netsurf/amiga/search.c

/*
 * Copyright 2004 John M Bell <jmb202@ecs.soton.ac.uk>
 * Copyright 2005 Adrian Lees <adrianl@users.sourceforge.net>
 * Copyright 2008 Chris Young <chris@unsatisfactorysoftware.co.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
 * Free text search (implementation)
 */

#include "utils/config.h"
#include <ctype.h>
#include <string.h>
#include "content/content.h"
#include "desktop/browser.h"
#include "desktop/gui.h"
#include "desktop/selection.h"
#include "render/box.h"
#include "render/html.h"
#include "utils/log.h"
#include "utils/messages.h"
#include "utils/utils.h"
#include "amiga/search.h"
#include "amiga/object.h"
#include <proto/intuition.h>
#include <proto/exec.h>

#include <proto/window.h>
#include <proto/layout.h>
#include <proto/string.h>
#include <proto/button.h>
#include <proto/label.h>
#include <classes/window.h>
#include <gadgets/layout.h>
#include <gadgets/string.h>
#include <gadgets/button.h>
#include <images/label.h>
#include <reaction/reaction_macros.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 gui_window *search_current_window = NULL;

static char *search_string = NULL;
static struct list_entry search_head = { 0, 0, NULL, NULL, NULL, NULL, NULL };
static struct list_entry *search_found = &search_head;
static struct list_entry *search_current = NULL;
static struct content *search_content = NULL;
static bool search_prev_case_sens = false;
static struct find_window *fwin = NULL;
#define RECENT_SEARCHES 8
bool search_insert;
static char *recent_search[RECENT_SEARCHES];

static void start_search(bool forwards,char *search_string);
static void do_search(char *string, int string_len, bool case_sens,
		bool forwards);
static const char *find_pattern(const char *string, int s_len,
		const char *pattern, int p_len, bool case_sens, int *m_len);
static bool find_occurrences_html(const char *pattern, int p_len,
		struct box *cur, bool case_sens);
static bool find_occurrences_text(const char *pattern, int p_len,
		struct content *c, bool case_sens);
static struct list_entry *add_entry(unsigned start_idx, unsigned end_idx);
static void free_matches(void);
static void show_all(bool all);
static void show_status(bool found);

/**
 * Begins/continues the search process
 * Note that this may be called many times for a single search.
 *
 * \param  forwards  search forwards from start/current position
 */

void start_search(bool forwards,char *string)
{
	int string_len;
	int i = 0;

	string_len = strlen(string);
	for(i = 0; i < string_len; i++)
		if (string[i] != '#' && string[i] != '*') break;
	if (i >= string_len) {
		free_matches();
		show_status(true);

		RefreshSetGadgetAttrs(fwin->gadgets[GID_PREV],fwin->win,NULL,
			GA_Disabled,TRUE,
			TAG_DONE);

		RefreshSetGadgetAttrs(fwin->gadgets[GID_NEXT],fwin->win,NULL,
			GA_Disabled,TRUE,
			TAG_DONE);

		gui_window_set_scroll(search_current_window, 0, 0);
		return;
	}

	do_search(string, string_len,
		false, // case sensitivity
		forwards);
}

/**
 * Ends the search process, invalidating all global state and
 * freeing the list of found boxes
 *
 * \param w	the search window handle (not used)
 */
void ami_gui_search_end(void)
{
	search_current_window = 0;

	if (search_string) {
		//ro_gui_search_add_recent(search_string);
		free(search_string);
	}
	search_string = 0;

	free_matches();

	search_current = 0;

	search_content = 0;

	search_prev_case_sens = false;
}


/**
 * Release the memory used by the list of matches,
 * deleting selection objects too
 */

void free_matches(void)
{
	struct list_entry *a = search_found->next;
	struct list_entry *b;

	/* empty the list before clearing and deleting the
	   selections because the the clearing updates the
	   screen immediately, causing nested accesses to the list */

	search_found->prev = 0;
	search_found->next = 0;

	for (; a; a = b) {
		b = a->next;
		if (a->sel) {
			selection_clear(a->sel, true);
			selection_destroy(a->sel);
		}
		free(a);
	}
}


