//
// "$Id: TextDisplay.h 5432 2006-09-16 02:03:04Z spitzak $"
//
// Header file for TextDisplay class.
//
// Copyright 2001-2006 by Bill Spitzak and others.
// Original code Copyright Mark Edel.  Permission to distribute under
// the LGPL for the FLTK library granted by Mark Edel.
//
// 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
//

#ifndef _fltk_TextDisplay_h_
#define _fltk_TextDisplay_h_

#include "draw.h"
#include "Group.h"
#include "Widget.h"
#include "Scrollbar.h"
#include "TextBuffer.h"
#include "Font.h"

namespace fltk {

typedef void (*UnfinishedStyleCb)(int, void *);

/** TextDisplay */
class FL_API TextDisplay: public Group {
public:
  enum {
    NORMAL_CURSOR, CARET_CURSOR, DIM_CURSOR,
    BLOCK_CURSOR, HEAVY_CURSOR
  };

  enum {
    CURSOR_POS, CHARACTER_POS
  };

  // drag types- they match fltk::event_clicks() so that single clicking to
  // start a collection selects by character, double clicking selects by
  // word and triple clicking selects by line.
  enum {
    DRAG_CHAR = 0, DRAG_WORD = 1, DRAG_LINE = 2
  };

  enum {
    ATTR_NONE = 0,
    ATTR_UNDERLINE = 1,
    ATTR_HIDDEN = 2
  };

  struct StyleTableEntry {
    Color	color;
    Font        *font;
    float       size;
    unsigned	attr;
  };

  TextDisplay(int X, int Y, int W, int H, const char *l = 0);
  ~TextDisplay();

  // Emulation of Input widget:
  int size() const { return buffer_->length(); }
  const char* text() const { return buffer_->text(); }
  void text( const char* v) { buffer_->text(v); }
  void static_text( const char* v) { buffer_->text(v); }
  char at(int i) const { return buffer_->character(i); }

  virtual int handle(int e);
  virtual void draw();
  virtual void layout();

  /** Associate 'buf' with display */
  void buffer(TextBuffer* buf);
  /** Associate 'buf' with display */
  void buffer(TextBuffer& buf) { buffer(&buf); }

  /** Return attached buffer */
  TextBuffer* buffer() { return buffer_; }
  /** Return attached buffer */
  const TextBuffer* buffer() const { return buffer_; }

  /** Append text to the end of the buffer */
  void append(const char *text) { insert_position(buffer()->length()); insert(text); }
  /** Insert text to current cursor position */
  void insert(const char *text);
  /** Overstrike text from current cursor position */
  void overstrike(const char *text);

  /** Set new cursor position */
  void insert_position(int newPos);
  /** Return current cursor position */
  int insert_position() const { return cursor_pos_; }
  /** Make cursor position visible in screen */
  void show_insert_position();

  /** Show cursor */
  void show_cursor(bool b = true);
  /** Hide cursor */
  void hide_cursor() { show_cursor(false); }
  /** Return cursor visibility state */
  bool cursor_on() const { return cursor_on_; }
  /** Set cursor style */
  void cursor_style(int style);

  /** Return cursor color */
  Color cursor_color() const { return cursor_color_;}
  /** Set cursor color */
  void cursor_color(Color n) { cursor_color_ = n; }

  /** Return begining of the word where 'pos' is located */
  int word_start(int pos) { return buffer()->word_start(pos); }
  /** Return end of the word where 'pos' is located */
  int word_end(int pos) { return buffer()->word_end(pos); }
  /** Go to next word */
  void next_word(void);
  /** Go to previous word */
  void previous_word(void);

  /** Set wrapping mode. wrap_margin is width to wrap at, zero means use w() */
  void wrap_mode(bool wrap, int wrap_margin=0);

  /** Set line number area width */
  void linenumber_width(int width);
  /** Return line number area width */
  int linenumber_width() const { return linenumwidth_; }

