netsurf/riscos/gui.c

/*
 * This file is part of NetSurf, http://netsurf.sourceforge.net/
 * Licensed under the GNU General Public License,
 *		  http://www.opensource.org/licenses/gpl-license
 * Copyright 2003 Phil Mellor <monkeyson@users.sourceforge.net>
 * Copyright 2004 James Bursa <bursa@users.sourceforge.net>
 * Copyright 2003 John M Bell <jmb202@ecs.soton.ac.uk>
 * Copyright 2005 Richard Wilson <info@tinct.net>
 * Copyright 2004 Andrew Timmins <atimmins@blueyonder.co.uk>
 */

#include <assert.h>
#include <errno.h>
#include <fpu_control.h>
#include <signal.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <features.h>
#include <unixlib/local.h>
#include "curl/curl.h"
#include "oslib/font.h"
#include "oslib/help.h"
#include "oslib/hourglass.h"
#include "oslib/inetsuite.h"
#include "oslib/os.h"
#include "oslib/osbyte.h"
#include "oslib/osfile.h"
#include "oslib/osfscontrol.h"
#include "oslib/osgbpb.h"
#include "oslib/osspriteop.h"
#include "oslib/pdriver.h"
#include "oslib/plugin.h"
#include "oslib/wimp.h"
#include "oslib/wimpspriteop.h"
#include "oslib/uri.h"
#include "rufl.h"
#include "netsurf/utils/config.h"
#include "netsurf/content/content.h"
#include "netsurf/content/urldb.h"
#include "netsurf/desktop/gui.h"
#include "netsurf/desktop/netsurf.h"
#include "netsurf/desktop/options.h"
#include "netsurf/desktop/tree.h"
#include "netsurf/render/box.h"
#include "netsurf/render/font.h"
#include "netsurf/render/html.h"
#include "netsurf/riscos/bitmap.h"
#include "netsurf/riscos/buffer.h"
#include "netsurf/riscos/dialog.h"
#include "netsurf/riscos/global_history.h"
#include "netsurf/riscos/gui.h"
#include "netsurf/riscos/help.h"
#include "netsurf/riscos/menus.h"
#include "netsurf/riscos/message.h"
#include "netsurf/riscos/options.h"
#ifdef WITH_PLUGIN
#include "netsurf/riscos/plugin.h"
#endif
#ifdef WITH_PRINT
#include "netsurf/riscos/print.h"
#endif
#include "netsurf/riscos/query.h"
#include "netsurf/riscos/save.h"
#include "netsurf/riscos/save_complete.h"
#include "netsurf/riscos/textselection.h"
#include "netsurf/riscos/theme.h"
#include "netsurf/riscos/treeview.h"
#ifdef WITH_URI
#include "netsurf/riscos/uri.h"
#endif
#ifdef WITH_URL
#include "netsurf/riscos/url_protocol.h"
#endif
#include "netsurf/riscos/url_complete.h"
#include "netsurf/riscos/wimp.h"
#include "netsurf/riscos/wimp_event.h"
#include "netsurf/utils/filename.h"
#include "netsurf/utils/log.h"
#include "netsurf/utils/messages.h"
#include "netsurf/utils/url.h"
#include "netsurf/utils/utils.h"



#ifndef FILETYPE_ACORN_URI
#define FILETYPE_ACORN_URI 0xf91
#endif
#ifndef FILETYPE_ANT_URL
#define FILETYPE_ANT_URL 0xb28
#endif
#ifndef FILETYPE_IEURL
#define FILETYPE_IEURL 0x1ba
#endif
#ifndef FILETYPE_HTML
#define FILETYPE_HTML 0xfaf
#endif
#ifndef FILETYPE_JNG
#define FILETYPE_JNG 0xf78
#endif
#ifndef FILETYPE_CSS
#define FILETYPE_CSS 0xf79
#endif
#ifndef FILETYPE_MNG
#define FILETYPE_MNG 0xf83
#endif
#ifndef FILETYPE_GIF
#define FILETYPE_GIF 0x695
#endif
#ifndef FILETYPE_BMP
#define FILETYPE_BMP 0x69c
#endif
#ifndef FILETYPE_ICO
#define FILETYPE_ICO 0x132
#endif
#ifndef FILETYPE_PNG
#define FILETYPE_PNG 0xb60
#endif
#ifndef FILETYPE_JPEG
#define FILETYPE_JPEG 0xc85
#endif
#ifndef FILETYPE_ARTWORKS
#define FILETYPE_ARTWORKS 0xd94
#endif

int os_version = 0;

const char * const __dynamic_da_name = "NetSurf";	/**< For UnixLib. */
int __dynamic_da_max_size = 128 * 1024 * 1024;	/**< For UnixLib. */
int __feature_imagefs_is_file = 1;		/**< For UnixLib. */
/* default filename handling */
int __riscosify_control = __RISCOSIFY_NO_SUFFIX |
			__RISCOSIFY_NO_REVERSE_SUFFIX;

const char * NETSURF_DIR;

char *default_stylesheet_url;
char *adblock_stylesheet_url;

#ifndef ncos
static const char *task_name = "NetSurf";
#define CHOICES_PREFIX "<Choices$Write>.WWW.NetSurf."
#else
static const char *task_name = "NCNetSurf";
#define CHOICES_PREFIX "<User$Path>.Choices.NetSurf."
#endif


/** The pointer is over a window which is tracking mouse movement. */
static bool gui_track = false;
/** Handle of window which the pointer is over. */
static wimp_w gui_track_wimp_w;
/** Browser window which the pointer is over, or 0 if none. */
static struct gui_window *gui_track_gui_window;

/** Some windows have been resized, and should be reformatted. */
bool gui_reformat_pending = false;

gui_drag_type gui_current_drag_type;
wimp_t task_handle;	/**< RISC OS wimp task handle. */
static clock_t gui_last_poll;	/**< Time of last wimp_poll. */
osspriteop_area *gui_sprites;	   /**< Sprite area containing pointer and hotlist sprites */

/** Previously registered signal handlers */
static struct {
	void (*sigabrt)(int);
	void (*sigfpe)(int);
	void (*sigill)(int);
	void (*sigint)(int);
	void (*sigsegv)(int);
	void (*sigterm)(int);
} prev_sigs;

/** Accepted wimp user messages. */
static wimp_MESSAGE_LIST(41) task_messages = { {
	message_HELP_REQUEST,
	message_DATA_SAVE,
	message_DATA_SAVE_ACK,
	message_DATA_LOAD,
	message_DATA_LOAD_ACK,
	message_DATA_OPEN,
	message_PRE_QUIT,
	message_SAVE_DESKTOP,
	message_MENU_WARNING,
	message_MENUS_DELETED,
	message_WINDOW_INFO,
	message_MODE_CHANGE,
	message_CLAIM_ENTITY,
	message_DATA_REQUEST,
	message_DRAGGING,
	message_DRAG_CLAIM,
#ifdef WITH_URI
	message_URI_PROCESS,
	message_URI_RETURN_RESULT,
#endif
#ifdef WITH_URL
	message_INET_SUITE_OPEN_URL,
#endif
#ifdef WITH_PLUGIN
	message_PLUG_IN_OPENING,
	message_PLUG_IN_CLOSED,
	message_PLUG_IN_RESHAPE_REQUEST,
	message_PLUG_IN_FOCUS,
	message_PLUG_IN_URL_ACCESS,
	message_PLUG_IN_STATUS,
	message_PLUG_IN_BUSY,
	message_PLUG_IN_STREAM_NEW,
	message_PLUG_IN_STREAM_WRITE,
	message_PLUG_IN_STREAM_WRITTEN,
	message_PLUG_IN_STREAM_DESTROY,
	message_PLUG_IN_OPEN,
	message_PLUG_IN_CLOSE,
	message_PLUG_IN_RESHAPE,
	message_PLUG_IN_STREAM_AS_FILE,
	message_PLUG_IN_NOTIFY,
	message_PLUG_IN_ABORT,
	message_PLUG_IN_ACTION,
	/* message_PLUG_IN_INFORMED, (not provided by oslib) */
#endif
#ifdef WITH_PRINT
	message_PRINT_SAVE,
	message_PRINT_ERROR,
	message_PRINT_TYPE_ODD,
#endif
	0
} };

static struct
{
	int	width;  /* in OS units */
	int	height;
} screen_info;

