netsurf/riscos/help.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 2004 Richard Wilson <not_ginger_matt@users.sourceforge.net>
 */

/** \file
 * Interactive help (implementation).
 */

#include <assert.h>
#include <stdio.h>
#include <string.h>
#include "oslib/help.h"
#include "oslib/os.h"
#include "oslib/taskmanager.h"
#include "oslib/wimp.h"
#include "netsurf/riscos/gui.h"
#include "netsurf/riscos/help.h"
#include "netsurf/riscos/toolbar.h"
#include "netsurf/riscos/wimp.h"
#include "netsurf/utils/messages.h"
#include "netsurf/utils/log.h"


/*	Recognised help keys
	====================

	HelpIconbar	 Iconbar (no icon suffix is used)

	HelpAppInfo	 Application info window
	HelpBrowser	 Browser window [*]
	HelpHistory	 History window [*]
	HelpObjInfo	 Object info window
	HelpPageInfo	 Page info window
	HelpSaveAs	 Save as window
	HelpScaleView	 Scale view window
	HelpStatus	 Status window
	HelpToolbar	 Toolbar window
	HelpHotlist	 Hotlist window [*]
	HelpHotToolbar	 Hotlist window toolbar
	HelpHotEntry	 Hotlist entry window
	HelpHotFolder	 Hotlist entry window

	HelpIconMenu	 Iconbar menu
	HelpBrowserMenu  Browser window menu
	HelpHotlistMenu  Hotlist window menu

	The prefixes are followed by either the icon number (eg 'HelpToolbar7'), or a series
	of numbers representing the menu structure (eg 'HelpBrowserMenu3-1-2').
	If '<key><identifier>' is not available, then simply '<key>' is then used. For example
	if 'HelpToolbar7' is not available then 'HelpToolbar' is then tried.
	
	If an item is greyed out then a suffix of 'g' is added (eg 'HelpToolbar7g'). For this to
	work, windows must have bit 4 of the window flag byte set and the user must be running
	RISC OS 5.03 or greater.

	For items marked with an asterisk [*] a call must be made to determine the required
	help text as the window does not contain any icons. An example of this is the hotlist
	window where ro_gui_hotlist_help() is called.
*/

static void ro_gui_interactive_help_broadcast(wimp_message *message, char *token);
static os_t help_time = 0;

/**
 * Attempts to process an interactive help message request
 *
 * \param  message the request message
 */
void ro_gui_interactive_help_request(wimp_message *message) {
	char message_token[32];
	char menu_buffer[4];
	wimp_selection menu_tree;
	help_full_message_request *message_data;
	wimp_w window;
	wimp_i icon;
	struct gui_window *g;
	unsigned int index;
	bool greyed = false;
	wimp_menu *test_menu;

	/*	Ensure we have a help request
	*/
	if ((!message) || (message->action != message_HELP_REQUEST)) return;

	/*	Remember the time of the request
	*/
	xos_read_monotonic_time(&help_time);

	/*	Initialise the basic token to a null byte
	*/
	message_token[0] = 0x00;

	/*	Get the message data
	*/
	message_data = (help_full_message_request *)message;
	window = message_data->w;
	icon = message_data->i;

	/*	Do the basic window checks
	*/
	if (window == (wimp_w)-2) {
		sprintf(message_token, "HelpIconbar");
	} else if (window == dialog_info) {
		sprintf(message_token, "HelpAppInfo%i", (int)icon);
	} else if (window == history_window) {
		sprintf(message_token, "HelpHistory%i", (int)icon);
	} else if (window == dialog_objinfo) {
		sprintf(message_token, "HelpObjInfo%i", (int)icon);
	} else if (window == dialog_pageinfo) {
		sprintf(message_token, "HelpPageInfo%i", (int)icon);
	} else if (window == dialog_saveas) {
		sprintf(message_token, "HelpSaveAs%i", (int)icon);
	} else if (window == dialog_zoom) {
		sprintf(message_token, "HelpScaleView%i", (int)icon);
	} else if (window == dialog_folder) {
		sprintf(message_token, "HelpHotFolder%i", (int)icon);
	} else if (window == dialog_entry) {
		sprintf(message_token, "HelpHotEntry%i", (int)icon);
	} else if (window == hotlist_window) {
		sprintf(message_token, "HelpHotlist%i",
				ro_gui_hotlist_help(message_data->pos.x,
						message_data->pos.y));
	} else if (hotlist_toolbar &&
			window == hotlist_toolbar->toolbar_handle) {
		sprintf(message_token, "HelpHotToolbar%i", (int)icon);
	} else if ((g = ro_gui_window_lookup(window))) {
		sprintf(message_token, "HelpBrowser%i", (int)icon);
	} else if ((g = ro_gui_toolbar_lookup(window))) {
		sprintf(message_token, "HelpToolbar%i", (int)icon);
	} else if ((g = ro_gui_status_lookup(window))) {
		sprintf(message_token, "HelpStatus%i", (int)icon);
	}