  /** Set new highlight data */
  void highlight_data(TextBuffer *styleBuffer,
		      StyleTableEntry *styleTable,
		      int nStyles, char unfinishedStyle,
		      UnfinishedStyleCb unfinishedHighlightCB,
		      void *cbArg);

  /** Move cursor right */
  bool move_right();
  /** Move cursor left */
  bool move_left();
  /** Move cursor down */
  bool move_up();
  /** Move cursor down */
  bool move_down();

  /** Redisplay text */
  void redisplay_range(int start, int end);

  /** Scroll to new position */
  void scroll(int topLineNum, int horizOffset);

  /** Returns true if position is inside selection */
  bool in_selection(int x, int y);

  /** Returns begining of the line where 'pos' is located */
  int line_start(int pos);

  /** Returns end of the line where 'pos' is located */
  int line_end(int pos, bool start_pos_is_line_start = false);

  /** Return number of visible lines */
  int visible_lines() const { return visiblelines_cnt_; }

  /** Return current visible topline */
  int top_line() const { return topline_num_; }

  /** Return current horizontal offset */
  int hor_offset() const { return horiz_offset_; }

  /** Find start of the next character, starting from 'pos'
   * If 'pos' points to start of character already, it is returned.
   * This is mainly used with UTF-8 strings
   */
  int find_next_char(int pos);

  /** Find start of the previous character, starting from 'pos'
   * If 'pos' points to start of character already, it is returned.
   * This is mainly used with UTF-8 strings
   */
  int find_prev_char(int pos);

  int xy_to_position(int X, int Y, int PosType = CHARACTER_POS);

  void xy_to_rowcol(int X, int Y, int *row, int *column, int PosType = CHARACTER_POS);

  bool position_to_xy(int pos, int *X, int *Y);

  int total_lines() {return count_lines(0, buffer_->length(), true);}

protected:
  void draw_text(int X, int Y, int W, int H);
  void draw_range(int start, int end);
  void draw_cursor(int, int);

  void draw_string(int style, int x, int y, int toX, const char *string,
		   int nChars);

  void draw_vline(int visLineNum, int leftClip, int rightClip,
		  int leftCharIndex, int rightCharIndex);

  void draw_line_numbers(bool clearAll);

  void clear_rect(int style, int x, int y, int width, int height);
  void display_insert();

  int count_lines(int start, int end, bool start_pos_is_line_start);
  int skip_lines(int startPos, int nLines, bool startPosIsLineStart);
  int rewind_lines(int startPos, int nLines);
  int position_style(int lineStartPos, int lineLen, int lineIndex, int dispIndex);

  int wrapped_column(int row, int column);
  int wrapped_row(int row);

  void offset_line_starts(int newTopLineNum);

  void calc_line_starts(int startLine, int endLine);

  void update_line_starts(int pos, int charsInserted, int charsDeleted,
			  int linesInserted, int linesDeleted, bool *scrolled);

  void calc_last_char();

  bool position_to_line(int pos, int* lineNum);
  int string_width(const char* string, int length, int style);

  static void buffer_predelete_cb(int pos, int nDeleted, void* cbArg);
  static void buffer_modified_cb(int pos, int nInserted, int nDeleted,
				 int nRestyled, const char* deletedText,
				 void* cbArg);

  static void h_scrollbar_cb(Scrollbar* w, TextDisplay* d);
  static void v_scrollbar_cb( Scrollbar* w, TextDisplay* d);
  void update_v_scrollbar();
  void update_h_scrollbar(int longestvline = 0);

  void blank_cursor_protrusions();
  int measure_vline(int visLineNum);
  int longest_vline();
  int empty_vlines();
  int vline_length(int visLineNum);

  void maintain_absolute_top_line_number(bool state);
  int get_absolute_top_line_number();
  void absolute_top_line_number(int oldFirstChar);
  int maintaining_absolute_top_line_number();
  void reset_absolute_top_line_number();
  bool position_to_linecol(int pos, int *lineNum, int *column);
  void scroll_(int topLineNum, int horizOffset);

  void extend_range_for_styles(int* start, int* end);

