr)&255))
          {
            if (*ptr == '\n')
            {
              if (xx > hsize_) break;

              line     = do_align(block, line, xx, newalign, links);
              xx       = block->x;
              yy       += hh;
              block->h += hh;
              hh       = fsize + 2;
            }
            else
              xx += (int)fl_width(' ');

            if ((fsize + 2) > hh)
              hh = fsize + 2;

            ptr ++;
          }

          if (xx > hsize_) {
            hsize_ = xx;
            done   = 0;
            break;
          }

          needspace = 0;
        }
        else
        {
          // Handle normal text or stuff in the <HEAD> section...
          while (isspace((*ptr)&255))
            ptr ++;
        }

        buf.clear();
      }

      if (*ptr == '<')
      {
        // Handle html tags..
        start = ptr;
        ptr ++;

        if (strncmp(ptr, "!--", 3) == 0)
        {
          // Comment...
          ptr += 3;
          if ((ptr = strstr(ptr, "-->")) != NULL)
          {
            ptr += 3;
            continue;
          }
          else
            break;
        }

        while (*ptr && *ptr != '>' && !isspace((*ptr)&255))
          buf.add(*ptr++);

        attrs = ptr;
        while (*ptr && *ptr != '>')
          ptr ++;

        if (*ptr == '>')
          ptr ++;

        if (buf.cmp("HEAD"))
          head = 1;
        else if (buf.cmp("/HEAD"))
          head = 0;
        else if (buf.cmp("TITLE"))
        {
          // Copy the title in the document...
          char *st;
          for (st = title_;
               *ptr != '<' && *ptr && st < (title_ + sizeof(title_) - 1);
               *st++ = *ptr++) {/*empty*/}

          *st = '\0';
          buf.clear();
        }
        else if (buf.cmp("A"))
        {
          if (get_attr(attrs, "NAME", attr, sizeof(attr)) != NULL)
            add_target(attr, yy - fsize - 2);

          if (get_attr(attrs, "HREF", attr, sizeof(attr)) != NULL)
            strlcpy(linkdest, attr, sizeof(linkdest));
        }
        else if (buf.cmp("/A"))
          linkdest[0] = '\0';
        else if (buf.cmp("BODY"))
        {
          bgcolor_   = get_color(get_attr(attrs, "BGCOLOR", attr, sizeof(attr)),
                                 color());
          textcolor_ = get_color(get_attr(attrs, "TEXT", attr, sizeof(attr)),
                                 textcolor());
          linkcolor_ = get_color(get_attr(attrs, "LINK", attr, sizeof(attr)),
                                 fl_contrast(FL_BLUE, color()));
        }
        else if (buf.cmp("BR"))
        {
          line     = do_align(block, line, xx, newalign, links);
          xx       = block->x;
          block->h += hh;
          yy       += hh;
          hh       = 0;
        }
        else if (buf.cmp("CENTER") ||
                 buf.cmp("P") ||
                 buf.cmp("H1") ||
                 buf.cmp("H2") ||
                 buf.cmp("H3") ||
                 buf.cmp("H4") ||
                 buf.cmp("H5") ||
                 buf.cmp("H6") ||
                 buf.cmp("UL") ||
                 buf.cmp("OL") ||
                 buf.cmp("DL") ||
                 buf.cmp("LI") ||
                 buf.cmp("DD") ||
                 buf.cmp("DT") ||
                 buf.cmp("HR") ||
                 buf.cmp("PRE") ||
                 buf.cmp("TABLE"))
        {
          block->end = start;
          line       = do_align(block, line, xx, newalign, links);
          newalign   = buf.cmp("CENTER") ? CENTER : LEFT;
          xx         = block->x;
          block->h   += hh;

          if (buf.cmp("UL") ||
              buf.cmp("OL") ||
              buf.cmp("DL"))
          {
            block->h += fsize + 2;
            xx       = margins.push(4 * fsize);
          }
          else if (buf.cmp("TABLE"))
          {
            if (get_attr(attrs, "BORDER", attr, sizeof(attr)))
              border = (uchar)atoi(attr);
            else
              border = 0;

            tc = rc = get_color(get_attr(attrs, "BGCOLOR", attr, sizeof(attr)), bgcolor_);

            block->h += fsize + 2;

            format_table(&table_width, columns, start);

            if ((xx + table_width) > hsize_) {
#ifdef DEBUG
              printf("xx=%d, table_width=%d, hsize_=%d\n", xx, table_width,
                     hsize_);
#endif // DEBUG
              hsize_ = xx + table_width;
              done   = 0;
              break;
            }

            switch (get_align(attrs, talign))
            {
              default :
                  table_offset = 0;
                  break;

              case CENTER :
                  table_offset = (hsize_ - table_width) / 2 - textsize_;
                  break;

              case RIGHT :
                  table_offset = hsize_ - table_width - textsize_;
                  break;
            }

            column = 0;
          }

          if (tolower(buf[0]) == 'h' && isdigit(buf[1]))
          {
            font  = FL_HELVETICA_BOLD;
            fsize = textsize_ + '7' - buf[1];
          }
          else if (buf.cmp("DT"))
          {
            font  = textfont_ | FL_ITALIC;
            fsize = textsize_;
          }
          else if (buf.cmp("PRE"))
          {
            font  = FL_COURIER;
            fsize = textsize_;
            pre   = 1;
          }
          else
          {
            font  = textfont_;
            fsize = textsize_;
          }

          pushfont(font, fsize);

          yy = block->y + block->h;
          hh = 0;

          if ((tolower(buf[0]) == 'h' && isdigit(buf[1])) ||
              buf.cmp("DD") ||
              buf.cmp("DT") ||
              buf.cmp("P"))
            yy += fsize + 2;
          else if (buf.cmp("HR"))
          {
            hh += 2 * fsize;
            yy += fsize;
          }

          if (row)
            block = add_block(start, xx, yy, block->w, 0);
          else
            block = add_block(start, xx, yy, hsize_, 0);

          needspace = 0;
          line      = 0;

          if (buf.cmp("CENTER"))
            newalign = talign = CENTER;
          else
            newalign = get_align(attrs, talign);
        }
        else if (buf.cmp("/CENTER") ||
                 buf.cmp("/P") ||
                 buf.cmp("/H1") ||
                 buf.cmp("/H2") ||
                 buf.cmp("/H3") ||
                 buf.cmp("/H4") ||
                 buf.cmp("/H5") ||
                 buf.cmp("/H6") ||
                 buf.cmp("/PRE") ||
                 buf.cmp("/UL") ||
                 buf.cmp("/OL") ||
                 buf.cmp("/DL") ||
                 buf.cmp("/TABLE"))
        {
          line       = do_align(block, line, xx, newalign, links);
          xx         = block->x;
          block->end = ptr;

          if (buf.cmp("/UL") ||
              buf.cmp("/OL") ||
              buf.cmp("/DL"))
          {
            xx       = margins.pop();
            block->h += fsize + 2;
          }
          else if (buf.cmp("/TABLE"))
          {
            block->h += fsize + 2;
            xx       = margins.current();
          }
          else if (buf.cmp("/PRE"))
          {
            pre = 0;
            hh  = 0;
          }
          else if (buf.cmp("/CENTER"))
            talign = LEFT;

          popfont(font, fsize, fcolor);

