r1283: Added a whole load of 'const' modifiers so we can do extra checking...

[rox-filer.git] / ROX-Filer / src / options.c

/*
 * $Id$
 *
 * ROX-Filer, filer for the ROX desktop project
 * Copyright (C) 2002, Thomas Leonard, <tal197@users.sourceforge.net>.
 *
 * This program 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; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* options.c - code for handling user choices */

/* How it works:
 *
 * On startup:
 *
 * - The <Choices>/PROJECT/Options file is read in. Each line
 *   is a name/value pair, and these are stored in the 'loading' hash table.
 *
 * - Each part of the filer then calls option_add_int(), or a related function,
 *   supplying the name for each option and a default value. Once an option is
 *   registered, it is removed from the loading table.
 *
 * - If things need to happen when values change, modules register with
 *   option_add_notify().
 *
 * - option_register_widget() can be used during initialisation (any time
 *   before the Options box is displayed) to tell the system how to render a
 *   particular type of option.
 *
 * - Finally, all notify callbacks are called. Use the Option->has_changed
 *   field to work out what has changed from the defaults.
 *
 * When the user opens the Options box:
 *
 * - The Options.xml file is read and used to create the Options dialog box.
 *   Each element in the file has a key corresponding to an option named
 *   above.
 *
 * - For each widget in the box, the current value of the option is used to
 *   set the widget's state.
 *
 * - All current values are saved for a possible Revert later.
 *
 * When the user changes an option or clicks on Revert:
 *
 * - The option values are updated.
 *
 * - All notify callbacks are called. Use the Option->has_changed field
 *   to see what changed.
 *
 * When Save is clicked:
 *
 * - All the options are written to the filesystem and the saver_callbacks are
 *   called.
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <gtk/gtk.h>
#include <libxml/parser.h>

#include "global.h"

#include "choices.h"
#include "options.h"
#include "main.h"
#include "gui_support.h"

/* Add all option tooltips to this group */
static GtkTooltips *option_tooltips = NULL;
#define OPTION_TIP(widget, tip) \
        gtk_tooltips_set_tip(option_tooltips, widget, tip, NULL)

/* The Options window. NULL if not yet created. */
static GtkWidget *window = NULL;

/* "filer_unique" -> (Option *) */
static GHashTable *option_hash = NULL;

/* A mapping (name -> value) for options which have been loaded by not
 * yet registered. The options in this table cannot be used until
 * option_add_*() is called to move them into option_hash.
 */
static GHashTable *loading = NULL;

/* A mapping (XML name -> OptionBuildFn). When reading the Options.xml
 * file, this table gives the function used to create the widgets.
 */
static GHashTable *widget_builder = NULL;

/* List of functions to call after all option values are updated */
static GList *notify_callbacks = NULL;

/* List of functions to call after all options are saved */
static GList *saver_callbacks = NULL;

static int updating_widgets = 0;        /* Ignore change signals when set */

/* Static prototypes */
static void save_options(gpointer unused);
static void revert_options(GtkWidget *widget, gpointer data);
static void build_options_window(void);
static GtkWidget *build_frame(void);
static void update_option_widgets(void);
static void button_patch_set_colour(GtkWidget *button, GdkColor *color);
static void option_add(Option *option, const gchar *key);
static void set_not_changed(gpointer key, gpointer value, gpointer data);
static void load_options(xmlDoc *doc);

static const char *process_option_line(gchar *line);

static GList *build_toggle(Option *option, xmlNode *node, guchar *label);
static GList *build_slider(Option *option, xmlNode *node, guchar *label);
static GList *build_entry(Option *option, xmlNode *node, guchar *label);
static GList *build_radio_group(Option *option, xmlNode *node, guchar *label);
static GList *build_colour(Option *option, xmlNode *node, guchar *label);
static GList *build_menu(Option *option, xmlNode *node, guchar *label);
static GList *build_font(Option *option, xmlNode *node, guchar *label);

static gboolean updating_file_format = FALSE;