static void ro_gui_create_dirs(void);
static void ro_gui_choose_language(void);
static void ro_gui_icon_bar_create(void);
static void ro_gui_signal(int sig);
static void ro_gui_cleanup(void);
static void ro_gui_handle_event(wimp_event_no event, wimp_block *block);
static void ro_gui_null_reason_code(void);
static void ro_gui_redraw_window_request(wimp_draw *redraw);
static void ro_gui_close_window_request(wimp_close *close);
static void ro_gui_pointer_leaving_window(wimp_leaving *leaving);
static void ro_gui_pointer_entering_window(wimp_entering *entering);
static void ro_gui_mouse_click(wimp_pointer *pointer);
static bool ro_gui_icon_bar_click(wimp_pointer *pointer);
static void ro_gui_check_resolvers(void);
static void ro_gui_drag_end(wimp_dragged *drag);
static void ro_gui_keypress(wimp_key *key);
static void ro_gui_user_message(wimp_event_no event, wimp_message *message);
static void ro_msg_dataload(wimp_message *block);
static char *ro_gui_uri_file_parse(const char *file_name, char **uri_title);
static bool ro_gui_uri_file_parse_line(FILE *fp, char *b);
static char *ro_gui_url_file_parse(const char *file_name);
static char *ro_gui_ieurl_file_parse(const char *file_name);
static void ro_msg_terminate_filename(wimp_full_message_data_xfer *message);
static void ro_msg_datasave(wimp_message *message);
static void ro_msg_datasave_ack(wimp_message *message);
static void ro_msg_dataopen(wimp_message *message);
static void ro_gui_get_screen_properties(void);
static void ro_msg_prequit(wimp_message *message);
static void ro_msg_save_desktop(wimp_message *message);
static void ro_msg_window_info(wimp_message *message);
static void ro_gui_view_source_bounce(wimp_message *message);


/**
 * Initialise the gui (RISC OS specific part).
 */

void gui_init(int argc, char** argv)
{
	char path[40];
	os_error *error;
	int length;
	char *nsdir_temp;

	/* re-enable all FPU exceptions/traps except inexact operations,
	 * which we're not interested in, and underflow which is incorrectly
	 * raised when converting an exact value of 0 from double-precision
	 * to single-precision on FPEmulator v4.09-4.11 (MVFD F0,#0:MVFS F0,F0)
	 * - UnixLib disables all FP exceptions by default */

	_FPU_SETCW(_FPU_IEEE & ~(_FPU_MASK_PM | _FPU_MASK_UM));

	xhourglass_start(1);

	/* read OS version for code that adapts to conform to the OS
	 * (remember that it's preferable to check for specific features
	 * being present) */
	xos_byte(osbyte_IN_KEY, 0, 0xff, &os_version, NULL);

	atexit(ro_gui_cleanup);
	prev_sigs.sigabrt = signal(SIGABRT, ro_gui_signal);
	prev_sigs.sigfpe = signal(SIGFPE, ro_gui_signal);
	prev_sigs.sigill = signal(SIGILL, ro_gui_signal);
	prev_sigs.sigint = signal(SIGINT, ro_gui_signal);
	prev_sigs.sigsegv = signal(SIGSEGV, ro_gui_signal);
	prev_sigs.sigterm = signal(SIGTERM, ro_gui_signal);

	if (prev_sigs.sigabrt == SIG_ERR || prev_sigs.sigfpe == SIG_ERR ||
			prev_sigs.sigill == SIG_ERR ||
			prev_sigs.sigint == SIG_ERR ||
			prev_sigs.sigsegv == SIG_ERR ||
			prev_sigs.sigterm == SIG_ERR)
		die("Failed registering signal handlers");

	filename_initialise();

#ifdef WITH_SAVE_COMPLETE
	save_complete_init();
#endif

	options_read("NetSurf:Choices");

	/* set defaults for absent strings */
	if (!option_theme)
		option_theme = strdup("Aletheia");
	if (!option_toolbar_browser)
		option_toolbar_browser = strdup("0123|58|9");
	if (!option_toolbar_hotlist)
		option_toolbar_hotlist = strdup("401|23");
	if (!option_toolbar_history)
		option_toolbar_history = strdup("01|23");
	if (!option_ca_bundle)
		option_ca_bundle = strdup("NetSurf:Resources.ca-bundle");
	if (!option_cookie_file)
		option_cookie_file = strdup("NetSurf:Cookies");
	if (!option_cookie_jar)
		option_cookie_jar = strdup(CHOICES_PREFIX "Cookies");
	if (!option_url_path)
		option_url_path = strdup("NetSurf:URL");
	if (!option_url_save)
		option_url_save = strdup(CHOICES_PREFIX "URL");
	if (!option_hotlist_path)
		option_hotlist_path = strdup("NetSurf:Hotlist");
	if (!option_hotlist_save)
		option_hotlist_save = strdup(CHOICES_PREFIX "Hotlist");
	if (!option_recent_path)
		option_recent_path = strdup("NetSurf:Recent");
	if (!option_recent_save)
		option_recent_save = strdup(CHOICES_PREFIX "Recent");
	if (!option_theme_path)
		option_theme_path = strdup("NetSurf:Themes");
	if (!option_theme_save)
		option_theme_save = strdup(CHOICES_PREFIX "Themes");

	if (!option_theme || ! option_toolbar_browser ||
			!option_toolbar_hotlist || !option_toolbar_history ||
			!option_ca_bundle || !option_cookie_file ||
			!option_cookie_jar || !option_url_path ||
			!option_url_save || !option_hotlist_path ||
			!option_hotlist_save || !option_recent_path ||
			!option_recent_save || !option_theme_path ||
			!option_theme_save)
		die("Failed initialising string options");

	/* create our choices directories */
	ro_gui_create_dirs();

	gui_sprites = ro_gui_load_sprite_file("NetSurf:Resources.Sprites");
	if (!gui_sprites)
		die("Unable to load Sprites.");
	ro_gui_choose_language();

	bitmap_initialise_memory();
	urldb_load(option_url_path);
	urldb_load_cookies(option_cookie_file);

	nsdir_temp = getenv("NetSurf$Dir");
	if (!nsdir_temp)
		die("Failed to locate NetSurf directory");
	NETSURF_DIR = strdup(nsdir_temp);
	if (!NETSURF_DIR)
		die("Failed duplicating NetSurf directory string");

	if ((length = snprintf(path, sizeof(path),
			"NetSurf:Resources.%s.Messages",
			option_language)) < 0 || length >= (int)sizeof(path))
		die("Failed to locate Messages resource.");
	messages_load(path);
	messages_load("NetSurf:Resources.LangNames");

	default_stylesheet_url = strdup("file:///NetSurf:/Resources/CSS");
	adblock_stylesheet_url = strdup("file:///NetSurf:/Resources/AdBlock");
	if (!default_stylesheet_url || !adblock_stylesheet_url)
		die("Failed initialising string constants.");

	error = xwimp_initialise(wimp_VERSION_RO38, task_name,
			(const wimp_message_list *) &task_messages, 0,
			&task_handle);
	if (error) {
		LOG(("xwimp_initialise: 0x%x: %s",
				error->errnum, error->errmess));
		die(error->errmess);
	}
	/* register our message handlers */
	ro_message_register_route(message_HELP_REQUEST,
			ro_gui_interactive_help_request);
	ro_message_register_route(message_DATA_OPEN,
			ro_msg_dataopen);
	ro_message_register_route(message_DATA_SAVE,
			ro_msg_datasave);
	ro_message_register_route(message_DATA_SAVE_ACK,
			ro_msg_datasave_ack);
	ro_message_register_route(message_PRE_QUIT,
			ro_msg_prequit);
	ro_message_register_route(message_SAVE_DESKTOP,
			ro_msg_save_desktop);
	ro_message_register_route(message_DRAGGING,
			ro_gui_selection_dragging);
	ro_message_register_route(message_DRAG_CLAIM,
			ro_gui_selection_drag_claim);
	ro_message_register_route(message_WINDOW_INFO,
			ro_msg_window_info);
	/* end of handler registration */

	nsfont_init();
	ro_gui_get_screen_properties();

	/* Issue a *Desktop to poke AcornURI into life */
	if (getenv("NetSurf$Start_URI_Handler"))
		xwimp_start_task("Desktop", 0);

	/*	Open the templates
	*/
	if ((length = snprintf(path, sizeof(path),
			"NetSurf:Resources.%s.Templates",
			option_language)) < 0 || length >= (int)sizeof(path))
		die("Failed to locate Templates resource.");
	error = xwimp_open_template(path);
	if (error) {
		LOG(("xwimp_open_template failed: 0x%x: %s",
				error->errnum, error->errmess));
		die(error->errmess);
	}
	ro_gui_theme_initialise(); /* initialise themes before dialogs */
	ro_gui_dialog_init(); /* must be done after sprite loading */
	ro_gui_download_init();
	ro_gui_menu_init();
	ro_gui_query_init();
	ro_gui_history_init();
	wimp_close_template();

	ro_gui_tree_initialise(); /* must be done after sprite loading */

	ro_gui_icon_bar_create();
	ro_gui_check_resolvers();
}

/**
 * Create intermediate directories for Choices and User Data files
 */
void ro_gui_create_dirs(void)
{
	char *path;
	char buf[256];

