diff options
Diffstat (limited to 'content/handlers/html/imagemap.c')
-rw-r--r-- | content/handlers/html/imagemap.c | 804 |
1 files changed, 804 insertions, 0 deletions
diff --git a/content/handlers/html/imagemap.c b/content/handlers/html/imagemap.c new file mode 100644 index 000000000..5f4dd54b3 --- /dev/null +++ b/content/handlers/html/imagemap.c @@ -0,0 +1,804 @@ +/* + * Copyright 2004 John M Bell <jmb202@ecs.soton.ac.uk> + * + * 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 + * Implementation of HTML image maps + * + * \todo should this should use the general hashmap instead of its own + */ + +#include <assert.h> +#include <stdbool.h> +#include <string.h> +#include <strings.h> + +#include <dom/dom.h> + +#include "utils/log.h" +#include "utils/corestrings.h" +#include "content/content_protected.h" +#include "content/hlcache.h" + +#include "html/box.h" +#include "html/html_internal.h" +#include "html/imagemap.h" + +#define HASH_SIZE 31 /* fixed size hash table */ + +typedef enum { + IMAGEMAP_DEFAULT, + IMAGEMAP_RECT, + IMAGEMAP_CIRCLE, + IMAGEMAP_POLY +} imagemap_entry_type; + +struct mapentry { + imagemap_entry_type type; /**< type of shape */ + nsurl *url; /**< absolute url to go to */ + char *target; /**< target frame (if any) */ + union { + struct { + int x; /**< x coordinate of centre */ + int y; /**< y coordinate of center */ + int r; /**< radius of circle */ + } circle; + struct { + int x0; /**< left hand edge */ + int y0; /**< top edge */ + int x1; /**< right hand edge */ + int y1; /**< bottom edge */ + } rect; + struct { + int num; /**< number of points */ + float *xcoords; /**< x coordinates */ + float *ycoords; /**< y coordinates */ + } poly; + } bounds; + struct mapentry *next; /**< next entry in list */ +}; + +struct imagemap { + char *key; /**< key for this entry */ + struct mapentry *list; /**< pointer to linked list of entries */ + struct imagemap *next; /**< next entry in this hash chain */ +}; + +/** + * Create hashtable of imagemaps + * + * \param c The containing content + * \return true on success, false otherwise + */ +static bool imagemap_create(html_content *c) +{ + assert(c != NULL); + + if (c->imagemaps == NULL) { + c->imagemaps = calloc(HASH_SIZE, sizeof(struct imagemap *)); + if (c->imagemaps == NULL) { + return false; + } + } + + return true; +} + +/** + * Hash function. + * + * \param key The key to hash. + * \return The hashed value. + */ +static unsigned int imagemap_hash(const char *key) +{ + unsigned int z = 0; + + if (key == 0) return 0; + + for (; *key != 0; key++) { + z += *key & 0x1f; + } + + return (z % (HASH_SIZE - 1)) + 1; +} + +/** + * Add an imagemap to the hashtable, creating it if it doesn't exist + * + * \param c The containing content + * \param key The name of the imagemap + * \param list List of map regions + * \return true on succes, false otherwise + */ +static bool +imagemap_add(html_content *c, dom_string *key, struct mapentry *list) +{ + struct imagemap *map; + unsigned int slot; + + assert(c != NULL); + assert(key != NULL); + assert(list != NULL); + + if (imagemap_create(c) == false) + return false; + + map = calloc(1, sizeof(*map)); + if (map == NULL) + return false; + + /* \todo Stop relying on NULL termination of dom_string */ + map->key = strdup(dom_string_data(key)); + if (map->key == NULL) { + free(map); + return false; + } + + map->list = list; + + slot = imagemap_hash(map->key); + + map->next = c->imagemaps[slot]; + c->imagemaps[slot] = map; + + return true; +} + +/** + * Free list of imagemap entries + * + * \param list Pointer to head of list + */ +static void imagemap_freelist(struct mapentry *list) +{ + struct