netsurf/content/handlers/html/search.c
2020-05-02 20:47:53 +01:00

663 lines
16 KiB
C

/*
* Copyright 2004 John M Bell <jmb202@ecs.soton.ac.uk>
* Copyright 2005 Adrian Lees <adrianl@users.sourceforge.net>
* Copyright 2009 Mark Benjamin <netsurf-browser.org.MarkBenjamin@dfgh.net>
*
* 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
* Free text search (core)
*/
#include <ctype.h>
#include <string.h>
#include <dom/dom.h>
#include "utils/config.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/utils.h"
#include "content/content.h"
#include "content/hlcache.h"
#include "desktop/selection.h"
#include "netsurf/search.h"
#include "netsurf/misc.h"
#include "desktop/gui_internal.h"
#include "text/textplain.h"
#include "html/box.h"
#include "html/box_inspect.h"
#include "html/html.h"
#include "html/private.h"
#include "html/search.h"
#ifndef NOF_ELEMENTS
#define NOF_ELEMENTS(array) (sizeof(array)/sizeof(*(array)))
#endif
struct list_entry {
unsigned start_idx; /* start position of match */
unsigned end_idx; /* end of match */
struct box *start_box; /* used only for html contents */
struct box *end_box;
struct selection *sel;
struct list_entry *prev;
struct list_entry *next;
};
struct search_context {
void *gui_p;
struct content *c;
struct list_entry *found;
struct list_entry *current; /* first for select all */
char *string;
bool prev_case_sens;
bool newsearch;
bool is_html;
};
/* Exported function documented in search.h */
struct search_context *
search_create_context(struct content *c, content_type type, void *gui_data)
{
struct search_context *context;
struct list_entry *search_head;
if (type != CONTENT_HTML && type != CONTENT_TEXTPLAIN) {
return NULL;
}
context = malloc(sizeof(struct search_context));
if (context == NULL) {
return NULL;
}
search_head = malloc(sizeof(struct list_entry));
if (search_head == NULL) {
free(context);
return NULL;
}
search_head->start_idx = 0;
search_head->end_idx = 0;
search_head->start_box = NULL;
search_head->end_box = NULL;
search_head->sel = NULL;
search_head->prev = NULL;
search_head->next = NULL;
context->found = search_head;
context->current = NULL;
context->string = NULL;
context->prev_case_sens = false;
context->newsearch = true;
context->c = c;
context->is_html = (type == CONTENT_HTML) ? true : false;
context->gui_p = gui_data;
return context;
}
/**
* Release the memory used by the list of matches,
* deleting selection objects too
*/
static void free_matches(struct search_context *context)
{
struct list_entry *a;
struct list_entry *b;
a = context->found->next;
/* empty the list before clearing and deleting the
* selections because the the clearing updates the
* screen immediately, causing nested accesses to the list */
context->found->prev = NULL;
context->found->next = NULL;
for (; a; a = b) {
b = a->next;
if (a->sel) {
selection_clear(a->sel, true);
selection_destroy(a->sel);
}
free(a);
}
}
/**
* Find the first occurrence of 'match' in 'string' and return its index
*
* \param string the string to be searched (unterminated)
* \param s_len length of the string to be searched
* \param pattern the pattern for which we are searching (unterminated)
* \param p_len length of pattern
* \param case_sens true iff case sensitive match required
* \param m_len accepts length of match in bytes
* \return pointer to first match, NULL if none
*/
static const char *find_pattern(const char *string, int s_len,
const char *pattern, int p_len, bool case_sens,
unsigned int *m_len)
{
struct { const char *ss, *s, *p; bool first; } context[16];
const char *ep = pattern + p_len;
const char *es = string + s_len;
const char *p = pattern - 1; /* a virtual '*' before the pattern */
const char *ss = string;
const char *s = string;
bool first = true;
int top = 0;
while (p < ep) {
bool matches;
if (p < pattern || *p == '*') {
char ch;
/* skip any further asterisks; one is the same as many
*/
do p++; while (p < ep && *p == '*');
/* if we're at the end of the pattern, yes, it matches
*/
if (p >= ep) break;
/* anything matches a # so continue matching from
here, and stack a context that will try to match
the wildcard against the next character */
ch = *p;
if (ch != '#') {
/* scan forwards until we find a match for
this char */
if (!case_sens) ch = toupper(ch);
while (s < es) {
if (case_sens) {
if (*s == ch) break;
} else if (toupper(*s) == ch)
break;
s++;
}
}
if (s < es) {
/* remember where we are in case the match
fails; we may then resume */
if (top < (int)NOF_ELEMENTS(context)) {
context[top].ss = ss;
context[top].s = s + 1;
context[top].p = p - 1;
/* ptr to last asterisk */
context[top].first = first;
top++;
}
if (first) {
ss = s;
/* remember first non-'*' char */
first = false;
}
matches = true;
} else {
matches = false;
}
} else if (s < es) {
char ch = *p;
if (ch == '#')
matches = true;
else {
if (case_sens)
matches = (*s == ch);
else
matches = (toupper(*s) == toupper(ch));
}
if (matches && first) {
ss = s; /* remember first non-'*' char */
first = false;
}
} else {
matches = false;
}
if (matches) {
p++; s++;
} else {
/* doesn't match,
* resume with stacked context if we have one */
if (--top < 0)
return NULL; /* no match, give up */
ss = context[top].ss;
s = context[top].s;
p = context[top].p;
first = context[top].first;
}
}
/* end of pattern reached */
*m_len = max(s - ss, 1);
return ss;
}
/**
* Add a new entry to the list of matches
*
* \param start_idx Offset of match start within textual representation
* \param end_idx Offset of match end
* \param context The search context to add the entry to.