	/* Choices */
	path = getenv("NetSurf$ChoicesSave");
	if (!path)
		die("Failed to find NetSurf Choices save path");

	snprintf(buf, sizeof(buf), "%s", path);
	path = buf;

	/* Given a path x.y.z, this will try to create x, x.y */
	while ((path = strchr(path, '.'))) {
		*path = '\0';
		xosfile_create_dir(buf, 0);
		*path++ = '.';
	}

	/* URL */
	snprintf(buf, sizeof(buf), "%s", option_url_save);
	path = buf;

	while ((path = strchr(path, '.'))) {
		*path = '\0';
		xosfile_create_dir(buf, 0);
		*path++ = '.';
	}

	/* Hotlist */
	snprintf(buf, sizeof(buf), "%s", option_hotlist_save);
	path = buf;

	while ((path = strchr(path, '.'))) {
		*path = '\0';
		xosfile_create_dir(buf, 0);
		*path++ = '.';
	}

	/* Recent */
	snprintf(buf, sizeof(buf), "%s", option_recent_save);
	path = buf;

	while ((path = strchr(path, '.'))) {
		*path = '\0';
		xosfile_create_dir(buf, 0);
		*path++ = '.';
	}

	/* Theme */
	snprintf(buf, sizeof(buf), "%s", option_theme_save);
	path = buf;

	while ((path = strchr(path, '.'))) {
		*path = '\0';
		xosfile_create_dir(buf, 0);
		*path++ = '.';
	}
	/* and the final directory part (as theme_save is a directory) */
	xosfile_create_dir(buf, 0);
}

/**
 * Choose the language to use.
 */

void ro_gui_choose_language(void)
{
	char path[40];

	/* if option_language exists and is valid, use that */
	if (option_language) {
		if (2 < strlen(option_language))
			option_language[2] = 0;
		sprintf(path, "NetSurf:Resources.%s", option_language);
		if (is_dir(path)) {
			if (!option_accept_language)
				option_accept_language = strdup(option_language);
			return;
		}
		free(option_language);
		option_language = 0;
	}

	option_language = strdup(ro_gui_default_language());
	assert(option_language);
	option_accept_language = strdup(option_language);
	assert(option_accept_language);
}


/**
 * Determine the default language to use.
 *
 * RISC OS has no standard way of determining which language the user prefers.
 * We have to guess from the 'Country' setting.
 */
const char *ro_gui_default_language(void) {
	char path[40];
	const char *lang;
	int country;
	os_error *error;

	/* choose a language from the configured country number */
	error = xosbyte_read(osbyte_VAR_COUNTRY_NUMBER, &country);
	if (error) {
		LOG(("xosbyte_read failed: 0x%x: %s",
				error->errnum, error->errmess));
		country = 1;
	}
	switch (country) {
		case 7: /* Germany */
		case 30: /* Austria */
		case 35: /* Switzerland (70% German-speaking) */
			lang = "de";
			break;
		case 6: /* France */
		case 18: /* Canada2 (French Canada?) */
			lang = "fr";
			break;
		case 34: /* Netherlands */
			lang = "nl";
			break;
		default:
			lang = "en";
			break;
	}
	sprintf(path, "NetSurf:Resources.%s", lang);
	if (is_dir(path))
		return lang;
	return "en";
		option_language = strdup("en");
	assert(option_language);
	if (!option_accept_language)
		option_accept_language = strdup(option_language);
}


/**
 * Create an iconbar icon.
 */

void ro_gui_icon_bar_create(void)
{
#ifndef ncos
	os_error *error;

	wimp_icon_create icon = {
		wimp_ICON_BAR_RIGHT,
		{ { 0, 0, 68, 68 },
		wimp_ICON_SPRITE | wimp_ICON_HCENTRED | wimp_ICON_VCENTRED |
				(wimp_BUTTON_CLICK << wimp_ICON_BUTTON_TYPE_SHIFT),
		{ "!netsurf" } } };
	error = xwimp_create_icon(&icon, 0);
	if (error) {
		LOG(("xwimp_create_icon: 0x%x: %s",
				error->errnum, error->errmess));
		die(error->errmess);
	}
	ro_gui_wimp_event_register_mouse_click(wimp_ICON_BAR,
			ro_gui_icon_bar_click);
#endif
}


/**
 * Warn the user if Inet$Resolvers is not set.
 */

void ro_gui_check_resolvers(void)
{
	char *resolvers;
	resolvers = getenv("Inet$Resolvers");
	if (resolvers && resolvers[0]) {
		LOG(("Inet$Resolvers '%s'", resolvers));
	} else {
		LOG(("Inet$Resolvers not set or empty"));
		warn_user("Resolvers", 0);
	}
}


/**
 * Last-minute gui init, after all other modules have initialised.
 */

void gui_init2(int argc, char** argv)
{
	char *url = 0;
	bool open_window = option_open_browser_at_startup;

	/* parse command-line arguments */
	if (argc == 2) {
		LOG(("parameters: '%s'", argv[1]));
		/* this is needed for launching URI files */
		if (strcasecmp(argv[1], "-nowin") == 0)
			open_window = false;
	}
	else if (argc == 3) {
		LOG(("parameters: '%s' '%s'", argv[1], argv[2]));
		open_window = true;

		/* HTML files */
		if (strcasecmp(argv[1], "-html") == 0) {
			url = path_to_url(argv[2]);
			if (!url) {
				LOG(("malloc failed"));
				die("Insufficient memory for URL");
			}
		}
		/* URL files */
		else if (strcasecmp(argv[1], "-urlf") == 0) {
			url = ro_gui_url_file_parse(argv[2]);
			if (!url) {
				LOG(("malloc failed"));
				die("Insufficient memory for URL");
			}
		}
		/* ANT URL Load */
		else if (strcasecmp(argv[1], "-url") == 0) {
			url = strdup(argv[2]);
			if (!url) {
				LOG(("malloc failed"));
				die("Insufficient memory for URL");
			}
		}
		/* Unknown => exit here. */
		else {
			LOG(("Unknown parameters: '%s' '%s'",
				argv[1], argv[2]));
			return;
		}
	}
	/* get user's homepage (if configured) */
	else if (option_homepage_url && option_homepage_url[0]) {
		url = calloc(strlen(option_homepage_url) + 5, sizeof(char));
		if (!url) {
			LOG(("malloc failed"));
			die("Insufficient memory for URL");
		}
		sprintf(url, "%s", option_homepage_url);
	}
	/* default homepage */
	else {
		url = calloc(80, sizeof(char));
		if (!url) {
			LOG(("malloc failed"));
			die("Insufficient memory for URL");
		}
		snprintf(url, 80, "file:///<NetSurf$Dir>/Docs/intro_%s",
			option_language);
	}

#ifdef WITH_KIOSK_BROWSING
	open_window = true;
#endif

	if (open_window)
			browser_window_create(url, NULL, 0, true);

	free(url);
}


/**
 * Close down the gui (RISC OS).
 */

void gui_quit(void)
{
	bitmap_quit();
	urldb_save_cookies(option_cookie_jar);
	urldb_save(option_url_save);
	ro_gui_window_quit();
	ro_gui_global_history_save();
	ro_gui_hotlist_save();
	ro_gui_saveas_quit();
	rufl_quit();
	free(gui_sprites);
	xwimp_close_down(task_handle);
	free(default_stylesheet_url);
	free(adblock_stylesheet_url);
	xhourglass_off();
}


/**
 * Handles a signal
 */

void ro_gui_signal(int sig)
{
	struct content *c;
	void (*prev_handler)(int);

	if (sig == SIGFPE || sig == SIGABRT) {
		os_colour old_sand, old_glass;

		xhourglass_on();
		xhourglass_colours(0x0000ffff, 0x000000ff,
				&old_sand, &old_glass);
		for (c = content_list; c; c = c->next)
			if (c->type == CONTENT_HTML && c->data.html.layout) {
				LOG(("Dumping: '%s'", c->url));
				box_dump(c->data.html.layout, 0);
			}
		options_dump();
		xhourglass_colours(old_sand, old_glass, 0, 0);
		xhourglass_off();
	}
	ro_gui_cleanup();