  void find_wrap_range(const char *deletedText, int pos, int nInserted,
			 int nDeleted, int *modRangeStart, int *modRangeEnd,
			 int *linesInserted, int *linesDeleted);
  void measure_deleted_lines(int pos, int nDeleted);
  void wrapped_line_counter(TextBuffer *buf, int startPos, int maxPos,
			     int maxLines, bool startPosIsLineStart,
			     int styleBufOffset, int *retPos, int *retLines,
			     int *retLineStart, int *retLineEnd,
			     bool countLastLineMissingNewLine = true);
  void find_line_end(int pos, bool start_pos_is_line_start, int *lineEnd,
		       int *nextLineStart);
  int measure_proportional_character(TextBuffer *buf, int bufpos, int colNum, int pos);
  int wrap_uses_character(int lineEndPos);
  int range_touches_selection(TextSelection *sel, int rangeStart, int rangeEnd);
  void text_drag_me(int pos);

  int damage_range1_start, damage_range1_end;
  int damage_range2_start, damage_range2_end;

  int cursor_pos_;
  bool cursor_on_;
  int cursor_oldx_;           /* X pos. of cursor for blanking */
  int cursor_oldy_;           /* Y pos. of cursor for blanking */
  int cursor_hint_;           /* Tells the buffer modified callback
				 where to move the cursor, to reduce
				 the number of redraw calls */
  int cursor_style_;          /* One of enum cursorStyles above */
  int cursor_preferred_col_;  /* Column for vert. cursor movement */
  int visiblelines_cnt_;      /* # of visible (displayed) lines */
  int bufferlines_cnt_;       /* # of newlines in the buffer */
  TextBuffer *buffer_;        /* Contains text to be displayed */
  TextBuffer *stylebuffer_;   /* Optional parallel buffer containing
				 color and font information */
  int firstchar_, lastchar_;  /* Buffer positions of first and last
				 displayed character (lastChar points
				 either to a newline or one character
				 beyond the end of the buffer) */
  bool own_buffer;	      /* True if buffer_ created by constructor */
  bool continuous_wrap_;      /* Wrap long lines when displaying */
  int wrapmargin_;            /* Margin in # of char positions for
				 wrapping in continuousWrap mode */
  int *linestarts_;
  int topline_num_;           /* Line number of top displayed line
				 of file (first line of file is 1) */
  int abs_topline_num_;       /* In continuous wrap mode, the line
				 number of the top line if the text
				 were not wrapped (note that this is
				 only maintained as needed). */
  bool need_abs_topline_num_; /* Externally settable flag to continue
				 maintaining absTopLineNum even if
				 it isn't needed for line # display */
  int horiz_offset_;          /* Horizontal scroll pos. in pixels */
  int numstyles_;             /* Number of entries in styleTable */
  const StyleTableEntry *styletable_; /* Table of fonts and colors for
					 coloring/syntax-highlighting */
  char unfinished_style_;     /* Style buffer entry which triggers
				 on-the-fly reparsing of region */
  UnfinishedStyleCb unfinished_highlight_cb_; /* Callback to parse "unfinished" */
					      /* regions */
  void *highlight_cbarg_;     /* Arg to unfinishedHighlightCB */
  int fixed_fontwidth_;       /* Font width if all current fonts are
				 fixed and match in width, else -1 */
  bool suppressresync_;       /* Suppress resynchronization of line
				 starts during buffer updates */
  int nlinesdeleted_;         /* Number of lines deleted during
				 buffer modification (only used
				 when resynchronization is suppressed) */

  int stdfontwidth_;
  int ascent_;
  int descent_;
  int maxsize_;

  Color cursor_color_;

  Scrollbar *hscrollbar;
  Scrollbar *vscrollbar;

  Rectangle text_area;

  int dragpos_, dragtype_, dragging_;
  int linenumleft_, linenumwidth_; /* Line number margin and width */
};

} /* namespace fltk */

#endif

//
// End of "$Id: TextDisplay.h 5432 2006-09-16 02:03:04Z spitzak $".
//