Area.cpp

/*
 * Portions Copyright (c) 1999 GMRS Software GmbH
 * Carl-von-Linde-Str. 38, D-85716 Unterschleissheim, http://www.gmrs.de
 *      All rights reserved.
 *
 * Author: Arno Unkrig <arno@unkrig.de>
 *
 * 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 in the file COPYING for more details.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "Area.h"
#include "html.h"
#include "string.h"
#include "iconvstream.h"

static void *malloc_error(size_t size) {
	void *ret = malloc(size);
	if (ret == NULL) {
		perror("html2text: error");
		abort();
	}
	return ret;
}

static void *realloc_error(void *ptr, size_t size) {
	void *ret = realloc(ptr, size);
	if (ret == NULL) {
		perror("html2text: error");
		abort();
	}
	return ret;
}

#define malloc_array(type, size) \
	((type *) malloc_error(sizeof(type) * (size)))
#define realloc_array(array, type, size) \
	((array) = (type *) realloc_error((array), sizeof(type) * (size)))
#define copy_array(from, to, type, count) \
	((void) memcpy((to), (from), (count) * sizeof(type)))

/* ------------------------------------------------------------------------- */

Line::Line(size_type l):
	length_(l),
	cells_(malloc_array(Cell, l))
{
	Cell *p, *end = cells_ + l;
	for (p = cells_; p != end; p++)
		p->clear();
}

Line::Line(const char *p):
	length_(strlen(p)),
	cells_(malloc_array(Cell, length_))
{
	Cell *q = cells_, *end = q + length_;
	while (q != end) {
		q->clear();
		q->character = *p++;
		q->attribute = Cell::NONE;
		q++;
	}
}

Line::Line(const string &s):
	length_(s.length()),
	cells_(malloc_array(Cell, length_))
{
	const char *p = s.c_str();
	Cell *q = cells_, *end = q + length_;
	while (q != end) {
		q->clear();
		q->character = *p++;
		q->attribute = Cell::NONE;
		q++;
	}
}

Line::Line(const istr &s):
	length_(s.length()),
	cells_(malloc_array(Cell, length_))
{
	Cell *q = cells_;
	for (size_t i = 0; i < (size_t)length_; i++) {
		q->clear();
		q->character = s[i];
		q->attribute = Cell::NONE;
		q++;
	}
}

Line::~Line()
{
	free(cells_);
}

void
Line::resize(size_type l)
{
	if (l == length())
		return;
	realloc_array(cells_, Cell, l);
	for (size_type x = length(); x < l; x++)
		cells_[x].clear();
	length_ = l;
}

void
Line::insert(const Line &l, size_type x)
{
	enlarge(x + l.length());
	const Cell *p = l.cells_, *end = p + l.length();
	Cell       *q = cells_ + x;
	while (p != end)
		*q++ = *p++;
}

void
Line::insert(const char *p, size_type x)
{
	enlarge(x + strlen(p));
	Cell *q = cells_ + x;
	while (*p)
		q++->character = *p++;
}

void
Line::insert(const string &s, size_type x)
{
	insert(s.c_str(), x);
}

void
Line::append(char c)
{
	size_type x = length_;
	resize(x + 1);
	cells_[x].character = c;
	cells_[x].attribute = Cell::NONE;
}

void
Line::append(const Line &l)
{
	size_type x = length_;
	enlarge(x + l.length_);
	const Cell *p = l.cells_, *end = p + l.length();
	Cell       *q = cells_ + x;
	while (p != end)
		*q++ = *p++;
}

void
Line::append(const char *p)
{
	size_type x = length_;
	enlarge(x + strlen(p));
	Cell *q = cells_ + x;
	for (; *p; ++p, ++q) {
		q->character = *p;
		q->attribute = Cell::NONE;
	}
}

void
Line::set_fgcolour(unsigned char clr)
{
	Cell *p = cells_, *end = cells_ + length_;
	for (; p != end; p++)
	{
		/* skip when already set, e.g. let elements deeper in the tree
		 * override colours set by their parent(s) */
		if (p->attribute &Cell::FGCOLOUR)
			continue;

		p->fgcolour = clr;
		p->attribute |= Cell::FGCOLOUR;
	}
}

void
Line::set_bgcolour(unsigned char clr)
{
	Cell *p = cells_, *end = cells_ + length_;
	for (; p != end; p++)
	{
		/* skip when already set, e.g. let elements deeper in the tree
		 * override colours set by their parent(s) */
		if (p->attribute &Cell::BGCOLOUR)
			continue;

		p->bgcolour = clr;
		p->attribute |= Cell::BGCOLOUR;
	}
}

void
Line::add_attribute(char addition)
{
	Cell *p = cells_, *end = cells_ + length_;

	while (p != end)
		p++->attribute |= addition;
}

bool Area::use_backspaces = false;
bool Area::use_ansi       = true;

