netsurf/render/list.c

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/*
* Copyright 2005 Richard Wilson <info@tinct.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
* HTML lists (implementation).
*/
#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "css/css.h"
#include "render/list.h"
#include "utils/log.h"
struct list_counter {
char *name; /** Counter name */
struct list_counter_state *first; /** First counter state */
struct list_counter_state *state; /** Current counter state */
struct list_counter *next; /** Next counter */
};
struct list_counter_state {
int count; /** Current count */
struct list_counter_state *parent; /** Parent counter, or NULL */
struct list_counter_state *next; /** Next counter, or NULL */
};
static struct list_counter *list_counter_pool = NULL;
static char list_counter_workspace[16];
static const char *list_counter_roman[] = { "I", "IV", "V", "IX",
"X", "XL", "L", "XC",
"C", "CD", "D", "CM",
"M"};
static const int list_counter_decimal[] = { 1, 4, 5, 9,
10, 40, 50, 90,
100, 400, 500, 900,
1000};
#define ROMAN_DECIMAL_CONVERSIONS (sizeof(list_counter_decimal) \
/ sizeof(list_counter_decimal[0]))
static struct list_counter *render_list_find_counter(char *name);
static char *render_list_encode_counter(struct list_counter_state *state,
css_list_style_type style);
static char *render_list_encode_roman(int value);
/*
static void render_list_counter_output(char *name);
*/
/**
* Finds a counter from the current pool, or adds a new one.
*
* \param name the name of the counter to find
* \return the counter, or NULL if it couldn't be found/created.
*/
static struct list_counter *render_list_find_counter(char *name) {
struct list_counter *counter;
assert(name);
/* find a current counter */
for (counter = list_counter_pool; counter; counter = counter->next)
if (!strcasecmp(name, counter->name))
return counter;
/* create a new counter */
counter = calloc(1, sizeof(struct list_counter));
if (!counter) {
LOG(("No memory for calloc()"));
return NULL;
}
counter->name = malloc(strlen(name) + 1);
if (!counter->name) {
LOG(("No memory for malloc()"));
return NULL;
}
strcpy(counter->name, name);
counter->next = list_counter_pool;
list_counter_pool = counter;
return counter;
}
/**
* Removes all counters from the current pool.
*/
void render_list_destroy_counters(void) {
struct list_counter *counter = list_counter_pool;
struct list_counter *next_counter;
struct list_counter_state *state;
struct list_counter_state *next_state;
while (counter) {
next_counter = counter->next;
free(counter->name);
state = counter->first;
free(counter);
counter = next_counter;
while (state) {
next_state = state->next;
free(state);
state = next_state;
}
}
list_counter_pool = NULL;
}
/**
* Resets a counter in accordance with counter-reset (CSS 2.1/12.4).
*
* \param name the name of the counter to reset
* \param value the value to reset the counter to
* \return true on success, false on failure.
*/
bool render_list_counter_reset(char *name, int value) {
struct list_counter *counter;
struct list_counter_state *state;
struct list_counter_state *link;
assert(name);
counter = render_list_find_counter(name);
if (!counter)
return false;
state = calloc(1, sizeof(struct list_counter_state));
if (!state) {
LOG(("No memory for calloc()"));
return false;
}
state->count = value;
state->parent = counter->state;
counter->state = state;
if (!counter->first) {
counter->first = state;
} else {
for (link = counter->first; link->next; link = link->next);
link->next = state;
}
/* render_list_counter_output(name);
*/ return true;
}
/**
* Increments a counter in accordance with counter-increment (CSS 2.1/12.4).
*
* \param name the name of the counter to reset
* \param value the value to increment the counter by
* \return true on success, false on failure.