* \return Pointer to added entry, NULL iff failed.
*/
static struct list_entry *
add_entry(unsigned start_idx, unsigned end_idx, struct search_context *context)
{
struct list_entry *entry;
/* found string in box => add to list */
entry = calloc(1, sizeof(*entry));
if (!entry) {
return NULL;
}
entry->start_idx = start_idx;
entry->end_idx = end_idx;
entry->sel = NULL;
entry->next = 0;
entry->prev = context->found->prev;
if (context->found->prev == NULL) {
context->found->next = entry;
} else {
context->found->prev->next = entry;
}
context->found->prev = entry;
return entry;
}
/**
* Finds all occurrences of a given string in the html box tree
*
* \param pattern the string pattern to search for
* \param p_len pattern length
* \param cur pointer to the current box
* \param case_sens whether to perform a case sensitive search
* \param context The search context to add the entry to.
* \return true on success, false on memory allocation failure
*/
static bool find_occurrences_html(const char *pattern, int p_len,
struct box *cur, bool case_sens,
struct search_context *context)
{
struct box *a;
/* ignore this box, if there's no visible text */
if (!cur->object && cur->text) {
const char *text = cur->text;
unsigned length = cur->length;
while (length > 0) {
struct list_entry *entry;
unsigned match_length;
unsigned match_offset;
const char *new_text;
const char *pos = find_pattern(text, length,
pattern, p_len, case_sens,
&match_length);
if (!pos)
break;
/* found string in box => add to list */
match_offset = pos - cur->text;
entry = add_entry(cur->byte_offset + match_offset,
cur->byte_offset +
match_offset +
match_length, context);
if (!entry)
return false;
entry->start_box = cur;
entry->end_box = cur;
new_text = pos + match_length;
length -= (new_text - text);
text = new_text;
}
}
/* and recurse */
for (a = cur->children; a; a = a->next) {
if (!find_occurrences_html(pattern, p_len, a, case_sens,
context))
return false;
}
return true;
}
/**
* Finds all occurrences of a given string in a textplain content
*
* \param pattern the string pattern to search for
* \param p_len pattern length
* \param c the content to be searched
* \param case_sens whether to perform a case sensitive search
* \param context The search context to add the entry to.
* \return true on success, false on memory allocation failure
*/
static bool find_occurrences_text(const char *pattern, int p_len,
struct content *c, bool case_sens,
struct search_context *context)
{
int nlines = textplain_line_count(c);
int line;
for(line = 0; line < nlines; line++) {
size_t offset, length;
const char *text = textplain_get_line(c, line,
&offset, &length);
if (text) {
while (length > 0) {
struct list_entry *entry;
unsigned match_length;
size_t start_idx;
const char *new_text;
const char *pos = find_pattern(text, length,
pattern, p_len, case_sens,
&match_length);
if (!pos)
break;
/* found string in line => add to list */
start_idx = offset + (pos - text);
entry = add_entry(start_idx, start_idx +
match_length, context);
if (!entry)
return false;
new_text = pos + match_length;
offset += (new_text - text);
length -= (new_text - text);
text = new_text;
}
}
}
return true;
}
/**
* Specifies whether all matches or just the current match should
* be highlighted in the search text.
*/
static void search_show_all(bool all, struct search_context *context)
{
struct list_entry *a;
for (a = context->found->next; a; a = a->next) {
bool add = true;
if (!all && a != context->current) {
add = false;
if (a->sel) {
selection_clear(a->sel, true);
selection_destroy(a->sel);
a->sel = NULL;
}
}
if (add && !a->sel) {
if (context->is_html == true) {
html_content *html = (html_content *)context->c;
a->sel = selection_create(context->c, true);
if (!a->sel)
continue;
selection_init(a->sel, html->layout,
&html->len_ctx);
} else {
a->sel = selection_create(context->c, false);
if (!a->sel)
continue;
selection_init(a->sel, NULL, NULL);
}
selection_set_start(a->sel, a->start_idx);
selection_set_end(a->sel, a->end_idx);
}
}
}
/**
* Search for a string in the box tree
*
* \param string the string to search for
* \param string_len length of search string
* \param context The search context to add the entry to.