          //#if defined(__GNUC__)
          //#warning FIXME this isspace & 255 test will probably not work on a utf8 stream... And we use it everywhere!
          //#endif /*__GNUC__*/
          while (isspace((*ptr)&255))
            ptr ++;

          block->h += hh;
          yy       += hh;

          if (tolower(buf[2]) == 'l')
            yy += fsize + 2;

          if (row)
            block = add_block(ptr, xx, yy, block->w, 0);
          else
            block = add_block(ptr, xx, yy, hsize_, 0);

          needspace = 0;
          hh        = 0;
          line      = 0;
          newalign  = talign;
        }
        else if (buf.cmp("TR"))
        {
          block->end = start;
          line       = do_align(block, line, xx, newalign, links);
          xx         = block->x;
          block->h   += hh;

          if (row)
          {
            yy = blocks_[row].y + blocks_[row].h;

            for (cell = blocks_ + row + 1; cell <= block; cell ++)
              if ((cell->y + cell->h) > yy)
                yy = cell->y + cell->h;

            block = blocks_ + row;

            block->h = yy - block->y + 2;

            for (i = 0; i < column; i ++)
              if (cells[i])
              {
                cell = blocks_ + cells[i];
                cell->h = block->h;
              }
          }

          memset(cells, 0, sizeof(cells));

          yy        = block->y + block->h - 4;
          hh        = 0;
          block     = add_block(start, xx, yy, hsize_, 0);
          row       = (int) (block - blocks_);
          needspace = 0;
          column    = 0;
          line      = 0;

          rc = get_color(get_attr(attrs, "BGCOLOR", attr, sizeof(attr)), tc);
        }
        else if (buf.cmp("/TR") && row)
        {
          line       = do_align(block, line, xx, newalign, links);
          block->end = start;
          block->h   += hh;
          talign     = LEFT;

          xx = blocks_[row].x;
          yy = blocks_[row].y + blocks_[row].h;

          for (cell = blocks_ + row + 1; cell <= block; cell ++)
            if ((cell->y + cell->h) > yy)
              yy = cell->y + cell->h;

          block = blocks_ + row;

          block->h = yy - block->y + 2;

          for (i = 0; i < column; i ++)
            if (cells[i])
            {
              cell = blocks_ + cells[i];
              cell->h = block->h;
            }

          yy        = block->y + block->h /*- 4*/;
          block     = add_block(start, xx, yy, hsize_, 0);
          needspace = 0;
          row       = 0;
          line      = 0;
        }
        else if ((buf.cmp("TD") ||
                  buf.cmp("TH")) && row)
        {
          int   colspan;                // COLSPAN attribute


          line       = do_align(block, line, xx, newalign, links);
          block->end = start;
          block->h   += hh;

          if (buf.cmp("TH"))
            font = textfont_ | FL_BOLD;
          else
            font = textfont_;

          fsize = textsize_;

          xx = blocks_[row].x + fsize + 3 + table_offset;
          for (i = 0; i < column; i ++)
            xx += columns[i] + 6;

          margins.push(xx - margins.current());

          if (get_attr(attrs, "COLSPAN", attr, sizeof(attr)) != NULL)
            colspan = atoi(attr);
          else
            colspan = 1;

          for (i = 0, ww = -6; i < colspan; i ++)
            ww += columns[column + i] + 6;

          if (block->end == block->start && nblocks_ > 1)
          {
            nblocks_ --;
            block --;
          }

          pushfont(font, fsize);

          yy        = blocks_[row].y;
          hh        = 0;
          block     = add_block(start, xx, yy, xx + ww, 0, border);
          needspace = 0;
          line      = 0;
          newalign  = get_align(attrs, tolower(buf[1]) == 'h' ? CENTER : LEFT);
          talign    = newalign;

          cells[column] = (int) (block - blocks_);

          column += colspan;

          block->bgcolor = get_color(get_attr(attrs, "BGCOLOR", attr,
                                              sizeof(attr)), rc);
        }
        else if ((buf.cmp("/TD") ||
                  buf.cmp("/TH")) && row)
        {
          line = do_align(block, line, xx, newalign, links);
          popfont(font, fsize, fcolor);
          xx = margins.pop();
          talign = LEFT;
        }
        else if (buf.cmp("FONT"))
        {
          if (get_attr(attrs, "FACE", attr, sizeof(attr)) != NULL) {
            if (!strncasecmp(attr, "helvetica", 9) ||
                !strncasecmp(attr, "arial", 5) ||
                !strncasecmp(attr, "sans", 4)) font = FL_HELVETICA;
            else if (!strncasecmp(attr, "times", 5) ||
                     !strncasecmp(attr, "serif", 5)) font = FL_TIMES;
            else if (!strncasecmp(attr, "symbol", 6)) font = FL_SYMBOL;
            else font = FL_COURIER;
          }

          if (get_attr(attrs, "SIZE", attr, sizeof(attr)) != NULL) {
            if (isdigit(attr[0] & 255)) {
              // Absolute size
              fsize = (int)(textsize_ * pow(1.2, atoi(attr) - 3.0));
            } else {
              // Relative size
              fsize = (int)(fsize * pow(1.2, atoi(attr)));
            }
          }

          pushfont(font, fsize);
        }
        else if (buf.cmp("/FONT"))
          popfont(font, fsize, fcolor);
        else if (buf.cmp("B") ||
                 buf.cmp("STRONG"))
          pushfont(font |= FL_BOLD, fsize);
        else if (buf.cmp("I") ||
                 buf.cmp("EM"))
          pushfont(font |= FL_ITALIC, fsize);
        else if (buf.cmp("CODE") ||
                 buf.cmp("TT"))
          pushfont(font = FL_COURIER, fsize);
        else if (buf.cmp("KBD"))
          pushfont(font = FL_COURIER_BOLD, fsize);
        else if (buf.cmp("VAR"))
          pushfont(font = FL_COURIER_ITALIC, fsize);
        else if (buf.cmp("/B") ||
                 buf.cmp("/STRONG") ||
                 buf.cmp("/I") ||
                 buf.cmp("/EM") ||
                 buf.cmp("/CODE") ||
                 buf.cmp("/TT") ||
                 buf.cmp("/KBD") ||
                 buf.cmp("/VAR"))
          popfont(font, fsize, fcolor);
        else if (buf.cmp("IMG"))
        {
          Fl_Shared_Image       *img = 0;
          int           width;
          int           height;


          get_attr(attrs, "WIDTH", wattr, sizeof(wattr));
          get_attr(attrs, "HEIGHT", hattr, sizeof(hattr));
          width  = get_length(wattr);
          height = get_length(hattr);

          if (get_attr(attrs, "SRC", attr, sizeof(attr))) {
            img    = get_image(attr, width, height);
            width  = img->w();
            height = img->h();
          }

          ww = width;

          if (ww > hsize_) {
            hsize_ = ww;
            done   = 0;
            break;
          }

          if (needspace && xx > block->x)
            ww += (int)fl_width(' ');

          if ((xx + ww) > block->w)
          {
            line     = do_align(block, line, xx, newalign, links);
            xx       = block->x;
            yy       += hh;
            block->h += hh;
            hh       = 0;
          }

          if (linkdest[0])
            add_link(linkdest, xx, yy-fsize, ww, height);

          xx += ww;
          if ((height + 2) > hh)
            hh = height + 2;

          needspace = 0;
        }
        buf.clear();
      }
      else if (*ptr == '\n' && pre)
      {
        if (linkdest[0])
          add_link(linkdest, xx, yy - hh, ww, hh);

        if (xx > hsize_) {
          hsize_ = xx;
          done   = 0;
          break;
        }

        line      = do_align(block, line, xx, newalign, links);
        xx        = block->x;
        yy        += hh;
        block->h  += hh;
        needspace = 0;
        ptr ++;
      }
      else if (isspace((*ptr)&255))
      {
        needspace = 1;
        if ( pre ) {
          xx += (int)fl_width(' ');
        }
        ptr ++;
      }
      else if (*ptr == '&')
      {
        // Handle html '&' codes, eg. "&amp;"
        ptr ++;

        int qch = quote_char(ptr);

        if (qch < 0)
          buf.add('&');
        else {
          buf.add(qch);
          ptr = strchr(ptr, ';') + 1;
        }

        if ((fsize + 2) > hh)
          hh = fsize + 2;
      }
      else
      {
        buf.add(*ptr++);

        if ((fsize + 2) > hh)
          hh = fsize + 2;
      }
    }

    if (buf.size() > 0 && !head)
    {
      ww = buf.width();