Area::size_type Area::widthsize  =  6;  /* px */
Area::size_type Area::heightsize = 16;  /* px, default fontsize */

Area::Area() :
	width_(0),
	height_(0),
	cells_(malloc_array(Cell *, 0))
{}

Area::Area(
	size_type w /*= 0*/,
	size_type h /*= 0*/,
	char c /*= ' '*/,
	char a    /*= Cell::NONE*/
	) :
	width_(w),
	height_(h),
	cells_(malloc_array(Cell *, h))
{
	for (size_type y = 0; y < h; y++) {
		Cell *p = cells_[y] = malloc_array(Cell, w), *end = p + w;
		while (p != end) {
			p->character = c;
			p->attribute = a;
			p++;
		}
	}
}

Area::Area(const char *p) :
	width_(strlen(p)),
	height_(1),
	cells_(malloc_array(Cell *, 1))
{
	cells_[0] = malloc_array(Cell, width_);
	Cell *q = cells_[0], *end = q + width_;
	while (q != end) {
		q->character = *p++;
		q->attribute = Cell::NONE;
		q++;
	}
}

Area::Area(const string &s) :
	width_(s.length()),
	height_(1),
	cells_(malloc_array(Cell *, 1))
{
	cells_[0] = malloc_array(Cell, width_);
	Cell *q = cells_[0];
	for (string::size_type i = 0; i < s.length(); ++i) {
		q->character = s[i];
		q->attribute = Cell::NONE;
		q++;
	}
}

Area::Area(const Line &l) :
	width_(l.length_),
	height_(1),
	cells_(malloc_array(Cell *, 1))
{
	cells_[0] = malloc_array(Cell, width_);
	copy_array(l.cells_, cells_[0], Cell, width_);
}

Area::Area(const istr &s):
	width_(s.length()),
	height_(1),
	cells_(malloc_array(Cell *, 1))
{
	cells_[0] = malloc_array(Cell, width_);
	Cell *q = cells_[0];
	for (string::size_type i = 0; i < s.length(); ++i) {
		q->character = s[i];
		q->attribute = Cell::NONE;
		q++;
	}
}

Area::~Area()
{
	for (size_type y = 0; y < height(); y++)
		free(cells_[y]);
	free(cells_);
}

const Area &
Area::operator>>=(size_type rs)
{
	if (rs > 0) {
		resize(width_ + rs, height_);
		for (size_type y = 0; y < height_; y++) {
			Cell *c = cells_[y];
			memmove(c + rs, c, (width_ - rs) * sizeof(Cell));
			for (size_type x = 0; x < rs; x++) {
				c[x].character = ' ';
				c[x].attribute = Cell::NONE;
			}
		}
	}
	return *this;
}

const Area &
Area::operator>>=(const char *prefix)
{
	size_type plen = 0;
	if (prefix != NULL)
		plen = strlen(prefix);

	if (plen > 0) {
		resize(width_ + plen, height_);
		for (size_type y = 0; y < height_; y++) {
			Cell *c = cells_[y];
			memmove(c + plen, c, (width_ - plen) * sizeof(Cell));
			for (size_type x = 0; x < plen; x++) {
				c[x].character = prefix[x];
				c[x].attribute = Cell::NONE;
			}
		}
	}
	return *this;
}

void
Area::resize(size_type w, size_type h)
{
	size_type y_max = h < height() ? h : height();

	if (w > width()) {
		for (size_type y = 0; y < y_max; y++) {
			realloc_array(cells_[y], Cell, w);
			Cell *p = cells_[y] + width(), *end = cells_[y] + w;
			while (p != end)
				p++->clear();
		}
	} else if (w < width()) {
		for (size_type y = 0; y < y_max; y++) {
			realloc_array(cells_[y], Cell, w);
		}
	}