	/* Get previous handler of this signal */
	switch (sig) {
		case SIGABRT:
			prev_handler = prev_sigs.sigabrt;
			break;
		case SIGFPE:
			prev_handler = prev_sigs.sigfpe;
			break;
		case SIGILL:
			prev_handler = prev_sigs.sigill;
			break;
		case SIGINT:
			prev_handler = prev_sigs.sigint;
			break;
		case SIGSEGV:
			prev_handler = prev_sigs.sigsegv;
			break;
		case SIGTERM:
			prev_handler = prev_sigs.sigterm;
			break;
		default:
			abort();
	}

	if (prev_handler != SIG_IGN && prev_handler != SIG_DFL) {
		/* User-registered handler, so call it direct */
		prev_handler(sig);
	} else if (prev_handler == SIG_DFL) {
		/* Default handler so set handler to that and raise() */
		prev_handler = signal(sig, SIG_DFL);
		if (prev_handler == SIG_ERR)
			abort();
		raise(sig);
	}
	/* If we reach here, previous handler was either SIG_IGN or
	 * the user-defined handler returned. In either case, we have
	 * nothing to do */
}


/**
 * Ensures the gui exits cleanly.
 */

void ro_gui_cleanup(void)
{
	ro_gui_buffer_close();
	xhourglass_off();
}


/**
 * Poll the OS for events (RISC OS).
 *
 * \param active return as soon as possible
 */

void gui_poll(bool active)
{
	wimp_event_no event;
	wimp_block block;
	const wimp_poll_flags mask = wimp_MASK_LOSE | wimp_MASK_GAIN;

	/* Poll wimp. */
	xhourglass_off();
	if (active) {
		event = wimp_poll(mask, &block, 0);
	} else if (sched_active || gui_track || gui_reformat_pending ||
			bitmap_maintenance) {
		os_t t = os_read_monotonic_time();

		if (gui_track)
			switch (gui_current_drag_type) {
				case GUI_DRAG_SELECTION:
				case GUI_DRAG_SCROLL:
					t += 4;	/* for smoother update */
					break;

				default:
					t += 10;
					break;
			}
		else
			t += 10;

		if (sched_active && (sched_time - t) < 0)
			t = sched_time;

		event = wimp_poll_idle(mask, &block, t, 0);
	} else {
		event = wimp_poll(wimp_MASK_NULL | mask, &block, 0);
	}
	xhourglass_on();
	gui_last_poll = clock();
	ro_gui_handle_event(event, &block);
	schedule_run();
        ro_gui_window_update_boxes();
	
	if (gui_reformat_pending && event == wimp_NULL_REASON_CODE)
		ro_gui_window_process_reformats();
	else if (bitmap_maintenance_priority ||
			(bitmap_maintenance && event == wimp_NULL_REASON_CODE))
		bitmap_maintain();
}


/**
 * Process a Wimp_Poll event.
 *
 * \param event wimp event number
 * \param block parameter block
 */

void ro_gui_handle_event(wimp_event_no event, wimp_block *block)
{
	switch (event) {
		case wimp_NULL_REASON_CODE:
			ro_gui_null_reason_code();
			break;

		case wimp_REDRAW_WINDOW_REQUEST:
			ro_gui_redraw_window_request(&block->redraw);
			break;

		case wimp_OPEN_WINDOW_REQUEST:
			ro_gui_open_window_request(&block->open);
			break;

		case wimp_CLOSE_WINDOW_REQUEST:
			ro_gui_close_window_request(&block->close);
			break;

		case wimp_POINTER_LEAVING_WINDOW:
			ro_gui_pointer_leaving_window(&block->leaving);
			break;

		case wimp_POINTER_ENTERING_WINDOW:
			ro_gui_pointer_entering_window(&block->entering);
			break;

		case wimp_MOUSE_CLICK:
			ro_gui_mouse_click(&block->pointer);
			break;

		case wimp_USER_DRAG_BOX:
			ro_gui_drag_end(&(block->dragged));
			break;

		case wimp_KEY_PRESSED:
			ro_gui_keypress(&(block->key));
			break;

		case wimp_MENU_SELECTION:
			ro_gui_menu_selection(&(block->selection));
			break;

		case wimp_SCROLL_REQUEST:
			ro_gui_scroll_request(&(block->scroll));
			break;

		case wimp_USER_MESSAGE:
		case wimp_USER_MESSAGE_RECORDED:
		case wimp_USER_MESSAGE_ACKNOWLEDGE:
			ro_gui_user_message(event, &(block->message));
			break;
	}
}


/**
 * Check for important events and yield CPU (RISC OS).
 *
 * Required on RISC OS for cooperative multitasking.
 */

void gui_multitask(void)
{
	wimp_event_no event;
	wimp_block block;

	if (clock() < gui_last_poll + 10)
		return;

	xhourglass_off();
	event = wimp_poll(wimp_MASK_LOSE | wimp_MASK_GAIN, &block, 0);
	xhourglass_on();
	gui_last_poll = clock();

	ro_gui_handle_event(event, &block);
}


/**
 * Handle Null_Reason_Code events.
 */

void ro_gui_null_reason_code(void)
{
	wimp_pointer pointer;
	os_error *error;

	ro_gui_throb();

	if (!gui_track)
		return;

	error = xwimp_get_pointer_info(&pointer);
	if (error) {
		LOG(("xwimp_get_pointer_info: 0x%x: %s",
			error->errnum, error->errmess));
		warn_user("WimpError", error->errmess);
		return;
	}

	switch (gui_current_drag_type) {

		/* pointer is allowed to wander outside the initiating window
			for certain drag types */

		case GUI_DRAG_SELECTION:
		case GUI_DRAG_SCROLL:
			assert(gui_track_gui_window);
			ro_gui_window_mouse_at(gui_track_gui_window, &pointer);
			break;

//		case GUI_DRAG_SAVE:
//			ro_gui_selection_send_dragging(&pointer);
//			break;

		default:
			if (gui_track_wimp_w == history_window)
				ro_gui_history_mouse_at(&pointer);
			if (gui_track_wimp_w == dialog_url_complete)
				ro_gui_url_complete_mouse_at(&pointer);
			else if (gui_track_gui_window)
				ro_gui_window_mouse_at(gui_track_gui_window, &pointer);
			break;
	}
}


/**
 * Handle Redraw_Window_Request events.
 */

void ro_gui_redraw_window_request(wimp_draw *redraw)
{
	struct gui_window *g;

	if (ro_gui_wimp_event_redraw_window(redraw))
		return;

	g = ro_gui_window_lookup(redraw->w);
	if (g)
		ro_gui_window_redraw(g, redraw);
}


/**
 * Handle Open_Window_Request events.
 */

void ro_gui_open_window_request(wimp_open *open)
{
	struct gui_window *g;
	os_error *error;

	if (ro_gui_wimp_event_open_window(open))
		return;

	g = ro_gui_window_lookup(open->w);
	if (g) {
		ro_gui_window_open(g, open);
	} else {
		error = xwimp_open_window(open);
		if (error) {
			LOG(("xwimp_open_window: 0x%x: %s",
					error->errnum, error->errmess));
			warn_user("WimpError", error->errmess);
			return;
		}

		g = ro_gui_status_lookup(open->w);
		if (g && g->toolbar)
			ro_gui_theme_resize_toolbar_status(g->toolbar);
	}
}


/**
 * Handle Close_Window_Request events.
 */

void ro_gui_close_window_request(wimp_close *close)
{
	struct gui_window *g;
	struct gui_download_window *dw;
	wimp_pointer pointer;
	os_error *error;
	char *temp_name, *r;
	char *filename;
	struct content *content = NULL;

	if ((g = ro_gui_window_lookup(close->w)) != NULL) {
		error = xwimp_get_pointer_info(&pointer);
		if (error) {
			LOG(("xwimp_get_pointer_info: 0x%x: %s",
					error->errnum, error->errmess));
			warn_user("WimpError", error->errmess);
			return;
		}
		if (g->bw)
			content = g->bw->current_content;
		if (pointer.buttons & wimp_CLICK_ADJUST) {
			filename = url_to_path(content->url);
			if (filename) {
				temp_name = malloc(strlen(filename) + 32);
				if (temp_name) {
					sprintf(temp_name, "Filer_OpenDir %s", filename);
					r = temp_name + strlen(temp_name);
					while (r > temp_name) {
						if (*r == '.') {
							*r = '\0';
							break;
						}
						*r--;
					}
					error = xos_cli(temp_name);
					if (error) {
						LOG(("xos_cli: 0x%x: %s",
								error->errnum, error->errmess));
						warn_user("MiscError", error->errmess);
						return;
					}
					free(temp_name);
				}
				free(filename);
			} else {
			  	/* this is pointless if we are about to close the window */
			  	if (ro_gui_shift_pressed())
			  	  	ro_gui_menu_handle_action(close->w, BROWSER_NAVIGATE_UP, true);
			}
		}
		if (ro_gui_shift_pressed())
			return;
		ro_gui_url_complete_close(NULL, 0);