  //    printf("line = %d, xx = %d, ww = %d, block->x = %d, block->w = %d\n",
  //       line, xx, ww, block->x, block->w);

      if (ww > hsize_) {
        hsize_ = ww;
        done   = 0;
        break;
      }

      if (needspace && xx > block->x)
        ww += (int)fl_width(' ');

      if ((xx + ww) > block->w)
      {
        line     = do_align(block, line, xx, newalign, links);
        xx       = block->x;
        yy       += hh;
        block->h += hh;
        hh       = 0;
      }

      if (linkdest[0])
        add_link(linkdest, xx, yy - fsize, ww, fsize);

      xx += ww;
    }

    do_align(block, line, xx, newalign, links);

    block->end = ptr;
    size_      = yy + hh;
  }

//  printf("margins.depth_=%d\n", margins.depth_);

  if (ntargets_ > 1)
    qsort(targets_, ntargets_, sizeof(Fl_Help_Target),
          (compare_func_t)compare_targets);

  int dx = Fl::box_dw(b) - Fl::box_dx(b);
  int dy = Fl::box_dh(b) - Fl::box_dy(b);
  int ss = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
  int dw = Fl::box_dw(b) + ss;
  int dh = Fl::box_dh(b);

  if (hsize_ > (w() - dw)) {
    hscrollbar_.show();

    dh += ss;

    if (size_ < (h() - dh)) {
      scrollbar_.hide();
      hscrollbar_.resize(x() + Fl::box_dx(b), y() + h() - ss - dy,
                         w() - Fl::box_dw(b), ss);
    } else {
      scrollbar_.show();
      scrollbar_.resize(x() + w() - ss - dx, y() + Fl::box_dy(b),
                        ss, h() - ss - Fl::box_dh(b));
      hscrollbar_.resize(x() + Fl::box_dx(b), y() + h() - ss - dy,
                         w() - ss - Fl::box_dw(b), ss);
    }
  } else {
    hscrollbar_.hide();

    if (size_ < (h() - dh)) scrollbar_.hide();
    else {
      scrollbar_.resize(x() + w() - ss - dx, y() + Fl::box_dy(b),
                        ss, h() - Fl::box_dh(b));
      scrollbar_.show();
    }
  }

  // Reset scrolling if it needs to be...
  if (scrollbar_.visible()) {
    int temph = h() - Fl::box_dh(b);
    if (hscrollbar_.visible()) temph -= ss;
    if ((topline_ + temph) > size_) topline(size_ - temph);
    else topline(topline_);
  } else topline(0);

  if (hscrollbar_.visible()) {
    int tempw = w() - ss - Fl::box_dw(b);
    if ((leftline_ + tempw) > hsize_) leftline(hsize_ - tempw);
    else leftline(leftline_);
  } else leftline(0);
}


/** Formats a table */
void
Fl_Help_View::format_table(int        *table_width,     // O - Total table width
                           int        *columns,         // O - Column widths
                           const char *table)           // I - Pointer to start of table
{
  int           column,                                 // Current column
                num_columns,                            // Number of columns
                colspan,                                // COLSPAN attribute
                width,                                  // Current width
                temp_width,                             // Temporary width
                max_width,                              // Maximum width
                incell,                                 // In a table cell?
                pre,                                    // <PRE> text?
                needspace;                              // Need whitespace?
  HV_Edit_Buffer buf;                                   // Text buffer
  char          attr[1024],                             // Other attribute
                wattr[1024],                            // WIDTH attribute
                hattr[1024];                            // HEIGHT attribute
  const char    *ptr,                                   // Pointer into table
                *attrs,                                 // Pointer to attributes
                *start;                                 // Start of element
  int           minwidths[MAX_COLUMNS];                 // Minimum widths for each column
  Fl_Font       font;
  Fl_Fontsize   fsize;                                  // Current font and size
  Fl_Color      fcolor;                                 // Currrent font color

  DEBUG_FUNCTION(__LINE__,__FUNCTION__);

  // Clear widths...
  *table_width = 0;
  for (column = 0; column < MAX_COLUMNS; column ++)
  {
    columns[column]   = 0;
    minwidths[column] = 0;
  }

  num_columns = 0;
  colspan     = 0;
  max_width   = 0;
  pre         = 0;
  needspace   = 0;
  fstack_.top(font, fsize, fcolor);

  // Scan the table...
  for (ptr = table, column = -1, width = 0, incell = 0; *ptr;)
  {
    if ((*ptr == '<' || isspace((*ptr)&255)) && buf.size() > 0 && incell)
    {
      // Check width...
      if (needspace)
      {
        buf.add(' ');
        needspace = 0;
      }

      temp_width = buf.width();
      buf.clear();

      if (temp_width > minwidths[column])
        minwidths[column] = temp_width;

      width += temp_width;

      if (width > max_width)
        max_width = width;
    }

    if (*ptr == '<')
    {
      start = ptr;

      for (buf.clear(), ptr ++; *ptr && *ptr != '>' && !isspace((*ptr)&255);)
        buf.add(*ptr++);

      attrs = ptr;
      while (*ptr && *ptr != '>')
        ptr ++;

      if (*ptr == '>')
        ptr ++;

      if (buf.cmp("BR") ||
          buf.cmp("HR"))
      {
        width     = 0;
        needspace = 0;
      }
      else if (buf.cmp("TABLE") && start > table)
        break;
      else if (buf.cmp("CENTER") ||
               buf.cmp("P") ||
               buf.cmp("H1") ||
               buf.cmp("H2") ||
               buf.cmp("H3") ||
               buf.cmp("H4") ||
               buf.cmp("H5") ||
               buf.cmp("H6") ||
               buf.cmp("UL") ||
               buf.cmp("OL") ||
               buf.cmp("DL") ||
               buf.cmp("LI") ||
               buf.cmp("DD") ||
               buf.cmp("DT") ||
               buf.cmp("PRE"))
      {
        width     = 0;
        needspace = 0;

        if (tolower(buf[0]) == 'h' && isdigit(buf[1]))
        {
          font  = FL_HELVETICA_BOLD;
          fsize = textsize_ + '7' - buf[1];
        }
        else if (buf.cmp("DT"))
        {
          font  = textfont_ | FL_ITALIC;
          fsize = textsize_;
        }
        else if (buf.cmp("PRE"))
        {
          font  = FL_COURIER;
          fsize = textsize_;
          pre   = 1;
        }
        else if (buf.cmp("LI"))
        {
          width  += 4 * fsize;
          font   = textfont_;
          fsize  = textsize_;
        }
        else
        {
          font  = textfont_;
          fsize = textsize_;
        }

        pushfont(font, fsize);
      }
      else if (buf.cmp("/CENTER") ||
               buf.cmp("/P") ||
               buf.cmp("/H1") ||
               buf.cmp("/H2") ||
               buf.cmp("/H3") ||
               buf.cmp("/H4") ||
               buf.cmp("/H5") ||
               buf.cmp("/H6") ||
               buf.cmp("/PRE") ||
               buf.cmp("/UL") ||
               buf.cmp("/OL") ||
               buf.cmp("/DL"))
      {
        width     = 0;
        needspace = 0;

        popfont(font, fsize, fcolor);
      }
      else if (buf.cmp("TR") || buf.cmp("/TR") ||
               buf.cmp("/TABLE"))
      {
//        printf("%s column = %d, colspan = %d, num_columns = %d\n",
//             buf.c_str(), column, colspan, num_columns);

        if (column >= 0)
        {
          // This is a hack to support COLSPAN...
          max_width /= colspan;

          while (colspan > 0)
          {
            if (max_width > columns[column])
              columns[column] = max_width;

            column ++;
            colspan --;
          }
        }

        if (buf.cmp("/TABLE"))
          break;

        needspace = 0;
        column    = -1;
        width     = 0;
        max_width = 0;
        incell    = 0;
      }
      else if (buf.cmp("TD") ||
               buf.cmp("TH"))
      {
//        printf("BEFORE column = %d, colspan = %d, num_columns = %d\n",
//             column, colspan, num_columns);

        if (column >= 0)
        {
          // This is a hack to support COLSPAN...
          max_width /= colspan;

          while (colspan > 0)
          {
            if (max_width > columns[column])
              columns[column] = max_width;

            column ++;
            colspan --;
          }
        }
        else
          column ++;

        if (get_attr(attrs, "COLSPAN", attr, sizeof(attr)) != NULL)
          colspan = atoi(attr);
        else
          colspan = 1;

//        printf("AFTER column = %d, colspan = %d, num_columns = %d\n",
//             column, colspan, num_columns);

        if ((column + colspan) >= num_columns)
          num_columns = column + colspan;

        needspace = 0;
        width     = 0;
        incell    = 1;

        if (buf.cmp("TH"))
          font = textfont_ | FL_BOLD;
        else
          font = textfont_;

        fsize = textsize_;

        pushfont(font, fsize);

        if (get_attr(attrs, "WIDTH", attr, sizeof(attr)) != NULL)
          max_width = get_length(attr);
        else
          max_width = 0;

