Fl_Simple_Terminal.H

//
// A simple terminal widget for Fast Light Tool Kit (FLTK).
//
// Copyright 1998-2011 by Bill Spitzak and others.
// Copyright 2017 by Greg Ercolano.
//
// 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
//
 
/* \file
   Fl_Simple_Terminal widget . */
 
#ifndef Fl_Simple_Terminal_H
#define Fl_Simple_Terminal_H
 
#include "Fl_Export.H"
#include <FL/Fl_Text_Display.H>
 
class FL_EXPORT Fl_Simple_Terminal : public Fl_Text_Display {
protected:
  Fl_Text_Buffer *buf;      // text buffer
  Fl_Text_Buffer *sbuf;     // style buffer
 
private:
  // Private class to handle parsing ESC sequences
  //    Holds all state information for parsing esc sequences,
  //    so sequences can span multiple block read(2) operations, etc.
  //
  class FL_EXPORT Fl_Escape_Seq {
  public:
    static const int maxbuf   = 80;
    static const int maxvals  = 10;
    // Return codes
    static const int success   = 0;   // operation succeeded
    static const int fail      = -1;  // operation failed
    static const int completed = 1;   // multi-step operation completed successfully
  private:
    char  esc_mode_;        // escape parsing mode state
    char  buf_[maxbuf];     // escape sequence being parsed
    char *bufp_;            // parsing ptr into buf[]
    char *bufendp_;         // end of buf[] (ptr to last valid buf char)
    char *valbufp_;         // pointer to first char in buf of integer being parsed
    int   vals_[maxvals];   // value array for parsing #'s in ESC[#;#;#..
    int   vali_;            // parsing index into vals_[], 0 if none
 
    int append_buf(char c);
    int append_val();
 
  public:
    Fl_Escape_Seq();
    void reset();
    char esc_mode() const;
    void esc_mode(char val);
    int  total_vals() const;
    int  val(int i) const;
    bool parse_in_progress() const;
    int parse(char c);
  };
 
private:
  int  history_lines_;      // max lines allowed in screen history
  bool stay_at_bottom_;     // lets scroller chase last line in buffer
  // scroll management
  int  lines_;              // #lines in buffer (optimization: Fl_Text_Buffer slow to calc this)
  bool scrollaway_;         // true when user changed vscroll away from bottom
  bool scrolling_;          // true while scroll callback active
  // Fl_Text_Display vscrollbar's callback+data
  Fl_Callback *orig_vscroll_cb_;
  void *orig_vscroll_data_;
  // Style table
  const Fl_Text_Display::Style_Table_Entry *stable_;  // the active style table
  int  stable_size_;         // active style table size (in bytes)
  int  normal_style_index_;  // "normal" style used by "\033[0m" reset sequence
  int  current_style_index_; // current style used for drawing text
  char current_style_;       // current 'style char' (e.g. 'A' = first style entry)
  // ANSI escape seq
  Fl_Escape_Seq escseq;      // escape sequence state handler
  bool ansi_;                // enables ANSI sequences
  bool ansi_show_unknown_;   // show '¿' for unknown ESC sequences (default: off)
  // String parsing vars initialized/used by append(), used by handle_backspace() etc.
  char *ntm_;                // new text memory  (ntm) - malloc()ed by append() for output text
  char *ntp_;                // new text ptr     (ntp) - points into ntm buffer
  char *nsm_;                // new style memory (nsm) - malloc()ed by append() for output style
  char *nsp_;                // new style ptr    (nsp) - points into nsm buffer
 
public:
  Fl_Simple_Terminal(int X,int Y,int W,int H,const char *l=0);
  ~Fl_Simple_Terminal();
 
  // Terminal options
  void stay_at_bottom(bool);
  bool stay_at_bottom() const;
  void history_lines(int);
  int  history_lines() const;
  void ansi(bool val);
  bool ansi() const;
  void ansi_show_unknown(bool val);
  bool ansi_show_unknown() const;
  void style_table(Fl_Text_Display::Style_Table_Entry *stable, int stable_size, int normal_style_index=0);
  const Fl_Text_Display::Style_Table_Entry *style_table() const;
  int style_table_size() const;
  void normal_style_index(int);
  int  normal_style_index() const;
  void current_style_index(int);
  int  current_style_index() const;
  int  current_style() const;
 
  // Terminal text management
  void append(const char *s, int len=-1);
  void text(const char *s, int len=-1);
  const char* text() const;
  void printf(const char *fmt, ...);
  void vprintf(const char *fmt, va_list ap);
  void clear();
  void remove_lines(int start, int count);
 
private:
  // Methods blocking public access to the subclass
  //    These are subclass methods that would give unexpected
  //    results if used. By making them private, we effectively
  //    "block" them.
  //
  //    TODO: There are probably other Fl_Text_Display methods that
  //          need to be blocked.
  //
  void insert(const char*) { }
 
protected:
  // Fltk
  void draw() FL_OVERRIDE;
 
  // Internal methods
  void enforce_stay_at_bottom();
  void enforce_history_lines();
  void vscroll_cb2(Fl_Widget*, void*);
  static void vscroll_cb(Fl_Widget*, void*);
  void backspace_buffer(unsigned int count);
  void handle_backspace();
  void append_ansi(const char *s, int len);
  void unknown_escape();
};
 
#endif