		/* search must be closed before the main window so that
		   the content still exists */
		ro_gui_dialog_close_persistent(close->w);
		browser_window_destroy(g->bw);
		return;

	} else if ((dw = ro_gui_download_window_lookup(close->w)) != NULL) {
		ro_gui_download_window_destroy(dw, false);
	} else {
		ro_gui_dialog_close(close->w);
	}
	ro_gui_dialog_close_persistent(close->w);
}


/**
 * Handle Pointer_Leaving_Window events.
 */

void ro_gui_pointer_leaving_window(wimp_leaving *leaving)
{
	if (gui_track_wimp_w == history_window) {
		os_error *error = xwimp_close_window(dialog_tooltip);
		if (error) {
			LOG(("xwimp_close_window: 0x%x: %s",
					error->errnum, error->errmess));
			warn_user("WimpError", error->errmess);
		}
	}

	switch (gui_current_drag_type) {
		case GUI_DRAG_SELECTION:
		case GUI_DRAG_SCROLL:
		case GUI_DRAG_SAVE:
			/* ignore Pointer_Leaving_Window event that the Wimp mysteriously
				issues when a Wimp_DragBox drag operation is started */
			break;

		default:
			gui_track = false;
			gui_window_set_pointer(gui_track_gui_window, GUI_POINTER_DEFAULT);
			break;
	}
}


/**
 * Handle Pointer_Entering_Window events.
 */

void ro_gui_pointer_entering_window(wimp_entering *entering)
{
	gui_track_wimp_w = entering->w;
	gui_track_gui_window = ro_gui_window_lookup(entering->w);
	gui_track = gui_track_gui_window || gui_track_wimp_w == history_window ||
			gui_track_wimp_w == dialog_url_complete;
}


/**
 * Handle Mouse_Click events.
 */

void ro_gui_mouse_click(wimp_pointer *pointer)
{
	struct gui_window *g;
	struct gui_download_window *dw;
	struct gui_query_window *qw;

	if (ro_gui_wimp_event_mouse_click(pointer))
		return;
	else if ((g = ro_gui_window_lookup(pointer->w)) != NULL)
		ro_gui_window_click(g, pointer);
	else if ((dw = ro_gui_download_window_lookup(pointer->w)) != NULL)
		ro_gui_download_window_click(dw, pointer);
	else if ((qw = ro_gui_query_window_lookup(pointer->w)) != NULL)
		ro_gui_query_window_click(qw, pointer);
}


/**
 * Handle Mouse_Click events on the iconbar icon.
 */

bool ro_gui_icon_bar_click(wimp_pointer *pointer)
{
	char url[80];
	int key_down = 0;

	if (pointer->buttons == wimp_CLICK_MENU) {
		ro_gui_menu_create(iconbar_menu, pointer->pos.x,
				   96 + iconbar_menu_height, wimp_ICON_BAR);

	} else if (pointer->buttons == wimp_CLICK_SELECT) {
		if (option_homepage_url && option_homepage_url[0]) {
			browser_window_create(option_homepage_url, NULL, 0, true);
		} else {
			snprintf(url, sizeof url,
					"file:///<NetSurf$Dir>/Docs/intro_%s",
					option_language);
			browser_window_create(url, NULL, 0, true);
		}

	} else if (pointer->buttons == wimp_CLICK_ADJUST) {
		xosbyte1(osbyte_SCAN_KEYBOARD, 0 ^ 0x80, 0, &key_down);
		if (key_down == 0)
			ro_gui_menu_handle_action(pointer->w, HOTLIST_SHOW,
					false);
		else
			ro_gui_debugwin_open();
	}
	return true;
}


/**
 * Handle User_Drag_Box events.
 */

void ro_gui_drag_end(wimp_dragged *drag)
{
	switch (gui_current_drag_type) {
		case GUI_DRAG_SELECTION:
			ro_gui_selection_drag_end(gui_track_gui_window, drag);
			break;

		case GUI_DRAG_SCROLL:
			ro_gui_window_scroll_end(gui_track_gui_window, drag);
			break;

		case GUI_DRAG_DOWNLOAD_SAVE:
			ro_gui_download_drag_end(drag);
			break;

		case GUI_DRAG_SAVE:
			ro_gui_save_drag_end(drag);
			break;

		case GUI_DRAG_STATUS_RESIZE:
			break;

		case GUI_DRAG_TREE_SELECT:
			ro_gui_tree_selection_drag_end(drag);
			break;

		case GUI_DRAG_TREE_MOVE:
			ro_gui_tree_move_drag_end(drag);
			break;

		case GUI_DRAG_TOOLBAR_CONFIG:
			ro_gui_theme_toolbar_editor_drag_end(drag);
			break;

		default:
			assert(gui_current_drag_type == GUI_DRAG_NONE);
			break;
	}
}


/**
 * Handle Key_Pressed events.
 */

void ro_gui_keypress(wimp_key *key)
{
	struct gui_download_window *dw;
	struct gui_query_window *qw;
	bool handled = false;
	struct gui_window *g;
	os_error *error;

	if (ro_gui_wimp_event_keypress(key))
		handled = true;
	else if ((g = ro_gui_window_lookup(key->w)) != NULL)
		handled = ro_gui_window_keypress(g, key->c, false);
	else if ((g = ro_gui_toolbar_lookup(key->w)) != NULL)
		handled = ro_gui_window_keypress(g, key->c, true);
	else if ((qw = ro_gui_query_window_lookup(key->w)) != NULL)
		handled = ro_gui_query_window_keypress(qw, key);
	else if ((dw = ro_gui_download_window_lookup(key->w)) != NULL)
		handled = ro_gui_download_window_keypress(dw, key);

	if (!handled) {
		error = xwimp_process_key(key->c);
		if (error) {
			LOG(("xwimp_process_key: 0x%x: %s",
					error->errnum, error->errmess));
			warn_user("WimpError", error->errmess);
		}
	}
}


/**
 * Handle the three User_Message events.
 */
void ro_gui_user_message(wimp_event_no event, wimp_message *message)
{
	/* attempt automatic routing */
	if (ro_message_handle_message(event, message))
		return;

	switch (message->action) {
		case message_DATA_LOAD:
			ro_msg_terminate_filename((wimp_full_message_data_xfer*)message);

			if (event == wimp_USER_MESSAGE_ACKNOWLEDGE) {
#ifdef WITH_PRINT
				if (print_current_window)
					print_dataload_bounce(message);
#endif
			}
			else
				ro_msg_dataload(message);
			break;

		case message_DATA_LOAD_ACK:
#ifdef WITH_PRINT
			if (print_current_window)
				print_cleanup();
#endif
			break;

		case message_MENU_WARNING:
			ro_gui_menu_warning((wimp_message_menu_warning *)
					&message->data);
			break;

		case message_MENUS_DELETED:
			ro_gui_menu_closed(true);
			break;

		case message_MODE_CHANGE:
			ro_gui_get_screen_properties();
			rufl_invalidate_cache();
			break;

		case message_CLAIM_ENTITY:
			ro_gui_selection_claim_entity((wimp_full_message_claim_entity*)message);
			break;

		case message_DATA_REQUEST:
			ro_gui_selection_data_request((wimp_full_message_data_request*)message);
			break;

#ifdef WITH_URI
		case message_URI_PROCESS:
			if (event != wimp_USER_MESSAGE_ACKNOWLEDGE)
				ro_uri_message_received(message);
			break;
		case message_URI_RETURN_RESULT:
			ro_uri_bounce(message);
			break;
#endif
#ifdef WITH_URL
		case message_INET_SUITE_OPEN_URL:
			if (event == wimp_USER_MESSAGE_ACKNOWLEDGE) {
				ro_url_bounce(message);
			}
			else {
				ro_url_message_received(message);
			}
			break;
#endif
#ifdef WITH_PLUGIN
		case message_PLUG_IN_OPENING:
			plugin_opening(message);
			break;
		case message_PLUG_IN_CLOSED:
			plugin_closed(message);
			break;
		case message_PLUG_IN_RESHAPE_REQUEST:
			plugin_reshape_request(message);
			break;
		case message_PLUG_IN_FOCUS:
			break;
		case message_PLUG_IN_URL_ACCESS:
			plugin_url_access(message);
			break;
		case message_PLUG_IN_STATUS:
			plugin_status(message);
			break;
		case message_PLUG_IN_BUSY:
			break;
		case message_PLUG_IN_STREAM_NEW:
			plugin_stream_new(message);
			break;
		case message_PLUG_IN_STREAM_WRITE:
			break;
		case message_PLUG_IN_STREAM_WRITTEN:
			plugin_stream_written(message);
			break;
		case message_PLUG_IN_STREAM_DESTROY:
			break;
		case message_PLUG_IN_OPEN:
			if (event == wimp_USER_MESSAGE_ACKNOWLEDGE)
				plugin_open_msg(message);
			break;
		case message_PLUG_IN_CLOSE:
			if (event == wimp_USER_MESSAGE_ACKNOWLEDGE)
				plugin_close_msg(message);
			break;
		case message_PLUG_IN_RESHAPE:
		case message_PLUG_IN_STREAM_AS_FILE:
		case message_PLUG_IN_NOTIFY:
		case message_PLUG_IN_ABORT:
		case message_PLUG_IN_ACTION:
			break;
#endif
#ifdef WITH_PRINT
		case message_PRINT_SAVE:
			if (event == wimp_USER_MESSAGE_ACKNOWLEDGE)
				print_save_bounce(message);
			break;
		case message_PRINT_ERROR:
			print_error(message);
			break;
		case message_PRINT_TYPE_ODD:
			print_type_odd(message);
			break;
#endif

