columnify.h

// columnify.h    -*-c++-*-
//
//  Copyright 2000, 2005 Daniel Burrows
//  Copyright (C) 2019 Manuel A. Fernandez Montecelo
//  
//  This program is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program 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 General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; see the file COPYING.  If not, write to
//  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
//  Boston, MA 02111-1307, USA.
//
//  Support for creating column-formatted strings.  Columns which exceed their
// size limit are truncated.  Columns are collected into 'groups', each of
// which starts at a particular location.  This allows things such as
// right-justification of text.  If one column group overlaps another, the
// conflict is resolved by adjusting the column which is situated farthest to
// the right (by moving it farther to the right).
//
//  Right-justification is now handled (somewhat hackily) by columnify; to
// use it, set the start_off to something negative.  The group will be aligned
// so the the right edge of the column is start_off+1 characters from the
// right-hand screen edge -- so to align something exactly with the right-hand
// edge of the screen, set start_off to -1.
 
#ifndef COLUMNIFY_H
#define COLUMNIFY_H
 
#include <list>
#include <string>
#include <cwidget/generic/util/eassert.h>
 
namespace cwidget
{
  struct column_disposition
  {
    std::wstring text;
    int minx;
 
    column_disposition(const std::wstring &_text, int _minx) : text(_text), minx(_minx) {}

    column_disposition(const std::string &_text, int _minx,
                       const char *encoding = nullptr);
  };
 
  struct column
  {
    column_disposition info;
    int width;
    bool expand, shrink;
 
    column(const column_disposition &_info, int _width, bool _expand, bool _shrink)
      : info(_info), width(_width), expand(_expand), shrink(_shrink)
    {
      eassert(_width>=0);
    }
  };
 
  typedef std::list<column> layout;
 
  /* \return a string formatted as requested.  The string will be no
   * wider than width columns.  I could probably use printf-style
   * strings, but with the groups it would probably turn into a major
   * pain..
   */
  std::wstring columnify(const layout &format, int width);
}
 
#endif