netsurf/desktop/save_text.c

303 lines
8.4 KiB
C

/*
* Copyright 2004 John M Bell <jmb202@ecs.soton.ac.uk>
* Copyright 2008 Michael Drake <tlsa@netsurf-browser.org>
*
* This file is part of NetSurf, http://www.netsurf-browser.org/
*
* NetSurf 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; version 2 of the License.
*
* NetSurf 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. If not, see <http://www.gnu.org/licenses/>.
*/
/** \file
* Text export of HTML (implementation).
*/
#include <assert.h>
#include <stdbool.h>
#include <string.h>
#include "utils/config.h"
#include "content/content.h"
#include "desktop/save_text.h"
#include "render/box.h"
#include "utils/log.h"
#include "utils/utf8.h"
#include "utils/utils.h"
static void extract_text(struct box *box, bool *first,
save_text_whitespace *before, struct save_text_state *save);
static bool save_text_add_to_buffer(const char *text, size_t length,
struct box *box, const char *whitespace_text,
size_t whitespace_length, struct save_text_state *save);
/**
* Extract the text from an HTML content and save it as a text file. Text is
* converted to the local encoding.
*
* \param c An HTML content.
* \param path Path to save text file too.
*/
void save_as_text(struct content *c, char *path)
{
FILE *out;
struct save_text_state save = { NULL, 0, 0 };
save_text_whitespace before = WHITESPACE_NONE;
bool first = true;
utf8_convert_ret ret;
char *result;
if (!c || c->type != CONTENT_HTML) {
return;
}
extract_text(c->data.html.layout, &first, &before, &save);
if (!save.block)
return;
ret = utf8_to_local_encoding(save.block, save.length, &result);
free(save.block);
if (ret != UTF8_CONVERT_OK) {
LOG(("failed to convert to local encoding, return %d", ret));
return;
}
out = fopen(path, "w");
if (out) {
int res = fputs(result, out);
if (res < 0) {
LOG(("Warning: write failed"));
}
res = fputs("\n", out);
if (res < 0) {
LOG(("Warning: failed writing trailing newline"));
}
fclose(out);
}
free(result);
}
/**
* Decide what whitespace to place before the next bit of content-related text
* that is saved. Any existing whitespace is overridden if the whitespace for
* this box is more "significant".
*
* \param box Pointer to box.
* \param first Whether this is before the first bit of content-related
* text to be saved.
* \param before Type of whitespace currently intended to be placed
* before the next bit of content-related text to be saved.
* Updated if this box is worthy of more significant
* whitespace.
* \param whitespace_text Whitespace to place before next bit of
* content-related text to be saved.
* Updated if this box is worthy of more significant
* whitespace.
* \param whitespace_length Length of whitespace_text.
* Updated if this box is worthy of more significant
* whitespace.
*/
void save_text_solve_whitespace(struct box *box, bool *first,
save_text_whitespace *before, const char **whitespace_text,
size_t *whitespace_length)
{
/* work out what whitespace should be placed before the next bit of
* text */
if (*before < WHITESPACE_TWO_NEW_LINES &&
/* significant box type */
(box->type == BOX_BLOCK ||
box->type == BOX_TABLE ||
box->type == BOX_FLOAT_LEFT ||
box->type == BOX_FLOAT_RIGHT) &&
/* and not a list element */
!box->list_marker &&
/* and not a marker... */
(!(box->parent && box->parent->list_marker == box) ||
/* ...unless marker follows WHITESPACE_TAB */
((box->parent && box->parent->list_marker == box) &&
*before == WHITESPACE_TAB))) {
*before = WHITESPACE_TWO_NEW_LINES;
}
else if (*before <= WHITESPACE_ONE_NEW_LINE &&
(box->type == BOX_TABLE_ROW ||
box->type == BOX_BR ||
(box->type != BOX_INLINE &&
(box->parent && box->parent->list_marker == box)) ||
(box->parent->style &&
(css_computed_white_space(box->parent->style) ==
CSS_WHITE_SPACE_PRE ||
css_computed_white_space(box->parent->style) ==
CSS_WHITE_SPACE_PRE_WRAP) &&
box->type == BOX_INLINE_CONTAINER))) {