		case message_QUIT:
			netsurf_quit = true;
			break;
	}
}


/**
 * Ensure that the filename in a data transfer message is NUL terminated
 * (some applications, especially BASIC programs use CR)
 *
 * \param  message  message to be corrected
 */

void ro_msg_terminate_filename(wimp_full_message_data_xfer *message)
{
	const char *ep = (char*)message + message->size;
	char *p = message->file_name;

	if ((size_t)message->size >= sizeof(*message))
		ep = (char*)message + sizeof(*message) - 1;

	while (p < ep && *p >= ' ') p++;
	*p = '\0';
}


/**
 * Handle Message_DataLoad (file dragged in).
 */

void ro_msg_dataload(wimp_message *message)
{
	int file_type = message->data.data_xfer.file_type;
	int tree_file_type = file_type;
	char *url = 0;
	char *title = NULL;
	struct gui_window *g;
	struct node *node;
	struct node *link;
	os_error *error;
	int x, y;
	bool before;
	const struct url_data *data;

	g = ro_gui_window_lookup(message->data.data_xfer.w);
	if (g) {
		if (ro_gui_window_dataload(g, message))
			return;
	}
	else {
		g = ro_gui_toolbar_lookup(message->data.data_xfer.w);
		if (g && ro_gui_toolbar_dataload(g, message))
			return;
	}

	switch (file_type) {
		case FILETYPE_ACORN_URI:
			url = ro_gui_uri_file_parse(message->data.data_xfer.file_name,
					&title);
			tree_file_type = 0xfaf;
			break;
		case FILETYPE_ANT_URL:
			url = ro_gui_url_file_parse(message->data.data_xfer.file_name);
			tree_file_type = 0xfaf;
			break;
		case FILETYPE_IEURL:
			url = ro_gui_ieurl_file_parse(message->data.data_xfer.file_name);
			tree_file_type = 0xfaf;
			break;

		case FILETYPE_HTML:
		case FILETYPE_JNG:
		case FILETYPE_CSS:
		case FILETYPE_MNG:
		case FILETYPE_GIF:
		case FILETYPE_BMP:
		case FILETYPE_ICO:
		case osfile_TYPE_DRAW:
		case FILETYPE_PNG:
		case FILETYPE_JPEG:
		case osfile_TYPE_SPRITE:
		case osfile_TYPE_TEXT:
		case FILETYPE_ARTWORKS:
			/* display the actual file */
			url = path_to_url(message->data.data_xfer.file_name);
			break;

		default:
			return;
	}

	if (!url)
		/* error has already been reported by one of the
		 * functions called above */
		return;

	if (g) {
		browser_window_go(g->bw, url, 0, true);
	} else if ((hotlist_tree) && ((wimp_w)hotlist_tree->handle ==
			message->data.data_xfer.w)) {
		data = urldb_get_url_data(url);
		if (!data) {
			urldb_add_url(url);
			urldb_set_url_persistence(url, true);
			data = urldb_get_url_data(url);
		}
		if (data) {
			ro_gui_tree_get_tree_coordinates(hotlist_tree,
					message->data.data_xfer.pos.x,
					message->data.data_xfer.pos.y,
					&x, &y);
			link = tree_get_link_details(hotlist_tree, x, y, &before);
			node = tree_create_URL_node(NULL, url, data, title);
			tree_link_node(link, node, before);
			tree_handle_node_changed(hotlist_tree, node, false, true);
			tree_redraw_area(hotlist_tree, node->box.x - NODE_INSTEP, 0,
					NODE_INSTEP, 16384);
			if ((!title) && (!data->title))
				ro_gui_tree_start_edit(hotlist_tree, &node->data, NULL);
		}
	} else {
		browser_window_create(url, 0, 0, true);
	}

	/* send DataLoadAck */
	message->action = message_DATA_LOAD_ACK;
	message->your_ref = message->my_ref;
	error = xwimp_send_message(wimp_USER_MESSAGE, message, message->sender);
	if (error) {
		LOG(("xwimp_send_message: 0x%x: %s",
				error->errnum, error->errmess));
		warn_user("WimpError", error->errmess);
		return;
	}

	free(url);
}


/**
 * Parse an Acorn URI file.
 *
 * \param  file_name  file to read
 * \param  uri_title  pointer to receive title data, or NULL for no data
 * \return  URL from file, or 0 on error and error reported
 */

char *ro_gui_uri_file_parse(const char *file_name, char **uri_title)
{
	/* See the "Acorn URI Handler Functional Specification" for the
	 * definition of the URI file format. */
	char line[400];
	char *url = NULL;
	FILE *fp;

	*uri_title = NULL;
	fp = fopen(file_name, "rb");
	if (!fp) {
		LOG(("fopen(\"%s\", \"rb\"): %i: %s",
				file_name, errno, strerror(errno)));
		warn_user("LoadError", strerror(errno));
		return 0;
	}

	/* "URI" */
	if (!ro_gui_uri_file_parse_line(fp, line) || strcmp(line, "URI") != 0)
		goto uri_syntax_error;

	/* version */
	if (!ro_gui_uri_file_parse_line(fp, line) ||
			strspn(line, "0123456789") != strlen(line))
		goto uri_syntax_error;

	/* URI */
	if (!ro_gui_uri_file_parse_line(fp, line))
		goto uri_syntax_error;
	url = strdup(line);
	if (!url) {
		warn_user("NoMemory", 0);
		fclose(fp);
		return 0;
	}

	/* title */
	if (!ro_gui_uri_file_parse_line(fp, line))
		goto uri_syntax_error;
	if (uri_title && line[0] && ((line[0] != '*') || line[1])) {
		*uri_title = strdup(line);
		if (!*uri_title) /* non-fatal */
			warn_user("NoMemory", 0);
	}
	fclose(fp);

	return url;

uri_syntax_error:
	fclose(fp);
	warn_user("URIError", 0);
	return 0;
}


/**
 * Read a "line" from an Acorn URI file.
 *
 * \param  fp  file pointer to read from
 * \param  b   buffer for line, size 400 bytes
 * \return  true on success, false on EOF
 */

bool ro_gui_uri_file_parse_line(FILE *fp, char *b)
{
	int c;
	unsigned int i = 0;

	c = getc(fp);
	if (c == EOF)
		return false;

	/* skip comment lines */
	while (c == '#') {
		do { c = getc(fp); } while (c != EOF && 32 <= c);
		if (c == EOF)
			return false;
		do { c = getc(fp); } while (c != EOF && c < 32);
		if (c == EOF)
			return false;
	}

	/* read "line" */
	do {
		if (i == 399)
			return false;
		b[i++] = c;
		c = getc(fp);
	} while (c != EOF && 32 <= c);