//        printf("max_width = %d\n", max_width);
      }
      else if (buf.cmp("/TD") ||
               buf.cmp("/TH"))
      {
        incell = 0;
        popfont(font, fsize, fcolor);
      }
      else if (buf.cmp("B") ||
               buf.cmp("STRONG"))
        pushfont(font |= FL_BOLD, fsize);
      else if (buf.cmp("I") ||
               buf.cmp("EM"))
        pushfont(font |= FL_ITALIC, fsize);
      else if (buf.cmp("CODE") ||
               buf.cmp("TT"))
        pushfont(font = FL_COURIER, fsize);
      else if (buf.cmp("KBD"))
        pushfont(font = FL_COURIER_BOLD, fsize);
      else if (buf.cmp("VAR"))
        pushfont(font = FL_COURIER_ITALIC, fsize);
      else if (buf.cmp("/B") ||
               buf.cmp("/STRONG") ||
               buf.cmp("/I") ||
               buf.cmp("/EM") ||
               buf.cmp("/CODE") ||
               buf.cmp("/TT") ||
               buf.cmp("/KBD") ||
               buf.cmp("/VAR"))
        popfont(font, fsize, fcolor);
      else if (buf.cmp("IMG") && incell)
      {
        Fl_Shared_Image *img = 0;
        int             iwidth, iheight;


        get_attr(attrs, "WIDTH", wattr, sizeof(wattr));
        get_attr(attrs, "HEIGHT", hattr, sizeof(hattr));
        iwidth  = get_length(wattr);
        iheight = get_length(hattr);

        if (get_attr(attrs, "SRC", attr, sizeof(attr))) {
          img     = get_image(attr, iwidth, iheight);
          iwidth  = img->w();
          iheight = img->h();
        }

        if (iwidth > minwidths[column])
          minwidths[column] = iwidth;

        width += iwidth;
        if (needspace)
          width += (int)fl_width(' ');

        if (width > max_width)
          max_width = width;

        needspace = 0;
      }
      buf.clear();
    }
    else if (*ptr == '\n' && pre)
    {
      width     = 0;
      needspace = 0;
      ptr ++;
    }
    else if (isspace((*ptr)&255))
    {
      needspace = 1;

      ptr ++;
    }
    else if (*ptr == '&' )
    {
      ptr ++;

      int qch = quote_char(ptr);

      if (qch < 0)
        buf.add('&');
      else {
        buf.add(qch);
        ptr = strchr(ptr, ';') + 1;
      }
    }
    else
    {
      buf.add(*ptr++);
    }
  }

  // Now that we have scanned the entire table, adjust the table and
  // cell widths to fit on the screen...
  if (get_attr(table + 6, "WIDTH", attr, sizeof(attr)))
    *table_width = get_length(attr);
  else
    *table_width = 0;

#ifdef DEBUG
  printf("num_columns = %d, table_width = %d\n", num_columns, *table_width);
#endif // DEBUG

  if (num_columns == 0)
    return;

  // Add up the widths...
  for (column = 0, width = 0; column < num_columns; column ++)
    width += columns[column];

#ifdef DEBUG
  printf("width = %d, w() = %d\n", width, w());
  for (column = 0; column < num_columns; column ++)
    printf("    columns[%d] = %d, minwidths[%d] = %d\n", column, columns[column],
           column, minwidths[column]);
#endif // DEBUG

  // Adjust the width if needed...
  int scale_width = *table_width;

  int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
  if (scale_width == 0) {
    if (width > (hsize_ - scrollsize)) scale_width = hsize_ - scrollsize;
    else scale_width = width;
  }

  if (width < scale_width) {
#ifdef DEBUG
    printf("Scaling table up to %d from %d...\n", scale_width, width);
#endif // DEBUG

    *table_width = 0;

    scale_width = (scale_width - width) / num_columns;

#ifdef DEBUG
    printf("adjusted scale_width = %d\n", scale_width);
#endif // DEBUG

    for (column = 0; column < num_columns; column ++) {
      columns[column] += scale_width;

      (*table_width) += columns[column];
    }
  }
  else if (width > scale_width) {
#ifdef DEBUG
    printf("Scaling table down to %d from %d...\n", scale_width, width);
#endif // DEBUG

    for (column = 0; column < num_columns; column ++) {
      width       -= minwidths[column];
      scale_width -= minwidths[column];
    }

#ifdef DEBUG
    printf("adjusted width = %d, scale_width = %d\n", width, scale_width);
#endif // DEBUG

    if (width > 0) {
      for (column = 0; column < num_columns; column ++) {
        columns[column] -= minwidths[column];
        columns[column] = scale_width * columns[column] / width;
        columns[column] += minwidths[column];
      }
    }

    *table_width = 0;
    for (column = 0; column < num_columns; column ++) {
      (*table_width) += columns[column];
    }
  }
  else if (*table_width == 0)
    *table_width = width;

#ifdef DEBUG
  printf("FINAL table_width = %d\n", *table_width);
  for (column = 0; column < num_columns; column ++)
    printf("    columns[%d] = %d\n", column, columns[column]);
#endif // DEBUG
}


/** Frees memory used for the document. */
void
Fl_Help_View::free_data() {
  // Release all images...
  if (value_) {
    const char  *ptr,           // Pointer into block
                *attrs;         // Pointer to start of element attributes
    HV_Edit_Buffer buf;         // Text buffer
    char        attr[1024],     // Attribute buffer
                wattr[1024],    // Width attribute buffer
                hattr[1024];    // Height attribute buffer

    DEBUG_FUNCTION(__LINE__,__FUNCTION__);

    for (ptr = value_; *ptr;)
    {
      if (*ptr == '<')
      {
        ptr ++;

        if (strncmp(ptr, "!--", 3) == 0)
        {
          // Comment...
          ptr += 3;
          if ((ptr = strstr(ptr, "-->")) != NULL)
          {
            ptr += 3;
            continue;
          }
          else
            break;
        }

        buf.clear();

        while (*ptr && *ptr != '>' && !isspace((*ptr)&255))
          buf.add(*ptr++);

        attrs = ptr;
        while (*ptr && *ptr != '>')
          ptr ++;

        if (*ptr == '>')
          ptr ++;

        if (buf.cmp("IMG"))
        {
          Fl_Shared_Image       *img;
          int           width;
          int           height;

          get_attr(attrs, "WIDTH", wattr, sizeof(wattr));
          get_attr(attrs, "HEIGHT", hattr, sizeof(hattr));
          width  = get_length(wattr);
          height = get_length(hattr);

          if (get_attr(attrs, "SRC", attr, sizeof(attr))) {
            // Get and release the image to free it from memory...
            img = get_image(attr, width, height);
            if ((void*)img != &broken_image) {
              img->release();
            }
          }
        }
      }
      else
        ptr ++;
    }

    free((void *)value_);
    value_ = 0;
  }

  // Free all of the arrays...
  if (nblocks_) {
    free(blocks_);

    ablocks_ = 0;
    nblocks_ = 0;
    blocks_  = 0;
  }

  if (nlinks_) {
    free(links_);

    alinks_ = 0;
    nlinks_ = 0;
    links_  = 0;
  }

  if (ntargets_) {
    free(targets_);

    atargets_ = 0;
    ntargets_ = 0;
    targets_  = 0;
  }
} // free_data()

/** Gets an alignment attribute. */
int                                     // O - Alignment
Fl_Help_View::get_align(const char *p,  // I - Pointer to start of attrs
                        int        a)   // I - Default alignment
{
  char  buf[255];                       // Alignment value


  if (get_attr(p, "ALIGN", buf, sizeof(buf)) == NULL)
    return (a);

  if (strcasecmp(buf, "CENTER") == 0)
    return (CENTER);
  else if (strcasecmp(buf, "RIGHT") == 0)
    return (RIGHT);
  else
    return (LEFT);
}


/** Gets an attribute value from the string. */
const char *                                    // O - Pointer to buf or NULL
Fl_Help_View::get_attr(const char *p,           // I - Pointer to start of attributes
                      const char *n,            // I - Name of attribute
                      char       *buf,          // O - Buffer for attribute value
                      int        bufsize)       // I - Size of buffer
{
  char  name[255],                              // Name from string
        *ptr,                                   // Pointer into name or value
        quote;                                  // Quote


  buf[0] = '\0';

  while (*p && *p != '>')
  {
    while (isspace((*p)&255))
      p ++;

    if (*p == '>' || !*p)
      return (NULL);

    for (ptr = name; *p && !isspace((*p)&255) && *p != '=' && *p != '>';)
      if (ptr < (name + sizeof(name) - 1))
        *ptr++ = *p++;
      else
        p ++;