if (*before == WHITESPACE_ONE_NEW_LINE)
*before = WHITESPACE_TWO_NEW_LINES;
else
*before = WHITESPACE_ONE_NEW_LINE;
}
else if (*before < WHITESPACE_TAB &&
(box->type == BOX_TABLE_CELL ||
box->list_marker)) {
*before = WHITESPACE_TAB;
}
if (*first) {
/* before the first bit of text to be saved; there is
* no preceding whitespace */
*whitespace_text = "";
*whitespace_length = 0;
} else {
/* set the whitespace that has been decided on */
switch (*before) {
case WHITESPACE_TWO_NEW_LINES:
*whitespace_text = "\n\n";
*whitespace_length = 2;
break;
case WHITESPACE_ONE_NEW_LINE:
*whitespace_text = "\n";
*whitespace_length = 1;
break;
case WHITESPACE_TAB:
*whitespace_text = "\t";
*whitespace_length = 1;
break;
case WHITESPACE_NONE:
*whitespace_text = "";
*whitespace_length = 0;
break;
default:
*whitespace_text = "";
*whitespace_length = 0;
break;
}
}
}
/**
* Traverse though the box tree and add all text to a save buffer.
*
* \param box Pointer to box.
* \param first Whether this is before the first bit of content-related
* text to be saved.
* \param before Type of whitespace currently intended to be placed
* before the next bit of content-related text to be saved.
* Updated if this box is worthy of more significant
* whitespace.
* \param save our save_text_state workspace pointer
* \return true iff the file writing succeeded and traversal should continue.
*/
void extract_text(struct box *box, bool *first, save_text_whitespace *before,
struct save_text_state *save)
{
struct box *child;
const char *whitespace_text = "";
size_t whitespace_length = 0;
assert(box);
/* If box has a list marker */
if (box->list_marker) {
/* do the marker box before continuing with the rest of the
* list element */
extract_text(box->list_marker, first, before, save);
}
/* read before calling the handler in case it modifies the tree */
child = box->children;
save_text_solve_whitespace(box, first, before, &whitespace_text,
&whitespace_length);
if (box->type != BOX_BR && !((box->type == BOX_FLOAT_LEFT ||
box->type == BOX_FLOAT_RIGHT) && !box->text) &&
box->length > 0 && box->text) {
/* Box meets criteria for export; add text to buffer */
save_text_add_to_buffer(box->text, box->length, box,
whitespace_text, whitespace_length, save);
*first = false;
*before = WHITESPACE_NONE;
}
/* Work though the children of this box, extracting any text */
while (child) {
extract_text(child, first, before, save);
child = child->next;
}
return;
}
/**
* Add text to save text buffer. Any preceding whitespace or following space is
* also added to the buffer.
*
* \param text Pointer to text being added.
* \param length Length of text to be appended (bytes).
* \param box Pointer to text box.
* \param whitespace_text Whitespace to place before text for formatting
* may be NULL.
* \param whitespace_length Length of whitespace_text.
* \param save Our save_text_state workspace pointer.
* \return true iff the file writing succeeded and traversal should continue.
*/
bool save_text_add_to_buffer(const char *text, size_t length, struct box *box,
const char *whitespace_text, size_t whitespace_length,
struct save_text_state *save)
{
size_t new_length;
int space = 0;
assert(save);
if (box->space > 0)
space = 1;
if (whitespace_text)
length += whitespace_length;
new_length = save->length + whitespace_length + length + space;
if (new_length >= save->alloc) {
size_t new_alloc = save->alloc + (save->alloc / 4);
char *new_block;
if (new_alloc < new_length) new_alloc = new_length;
new_block = realloc(save->block, new_alloc);
if (!new_block) return false;
save->block = new_block;
save->alloc = new_alloc;
}
if (whitespace_text) {
memcpy(save->block + save->length, whitespace_text,
whitespace_length);
}
memcpy(save->block + save->length + whitespace_length, text, length);
save->length += length;
if (space == 1)
save->block[save->length++] = ' ';
return true;
}