	/* skip line ending control characters */
	while (c != EOF && c < 32)
		c = getc(fp);

	if (c != EOF)
		ungetc(c, fp);

	b[i] = 0;
	return true;
}


/**
 * Parse an ANT URL file.
 *
 * \param  file_name  file to read
 * \return  URL from file, or 0 on error and error reported
 */

char *ro_gui_url_file_parse(const char *file_name)
{
	char line[400];
	char *url;
	FILE *fp;

	fp = fopen(file_name, "r");
	if (!fp) {
		LOG(("fopen(\"%s\", \"r\"): %i: %s",
				file_name, errno, strerror(errno)));
		warn_user("LoadError", strerror(errno));
		return 0;
	}

	if (!fgets(line, sizeof line, fp)) {
		if (ferror(fp)) {
			LOG(("fgets: %i: %s",
					errno, strerror(errno)));
			warn_user("LoadError", strerror(errno));
		} else
			warn_user("LoadError", messages_get("EmptyError"));
		fclose(fp);
		return 0;
	}

	fclose(fp);

	if (line[strlen(line) - 1] == '\n')
		line[strlen(line) - 1] = '\0';

	url = strdup(line);
	if (!url) {
		warn_user("NoMemory", 0);
		return 0;
	}

	return url;
}


/**
 * Parse an IEURL file.
 *
 * \param  file_name  file to read
 * \return  URL from file, or 0 on error and error reported
 */

char *ro_gui_ieurl_file_parse(const char *file_name)
{
	char line[400];
	char *url = 0;
	FILE *fp;

	fp = fopen(file_name, "r");
	if (!fp) {
		LOG(("fopen(\"%s\", \"r\"): %i: %s",
				file_name, errno, strerror(errno)));
		warn_user("LoadError", strerror(errno));
		return 0;
	}

	while (fgets(line, sizeof line, fp)) {
		if (strncmp(line, "URL=", 4) == 0) {
			if (line[strlen(line) - 1] == '\n')
				line[strlen(line) - 1] = '\0';
			url = strdup(line + 4);
			if (!url) {
				fclose(fp);
				warn_user("NoMemory", 0);
				return 0;
			}
			break;
		}
	}
	if (ferror(fp)) {
		LOG(("fgets: %i: %s",
				errno, strerror(errno)));
		warn_user("LoadError", strerror(errno));
		fclose(fp);
		return 0;
	}

	fclose(fp);

	if (!url)
		warn_user("URIError", 0);

	return url;
}


/**
 * Handle Message_DataSave
 */

void ro_msg_datasave(wimp_message *message)
{
	wimp_full_message_data_xfer *dataxfer = (wimp_full_message_data_xfer*)message;

	/* remove ghost caret if drag-and-drop protocol was used */
//	ro_gui_selection_drag_reset();

	ro_msg_terminate_filename(dataxfer);

	switch (dataxfer->file_type) {
		case FILETYPE_ACORN_URI:
		case FILETYPE_ANT_URL:
		case FILETYPE_IEURL:
		case FILETYPE_HTML:
		case FILETYPE_JNG:
		case FILETYPE_CSS:
		case FILETYPE_MNG:
		case FILETYPE_GIF:
		case FILETYPE_BMP:
		case FILETYPE_ICO:
		case osfile_TYPE_DRAW:
		case FILETYPE_PNG:
		case FILETYPE_JPEG:
		case osfile_TYPE_SPRITE:
		case osfile_TYPE_TEXT:
		case FILETYPE_ARTWORKS: {
			os_error *error;

			dataxfer->your_ref = dataxfer->my_ref;
			dataxfer->size = offsetof(wimp_full_message_data_xfer, file_name) + 16;
			dataxfer->action = message_DATA_SAVE_ACK;
			dataxfer->est_size = -1;
			memcpy(dataxfer->file_name, "<Wimp$Scrap>", 13);

			error = xwimp_send_message(wimp_USER_MESSAGE, (wimp_message*)dataxfer, message->sender);
			if (error) {
				LOG(("xwimp_send_message: 0x%x: %s", error->errnum, error->errmess));
				warn_user("WimpError", error->errmess);
			}
		}
		break;
	}
}


/**
 * Handle Message_DataSaveAck.
 */

void ro_msg_datasave_ack(wimp_message *message)
{
	ro_msg_terminate_filename((wimp_full_message_data_xfer*)message);

#ifdef WITH_PRINT
	if (print_ack(message))
		return;
#endif

	switch (gui_current_drag_type) {
		case GUI_DRAG_DOWNLOAD_SAVE:
			ro_gui_download_datasave_ack(message);
			break;

		case GUI_DRAG_SAVE:
			ro_gui_save_datasave_ack(message);
			gui_current_drag_type = GUI_DRAG_NONE;
			break;

		default:
			break;
	}
}


/**
 * Handle Message_DataOpen (double-click on file in the Filer).
 */

void ro_msg_dataopen(wimp_message *message)
{
	int file_type = message->data.data_xfer.file_type;
	char *url = 0;
	size_t len;
	os_error *error;

	if (file_type == 0xb28)			/* ANT URL file */
		url = ro_gui_url_file_parse(message->data.data_xfer.file_name);
	else if (file_type == 0xfaf)		/* HTML file */
		url = path_to_url(message->data.data_xfer.file_name);
	else if (file_type == 0x1ba)		/* IEURL file */
		url = ro_gui_ieurl_file_parse(message->
				data.data_xfer.file_name);
	else if (file_type == 0x2000) {		/* application */
		len = strlen(message->data.data_xfer.file_name);
		if (len < 9 || strcmp(".!NetSurf",
				message->data.data_xfer.file_name + len - 9))
			return;
		if (option_homepage_url && option_homepage_url[0]) {
			url = strdup(option_homepage_url);
		} else {
			url = malloc(80);
			if (url)
				snprintf(url, 80,
					"file:///<NetSurf$Dir>/Docs/intro_%s",
					option_language);
		}
		if (!url)
			warn_user("NoMemory", 0);
	} else
		return;

	/* send DataLoadAck */
	message->action = message_DATA_LOAD_ACK;
	message->your_ref = message->my_ref;
	error = xwimp_send_message(wimp_USER_MESSAGE, message, message->sender);
	if (error) {
		LOG(("xwimp_send_message: 0x%x: %s",
				error->errnum, error->errmess));
		warn_user("WimpError", error->errmess);
		return;
	}

	if (!url)
		/* error has already been reported by one of the
		 * functions called above */
		return;

	/* create a new window with the file */
	browser_window_create(url, NULL, 0, true);

	free(url);
}


/**
 * Handle PreQuit message
 *
 * \param  message  PreQuit message from Wimp
 */

void ro_msg_prequit(wimp_message *message)
{
	if (!ro_gui_prequit()) {
		os_error *error;

		/* we're objecting to the close down */
		message->your_ref = message->my_ref;
		error = xwimp_send_message(wimp_USER_MESSAGE_ACKNOWLEDGE,
						message, message->sender);
		if (error) {
			LOG(("xwimp_send_message: 0x%x:%s", error->errnum, error->errmess));
			warn_user("WimpError", error->errmess);
		}
	}
}


/**
 * Handle SaveDesktop message
 *
 * \param  message  SaveDesktop message from Wimp
 */

void ro_msg_save_desktop(wimp_message *message)
{
	os_error *error;

	error = xosgbpb_writew(message->data.save_desktopw.file,
				(const byte*)"Run ", 4, NULL);
	if (!error) {
		error = xosgbpb_writew(message->data.save_desktopw.file,
					(const byte*)NETSURF_DIR, strlen(NETSURF_DIR), NULL);
		if (!error)
			error = xos_bputw('\n', message->data.save_desktopw.file);
	}

	if (error) {
		LOG(("xosgbpb_writew/xos_bputw: 0x%x:%s", error->errnum, error->errmess));
		warn_user("SaveError", error->errmess);

		/* we must cancel the save by acknowledging the message */
		message->your_ref = message->my_ref;
		error = xwimp_send_message(wimp_USER_MESSAGE_ACKNOWLEDGE,
						message, message->sender);
		if (error) {
			LOG(("xwimp_send_message: 0x%x:%s", error->errnum, error->errmess));
			warn_user("WimpError", error->errmess);
		}
	}
}


/**
 * Handle WindowInfo message (part of the iconising protocol)
 *
 * \param  message  WindowInfo message from the Iconiser
 */

void ro_msg_window_info(wimp_message *message)
{
	wimp_full_message_window_info *wi;
	struct gui_window *g;

	/* allow the user to turn off thumbnail icons */
	if (!option_thumbnail_iconise)
		return;
		
	wi = (wimp_full_message_window_info*)message;
	g = ro_gui_window_lookup(wi->w);

	/* ic_<task name> will suffice for our other windows */
	if (g) ro_gui_window_iconise(g, wi);
}


/**
 * Convert a RISC OS pathname to a file: URL.
 *
 * \param  path  RISC OS pathname
 * \return  URL, allocated on heap, or 0 on failure
 */

char *path_to_url(const char *path)
{
	int spare;
	char *buffer = 0;
	char *url = 0;
	os_error *error;

	error = xosfscontrol_canonicalise_path(path, 0, 0, 0, 0, &spare);
	if (error) {
		LOG(("xosfscontrol_canonicalise_path failed: 0x%x: %s",
				error->errnum, error->errmess));
		warn_user("PathToURL", error->errmess);
		return 0;
	}

	buffer = malloc(1 - spare);
	url = malloc(1 - spare + 10);
	if (!buffer || !url) {
		LOG(("malloc failed"));
		warn_user("NoMemory", 0);
		free(buffer);
		free(url);
		return 0;
	}

	error = xosfscontrol_canonicalise_path(path, buffer, 0, 0, 1 - spare,
			0);
	if (error) {
		LOG(("xosfscontrol_canonicalise_path failed: 0x%x: %s",
				error->errnum, error->errmess));
		warn_user("PathToURL", error->errmess);
		free(buffer);
		free(url);
		return 0;
	}

	strcpy(url, "file://");
	__unixify(buffer, __RISCOSIFY_NO_REVERSE_SUFFIX, url + 7,
			1 - spare + 3 /* 10 - "file://" */, 0);
	free(buffer);
	return url;
}