    *ptr = '\0';

    if (isspace((*p)&255) || !*p || *p == '>')
      buf[0] = '\0';
    else
    {
      if (*p == '=')
        p ++;

      for (ptr = buf; *p && !isspace((*p)&255) && *p != '>';)
        if (*p == '\'' || *p == '\"')
        {
          quote = *p++;

          while (*p && *p != quote)
            if ((ptr - buf + 1) < bufsize)
              *ptr++ = *p++;
            else
              p ++;

          if (*p == quote)
            p ++;
        }
        else if ((ptr - buf + 1) < bufsize)
          *ptr++ = *p++;
        else
          p ++;

      *ptr = '\0';
    }

    if (strcasecmp(n, name) == 0)
      return (buf);
    else
      buf[0] = '\0';

    if (*p == '>')
      return (NULL);
  }

  return (NULL);
}


/** Gets a color attribute. */
Fl_Color                                // O - Color value
Fl_Help_View::get_color(const char *n,  // I - Color name
                        Fl_Color   c)   // I - Default color value
{
  int   i;                              // Looping var
  int   rgb, r, g, b;                   // RGB values
  static const struct {                 // Color name table
    const char *name;
    int r, g, b;
  }     colors[] = {
    { "black",          0x00, 0x00, 0x00 },
    { "red",            0xff, 0x00, 0x00 },
    { "green",          0x00, 0x80, 0x00 },
    { "yellow",         0xff, 0xff, 0x00 },
    { "blue",           0x00, 0x00, 0xff },
    { "magenta",        0xff, 0x00, 0xff },
    { "fuchsia",        0xff, 0x00, 0xff },
    { "cyan",           0x00, 0xff, 0xff },
    { "aqua",           0x00, 0xff, 0xff },
    { "white",          0xff, 0xff, 0xff },
    { "gray",           0x80, 0x80, 0x80 },
    { "grey",           0x80, 0x80, 0x80 },
    { "lime",           0x00, 0xff, 0x00 },
    { "maroon",         0x80, 0x00, 0x00 },
    { "navy",           0x00, 0x00, 0x80 },
    { "olive",          0x80, 0x80, 0x00 },
    { "purple",         0x80, 0x00, 0x80 },
    { "silver",         0xc0, 0xc0, 0xc0 },
    { "teal",           0x00, 0x80, 0x80 }
  };


  if (!n || !n[0]) return c;

  if (n[0] == '#') {
    // Do hex color lookup
    rgb = strtol(n + 1, NULL, 16);

    if (strlen(n) > 4) {
      r = rgb >> 16;
      g = (rgb >> 8) & 255;
      b = rgb & 255;
    } else {
      r = (rgb >> 8) * 17;
      g = ((rgb >> 4) & 15) * 17;
      b = (rgb & 15) * 17;
    }
    return (fl_rgb_color((uchar)r, (uchar)g, (uchar)b));
  } else {
    for (i = 0; i < (int)(sizeof(colors) / sizeof(colors[0])); i ++)
      if (!strcasecmp(n, colors[i].name)) {
        return fl_rgb_color(colors[i].r, colors[i].g, colors[i].b);
      }
    return c;
  }
}


/** Gets an inline image.

  The image reference count is maintained accordingly, such that
  the image can be released exactly once when the document is closed.

  \return a pointer to a cached Fl_Shared_Image, if the image can be loaded,
          otherwise a pointer to an internal Fl_Pixmap (broken_image).

  \todo Fl_Help_View::get_image() returns a pointer to the internal
  Fl_Pixmap broken_image, but this is _not_ compatible with the
  return type Fl_Shared_Image (release() must not be called).
*/

/* Implementation note: (A.S. Apr 05, 2009)

  Fl_Help_View::get_image() uses a static global flag (initial_load)
  to determine, if it is called from the initial loading of a document
  (load() or value()), or from resize() or draw().

  A better solution would be to manage all loaded images in an own
  structure like Fl_Help_Target (Fl_Help_Image ?) to avoid using this
  global flag, but this would break the ABI !

  This should be fixed in FLTK 1.3 !


  If initial_load is true, then Fl_Shared_Image::get() is called to
  load the image, and the reference count of the shared image is
  increased by one.

  If initial_load is false, then Fl_Shared_Image::find() is called to
  load the image, and the image is released immediately. This avoids
  increasing the reference count when calling get_image() from draw()
  or resize().

  Calling Fl_Shared_Image::find() instead of Fl_Shared_Image::get() avoids
  doing unnecessary i/o for "broken images" within each resize/redraw.

  Each image must be released exactly once in the destructor or before
  a new document is loaded: see free_data().
*/

Fl_Shared_Image *
Fl_Help_View::get_image(const char *name, int W, int H) {
  const char    *localname;             // Local filename
  char          dir[FL_PATH_MAX];       // Current directory
  char          temp[2 * FL_PATH_MAX],  // Temporary filename
                *tempptr;               // Pointer into temporary name
  Fl_Shared_Image *ip;                  // Image pointer...

  // See if the image can be found...
  if (strchr(directory_, ':') != NULL && strchr(name, ':') == NULL) {
    if (name[0] == '/') {
      strlcpy(temp, directory_, sizeof(temp));

      if ((tempptr = strrchr(strchr(directory_, ':') + 3, '/')) != NULL) {
        strlcpy(tempptr, name, sizeof(temp) - (tempptr - temp));
      } else {
        strlcat(temp, name, sizeof(temp));
      }
    } else {
      snprintf(temp, sizeof(temp), "%s/%s", directory_, name);
    }

    if (link_) localname = (*link_)(this, temp);
    else localname = temp;
  } else if (name[0] != '/' && strchr(name, ':') == NULL) {
    if (directory_[0]) snprintf(temp, sizeof(temp), "%s/%s", directory_, name);
    else {
      fl_getcwd(dir, sizeof(dir));
      snprintf(temp, sizeof(temp), "file:%s/%s", dir, name);
    }

    if (link_) localname = (*link_)(this, temp);
    else localname = temp;
  } else if (link_) localname = (*link_)(this, name);
  else localname = name;

  if (!localname) return 0;

  if (strncmp(localname, "file:", 5) == 0) localname += 5;

  if (initial_load) {
    if ((ip = Fl_Shared_Image::get(localname, W, H)) == NULL) {
      ip = (Fl_Shared_Image *)&broken_image;
    }
  } else { // draw or resize
    if ((ip = Fl_Shared_Image::find(localname, W, H)) == NULL) {
      ip = (Fl_Shared_Image *)&broken_image;
    } else {
      ip->release();
    }
  }

  return ip;
}


/** Gets a length value, either absolute or %. */
int
Fl_Help_View::get_length(const char *l) {       // I - Value
  int   val;                                    // Integer value

  if (!l[0]) return 0;

  val = atoi(l);
  if (l[strlen(l) - 1] == '%') {
    if (val > 100) val = 100;
    else if (val < 0) val = 0;

    int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
    val = val * (hsize_ - scrollsize) / 100;
  }

  return val;
}


Fl_Help_Link *Fl_Help_View::find_link(int xx, int yy)
{
  int           i;
  Fl_Help_Link  *linkp;
  for (i = nlinks_, linkp = links_; i > 0; i --, linkp ++) {
    if (xx >= linkp->x && xx < linkp->w &&
        yy >= linkp->y && yy < linkp->h)
      break;
  }
  return i ? linkp : 0L;
}

void Fl_Help_View::follow_link(Fl_Help_Link *linkp)
{
  char          target[32];     // Current target

  clear_selection();

  strlcpy(target, linkp->name, sizeof(target));

  set_changed();

  if (strcmp(linkp->filename, filename_) != 0 && linkp->filename[0])
  {
    char        dir[FL_PATH_MAX];       // Current directory
    char        temp[2 * FL_PATH_MAX],  // Temporary filename
              *tempptr; // Pointer into temporary filename


    if (strchr(directory_, ':') != NULL &&
        strchr(linkp->filename, ':') == NULL)
    {
      if (linkp->filename[0] == '/')
      {
        strlcpy(temp, directory_, sizeof(temp));
        if ((tempptr = strrchr(strchr(directory_, ':') + 3, '/')) != NULL)
          strlcpy(tempptr, linkp->filename, sizeof(temp));
        else
          strlcat(temp, linkp->filename, sizeof(temp));
      }
      else
        snprintf(temp, sizeof(temp), "%s/%s", directory_, linkp->filename);
    }
    else if (linkp->filename[0] != '/' && strchr(linkp->filename, ':') == NULL)
    {
      if (directory_[0])
        snprintf(temp, sizeof(temp), "%s/%s", directory_, linkp->filename);
      else
      {
          fl_getcwd(dir, sizeof(dir));
        snprintf(temp, sizeof(temp), "file:%s/%s", dir, linkp->filename);
      }
    }
    else
      strlcpy(temp, linkp->filename, sizeof(temp));