/**
 * Search for a string in the box tree
 *
 * \param string the string to search for
 * \param string_len length of search string
 * \param case_sens whether to perform a case sensitive search
 * \param forwards direction to search in
 */
void do_search(char *string, int string_len, bool case_sens, bool forwards)
{
	struct rect bounds;
	struct content *c;
	struct box *box;
	bool new = false;

	if (!search_current_window)
		return;

	c = search_current_window->shared->bw->current_content;

	/* only handle html contents */
	if ((!c) || (c->type != CONTENT_HTML &&
			c->type != CONTENT_TEXTPLAIN))
		return;

	box = c->data.html.layout;

	if (!box)
		return;

//	LOG(("do_search '%s' - '%s' (%p, %p) %p (%d, %d) %d",
//		search_string, string, search_content, c, search_found->next,
//		search_prev_case_sens, case_sens, forwards));

	/* check if we need to start a new search or continue an old one */
	if (!search_string || c != search_content || !search_found->next ||
	    search_prev_case_sens != case_sens ||
	    (case_sens && strcmp(string, search_string) != 0) ||
	    (!case_sens && strcasecmp(string, search_string) != 0)) {
		bool res;

		if (search_string)
			free(search_string);
		search_current = 0;
		free_matches();

		search_string = malloc(string_len + 1);
		if (search_string) {
			memcpy(search_string, string, string_len);
			search_string[string_len] = '\0';
		}

//		xhourglass_on();

		if (c->type == CONTENT_HTML)
			res = find_occurrences_html(string, string_len,
					box, case_sens);
		else {
			assert(c->type == CONTENT_TEXTPLAIN);
			res = find_occurrences_text(string, string_len,
					c, case_sens);
		}

		if (!res) {
			free_matches();
			//xhourglass_off();
			return;
		}
		//xhourglass_off();

		new = true;
		search_content = c;
		search_prev_case_sens = case_sens;
	}

//	LOG(("%d %p %p (%p, %p)", new, search_found->next, search_current, search_current->prev, search_current->next));

	if (new) {
		/* new search, beginning at the top of the page */
		search_current = search_found->next;
	}
	else if (search_current) {
		/* continued search in the direction specified */
		if (forwards) {
			if (search_current->next)
				search_current = search_current->next;
		}
		else {
			if (search_current->prev)
				search_current = search_current->prev;
		}
	}

	show_status(search_current != NULL);
	show_all(false);

		RefreshSetGadgetAttrs(fwin->gadgets[GID_PREV],fwin->win,NULL,
			GA_Disabled,(!search_current || !search_current->prev),
			TAG_DONE);

		RefreshSetGadgetAttrs(fwin->gadgets[GID_NEXT],fwin->win,NULL,
			GA_Disabled,(!search_current || !search_current->next),
			TAG_DONE);

	if (!search_current)
		return;

	switch (c->type) {
		case CONTENT_HTML:
			/* get box position and jump to it */
			box_coords(search_current->start_box,
					&bounds.x0, &bounds.y0);
			/* \todo: move x0 in by correct idx */
			box_coords(search_current->end_box,
					&bounds.x1, &bounds.y1);
			/* \todo: move x1 in by correct idx */
			bounds.x1 += search_current->end_box->width;
			bounds.y1 += search_current->end_box->height;
			break;

		default:
			assert(c->type == CONTENT_TEXTPLAIN);
			textplain_coords_from_range(c,
					search_current->start_idx,
					search_current->end_idx, &bounds);
			break;
	}

	gui_window_scroll_visible(search_current_window,
			bounds.x0, bounds.y0, bounds.x1, bounds.y1);
}


/**
 * 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
 */

const char *find_pattern(const char *string, int s_len, const char *pattern,
		int p_len, bool case_sens, 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 can 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;
}