mapentry *entry, *prev; + + assert(list != NULL); + + entry = list; + + while (entry != NULL) { + prev = entry; + + nsurl_unref(entry->url); + + if (entry->target) + free(entry->target); + + if (entry->type == IMAGEMAP_POLY) { + free(entry->bounds.poly.xcoords); + free(entry->bounds.poly.ycoords); + } + + entry = entry->next; + free(prev); + } +} + +/** + * Destroy hashtable of imagemaps + * + * \param c The containing content + */ +void imagemap_destroy(html_content *c) +{ + unsigned int i; + + assert(c != NULL); + + /* no imagemaps -> return */ + if (c->imagemaps == NULL) + return; + + for (i = 0; i != HASH_SIZE; i++) { + struct imagemap *map, *next; + + map = c->imagemaps[i]; + while (map != NULL) { + next = map->next; + imagemap_freelist(map->list); + free(map->key); + free(map); + map = next; + } + } + + free(c->imagemaps); +} + +/** + * Dump imagemap data to the log + * + * \param c The containing content + */ +void imagemap_dump(html_content *c) +{ + unsigned int i; + + int j; + + assert(c != NULL); + + if (c->imagemaps == NULL) + return; + + for (i = 0; i != HASH_SIZE; i++) { + struct imagemap *map; + struct mapentry *entry; + + map = c->imagemaps[i]; + while (map != NULL) { + NSLOG(netsurf, INFO, "Imagemap: %s", map->key); + + for (entry = map->list; entry; entry = entry->next) { + switch (entry->type) { + case IMAGEMAP_DEFAULT: + NSLOG(netsurf, INFO, "\tDefault: %s", + nsurl_access(entry->url)); + break; + case IMAGEMAP_RECT: + NSLOG(netsurf, INFO, + "\tRectangle: %s: [(%d,%d),(%d,%d)]", + nsurl_access(entry->url), + entry->bounds.rect.x0, + entry->bounds.rect.y0, + entry->bounds.rect.x1, + entry->bounds.rect.y1); + break; + case IMAGEMAP_CIRCLE: + NSLOG(netsurf, INFO, + "\tCircle: %s: [(%d,%d),%d]", + nsurl_access(entry->url), + entry->bounds.circle.x, + entry->bounds.circle.y, + entry->bounds.circle.r); + break; + case IMAGEMAP_POLY: + NSLOG(netsurf, INFO, + "\tPolygon: %s:", + nsurl_access(entry->url)); + for (j = 0; j != entry->bounds.poly.num; + j++) { + fprintf(stderr, "(%d,%d) ", + (int)entry->bounds.poly.xcoords[j], + (int)entry->bounds.poly.ycoords[j]); + } + fprintf(stderr,"\n"); + break; + } + } + map = map->next; + } + } +} + +/** + * Adds an imagemap entry to the list + * + * \param c The html content that the imagemap belongs to + * \param n The xmlNode representing the entry to add + * \param base_url Base URL for resolving relative URLs + * \param entry Pointer to list of entries + * \param tagtype The type of tag + * \return false on memory exhaustion, true otherwise + */ +static bool +imagemap_addtolist(const struct html_content *c, dom_node *n, nsurl *base_url, + struct mapentry **entry, dom_string *tagtype) +{ + dom_exception exc; + dom_string *href = NULL, *target = NULL, *shape = NULL; + dom_string *coords = NULL; + struct mapentry *new_map, *temp; + bool ret = true; + + if (dom_string_caseless_isequal(tagtype, corestring_dom_area)) { + bool nohref = false; + exc = dom_element_has_attribute(n, + corestring_dom_nohref, &nohref); + if ((exc != DOM_NO_ERR) || nohref) + /* Skip <area nohref="anything" /> */ + goto ok_out; + } + + exc = dom_element_get_attribute(n, corestring_dom_href, &href); + if (exc != DOM_NO_ERR || href == NULL) { + /* No href="" attribute, skip this element */ + goto ok_out; + } + + exc = dom_element_get_attribute(n, corestring_dom_target, &target); + if (exc != DOM_NO_ERR) { + goto ok_out; + } + + exc = dom_element_get_attribute(n, corestring_dom_shape, &shape); + if (exc != DOM_NO_ERR) { + goto ok_out; + } + + /* If there's no shape, we default to rectangles */ + if (shape == NULL) + shape = dom_string_ref(corestring_dom_rect); + + if (!dom_string_caseless_lwc_isequal(shape, corestring_lwc_default)) { + /* If not 'default' and there's no 'coords' give up */ + exc = dom_element_get_attribute(n, corestring_dom_coords, + &coords); + if (exc != DOM_NO_ERR || coords == NULL) { + goto ok_out; + } + } + + new_map = calloc(1, sizeof(*new_map)); + if (new_map == NULL) { + goto bad_out; + } + + if (dom_string_caseless_lwc_isequal(shape, corestring_lwc_rect) || + dom_string_caseless_lwc_isequal(shape, corestring_lwc_rectangle)) + new_map->type = IMAGEMAP_RECT; + else if (dom_string_caseless_lwc_isequal(shape, corestring_lwc_circle)) + new_map->type = IMAGEMAP_CIRCLE; + else if (dom_string_caseless_lwc_isequal(shape, corestring_lwc_poly) || + dom_string_caseless_lwc_isequal(shape, corestring_lwc_polygon)) + new_map->type = IMAGEMAP_POLY; + else if (dom_string_caseless_lwc_isequal(shape, corestring_lwc_default)) + new_map->type = IMAGEMAP_DEFAULT; + else + goto bad_out; + + if (box_extract_link(c, href, base_url, &new_map->url) == false) + goto bad_out; + + if (new_map->url == NULL) { + /* non-fatal error -> ignore this */ + goto ok_free_map_out; + } + + if (target != NULL) { + /* Copy target into the map */ + new_map->target = malloc(dom_string_byte_length(target) + 1); + if (new_map->target == NULL) + goto bad_out; + /* Safe, but relies on dom_strings being NULL terminated */ + /* \todo Do this better */ + strcpy(new_map->target, dom_string_data(target)); + } + + if (new_map->type != IMAGEMAP_DEFAULT) { + int x, y; + float *xcoords, *ycoords; + /* coordinates are a comma-separated list of values */ + char *val = strtok((char *)dom_string_data(coords), ","); + int num = 1; + + switch (new_map->type) { + case IMAGEMAP_RECT: + /* (left, top, right, bottom) */ + while (val != NULL && num <= 4) { + switch (num) { + case 1: + new_map->bounds.rect.x0 = atoi(val); + break; + case 2: + new_map->bounds.rect.y0 = atoi(val); + break; + case 3: + new_map->bounds.rect.x1 = atoi(val); + break; + case 4: + new_map->bounds.rect.y1 = atoi(val); + break; + } + + num++; + val = strtok(NULL, ","); + } + break; + case IMAGEMAP_CIRCLE: + /* (x, y, radius ) */ + while (val != NULL && num <= 3) { + switch (num) { + case 1: + new_map->bounds.circle.x = atoi(val); + break; + case 2: + new_map->bounds.circle.y = atoi(val); + break; + case 3: + new_map->bounds.circle.r = atoi(val); + break; + } + + num++; + val = strtok(NULL, ","); + } + break; + case IMAGEMAP_POLY: + new_map->bounds.poly.xcoords = NULL; + new_map->bounds.poly.ycoords = NULL; + + while (val != NULL) { + x = atoi(val); + + val = strtok(NULL, ","); + if (val == NULL) + break; + + y = atoi(val); + + xcoords = realloc(new_map->bounds.poly.xcoords, + num * sizeof(float)); + if (xcoords == NULL) { + goto bad_out; + } + new_map->bounds.poly.xcoords = xcoords; + + ycoords = realloc(new_map->bounds.poly.ycoords, + num * sizeof(float)); + if (ycoords == NULL) { + goto bad_out; + } + new_map->bounds.poly.ycoords = ycoords; + + new_map->bounds.poly.xcoords[num - 1] = x; + new_map->bounds.poly.ycoords[num - 1] = y; + + num++; + val = strtok(NULL, ","); + } + + new_map->bounds.poly.num = num - 1; + + break; + default: + break; + } + } + + new_map->next = NULL; + + if (*entry) { + /* add to END of list */ + for (temp = (*entry); temp->next != NULL; temp = temp->next) + ; + temp->next = new_map; + } else { + (*entry) = new_map; + } + + /* All good, linked in, let's clean up */ + goto ok_out; + +bad_out: + ret = false; +ok_free_map_out: + if (new_map != NULL) { + if (new_map->url != NULL) + nsurl_unref(new_map->url); + if (new_map->type == IMAGEMAP_POLY && + new_map->bounds.poly.ycoords != NULL) + free(new_map->bounds.poly.ycoords); + if (new_map->type == IMAGEMAP_POLY && + new_map->bounds.poly.xcoords != NULL) + free(new_map->bounds.poly.xcoords); + if (new_map->target != NULL) + free(new_map->target); + + free(new_map); + } +ok_out: + if (href != NULL) + dom_string_unref(href); + if (target != NULL) + dom_string_unref(target); + if (shape != NULL) + dom_string_unref(shape); + if (coords != NULL) + dom_string_unref(coords); + + return ret; +} + +/** + * Extract an imagemap from html source + * + * \param node XML node containing map + * \param c Content containing document + * \param entry List of map entries + * \param tname The sub-tags to consider on this pass + * \return false on memory exhaustion, true otherwise + */ +static bool +imagemap_extract_map_entries(dom_node *node, html_content *c, + struct mapentry **entry, dom_string *tname) +{ + dom_nodelist *nlist; + dom_exception exc; + unsigned long ent; + uint32_t tag_count; + + exc = dom_element_get_elements_by_tag_name(node, tname, &nlist); + if (exc != DOM_NO_ERR) { + return false; + } + + exc = dom_nodelist_get_length(nlist, &tag_count); + if (exc != DOM_NO_ERR) { + dom_nodelist_unref(nlist); + return false; + } + + for (ent = 0; ent < tag_count; ++ent) { + dom_node *subnode; + + exc = dom_nodelist_item(nlist, ent, &subnode); + if (exc != DOM_NO_ERR) { + dom_nodelist_unref(nlist); + return false; + } + if (imagemap_addtolist(c, subnode, c->base_url, + entry, tname) == false) { + dom_node_unref(subnode); + dom_nodelist_unref(nlist); + return false; + } + dom_node_unref(subnode); + } + + dom_nodelist_unref(nlist); + + return true; +} + +/** + * Extract an imagemap from html source + * + * \param node XML node containing map + * \param c Content containing document + * \param entry List of map entries + * \return false on memory exhaustion, true otherwise + */ +static bool imagemap_extract_map(dom_node *node, html_content *c, + struct mapentry **entry) +{ + if (imagemap_extract_map_entries(node, c, entry, + corestring_dom_area) == false) + return false; + return imagemap_extract_map_entries(node, c, entry, + corestring_dom_a); +} + +/** + * Extract all imagemaps from a document tree + * + * \param c The content to extract imagemaps from. + * \return false on memory exhaustion, true otherwise + */ +nserror +imagemap_extract(html_content *c) +{ + dom_nodelist *nlist; + dom_exception exc; + unsigned long mapnr; + uint32_t maybe_maps; + nserror ret = NSERROR_OK; + + exc = dom_document_get_elements_by_tag_name(c->document, + corestring_dom_map, + &nlist); + if (exc != DOM_NO_ERR) { + return NSERROR_DOM; + } + + exc = dom_nodelist_get_length(nlist, &maybe_maps); + if (exc != DOM_NO_ERR) { + ret = NSERROR_DOM; + goto out_nlist; + } + + for (mapnr = 0; mapnr < maybe_maps; ++mapnr) { + dom_node *node; + dom_string *name; + exc = dom_nodelist_item(nlist, mapnr, &node); + if (exc != DOM_NO_ERR) { + ret = NSERROR_DOM; + goto out_nlist; + } + + exc = dom_element_get_attribute(node, corestring_dom_id, + &name); + if (exc != DOM_NO_ERR) { + dom_node_unref(node); + ret = NSERROR_DOM; + goto out_nlist; + } + + if (name == NULL) { + exc = dom_element_get_attribute(node, + corestring_dom_name, + &name); + if (exc != DOM_NO_ERR) { + dom_node_unref(node); + ret = NSERROR_DOM; + goto out_nlist; + } + } + + if (name != NULL) { + struct mapentry *entry = NULL; + if (imagemap_extract_map(node, c, &entry) == false) { + if (entry != NULL) { + imagemap_freelist(entry); + } + + dom_string_unref(name); + dom_node_unref(node); + ret = NSERROR_NOMEM; /** @todo check this */ + goto out_nlist; + } + + /* imagemap_extract_map may not extract anything, + * so entry can still be NULL here. This isn't an + * error as it just means that we've encountered + * an incorrectly defined <map>...