* \param flags flags to control the search.
*/
static void
search_text(const char *string,
int string_len,
struct search_context *context,
search_flags_t flags)
{
struct rect bounds;
struct box *box = NULL;
union content_msg_data msg_data;
bool case_sensitive, forwards, showall;
case_sensitive = ((flags & SEARCH_FLAG_CASE_SENSITIVE) != 0) ?
true : false;
forwards = ((flags & SEARCH_FLAG_FORWARDS) != 0) ? true : false;
showall = ((flags & SEARCH_FLAG_SHOWALL) != 0) ? true : false;
if (context->c == NULL)
return;
if (context->is_html == true) {
html_content *html = (html_content *)context->c;
box = html->layout;
if (!box)
return;
}
/* check if we need to start a new search or continue an old one */
if ((context->newsearch) ||
(context->prev_case_sens != case_sensitive)) {
bool res;
if (context->string != NULL)
free(context->string);
context->current = NULL;
free_matches(context);
context->string = malloc(string_len + 1);
if (context->string != NULL) {
memcpy(context->string, string, string_len);
context->string[string_len] = '\0';
}
guit->search->hourglass(true, context->gui_p);
if (context->is_html == true) {
res = find_occurrences_html(string, string_len,
box, case_sensitive, context);
} else {
res = find_occurrences_text(string, string_len,
context->c, case_sensitive, context);
}
if (!res) {
free_matches(context);
guit->search->hourglass(false, context->gui_p);
return;
}
guit->search->hourglass(false, context->gui_p);
context->prev_case_sens = case_sensitive;
/* new search, beginning at the top of the page */
context->current = context->found->next;
context->newsearch = false;
} else if (context->current != NULL) {
/* continued search in the direction specified */
if (forwards) {
if (context->current->next)
context->current = context->current->next;
} else {
if (context->current->prev)
context->current = context->current->prev;
}
}
guit->search->status((context->current != NULL), context->gui_p);
search_show_all(showall, context);
guit->search->back_state((context->current != NULL) &&
(context->current->prev != NULL),
context->gui_p);
guit->search->forward_state((context->current != NULL) &&
(context->current->next != NULL),
context->gui_p);
if (context->current == NULL)
return;
if (context->is_html == true) {
/* get box position and jump to it */
box_coords(context->current->start_box, &bounds.x0, &bounds.y0);
/* \todo: move x0 in by correct idx */
box_coords(context->current->end_box, &bounds.x1, &bounds.y1);
/* \todo: move x1 in by correct idx */
bounds.x1 += context->current->end_box->width;
bounds.y1 += context->current->end_box->height;
} else {
textplain_coords_from_range(context->c,
context->current->start_idx,
context->current->end_idx, &bounds);
}
msg_data.scroll.area = true;
msg_data.scroll.x0 = bounds.x0;
msg_data.scroll.y0 = bounds.y0;
msg_data.scroll.x1 = bounds.x1;
msg_data.scroll.y1 = bounds.y1;
content_broadcast(context->c, CONTENT_MSG_SCROLL, &msg_data);
}
/* Exported function documented in search.h */
void
search_step(struct search_context *context,
search_flags_t flags,
const char *string)
{
int string_len;
int i = 0;
assert(context != NULL);
guit->search->add_recent(string, context->gui_p);
string_len = strlen(string);
for (i = 0; i < string_len; i++)
if (string[i] != '#' && string[i] != '*')
break;
if (i >= string_len) {
union content_msg_data msg_data;
free_matches(context);
guit->search->status(true, context->gui_p);
guit->search->back_state(false, context->gui_p);
guit->search->forward_state(false, context->gui_p);
msg_data.scroll.area = false;
msg_data.scroll.x0 = 0;
msg_data.scroll.y0 = 0;
content_broadcast(context->c, CONTENT_MSG_SCROLL, &msg_data);
return;
}
search_text(string, string_len, context, flags);
}
/* Exported function documented in search.h */
bool search_term_highlighted(struct content *c,
unsigned start_offset, unsigned end_offset,
unsigned *start_idx, unsigned *end_idx,
struct search_context *context)
{
if (c == context->c) {
struct list_entry *a;
for (a = context->found->next; a; a = a->next)
if (a->sel && selection_defined(a->sel) &&
selection_highlighted(a->sel,
start_offset, end_offset,
start_idx, end_idx))
return true;
}
return false;
}
/* Exported function documented in search.h */
void search_destroy_context(struct search_context *context)
{
assert(context != NULL);
if (context->string != NULL) {
guit->search->add_recent(context->string, context->gui_p);
free(context->string);
}
guit->search->forward_state(true, context->gui_p);
guit->search->back_state(true, context->gui_p);
free_matches(context);
free(context);
}