    if (linkp->name[0])
      snprintf(temp + strlen(temp), sizeof(temp) - strlen(temp), "#%s",
               linkp->name);

    load(temp);
  }
  else if (target[0])
    topline(target);
  else
    topline(0);

  leftline(0);
}

/** Removes the current text selection. */
void Fl_Help_View::clear_selection()
{
  if (current_view==this)
    clear_global_selection();
}
/** Selects all the text in the view. */
void Fl_Help_View::select_all()
{
  clear_global_selection();
  if (!value_) return;
  current_view = this;
  selection_drag_last = selection_last = (int) strlen(value_);
  selected = 1;
}

void Fl_Help_View::clear_global_selection()
{
  if (selected) redraw();
  selection_push_first = selection_push_last = 0;
  selection_drag_first = selection_drag_last = 0;
  selection_first = selection_last = 0;
  selected = 0;
}

char Fl_Help_View::begin_selection()
{
  clear_global_selection();

  if (!fl_help_view_buffer) fl_help_view_buffer = fl_create_offscreen(1, 1);

  mouse_x = Fl::event_x();
  mouse_y = Fl::event_y();
  draw_mode = 1;

    current_view = this;
    fl_begin_offscreen(fl_help_view_buffer);
    draw();
    fl_end_offscreen();

  draw_mode = 0;

  if (selection_push_last) return 1;
  else return 0;
}

char Fl_Help_View::extend_selection()
{
  if (Fl::event_is_click())
    return 0;

//  printf("old selection_first=%d, selection_last=%d\n",
//         selection_first, selection_last);

  int sf = selection_first, sl = selection_last;

  selected = 1;
  mouse_x = Fl::event_x();
  mouse_y = Fl::event_y();
  draw_mode = 2;

    fl_begin_offscreen(fl_help_view_buffer);
    draw();
    fl_end_offscreen();

  draw_mode = 0;

  if (selection_push_first < selection_drag_first) {
    selection_first = selection_push_first;
  } else {
    selection_first = selection_drag_first;
  }

  if (selection_push_last > selection_drag_last) {
    selection_last = selection_push_last;
  } else {
    selection_last = selection_drag_last;
  }

//  printf("new selection_first=%d, selection_last=%d\n",
//         selection_first, selection_last);

  if (sf!=selection_first || sl!=selection_last) {
//    puts("REDRAW!!!\n");
    return 1;
  } else {
//    puts("");
    return 0;
  }
}

// convert a command with up to four letters into an unsigned int
static unsigned int command(const char *cmd)
{
  unsigned int ret = (tolower(cmd[0])<<24);
  char c = cmd[1];
  if (c=='>' || c==' ' || c==0) return ret;
  ret |= (tolower(c)<<16);
  c = cmd[2];
  if (c=='>' || c==' ' || c==0) return ret;
  ret |= (tolower(c)<<8);
  c = cmd[3];
  if (c=='>' || c==' ' || c==0) return ret;
  ret |= tolower(c);
  c = cmd[4];
  if (c=='>' || c==' ' || c==0) return ret;
  return 0;
}

#define CMD(a, b, c, d) ((a<<24)|(b<<16)|(c<<8)|d)

void Fl_Help_View::end_selection(int clipboard)
{
  if (!selected || current_view!=this)
    return;
  // convert the select part of our html text into some kind of somewhat readable UTF-8
  // and store it in the selection buffer
  int p = 0;
  char pre = 0;
  int len = (int) strlen(value_);
  char *txt = (char*)malloc(len+1), *d = txt;
  const char *s = value_, *cmd, *src;
  for (;;) {
    int c = (*s++) & 0xff;
    if (c==0) break;
    if (c=='<') { // begin of some html command. Skip until we find a '>'
      cmd = s;
      for (;;) {
        c = (*s++) & 0xff;
        if (c==0 || c=='>') break;
      }
      if (c==0) break;
      // do something with this command... .
      // The replacement string must not be longer than the command
      // itself plus '<' and '>'
      src = 0;
      switch (command(cmd)) {
        case CMD('p','r','e', 0 ): pre = 1; break;
        case CMD('/','p','r','e'): pre = 0; break;
        case CMD('t','d', 0 , 0 ):
        case CMD('p', 0 , 0 , 0 ):
        case CMD('/','p', 0 , 0 ):
        case CMD('b','r', 0 , 0 ): src = "\n"; break;
        case CMD('l','i', 0 , 0 ): src = "\n * "; break;
        case CMD('/','h','1', 0 ):
        case CMD('/','h','2', 0 ):
        case CMD('/','h','3', 0 ):
        case CMD('/','h','4', 0 ):
        case CMD('/','h','5', 0 ):
        case CMD('/','h','6', 0 ): src = "\n\n"; break;
        case CMD('t','r', 0 , 0 ):
        case CMD('h','1', 0 , 0 ):
        case CMD('h','2', 0 , 0 ):
        case CMD('h','3', 0 , 0 ):
        case CMD('h','4', 0 , 0 ):
        case CMD('h','5', 0 , 0 ):
        case CMD('h','6', 0 , 0 ): src = "\n\n"; break;
        case CMD('d','t', 0 , 0 ): src = "\n "; break;
        case CMD('d','d', 0 , 0 ): src = "\n - "; break;
      }
      int n = (int) (s-value_);
      if (src && n>selection_first && n<=selection_last) {
        while (*src) {
          *d++ = *src++;
        }
        c = src[-1] & 0xff;
        p = isspace(c) ? ' ' : c;
      }
      continue;
    }
    const char *s2 = s;
    if (c=='&') { // special characters (HTML entities)
      int xx = quote_char(s);
      if (xx >= 0) {
        c = xx;
        for (;;) {
          char cc = *s++;
          if (!cc || cc==';') break;
        }
      }
    }
    int n = (int) (s2-value_);
    if (n>selection_first && n<=selection_last) {
      if (!pre && c < 256 && isspace(c)) c = ' ';
      if (p != ' ' || c != ' ') {
        if (s2 != s) { // c was an HTML entity
          d += fl_utf8encode(c, d);
        }
        else *d++ = c;
      }
      p = c;
    }
    if (n>selection_last) break; // stop parsing html after end of selection
  }
  *d = 0;
  Fl::copy(txt, (int) strlen(txt), clipboard);
  // printf("copy [%s]\n", txt);
  free(txt);
}

/** Handles events in the widget. */
int                             // O - 1 if we handled it, 0 otherwise
Fl_Help_View::handle(int event) // I - Event to handle
{
  static Fl_Help_Link *linkp;   // currently clicked link

  int xx = Fl::event_x() - x() + leftline_;
  int yy = Fl::event_y() - y() + topline_;

  switch (event)
  {
    case FL_FOCUS:
      redraw();
      return 1;
    case FL_UNFOCUS:
      clear_selection();
      redraw();
      return 1;
    case FL_ENTER :
      Fl_Group::handle(event);
      return 1;
    case FL_LEAVE :
      fl_cursor(FL_CURSOR_DEFAULT);
      break;
    case FL_MOVE:
      if (find_link(xx, yy)) fl_cursor(FL_CURSOR_HAND);
      else fl_cursor(FL_CURSOR_DEFAULT);
      return 1;
    case FL_PUSH:
      if (Fl_Group::handle(event)) return 1;
      linkp = find_link(xx, yy);
      if (linkp) {
        fl_cursor(FL_CURSOR_HAND);
        return 1;
      }
      if (begin_selection()) {
        fl_cursor(FL_CURSOR_INSERT);
        return 1;
      }
      fl_cursor(FL_CURSOR_DEFAULT);
      return 1;
    case FL_DRAG:
      if (linkp) {
        if (Fl::event_is_click()) {
          fl_cursor(FL_CURSOR_HAND);
        } else {
          fl_cursor(FL_CURSOR_DEFAULT); // should be "FL_CURSOR_CANCEL" if we had it
        }
        return 1;
      }
      if (current_view==this && selection_push_last) {
        if (extend_selection()) redraw();
        fl_cursor(FL_CURSOR_INSERT);
        return 1;
      }
      fl_cursor(FL_CURSOR_DEFAULT);
      return 1;
    case FL_RELEASE:
      if (linkp) {
        if (Fl::event_is_click()) {
          follow_link(linkp);
        }
        fl_cursor(FL_CURSOR_DEFAULT);
        linkp = 0;
        return 1;
      }
      if (current_view==this && selection_push_last) {
        end_selection();
        return 1;
      }
      return 1;
    case FL_SHORTCUT: {
      int mods = Fl::event_state() & (FL_META|FL_CTRL|FL_ALT|FL_SHIFT);
      if ( mods == FL_COMMAND) {
        switch ( Fl::event_key() ) {
          case 'a': select_all(); redraw(); return 1;
          case 'c':
          case 'x': end_selection(1); return 1;
        }
      }
      break; }
  }
  return (Fl_Group::handle(event));
}

