fltk/FL/Fl_Help_View.H

//
// "$Id$"
//
// Help Viewer widget definitions.
//
// Copyright 1997-2005 by Easy Software Products.
// Image support donated by Matthias Melcher, Copyright 2000.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA.
//
// Please report all bugs and problems on the following page:
//
//     http://www.fltk.org/str.php
//

/** \file
   Fl_Help_View widget . */

#ifndef Fl_Help_View_H
#  define Fl_Help_View_H

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

#  include <stdio.h>
#  include "Fl.H"
#  include "Fl_Group.H"
#  include "Fl_Scrollbar.H"
#  include "fl_draw.H"
#  include "Fl_Shared_Image.H"


//
// Fl_Help_Func type - link callback function for files...
//


typedef const char *(Fl_Help_Func)(Fl_Widget *, const char *);


//
// Fl_Help_Block structure...
//

struct Fl_Help_Block
{
  const char	*start,		// Start of text
		*end;		// End of text
  uchar		border;		// Draw border?
  Fl_Color	bgcolor;	// Background color
  int		x,		// Indentation/starting X coordinate
		y,		// Starting Y coordinate
		w,		// Width
		h;		// Height
  int		line[32];	// Left starting position for each line
};

//
// Fl_Help_Link structure...
//

struct Fl_Help_Link
{
  char		filename[192],	// Reference filename
		name[32];	// Link target (blank if none)
  int		x,		// X offset of link text
		y,		// Y offset of link text
		w,		// Width of link text
		h;		// Height of link text
};

//
// Fl_Help_Target structure...
//

struct Fl_Help_Target
{
  char		name[32];	// Target name
  int		y;		// Y offset of target
};

/**
  The Fl_Help_View widget displays HTML text. Most HTML 2.0
  elements are supported, as well as a primitive implementation of tables.
  GIF, JPEG, and PNG images are displayed inline.
*/
class FL_EXPORT Fl_Help_View : public Fl_Group	//// Help viewer widget
{
  enum { RIGHT = -1, CENTER, LEFT };	// Alignments

  char		title_[1024];		// Title string
  Fl_Color	defcolor_,		// Default text color
		bgcolor_,		// Background color
		textcolor_,		// Text color
		linkcolor_;		// Link color
  Fl_Font       textfont_;		// Default font for text
  Fl_Fontsize  textsize_;		// Default font size
  const char	*value_;		// HTML text value

  int		nblocks_,		// Number of blocks/paragraphs
		ablocks_;		// Allocated blocks
  Fl_Help_Block	*blocks_;		// Blocks

  int		nfonts_;		// Number of fonts in stack
  Fl_Font       fonts_[100];		// Font stack
  Fl_Fontsize  font_sizes_[100];       // Font Size stack

  Fl_Help_Func	*link_;			// Link transform function

  int		nlinks_,		// Number of links
		alinks_;		// Allocated links
  Fl_Help_Link	*links_;		// Links

  int		ntargets_,		// Number of targets
		atargets_;		// Allocated targets
  Fl_Help_Target *targets_;		// Targets

  char		directory_[1024];	// Directory for current file
  char		filename_[1024];	// Current filename
  int		topline_,		// Top line in document
		leftline_,		// Lefthand position
		size_,			// Total document length
		hsize_;			// Maximum document width
  Fl_Scrollbar	scrollbar_,		// Vertical scrollbar for document
		hscrollbar_;		// Horizontal scrollbar

  static int    selection_first;
  static int    selection_last;
  static int    selection_push_first;
  static int    selection_push_last;
  static int    selection_drag_first;
  static int    selection_drag_last;
  static int    selected;
  static int    draw_mode;
  static int    mouse_x;
  static int    mouse_y;
  static int    current_pos;
  static Fl_Help_View *current_view;
  static Fl_Color hv_selection_color;
  static Fl_Color hv_selection_text_color;