	if (h > height()) {
		realloc_array(cells_, Cell *, h);
		for (size_type y = height(); y < h; y++) {
			Cell *p = cells_[y] = malloc_array(Cell, w), *end = p + w;
			while (p != end)
				p++->clear();
		}
	} else if (h < height()) {
		for (size_type y = h; y < height(); y++)
			free(cells_[y]);
		realloc_array(cells_, Cell *, h);
	}

	width_ = w;
	height_ = h;
}

void
Area::enlarge(size_type w, size_type h)
{
	if (w > width() || h > height()) {
		resize(w > width() ? w : width(), h > height() ? h : height());
	}
}

void
Area::insert(const Area &a, size_type x, size_type y)
{
	enlarge(x + a.width(), y + a.height());

	for (size_type i = 0; i < a.height(); i++) {
		const Cell *p = a.cells_[i], *end = p + a.width();
		Cell       *q = cells_[y + i] + x;
		while (p != end)
			*q++ = *p++;
	}
}

void
Area::insert(
	const Area &a,
	size_type x,
	size_type y,
	size_type w,
	size_type h,
	int halign,
	int valign
	)
{
	if (halign != LEFT && a.width() < w)
		x += (
			halign == CENTER ? (w - a.width()) / 2 :
			halign == RIGHT  ? w - a.width()       :
			0
			);
	if (valign != TOP && a.height() < h)
		y += (
			valign == MIDDLE ? (h - a.height()) / 2 :
			valign == BOTTOM ? h - a.height()       :
			0
			);
	insert(a, x, y);
}

void
Area::insert(const Cell &c, size_type x, size_type y)
{
	enlarge(x + 1, y + 1);
	cells_[y][x] = c;
}

void
Area::fill(const Cell &c, size_type x, size_type y, size_type w, size_type h)
{
	enlarge(x + w, y + h);
	for (size_type yy = y; yy < y + h; yy++) {
		Cell *p = &cells_[yy][x];
		for (size_type i = 0; i < w; i++)
			*p++ = c;
	}
}

void
Area::insert(const Cell *p, size_type count, size_type x, size_type y)
{
	enlarge(x + count, y + 1);
	Cell *q = &cells_[y][x];
	while (count--)
		*q++ = *p++;
}

void
Area::insert(char c, size_type x, size_type y)
{
	enlarge(x + 1, y + 1);
	cells_[y][x].character = c;
}

void
Area::insert(const string &s, size_type x, size_type y)
{
	enlarge(x + s.length(), y + 1);
	Cell *cell = &cells_[y][x];
	for (string::size_type i = 0; i < s.length(); i++) {
		cell->character = s[i];
		cell->attribute = Cell::NONE;
		cell++;
	}
}

void
Area::prepend(int n)
{
	if (n <= 0)
		return;

	realloc_array(cells_, Cell *, height() + n);
	memmove(cells_ + n, cells_, height() * sizeof(*cells_));
	for (int y = 0; y < n; ++y) {
		Cell *p = cells_[y] = malloc_array(Cell, width()), *end = p + width();
		while (p != end)
			p++->clear();
	}
	height_ += n;
}

const Area &
Area::operator+=(const Area &x)
{
	insert(x, 0, height());
	return *this;
}

void
Area::fill(char c, size_type x, size_type y, size_type w, size_type h)
{
	enlarge(x + w, y + h);
	for (size_type yy = y; yy < y + h; yy++) {
		Cell *p = &cells_[yy][x];
		for (size_type i = 0; i < w; i++)
			p++->character = c;
	}
}

void
Area::set_bgcolour(unsigned char clr)
{
	for (size_type y = 0; y < height(); y++) {
		Cell *p = cells_[y], *end = p + width();
		while (p != end) {
			/* skip when already set, e.g. let elements deeper in the
			 * tree override colours set by their parent(s) */
			if (!(p->attribute & Cell::BGCOLOUR)) {
				p->bgcolour   = clr;
				p->attribute |= Cell::BGCOLOUR;
			}
			p++;
		}
	}
}

void
Area::set_fgcolour(unsigned char clr)
{
	for (size_type y = 0; y < height(); y++) {
		Cell *p = cells_[y], *end = p + width();
		while (p != end) {
			/* skip when already set, e.g. let elements deeper in the
			 * tree override colours set by their parent(s) */
			if (!(p->attribute & Cell::FGCOLOUR)) {
				p->fgcolour   = clr;
				p->attribute |= Cell::FGCOLOUR;
			}
			p++;
		}
	}
}