/**
  The constructor creates the Fl_Help_View widget at the specified
  position and size.
*/
Fl_Help_View::Fl_Help_View(int        xx,       // I - Left position
                           int        yy,       // I - Top position
                           int        ww,       // I - Width in pixels
                           int        hh,       // I - Height in pixels
                           const char *l)
    : Fl_Group(xx, yy, ww, hh, l),
      scrollbar_(xx + ww - Fl::scrollbar_size(), yy,
                 Fl::scrollbar_size(), hh - Fl::scrollbar_size()),
      hscrollbar_(xx, yy + hh - Fl::scrollbar_size(),
                  ww - Fl::scrollbar_size(), Fl::scrollbar_size())
{
  color(FL_BACKGROUND2_COLOR, FL_SELECTION_COLOR);

  title_[0]     = '\0';
  defcolor_     = FL_FOREGROUND_COLOR;
  bgcolor_      = FL_BACKGROUND_COLOR;
  textcolor_    = FL_FOREGROUND_COLOR;
  linkcolor_    = FL_SELECTION_COLOR;
  textfont_     = FL_TIMES;
  textsize_     = 12;
  value_        = NULL;

  ablocks_      = 0;
  nblocks_      = 0;
  blocks_       = (Fl_Help_Block *)0;

  link_         = (Fl_Help_Func *)0;

  alinks_       = 0;
  nlinks_       = 0;
  links_        = (Fl_Help_Link *)0;

  atargets_     = 0;
  ntargets_     = 0;
  targets_      = (Fl_Help_Target *)0;

  directory_[0] = '\0';
  filename_[0]  = '\0';

  topline_      = 0;
  leftline_     = 0;
  size_         = 0;
  hsize_        = 0;
  scrollbar_size_ = 0;

  scrollbar_.value(0, hh, 0, 1);
  scrollbar_.step(8.0);
  scrollbar_.show();
  scrollbar_.callback(scrollbar_callback);

  hscrollbar_.value(0, ww, 0, 1);
  hscrollbar_.step(8.0);
  hscrollbar_.show();
  hscrollbar_.callback(hscrollbar_callback);
  hscrollbar_.type(FL_HORIZONTAL);
  end();

  resize(xx, yy, ww, hh);
}


/** Destroys the Fl_Help_View widget.

  The destructor destroys the widget and frees all memory that has been
  allocated for the current document.
*/
Fl_Help_View::~Fl_Help_View()
{
  clear_selection();
  free_data();
}


/** Loads the specified file.

 This method loads the specified file or URL. The filename may end in a
 \c \#name style target.

 If the URL starts with \a ftp, \a http, \a https, \a ipp, \a mailto, or
 \a news, followed by a colon, FLTK will use fl_open_uri() to show the
 requested page in an external browser.

 In all other cases, the URL is interpreted as a filename. The file is read and
 displayed in this borwser. Note that MSWindows style backslashes are not
 supported in the file name.

 \param[in] f filename or URL

 \return 0 on success, -1 on error

 \see fl_open_uri()
*/
int Fl_Help_View::load(const char *f)
{
  FILE          *fp;            // File to read from
  long          len;            // Length of file
  char          *target;        // Target in file
  char          *slash;         // Directory separator
  const char    *localname;     // Local filename
  char          error[2 * FL_PATH_MAX]; // Error buffer
  char          newname[FL_PATH_MAX];   // New filename buffer

  // printf("load(%s)\n",f); fflush(stdout);

  if (strncmp(f, "ftp:", 4) == 0 ||
      strncmp(f, "http:", 5) == 0 ||
      strncmp(f, "https:", 6) == 0 ||
      strncmp(f, "ipp:", 4) == 0 ||
      strncmp(f, "mailto:", 7) == 0 ||
      strncmp(f, "news:", 5) == 0)
  {
    char urimsg[FL_PATH_MAX];
    if ( fl_open_uri(f, urimsg, sizeof(urimsg)) == 0 ) {
      clear_selection();

      strlcpy(newname, f, sizeof(newname));
      if ((target = strrchr(newname, '#')) != NULL)
        *target++ = '\0';

      if (link_)
        localname = (*link_)(this, newname);
      else
        localname = filename_;

      if (!localname)
        return (0);

      free_data();

      strlcpy(filename_, newname, sizeof(filename_));
      strlcpy(directory_, newname, sizeof(directory_));

      // Note: We do not support Windows backslashes, since they are illegal
      //       in URLs...
      if ((slash = strrchr(directory_, '/')) == NULL)
        directory_[0] = '\0';
      else if (slash > directory_ && slash[-1] != '/')
        *slash = '\0';

      snprintf(error, sizeof(error),
               "<HTML><HEAD><TITLE>Error</TITLE></HEAD>"
               "<BODY><H1>Error</H1>"
               "<P>Unable to follow the link \"%s\" - "
               "%s.</P></BODY>",
               f, urimsg);
      value(error);
      return -1;
    } else {
      return 0;
    }
  }

  clear_selection();

  strlcpy(newname, f, sizeof(newname));
  if ((target = strrchr(newname, '#')) != NULL)
    *target++ = '\0';

  if (link_)
    localname = (*link_)(this, newname);
  else
    localname = filename_;

  if (!localname)
    return -1;

  free_data();

  strlcpy(filename_, newname, sizeof(filename_));
  strlcpy(directory_, newname, sizeof(directory_));

  // Note: We do not support Windows backslashes, since they are illegal
  //       in URLs...
  if ((slash = strrchr(directory_, '/')) == NULL)
    directory_[0] = '\0';
  else if (slash > directory_ && slash[-1] != '/')
    *slash = '\0';

  if (strncmp(localname, "file:", 5) == 0)
    localname += 5;     // Adjust for local filename...

  int ret = 0;
  if ((fp = fl_fopen(localname, "rb")) != NULL)
  {
    fseek(fp, 0, SEEK_END);
    len = ftell(fp);
    rewind(fp);

    value_ = (const char *)calloc(len + 1, 1);
    if (fread((void *)value_, 1, len, fp)==0) { /* use default 0 */ }
    fclose(fp);
  }
  else
  {
    snprintf(error, sizeof(error),
             "<HTML><HEAD><TITLE>Error</TITLE></HEAD>"
             "<BODY><H1>Error</H1>"
             "<P>Unable to follow the link \"%s\" - "
             "%s.</P></BODY>",
             localname, strerror(errno));
    value_ = fl_strdup(error);
    ret = -1;
  }

  initial_load = 1;
  format();
  initial_load = 0;

  if (target)
    topline(target);
  else
    topline(0);

  return ret;
}


/** Resizes the help widget. */

void
Fl_Help_View::resize(int xx,    // I - New left position
                     int yy,    // I - New top position
                     int ww,    // I - New width
                     int hh)    // I - New height
{
  Fl_Boxtype            b = box() ? box() : FL_DOWN_BOX;
                                        // Box to draw...


  Fl_Widget::resize(xx, yy, ww, hh);

  int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
  scrollbar_.resize(x() + w() - scrollsize - Fl::box_dw(b) + Fl::box_dx(b),
                    y() + Fl::box_dy(b), scrollsize, h() - scrollsize - Fl::box_dh(b));
  hscrollbar_.resize(x() + Fl::box_dx(b),
                     y() + h() - scrollsize - Fl::box_dh(b) + Fl::box_dy(b),
                     w() - scrollsize - Fl::box_dw(b), scrollsize);

  format();
}


/** Scrolls the text to the indicated position, given a named destination.

  \param[in] n target name
*/
void
Fl_Help_View::topline(const char *n)    // I - Target name
{
  Fl_Help_Target key,                   // Target name key
                *target;                // Pointer to matching target


  if (ntargets_ == 0)
    return;

  strlcpy(key.name, n, sizeof(key.name));

  target = (Fl_Help_Target *)bsearch(&key, targets_, ntargets_, sizeof(Fl_Help_Target),
                                 (compare_func_t)compare_targets);

  if (target != NULL)
    topline(target->y);
}


/** Scrolls the text to the indicated position, given a pixel line.