/****************************************************************
 *                      EXTERNAL INTERFACE                      *
 ****************************************************************/

void options_init(void)
{
        char    *path;
        xmlDoc  *doc;

        loading = g_hash_table_new(g_str_hash, g_str_equal);
        option_hash = g_hash_table_new(g_str_hash, g_str_equal);
        widget_builder = g_hash_table_new(g_str_hash, g_str_equal);

        path = choices_find_path_load("Options", PROJECT);
        if (path)
        {
                /* Load in all the options set in the filer, storing them
                 * temporarily in the loading hash table.
                 * They get moved to option_hash when they're registered.
                 */
                doc = xmlParseFile(path);
                if (doc)
                {
                        load_options(doc);
                        xmlFreeDoc(doc);
                }
                else
                {
                        parse_file(path, process_option_line);
                        updating_file_format = TRUE;
                }

                g_free(path);
        }

        option_register_widget("toggle", build_toggle);
        option_register_widget("slider", build_slider);
        option_register_widget("entry", build_entry);
        option_register_widget("radio-group", build_radio_group);
        option_register_widget("colour", build_colour);
        option_register_widget("menu", build_menu);
        option_register_widget("font", build_font);
}

/* When parsing the XML file, process an element named 'name' by
 * calling 'builder(option, xml_node, label)'.
 * builder returns the new widgets to add to the options box.
 * 'name' should be a static string. Call 'option_check_widget' when
 * the widget's value is modified.
 *
 * Functions to set or get the widget's state can be stored in 'option'.
 * If the option doesn't have a name attribute in Options.xml then
 * ui will be NULL on entry (this is used for buttons).
 */
void option_register_widget(char *name, OptionBuildFn builder)
{
        g_hash_table_insert(widget_builder, name, builder);
}

/* This is called when the widget's value is modified by the user.
 * Reads the new value of the widget into the option and calls
 * the notify callbacks.
 */
void option_check_widget(Option *option)
{
        guchar          *new = NULL;

        if (updating_widgets)
                return;         /* Not caused by the user... */

        g_return_if_fail(option->read_widget != NULL);

        new = option->read_widget(option);

        g_return_if_fail(new != NULL);

        g_hash_table_foreach(option_hash, set_not_changed, NULL);

        option->has_changed = strcmp(option->value, new) != 0;

        if (!option->has_changed)
        {
                g_free(new);
                return;
        }

        g_free(option->value);
        option->value = new;
        option->int_value = atoi(new);

        options_notify();
}

/* Call all the notify callbacks. This should happen after any options
 * have their values changed. Set each has_changed before calling.
 */
void options_notify(void)
{
        GList   *next;

        for (next = notify_callbacks; next; next = next->next)
        {
                OptionNotify *cb = (OptionNotify *) next->data;

                cb();
        }

        if (updating_file_format)
        {
                updating_file_format = FALSE;
                save_options(NULL);
                report_error(_("ROX-Filer has converted your Options file "
                                "to the new XML format"));
        }
}

/* Store values used by Revert */
static void store_backup(gpointer key, gpointer value, gpointer data)
{
        Option *option = (Option *) value;

        g_free(option->backup);
        option->backup = g_strdup(option->value);
}

/* Allow the user to edit the options. Returns the window widget (you don't
 * normally need this). NULL if already open.
 */
GtkWidget *options_show(void)
{
        if (!option_tooltips)
                option_tooltips = gtk_tooltips_new();

        if (g_hash_table_size(loading) != 0)
        {
                g_printerr(PROJECT ": Some options loaded but not used:\n");
                g_hash_table_foreach(loading, (GHFunc) puts, NULL);
        }

        if (window)
        {
                gtk_window_present(GTK_WINDOW(window));
                return NULL;
        }

        g_hash_table_foreach(option_hash, store_backup, NULL);
                        
        build_options_window();

        update_option_widgets();
        
        gtk_widget_show_all(window);

        return window;
}

/* Initialise and register a new integer option */
void option_add_int(Option *option, const gchar *key, int value)
{
        option->value = g_strdup_printf("%d", value);
        option->int_value = value;
        option_add(option, key);
}

void option_add_string(Option *option, const gchar *key, const gchar *value)
{
        option->value = g_strdup(value);
        option->int_value = atoi(value);
        option_add(option, key);
}

/* Add a callback which will be called after any options have changed their
 * values. If serveral options change at once, this is called after all
 * changes.
 */
void option_add_notify(OptionNotify *callback)
{
        g_return_if_fail(callback != NULL);

        notify_callbacks = g_list_append(notify_callbacks, callback);
}

/* Call 'callback' after all the options have been saved */
void option_add_saver(OptionNotify *callback)
{
        g_return_if_fail(callback != NULL);

        saver_callbacks = g_list_append(saver_callbacks, callback);
}

/****************************************************************
 *                      INTERNAL FUNCTIONS                      *
 ****************************************************************/