  Fl_Help_Block	*add_block(const char *s, int xx, int yy, int ww, int hh, uchar border = 0);
  void		add_link(const char *n, int xx, int yy, int ww, int hh);
  void		add_target(const char *n, int yy);
  static int	compare_targets(const Fl_Help_Target *t0, const Fl_Help_Target *t1);
  int		do_align(Fl_Help_Block *block, int line, int xx, int a, int &l);
  void		draw();
  void		format();
  void		format_table(int *table_width, int *columns, const char *table);
  void		free_data();
  int		get_align(const char *p, int a);
  const char	*get_attr(const char *p, const char *n, char *buf, int bufsize);
  Fl_Color	get_color(const char *n, Fl_Color c);
  Fl_Shared_Image *get_image(const char *name, int W, int H);
  int		get_length(const char *l);
  int		handle(int);

  void		initfont(Fl_Font &f, Fl_Fontsize &s) { nfonts_ = 0;
			fl_font(f = fonts_[0] = textfont_,
			        s = font_sizes_[0] = textsize_); }
  void		pushfont(Fl_Font f, Fl_Fontsize s) { if (nfonts_ < 99) nfonts_ ++;
			fl_font(fonts_[nfonts_] = f,
			        font_sizes_[nfonts_] = s); }
  void		popfont(Fl_Font &f, Fl_Fontsize &s) { if (nfonts_ > 0) nfonts_ --;
			fl_font(f = fonts_[nfonts_],
			        s = font_sizes_[nfonts_]); }

  void          hv_draw(const char *t, int x, int y);
  char          begin_selection();
  char          extend_selection();
  void          end_selection(int c=0);
  void          clear_global_selection();
  Fl_Help_Link  *find_link(int, int);
  void          follow_link(Fl_Help_Link*);

public:

  Fl_Help_View(int xx, int yy, int ww, int hh, const char *l = 0);
  ~Fl_Help_View();
  /**    This method returns the current directory for the text in the buffer.  */
  const char	*directory() const { if (directory_[0]) return (directory_);
  					else return ((const char *)0); }
  /**    This method returns the current filename for the text in the buffer.  */
  const char	*filename() const { if (filename_[0]) return (filename_);
  					else return ((const char *)0); }
  int		find(const char *s, int p = 0);
  /**
    This method assigns a callback function to use when a link is
    followed or a file is loaded (via
    Fl_Help_View::load()) that requires a different
    file or path. The callback function receives a pointer to the
    Fl_Help_View widget and the URI or full pathname
    for the file in question. It must return a pathname that can be
    opened as a local file or NULL:</P>
    
    \code
    const char *fn(Fl_Widget *w, const char *uri);
    \endcode
    
    <P>The link function can be used to retrieve remote or virtual
    documents, returning a temporary file that contains the actual
    data. If the link function returns NULL, the value of
    the Fl_Help_View widget will remain unchanged.</P>
    
    <P>If the link callback cannot handle the URI scheme, it should
    return the uri value unchanged or set the value() of the widget
    before returning NULL.
  */
  void		link(Fl_Help_Func *fn) { link_ = fn; }
  int		load(const char *f);
  void		resize(int,int,int,int);
  /** Gets the size of the Help view */
  int		size() const { return (size_); }
  void		size(int W, int H) { Fl_Widget::size(W, H); }
  /** Sets the default text color. */
  void		textcolor(Fl_Color c) { if (textcolor_ == defcolor_) textcolor_ = c; defcolor_ = c; }
  /** Returns    the current default text color. */
  Fl_Color	textcolor() const { return (defcolor_); }
  /** Sets the default text font. */
  void		textfont(Fl_Font f) { textfont_ = f; format(); }
  /** Returns the current default text font. */
  Fl_Font       textfont() const { return (textfont_); }
  /** Sets the default text size. */
  void		textsize(Fl_Fontsize s) { textsize_ = s; format(); }
  /** Gets the default text size. */
  Fl_Fontsize  textsize() const { return (textsize_); }
  /** Returns the current document title, or NULL if there is no title. */
  const char	*title() { return (title_); }
  void		topline(const char *n);
  void		topline(int);
  /** Returns the current top line in pixels.  */
  int		topline() const { return (topline_); }
  void		leftline(int);
  /** Gets the left position. */
  int		leftline() const { return (leftline_); }
  void		value(const char *v);
  /** Returns the current buffer contents. */
  const char	*value() const { return (value_); }
  void          clear_selection();
  void          select_all();
};

#endif // !Fl_Help_View_H

//
// End of "$Id$".
//