/**
 * 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
 * \return true on success, false on memory allocation failure
 */
bool find_occurrences_html(const char *pattern, int p_len, struct box *cur,
		bool case_sens)
{
	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);
			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))
			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 wheteher to perform a case sensitive search
 * \return true on success, false on memory allocation failure
 */

bool find_occurrences_text(const char *pattern, int p_len,
		struct content *c, bool case_sens)
{
	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);
				if (!entry)
					return false;

				new_text = pos + match_length;
				offset += (new_text - text);
				length -= (new_text - text);
				text = new_text;
			}
		}
	}

	return true;
}


/**
 * 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
 * \return pointer to added entry, NULL iff failed
 */

struct list_entry *add_entry(unsigned start_idx, unsigned end_idx)
{
	struct list_entry *entry;

	/* found string in box => add to list */
	entry = calloc(1, sizeof(*entry));
	if (!entry) {
		warn_user("NoMemory", 0);
		return NULL;
	}

	entry->start_idx = start_idx;
	entry->end_idx = end_idx;
	entry->sel = NULL;

	entry->next = 0;
	entry->prev = search_found->prev;
	if (!search_found->prev)
		search_found->next = entry;
	else
		search_found->prev->next = entry;
	search_found->prev = entry;

	return entry;
}


/**
 * Determines whether any portion of the given text box should be
 * selected because it matches the current search string.
 *
 * \param  g             gui window
<EFBFBD>* \param  start_offset  byte offset within text of string to be checked
 * \param  end_offset    byte offset within text
 * \param  start_idx     byte offset within string of highlight start
 * \param  end_idx       byte offset of highlight end
 * \return true iff part of the box should be highlighted
 */

bool gui_search_term_highlighted(struct gui_window *g,
		unsigned start_offset, unsigned end_offset,
		unsigned *start_idx, unsigned *end_idx)
{
	if (g == search_current_window) {
		struct list_entry *a;
		for(a = search_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;
}


/**
 * Specifies whether all matches or just the current match should
 * be highlighted in the search text.
 */

void show_all(bool all)
{
	struct list_entry *a;

	for (a = search_found->next; a; a = a->next) {
		bool add = true;
		if (!all && a != search_current) {
			add = false;
			if (a->sel) {
				selection_clear(a->sel, true);
				selection_destroy(a->sel);
				a->sel = NULL;
			}
		}
		if (add && !a->sel) {
			a->sel = selection_create(search_current_window->shared->bw);
			if (a->sel) {
				struct content *c = search_current_window->shared->bw->current_content;
				switch (c->type) {
					case CONTENT_HTML:
						selection_init(a->sel,
							c->data.html.layout);
						break;
					default:
						assert(c->type ==
							CONTENT_TEXTPLAIN);
						selection_init(a->sel, NULL);
						break;
				}
				selection_set_start(a->sel, a->start_idx);
				selection_set_end(a->sel, a->end_idx);
			}
		}
	}
}


/**
 * Change the displayed search status.
 *
 * \param found  search pattern matched in text
 */

void show_status(bool found)
{
/*
	ro_gui_set_icon_string(dialog_search, ICON_SEARCH_STATUS,
			found ? "" : messages_get("NotFound"), true);
*/
}

void ami_search_open(struct gui_window *gwin)
{
	struct content *c = gwin->shared->bw->current_content;

	/* only handle html/textplain contents */
	if ((!c) || (c->type != CONTENT_HTML &&
			c->type != CONTENT_TEXTPLAIN))
		return;

	search_current_window = gwin;
	search_insert = true;

	if(fwin)
	{
		ami_gui_search_end();
		fwin->gwin->shared->searchwin = NULL;
		fwin->gwin = gwin;
		gwin->shared->searchwin = fwin;
		WindowToFront(fwin->win);
		ActivateWindow(fwin->win);
		return;
	}

	fwin = AllocVec(sizeof(struct find_window),MEMF_PRIVATE | MEMF_CLEAR);