*/
bool render_list_counter_increment(char *name, int value) {
struct list_counter *counter;
assert(name);
counter = render_list_find_counter(name);
if (!counter)
return false;
/* if no counter-reset used, it is assumed the counter has been reset
* to 0 by the root element. */
if (!counter->state) {
if (counter->first) {
counter->state = counter->first;
counter->state->count = 0;
} else {
render_list_counter_reset(name, 0);
}
}
if (counter->state)
counter->state->count += value;
/* render_list_counter_output(name);
*/ return counter->state != NULL;
}
/**
* Ends the scope of a counter.
*
* \param name the name of the counter to end the scope for
* \return true on success, false on failure.
*/
bool render_list_counter_end_scope(char *name) {
struct list_counter *counter;
assert(name);
counter = render_list_find_counter(name);
if ((!counter) || (!counter->state))
return false;
counter->state = counter->state->parent;
/* render_list_counter_output(name);
*/ return true;
}
/**
* Returns a textual representation of a counter for counter() or counters()
* (CSS 2.1/12.2).
*
* \param css_counter the counter to convert
* \return a textual representation of the counter, or NULL on failure
*/
char *render_list_counter(struct css_counter *css_counter) {
struct list_counter *counter;
struct list_counter_state *state;
char *compound = NULL;
char *merge, *extend;
assert(css_counter);
counter = render_list_find_counter(css_counter->name);
if (!counter) {
LOG(("Failed to find/create counter for conversion"));
return NULL;
}
/* handle counter() first */
if (!css_counter->separator)
return render_list_encode_counter(counter->state,
css_counter->style);
/* loop through all states for counters() */
for (state = counter->first; state; state = state->next) {
merge = render_list_encode_counter(state,
css_counter->style);
if (!merge) {
free(compound);
return NULL;
}
if (!compound) {
compound = merge;
} else {
extend = realloc(compound, strlen(compound) +
strlen(merge) + 1);
if (!extend) {
LOG(("No memory for realloc()"));
free(compound);
free(merge);
return NULL;
}
compound = extend;
strcat(compound, merge);
}
if (state->next) {
merge = realloc(compound, strlen(compound) +
strlen(css_counter->separator) + 1);
if (!merge) {
LOG(("No memory for realloc()"));
free(compound);
return NULL;
}
compound = merge;
strcat(compound, css_counter->separator);
}
}
return compound;
}
/**
* Returns a textual representation of a counter state in a specified style.
*
* \param state the counter state to represent
* \param style the counter style to use
* \return a textual representation of the counter state, or NULL on failure
*/
static char *render_list_encode_counter(struct list_counter_state *state,
css_list_style_type style) {
char *result = NULL;
int i;
/* no counter state means that the counter is currently out of scope */
if (!state) {
result = malloc(1);
if (!result)
return NULL;
result[0] = '\0';
return result;
}
/* perform the relevant encoding to upper case where applicable */
switch (style) {
case CSS_LIST_STYLE_TYPE_LOWER_ALPHA:
case CSS_LIST_STYLE_TYPE_UPPER_ALPHA:
if (state->count <= 0)
result = calloc(1, 1);
else
result = malloc(2);
if (!result)
return NULL;
if (state->count > 0) {
result[0] = 'A' + (state->count - 1) % 26;
result[1] = '\0';
}
break;
case CSS_LIST_STYLE_TYPE_DISC:
case CSS_LIST_STYLE_TYPE_CIRCLE:
case CSS_LIST_STYLE_TYPE_SQUARE:
result = malloc(2);
if (!result)
return NULL;
result[0] = '?';
result[1] = '\0';
break;
case CSS_LIST_STYLE_TYPE_LOWER_ROMAN:
case CSS_LIST_STYLE_TYPE_UPPER_ROMAN:
result = render_list_encode_roman(state->count);
if (!result)
return NULL;
break;
case CSS_LIST_STYLE_TYPE_DECIMAL:
snprintf(list_counter_workspace,
sizeof list_counter_workspace,
"%i", state->count);
result = malloc(strlen(list_counter_workspace) + 1);
if (!result)
return NULL;
strcpy(result, list_counter_workspace);
break;
case CSS_LIST_STYLE_TYPE_NONE:
result = malloc(1);
if (!result)
return NULL;
result[0] = '\0';
break;
case CSS_LIST_STYLE_TYPE_INHERIT:
case CSS_LIST_STYLE_TYPE_UNKNOWN:
case CSS_LIST_STYLE_TYPE_NOT_SET:
assert(0);
break;
}
/* perform case conversion */
if ((style == CSS_LIST_STYLE_TYPE_LOWER_ALPHA) ||
(style == CSS_LIST_STYLE_TYPE_LOWER_ROMAN))
for (i = 0; result[i]; i++)
result[i] = tolower(result[i]);
return result;
}
/**
* Encodes a value in roman numerals.