  If the given pixel value \p top is out of range, then the text is
  scrolled to the top or bottom of the document, resp.

  \param[in] top top line number in pixels (0 = start of document)
*/
void
Fl_Help_View::topline(int top)  // I - Top line number
{
  if (!value_)
    return;

  int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
  if (size_ < (h() - scrollsize) || top < 0)
    top = 0;
  else if (top > size_)
    top = size_;

  topline_ = top;

  scrollbar_.value(topline_, h() - scrollsize, 0, size_);

  do_callback();

  redraw();
}


/** Scrolls the text to the indicated position, given a pixel column.

  If the given pixel value \p left is out of range, then the text is
  scrolled to the left or right side of the document, resp.

  \param[in] left left column number in pixels (0 = left side)
*/
void
Fl_Help_View::leftline(int left)        // I - Left position
{
  if (!value_)
    return;

  int scrollsize = scrollbar_size_ ? scrollbar_size_ : Fl::scrollbar_size();
  if (hsize_ < (w() - scrollsize) || left < 0)
    left = 0;
  else if (left > hsize_)
    left = hsize_;

  leftline_ = left;

  hscrollbar_.value(leftline_, w() - scrollsize, 0, hsize_);

  redraw();
}


/** Sets the current help text buffer to the string provided and reformats the text.

  The provided character string \p val is copied internally and will be
  freed when value() is called again, or when the widget is destroyed.

  If \p val is NULL, then the widget is cleared.
*/
void
Fl_Help_View::value(const char *val)    // I - Text to view
{
  clear_selection();
  free_data();
  set_changed();

  if (!val)
    return;

  value_ = fl_strdup(val);

  initial_load = 1;
  format();
  initial_load = 0;

  topline(0);
  leftline(0);
}


/*  Returns the Unicode Code Point associated with a quoted character
    (aka "HTML Entity").

    Possible encoding formats:
     - &name;           named entity
     - &#nn..;          numeric (decimal) Unicode Code Point
     - &#xnn..;         numeric (hexadecimal) Unicode Code Point
     - &#Xnn..;         numeric (hexadecimal) Unicode Code Point
    'nn..' = decimal or hexadecimal number, resp.

    Contents of the table names[] below:

    All printable ASCII (32-126) and ISO-8859-1 (160-255) characters
    are encoded with the same value in Unicode. Special characters
    outside the range [0-255] are encoded with their Unicode Code Point
    as hexadecimal constants. Example:
     - Euro sign: (Unicode) U+20ac = (hex) 0x20ac

    Note: Converted to correct Unicode values and tested (compared with
    the display of Firefox). AlbrechtS, 14 Feb. 2016.

    Note to devs: if you add or remove items to/from this list, please
    update the documentation in FL/Fl_Help_View.H.
*/
static int                      // O - Code or -1 on error
quote_char(const char *p) {     // I - Quoted string
  int   i;                      // Looping var
  static const struct {
    const char  *name;
    int         namelen;
    int         code;
  }     *nameptr,               // Pointer into name array
        names[] = {             // Quoting names
    { "Aacute;", 7, 193 },
    { "aacute;", 7, 225 },
    { "Acirc;",  6, 194 },
    { "acirc;",  6, 226 },
    { "acute;",  6, 180 },
    { "AElig;",  6, 198 },
    { "aelig;",  6, 230 },
    { "Agrave;", 7, 192 },
    { "agrave;", 7, 224 },
    { "amp;",    4, '&' },
    { "Aring;",  6, 197 },
    { "aring;",  6, 229 },
    { "Atilde;", 7, 195 },
    { "atilde;", 7, 227 },
    { "Auml;",   5, 196 },
    { "auml;",   5, 228 },
    { "brvbar;", 7, 166 },
    { "bull;",   5, 0x2022 },
    { "Ccedil;", 7, 199 },
    { "ccedil;", 7, 231 },
    { "cedil;",  6, 184 },
    { "cent;",   5, 162 },
    { "copy;",   5, 169 },
    { "curren;", 7, 164 },
    { "dagger;", 7, 0x2020 },
    { "deg;",    4, 176 },
    { "divide;", 7, 247 },
    { "Eacute;", 7, 201 },
    { "eacute;", 7, 233 },
    { "Ecirc;",  6, 202 },
    { "ecirc;",  6, 234 },
    { "Egrave;", 7, 200 },
    { "egrave;", 7, 232 },
    { "ETH;",    4, 208 },
    { "eth;",    4, 240 },
    { "Euml;",   5, 203 },
    { "euml;",   5, 235 },
    { "euro;",   5, 0x20ac },
    { "frac12;", 7, 189 },
    { "frac14;", 7, 188 },
    { "frac34;", 7, 190 },
    { "gt;",     3, '>' },
    { "Iacute;", 7, 205 },
    { "iacute;", 7, 237 },
    { "Icirc;",  6, 206 },
    { "icirc;",  6, 238 },
    { "iexcl;",  6, 161 },
    { "Igrave;", 7, 204 },
    { "igrave;", 7, 236 },
    { "iquest;", 7, 191 },
    { "Iuml;",   5, 207 },
    { "iuml;",   5, 239 },
    { "laquo;",  6, 171 },
    { "lt;",     3, '<' },
    { "macr;",   5, 175 },
    { "micro;",  6, 181 },
    { "middot;", 7, 183 },
    { "nbsp;",   5, ' ' },
    { "not;",    4, 172 },
    { "Ntilde;", 7, 209 },
    { "ntilde;", 7, 241 },
    { "Oacute;", 7, 211 },
    { "oacute;", 7, 243 },
    { "Ocirc;",  6, 212 },
    { "ocirc;",  6, 244 },
    { "Ograve;", 7, 210 },
    { "ograve;", 7, 242 },
    { "ordf;",   5, 170 },
    { "ordm;",   5, 186 },
    { "Oslash;", 7, 216 },
    { "oslash;", 7, 248 },
    { "Otilde;", 7, 213 },
    { "otilde;", 7, 245 },
    { "Ouml;",   5, 214 },
    { "ouml;",   5, 246 },
    { "para;",   5, 182 },
    { "permil;", 7, 0x2030 },
    { "plusmn;", 7, 177 },
    { "pound;",  6, 163 },
    { "quot;",   5, '\"' },
    { "raquo;",  6, 187 },
    { "reg;",    4, 174 },
    { "sect;",   5, 167 },
    { "shy;",    4, 173 },
    { "sup1;",   5, 185 },
    { "sup2;",   5, 178 },
    { "sup3;",   5, 179 },
    { "szlig;",  6, 223 },
    { "THORN;",  6, 222 },
    { "thorn;",  6, 254 },
    { "times;",  6, 215 },
    { "trade;",  6, 0x2122 },
    { "Uacute;", 7, 218 },
    { "uacute;", 7, 250 },
    { "Ucirc;",  6, 219 },
    { "ucirc;",  6, 251 },
    { "Ugrave;", 7, 217 },
    { "ugrave;", 7, 249 },
    { "uml;",    4, 168 },
    { "Uuml;",   5, 220 },
    { "uuml;",   5, 252 },
    { "Yacute;", 7, 221 },
    { "yacute;", 7, 253 },
    { "yen;",    4, 165 },
    { "Yuml;",   5, 0x0178 },
    { "yuml;",   5, 255 }
  };

  if (!strchr(p, ';')) return -1;
  if (*p == '#') {
    if (*(p+1) == 'x' || *(p+1) == 'X') return strtol(p+2, NULL, 16);
    else return atoi(p+1);
  }
  for (i = (int)(sizeof(names) / sizeof(names[0])), nameptr = names; i > 0; i --, nameptr ++)
    if (strncmp(p, nameptr->name, nameptr->namelen) == 0)
      return nameptr->code;

  return -1;
}


/** The vertical scrollbar callback. */
static void
scrollbar_callback(Fl_Widget *s, void *)
{
  ((Fl_Help_View *)(s->parent()))->topline(int(((Fl_Scrollbar*)s)->value()));
}


/** The horizontal scrollbar callback. */
static void
hscrollbar_callback(Fl_Widget *s, void *)
{
  ((Fl_Help_View *)(s->parent()))->leftline(int(((Fl_Scrollbar*)s)->value()));
}