	/*	If we've managed to find something so far then we broadcast it
	*/
	if (message_token[0] != 0x00) {
		/*	Check to see if we are greyed out
		*/
		if ((icon >= 0) && (ro_gui_get_icon_shaded_state(window, icon))) {
			strcat(message_token, "g");
		}
		
		/*	Broadcast out message
		*/
		ro_gui_interactive_help_broadcast(message, &message_token[0]);
		return;
	}

	/*	If we are not on an icon, we can't be in a menu (which stops separators
		giving help for their parent) so we abort. You don't even want to think
		about the awful hack I was considering before I realised this...
	*/
	if (icon == (wimp_i)-1) return;

	/*	As a last resort, check for menu help.
	*/
	if (xwimp_get_menu_state((wimp_menu_state_flags)1,
				&menu_tree,
				window, icon)) return;
	if (menu_tree.items[0] == -1) return;

	/*	Set the prefix
	*/
	if (current_menu == iconbar_menu) {
		sprintf(message_token, "HelpIconMenu");
	} else if (current_menu == browser_menu) {
		sprintf(message_token, "HelpBrowserMenu");
	} else if (current_menu == hotlist_menu) {
		sprintf(message_token, "HelpHotlistMenu");
	} else {
		return;
	}

	/*	Decode the menu
	*/
	index = 0;
	test_menu = current_menu;
	while (menu_tree.items[index] != -1) {
		/*	Check if we're greyed out
		*/
		greyed |= test_menu->entries[menu_tree.items[index]].icon_flags & wimp_ICON_SHADED;
		test_menu = test_menu->entries[menu_tree.items[index]].sub_menu;
	  	
		/*	Continue adding the entries
		*/
		if (index == 0) {
			sprintf(menu_buffer, "%i", menu_tree.items[index]);
		} else {
			sprintf(menu_buffer, "-%i", menu_tree.items[index]);
		}
		strcat(message_token, menu_buffer);
		index++;
	}
	if (greyed) strcat(message_token, "g");

	/*	Finally, broadcast the menu help
	*/
	ro_gui_interactive_help_broadcast(message, &message_token[0]);
}


/**
 * Broadcasts a help reply
 *
 * \param  message the original request message
 * \param  token the token to look up
 */
static void ro_gui_interactive_help_broadcast(wimp_message *message, char *token) {
	const char *translated_token;
	help_full_message_reply *reply;
	char *base_token;

	/*	Start off with an empty reply
	*/
	reply = (help_full_message_reply *)message;
	reply->reply[0] = '\0';

	/*	Check if the message exists
	*/
	translated_token = messages_get(token);
	if (translated_token == token) {
		/*	We must never provide default help for a 'g' suffix.
		*/
		if (token[strlen(token) - 1] != 'g') {
			/*	Find the key from the token.
			*/
			base_token = token;
			while (base_token[0] != 0x00) {
				if ((base_token[0] == '-') ||
						((base_token[0] >= '0') && (base_token[0] <= '9'))) {	
					base_token[0] = 0x00;
				} else {
					++base_token;
				}
			}

			/*	Check if the base key exists and use an empty string if not
			*/
			translated_token = messages_get(token);
		}
	}
	

	/*	Copy our message string
	*/
	if (translated_token != token) {
		reply->reply[235] = 0;
		strncpy(reply->reply, translated_token, 235);
	}

	/*	Broadcast the help reply
	*/
	reply->size = 256;
	reply->action = message_HELP_REPLY;
	reply->your_ref = reply->my_ref;
	wimp_send_message(wimp_USER_MESSAGE, (wimp_message *)reply, reply->sender);
}


/**
 * Checks if interactive help is running
 *
 * \return non-zero if interactive help is available, or 0 if not available
 */
int ro_gui_interactive_help_available() {
	taskmanager_task task;
	int context = 0;
	char *end;
	os_t time;

	/*	Check if we've received a help request in the last 0.5s to test for generic
		interactive help applications
	*/
	xos_read_monotonic_time(&time);
	if ((help_time + 50) > time) return true;

	/*	Attempt to find the task 'Help'
	*/
	do {
		if (xtaskmanager_enumerate_tasks(context, &task, sizeof(taskmanager_task),
					&context, &end)) return 0;

		/*	We can't just use strcmp due to string termination issues.
		*/
		if (strncmp(task.name, "Help", 4) == 0) {
			if (task.name[4] < 32) return true;
		}
	} while (context >= 0);

	/*	Return failure
	*/
	return 0;
}