	fwin->objects[OID_MAIN] = WindowObject,
      	WA_ScreenTitle,nsscreentitle,
           	WA_Title,messages_get("FindTextNS"),
           	WA_Activate, TRUE,
           	WA_DepthGadget, TRUE,
           	WA_DragBar, TRUE,
           	WA_CloseGadget, TRUE,
           	WA_SizeGadget, TRUE,
		WA_CustomScreen,scrn,
		WINDOW_SharedPort,sport,
		WINDOW_UserData,fwin,
		WINDOW_IconifyGadget, FALSE,
		WINDOW_LockHeight,TRUE,
         	WINDOW_Position, WPOS_CENTERSCREEN,
           	WINDOW_ParentGroup, fwin->gadgets[GID_MAIN] = VGroupObject,
				LAYOUT_AddChild, fwin->gadgets[GID_SEARCHSTRING] = StringObject,
					GA_ID,GID_SEARCHSTRING,
					GA_TabCycle,TRUE,
					GA_RelVerify,TRUE,
				StringEnd,
/*
				CHILD_Label, LabelObject,
					LABEL_Text,messages_get("searchstring"),
				LabelEnd,
*/
				CHILD_WeightedHeight,0,
				LAYOUT_AddChild, HGroupObject,
					LAYOUT_AddChild, fwin->gadgets[GID_PREV] = ButtonObject,
						GA_ID,GID_PREV,
						GA_RelVerify,TRUE,
						GA_Text,messages_get("Prev"),
						GA_TabCycle,TRUE,
						GA_Disabled,TRUE,
					ButtonEnd,
					CHILD_WeightedHeight,0,
					LAYOUT_AddChild, fwin->gadgets[GID_NEXT] = ButtonObject,
						GA_ID,GID_NEXT,
						GA_RelVerify,TRUE,
						GA_Text,messages_get("Next"),
						GA_TabCycle,TRUE,
						GA_Disabled,TRUE,
					ButtonEnd,
				LayoutEnd,
				CHILD_WeightedHeight,0,
			EndGroup,
		EndWindow;

	fwin->win = (struct Window *)RA_OpenWindow(fwin->objects[OID_MAIN]);
	fwin->gwin = gwin;
	fwin->node = AddObject(window_list,AMINS_FINDWINDOW);
	fwin->node->objstruct = fwin;
	gwin->shared->searchwin = fwin;
}

void ami_search_close(void)
{
	ami_gui_search_end();
	fwin->gwin->shared->searchwin = NULL;
	DisposeObject(fwin->objects[OID_MAIN]);
	DelObject(fwin->node);
	fwin=NULL;
}

BOOL ami_search_event(void)
{
	/* return TRUE if window destroyed */
	ULONG class,result,relevent = 0;
	ULONG column;
	uint16 code;
	char *text;

	while((result = RA_HandleInput(fwin->objects[OID_MAIN],&code)) != WMHI_LASTMSG)
	{
       	switch(result & WMHI_CLASSMASK) // class
   		{
			case WMHI_GADGETUP:
				switch(result & WMHI_GADGETMASK)
				{
					case GID_NEXT:
						search_insert = true;
						GetAttr(STRINGA_TextVal,fwin->gadgets[GID_SEARCHSTRING],(ULONG *)&text);
						start_search(true,text);
					break;

					case GID_PREV:
						search_insert = true;
						GetAttr(STRINGA_TextVal,fwin->gadgets[GID_SEARCHSTRING],(ULONG *)&text);
						start_search(false,text);
					break;

					case GID_SEARCHSTRING:
						RefreshSetGadgetAttrs(fwin->gadgets[GID_PREV],fwin->win,NULL,
							GA_Disabled,FALSE,
							TAG_DONE);

						RefreshSetGadgetAttrs(fwin->gadgets[GID_NEXT],fwin->win,NULL,
							GA_Disabled,FALSE,
							TAG_DONE);
					break;
				}
			break;

			case WMHI_CLOSEWINDOW:
				ami_search_close();
				return TRUE;
			break;
		}
	}
	return FALSE;
}