</map> block + */ + if ((entry != NULL) && + (imagemap_add(c, name, entry) == false)) { + imagemap_freelist(entry); + + dom_string_unref(name); + dom_node_unref(node); + ret = NSERROR_NOMEM; /** @todo check this */ + goto out_nlist; + } + } + + dom_string_unref(name); + dom_node_unref(node); + } + +out_nlist: + + dom_nodelist_unref(nlist); + + return ret; +} + +/** + * Test if a point lies within an arbitrary polygon + * Modified from comp.graphics.algorithms FAQ 2.03 + * + * \param num Number of vertices + * \param xpt Array of x coordinates + * \param ypt Array of y coordinates + * \param x Left hand edge of containing box + * \param y Top edge of containing box + * \param click_x X coordinate of click + * \param click_y Y coordinate of click + * \return 1 if point is in polygon, 0 if outside. 0 or 1 if on boundary + */ +static int +imagemap_point_in_poly(int num, float *xpt, float *ypt, unsigned long x, + unsigned long y, unsigned long click_x, unsigned long click_y) +{ + int i, j, c = 0; + + assert(xpt != NULL); + assert(ypt != NULL); + + for (i = 0, j = num - 1; i < num; j = i++) { + if ((((ypt[i] + y <= click_y) && (click_y < ypt[j] + y)) || + ((ypt[j] + y <= click_y) && (click_y < ypt[i] + y))) && + (click_x < (xpt[j] - xpt[i]) * + (click_y - (ypt[i] + y)) / (ypt[j] - ypt[i]) + xpt[i] + x)) + c = !c; + } + + return c; +} + +/** + * Retrieve url associated with imagemap entry + * + * \param c The containing content + * \param key The map name to search for + * \param x The left edge of the containing box + * \param y The top edge of the containing box + * \param click_x The horizontal location of the click + * \param click_y The vertical location of the click + * \param target Pointer to location to receive target pointer (if any) + * \return The url associated with this area, or NULL if not found + */ +nsurl *imagemap_get(struct html_content *c, const char *key, + unsigned long x, unsigned long y, + unsigned long click_x, unsigned long click_y, + const char **target) +{ + unsigned int slot = 0; + struct imagemap *map; + struct mapentry *entry; + unsigned long cx, cy; + + assert(c != NULL); + + if (key == NULL) + return NULL; + + if (c->imagemaps == NULL) + return NULL; + + slot = imagemap_hash(key); + + for (map = c->imagemaps[slot]; map != NULL; map = map->next) { + if (map->key != NULL && strcasecmp(map->key, key) == 0) + break; + } + + if (map == NULL || map->list == NULL) + return NULL; + + for (entry = map->list; entry; entry = entry->next) { + switch (entry->type) { + case IMAGEMAP_DEFAULT: + /* just return the URL. no checks required */ + if (target) + *target = entry->target; + return entry->url; + break; + case IMAGEMAP_RECT: + if (click_x >= x + entry->bounds.rect.x0 && + click_x <= x + entry->bounds.rect.x1 && + click_y >= y + entry->bounds.rect.y0 && + click_y <= y + entry->bounds.rect.y1) { + if (target) + *target = entry->target; + return entry->url; + } + break; + case IMAGEMAP_CIRCLE: + cx = x + entry->bounds.circle.x - click_x; + cy = y + entry->bounds.circle.y - click_y; + if ((cx * cx + cy * cy) <= + (unsigned long) (entry->bounds.circle.r * + entry->bounds.circle.r)) { + if (target) + *target = entry->target; + return entry->url; + } + break; + case IMAGEMAP_POLY: + if (imagemap_point_in_poly(entry->bounds.poly.num, + entry->bounds.poly.xcoords, + entry->bounds.poly.ycoords, x, y, + click_x, click_y)) { + if (target) + *target = entry->target; + return entry->url; + } + break; + } + } + + if (target) + *target = NULL; + + return NULL; +} |