void
Area::add_attribute(char addition)
{
	for (size_type y = 0; y < height(); y++) {
		Cell *p = cells_[y], *end = p + width();
		while (p != end && p->character == ' ')
			++p;
		Cell *q = p;
		while (p != end) {
			if (p++->character != ' ') {
				while (q < p)
					q++->attribute |= addition;
			}
		}
	}
}

void
Area::add_attribute(
	char addition,
	size_type x,
	size_type y,
	size_type w,
	size_type h
	)
{
	enlarge(x + w, y + h);
	for (size_type yy = y; yy < y + h; yy++) {
		Cell *p = &cells_[yy][x], *end = p + w;
		while (p != end)
			p++->attribute |= addition;
	}
}

static char backspace = '\b';

iconvstream &
operator<<(iconvstream& os, const Area &a)
{
	for (Area::size_type y = 0; y < a.height(); y++) {
		/* compute visible part */
		const Cell   *cell     = a.cells_[y];
		const Cell   *end      = cell + a.width();
		char          attrs    = Cell::NONE;
		unsigned char fgcolour = Cell::BLACK;
		unsigned char bgcolour = Cell::WHITE;

		/* trim off trailing spaces when they are not "visible" due to
		 * attributes (underline/strikethrough) */
		while (end != cell &&
			   end[-1].character == ' ' &&
			   (end[-1].attribute & (Cell::UNDERLINE |
									 Cell::STRIKETHROUGH)) == 0)
			end--;

		for (const Cell *p = cell; p != end; p++) {
			int  c    = p->character;
			char a    = p->attribute;
			char u[5] = {0, 0, 0, 0, 0};

			/* compute codepoint, this is a bit unfortunate and should
			 * go away once we use wchar_t */
			u[0] = c & 0xFF;
			if ((c >> 7) & 1) {
				unsigned int  d     = c;
				unsigned char point = 1;
				while ((c >> (7 - point++)) & 1) {
					d >>= 8;
					u[point - 1] = d & 0xFF;
				}
			}

			if (Area::use_ansi) {
				/* use ANSI escape sequences to produce colours, bold
				 * and underline */

				/* see if there's something that needs disabling */
				if (attrs != a ||
					(a & Cell::COLOUR &&
					 (p->fgcolour != fgcolour ||
					  p->bgcolour != bgcolour)))
				{
					/* reset all properties, rebuild afterwards
					 * we do this also because it's the only way to
					 * unset something :) */
					os << "\e[0";

					attrs    = a;
					fgcolour = p->fgcolour;
					bgcolour = p->bgcolour;

					/* enable needed properties */
					if (attrs & Cell::UNDERLINE) {
						os << ";4";
					}
					if (attrs & Cell::BOLD) {
						os << ";1";
					}
					if (attrs & Cell::ITALICS) {
						os << ";3";
					}
					if (attrs & Cell::STRIKETHROUGH) {
						os << ";9";
					}
					if (attrs & Cell::FGCOLOUR) {
						os << ";38;5;" << std::to_string(fgcolour);
					}
					if (attrs & Cell::BGCOLOUR) {
						os << ";48;5;" << std::to_string(bgcolour);
					}

					/* finish sequence */
					os << "m";
				}
				os << u;
			} else if (Area::use_backspaces &&
					   a != Cell::NONE)
			{
				/* old method of producing bold and underline */

				/* No LESS / terminal combination that I know of
				 * supports dash-backspace-character as
				 * "strikethrough". Pity.
				 * (For historical reasons we're still doing it though.) */
				if (a & Cell::STRIKETHROUGH)
					os << '-' << backspace;

				/* No LESS that I know of can combine underlining
				 * and boldface. In practice, boldface always takes
				 * precedence.
				 *
				 * It's not a good idea to optimize an underlined
				 * space as a single underscore (as opposed to
				 * underscore-backspace-space) -- this would not
				 * look nice next to an underlined character. */
				if ((a & Cell::UNDERLINE))
					os << '_' << backspace;
				if ((a & Cell::BOLD     ) && c != ' ')
					os << u << backspace;
				os << u;
			} else {
				/* no rendering, historical behaviour to turn spaces
				 * into underscores when the input is underlined */
				os << (c == ' ' && (a & Cell::UNDERLINE) ? "_" : u);
			}
		}

		/* if we haven't yet, unset all features */
		if (Area::use_ansi && attrs != Cell::NONE)
			os << "\e[0;m";

		os << endl;
	}

	return os;
}