/**
 * Convert a file: URL to a RISC OS pathname.
 *
 * \param  url  a file: URL
 * \return  RISC OS pathname, allocated on heap, or 0 on failure
 */

char *url_to_path(const char *url)
{
	char *temp_name, *r;
	char *filename;

	if (strncmp(url, "file:///", 8))
		return NULL;

	temp_name = curl_unescape(url + 7, strlen(url) - 7);

	if (!temp_name) {
		warn_user("NoMemory", 0);
		return NULL;
	}

	filename = malloc(strlen(temp_name) + 100);
	if (!filename) {
		curl_free(temp_name);
		warn_user("NoMemory", 0);
		return NULL;
	}
	r = __riscosify(temp_name, 0, __RISCOSIFY_NO_SUFFIX,
			filename, strlen(temp_name) + 100, 0);
	if (r == 0) {
		LOG(("__riscosify failed"));
		return NULL;
	}
	curl_free(temp_name);
	return filename;
}


/**
 * Get screen properties following a mode change.
 */

void ro_gui_get_screen_properties(void)
{
	const os_VDU_VAR_LIST(5) vars = {
		{ os_MODEVAR_XWIND_LIMIT,
		os_MODEVAR_YWIND_LIMIT,
		os_MODEVAR_XEIG_FACTOR,
		os_MODEVAR_YEIG_FACTOR,
		os_VDUVAR_END_LIST }
	};
	os_error *error;
	int vals[4];

	error = xos_read_vdu_variables((const os_vdu_var_list*)&vars, vals);
	if (error) {
		LOG(("xos_read_vdu_variables: 0x%x: %s",
			error->errnum, error->errmess));
		warn_user("MiscError", error->errmess);
		return;
	}
	screen_info.width  = (vals[0] + 1) << vals[2];
	screen_info.height = (vals[1] + 1) << vals[3];
}


/**
 * Find screen size in OS units.
 */

void ro_gui_screen_size(int *width, int *height)
{
	*width = screen_info.width;
	*height = screen_info.height;
}


/**
 * Opens a language sensitive help page
 *
 * \param page  the page to open
 */
void ro_gui_open_help_page(const char *page)
{
	char url[80];
	int length;

	if ((length = snprintf(url, sizeof url,
			"file:///<NetSurf$Dir>/Docs/%s_%s",
			page, option_language)) >= 0 && length < (int)sizeof(url))
		browser_window_create(url, NULL, 0, true);
}

/**
 * Send the source of a content to a text editor.
 */

void ro_gui_view_source(struct content *content)
{
	os_error *error;
	char full_name[256];
	char *temp_name, *r;
	wimp_full_message_data_xfer message;
	int objtype;
	bool done = false;

	if (!content || !content->source_data) {
		warn_user("MiscError", "No document source");
		return;
	}

	/* try to load local files directly. */
	temp_name = url_to_path(content->url);
	if (temp_name) {
		error = xosfile_read_no_path(temp_name, &objtype, 0, 0, 0, 0);
		if ((!error) && (objtype == osfile_IS_FILE)) {
			snprintf(message.file_name, 212, "%s", temp_name);
			message.file_name[211] = '\0';
			done = true;
		}
		free(temp_name);
	}
	if (!done) {
		/* We cannot release the requested filename until after it
		 * has finished being used. As we can't easily find out when
		 * this is, we simply don't bother releasing it and simply
		 * allow it to be re-used next time NetSurf is started. The
		 * memory overhead from doing this is under 1 byte per
		 * filename. */
		const char *filename = filename_request();
		if (!filename) {
			warn_user("NoMemory", 0);
			return;
		}
		snprintf(full_name, 256, "%s/%s", TEMP_FILENAME_PREFIX,
				filename);
		full_name[255] = '\0';
		r = __riscosify(full_name, 0, __RISCOSIFY_NO_SUFFIX,
				message.file_name, 212, 0);
		if (r == 0) {
			LOG(("__riscosify failed"));
			return;
		}
		message.file_name[211] = '\0';
		error = xosfile_save_stamped(message.file_name,
				ro_content_filetype(content),
				content->source_data,
				content->source_data + content->source_size);
		if (error) {
			LOG(("xosfile_save_stamped failed: 0x%x: %s",
					error->errnum, error->errmess));
			warn_user("MiscError", error->errmess);
			return;
		}
	}

	/* begin the DataOpen protocol */
	message.your_ref = 0;
	message.size = 44 + ((strlen(message.file_name) + 4) & (~3u));
	message.action = message_DATA_OPEN;
	message.w = 0;
	message.i = 0;
	message.pos.x = 0;
	message.pos.y = 0;
	message.est_size = 0;
	message.file_type = 0xfff;
	ro_message_send_message(wimp_USER_MESSAGE_RECORDED,
			(wimp_message*)&message, 0,
			ro_gui_view_source_bounce);
}


void ro_gui_view_source_bounce(wimp_message *message) {
	char *filename;
	os_error *error;
	char command[256];

	/* run the file as text */
	filename = ((wimp_full_message_data_xfer *)message)->file_name;
	sprintf(command, "@RunType_FFF %s", filename);
	error = xwimp_start_task(command, 0);
	if (error) {
		LOG(("xwimp_start_task failed: 0x%x: %s",
					error->errnum, error->errmess));
		warn_user("WimpError", error->errmess);
	}
}


/**
 * Broadcast an URL that we can't handle.
 */

void gui_launch_url(const char *url)
{
#ifdef WITH_URL
	/* Try ant broadcast first */
	ro_url_broadcast(url);
#endif
}


/**
 * Display a warning for a serious problem (eg memory exhaustion).
 *
 * \param  warning  message key for warning message
 * \param  detail   additional message, or 0
 */

void warn_user(const char *warning, const char *detail)
{
	LOG(("%s %s", warning, detail));

	if (dialog_warning) {
		char warn_buffer[300];
		snprintf(warn_buffer, sizeof warn_buffer, "%s %s",
				messages_get(warning),
				detail ? detail : "");
		warn_buffer[sizeof warn_buffer - 1] = 0;
		ro_gui_set_icon_string(dialog_warning, ICON_WARNING_MESSAGE,
				warn_buffer);
		xwimp_set_icon_state(dialog_warning, ICON_WARNING_HELP,
				wimp_ICON_DELETED, wimp_ICON_DELETED);
		ro_gui_dialog_open(dialog_warning);
		xos_bell();
	}
	else {
		/* probably haven't initialised (properly), use a
		   non-multitasking error box */
		os_error error;
		snprintf(error.errmess, sizeof error.errmess, "%s %s",
				messages_get(warning),
				detail ? detail : "");
		error.errmess[sizeof error.errmess - 1] = 0;
		xwimp_report_error_by_category(&error,
				wimp_ERROR_BOX_OK_ICON |
				wimp_ERROR_BOX_GIVEN_CATEGORY |
				wimp_ERROR_BOX_CATEGORY_ERROR <<
					wimp_ERROR_BOX_CATEGORY_SHIFT,
				"NetSurf", "!netsurf",
				(osspriteop_area *) 1, 0, 0);
	}
}


/**
 * Display an error and exit.
 *
 * Should only be used during initialisation.
 */

void die(const char *error)
{
	os_error warn_error;

	warn_error.errnum = 1; /* \todo: reasonable ? */
	strncpy(warn_error.errmess, messages_get(error),
			sizeof(warn_error.errmess)-1);
	warn_error.errmess[sizeof(warn_error.errmess)-1] = '\0';
	xwimp_report_error_by_category(&warn_error,
			wimp_ERROR_BOX_OK_ICON |
			wimp_ERROR_BOX_GIVEN_CATEGORY |
			wimp_ERROR_BOX_CATEGORY_ERROR <<
				wimp_ERROR_BOX_CATEGORY_SHIFT,
			"NetSurf", "!netsurf",
			(osspriteop_area *) 1, 0, 0);
	exit(EXIT_FAILURE);
}


/**
 * Test whether it's okay to shutdown, prompting the user if not.
 *
 * \return true iff it's okay to shutdown immediately
 */

bool ro_gui_prequit(void)
{
	return ro_gui_download_prequit();
}