* For values that cannot be represented (ie <=0) an empty string is returned.
*
* \param value the value to represent
* \return a string containing the representation, or NULL on failure
*/
static char *render_list_encode_roman(int value) {
int i, overflow, p = 0;
char temp[10];
char *result;
/* zero and below is returned as an empty string and not erred as
* if it is counters() will fail to complete other scopes. */
if (value <= 0) {
result = malloc(1);
if (!result)
return NULL;
result[0] = '\0';
return result;
}
/* we only calculate 1->999 and then add a M for each thousand */
overflow = value / 1000;
value = value % 1000;
/* work backwards through the array */
for (i = ROMAN_DECIMAL_CONVERSIONS - 1; i >= 0; i--) {
while (value >= list_counter_decimal[0]) {
if (value - list_counter_decimal[i] <
list_counter_decimal[0] - 1)
break;
value -= list_counter_decimal[i];
temp[p++] = list_counter_roman[i][0];
if (i & 0x1)
temp[p++] = list_counter_roman[i][1];
}
}
temp[p] = '\0';
/* create a copy for the caller including thousands */
result = malloc(p + overflow + 1);
if (!result)
return NULL;
for (i = 0; i < overflow; i++)
result[i] = 'M';
strcpy(&result[overflow], temp);
return result;
}
void render_list_test(void) {
/* example given in CSS2.1/12.4.1 */
/* render_list_counter_reset("item", 0);
render_list_counter_increment("item", 1);
render_list_counter_increment("item", 1);
render_list_counter_reset("item", 0);
render_list_counter_increment("item", 1);
render_list_counter_increment("item", 1);
render_list_counter_increment("item", 1);
render_list_counter_reset("item", 0);
render_list_counter_increment("item", 1);
render_list_counter_end_scope("item");
render_list_counter_reset("item", 0);
render_list_counter_increment("item", 1);
render_list_counter_end_scope("item");
render_list_counter_increment("item", 1);
render_list_counter_end_scope("item");
render_list_counter_increment("item", 1);
render_list_counter_increment("item", 1);
render_list_counter_end_scope("item");
render_list_counter_reset("item", 0);
render_list_counter_increment("item", 1);
render_list_counter_increment("item", 1);
render_list_counter_end_scope("item");
*/
}
/*
static void render_list_counter_output(char *name) {
struct list_counter *counter;
char *result;
struct css_counter css_counter;
assert(name);
counter = render_list_find_counter(name);
if (!counter) {
fprintf(stderr, "Unable to create counter '%s'\n", name);
return;
}
css_counter.name = name;
css_counter.style = CSS_LIST_STYLE_TYPE_LOWER_ALPHA;
css_counter.separator = NULL;
result = render_list_counter(&css_counter);
if (!result) {
fprintf(stderr, "Failed to output counter('%s')\n", name);
} else {
fprintf(stderr, "counter('%s') is '%s'\n", name, result);
free(result);
}
css_counter.separator = ".";
result = render_list_counter(&css_counter);
if (!result) {
fprintf(stderr, "Failed to output counters('%s', '.')\n", name);
} else {
fprintf(stderr, "counters('%s', '.') is '%s'\n", name, result);
free(result);
}
}
*/