/* Option should contain the default value.
 * It must never be destroyed after being registered (Options are typically
 * statically allocated).
 * The key corresponds to the option's name in Options.xml, and to the key
 * in the saved options file.
 *
 * On exit, the value will have been updated to the loaded value, if
 * different to the default.
 */
static void option_add(Option *option, const gchar *key)
{
        gpointer okey, value;

        g_return_if_fail(option_hash != NULL);
        g_return_if_fail(g_hash_table_lookup(option_hash, key) == NULL);
        g_return_if_fail(option->value != NULL);
        
        option->has_changed = FALSE;

        option->widget = NULL;
        option->update_widget = NULL;
        option->read_widget = NULL;
        option->backup = NULL;

        g_hash_table_insert(option_hash, (gchar *) key, option);

        /* Use the value loaded from the file, if any */
        if (g_hash_table_lookup_extended(loading, key, &okey, &value))
        {
                option->has_changed = strcmp(option->value, value) != 0;
                        
                g_free(option->value);
                option->value = value;
                option->int_value = atoi(value);
                g_hash_table_remove(loading, key);
                g_free(okey);
        }
}

static GtkColorSelectionDialog *current_csel_box = NULL;
static GtkFontSelectionDialog *current_fontsel_box = NULL;

static void get_new_colour(GtkWidget *ok, Option *option)
{
        GtkWidget       *csel;
        gdouble         c[4];
        GdkColor        colour;

        g_return_if_fail(current_csel_box != NULL);

        csel = current_csel_box->colorsel;

        gtk_color_selection_get_color(GTK_COLOR_SELECTION(csel), c);
        colour.red = c[0] * 0xffff;
        colour.green = c[1] * 0xffff;
        colour.blue = c[2] * 0xffff;

        button_patch_set_colour(option->widget, &colour);
        
        gtk_widget_destroy(GTK_WIDGET(current_csel_box));

        option_check_widget(option);
}

static void set_to_null(gpointer *data)
{
        *data = NULL;
}

static void open_coloursel(GtkWidget *button, Option *option)
{
        GtkColorSelectionDialog *csel;
        GtkWidget               *dialog, *patch;
        gdouble                 c[4];

        if (current_csel_box)
                gtk_widget_destroy(GTK_WIDGET(current_csel_box));

        dialog = gtk_color_selection_dialog_new(NULL);
        csel = GTK_COLOR_SELECTION_DIALOG(dialog);
        current_csel_box = csel;
        gtk_window_set_position(GTK_WINDOW(csel), GTK_WIN_POS_MOUSE);

        gtk_signal_connect_object(GTK_OBJECT(dialog), "destroy",
                        GTK_SIGNAL_FUNC(set_to_null),
                        (GtkObject *) &current_csel_box);
        gtk_widget_hide(csel->help_button);
        gtk_signal_connect_object(GTK_OBJECT(csel->cancel_button), "clicked",
                        GTK_SIGNAL_FUNC(gtk_widget_destroy),
                        GTK_OBJECT(dialog));
        gtk_signal_connect(GTK_OBJECT(csel->ok_button), "clicked",
                        GTK_SIGNAL_FUNC(get_new_colour), option);

        patch = GTK_BIN(button)->child;

        c[0] = ((gdouble) patch->style->bg[GTK_STATE_NORMAL].red) / 0xffff;
        c[1] = ((gdouble) patch->style->bg[GTK_STATE_NORMAL].green) / 0xffff;
        c[2] = ((gdouble) patch->style->bg[GTK_STATE_NORMAL].blue) / 0xffff;
        gtk_color_selection_set_color(GTK_COLOR_SELECTION(csel->colorsel), c);

        gtk_widget_show(dialog);
}

static void font_chosen(GtkWidget *dialog, gint response, Option *option)
{
        gchar *font;

        if (response != GTK_RESPONSE_OK)
                goto out;

        font = gtk_font_selection_dialog_get_font_name(
                                        GTK_FONT_SELECTION_DIALOG(dialog));

        gtk_label_set_text(GTK_LABEL(option->widget), font);

        g_free(font);

        option_check_widget(option);

out:
        gtk_widget_destroy(dialog);

}

static void open_fontsel(GtkWidget *button, Option *option)
{
        if (current_fontsel_box)
                gtk_widget_destroy(GTK_WIDGET(current_fontsel_box));

        current_fontsel_box = GTK_FONT_SELECTION_DIALOG(
                                gtk_font_selection_dialog_new(PROJECT));

        gtk_window_set_position(GTK_WINDOW(current_fontsel_box),
                                GTK_WIN_POS_MOUSE);

        gtk_signal_connect_object(GTK_OBJECT(current_fontsel_box), "destroy",
                        GTK_SIGNAL_FUNC(set_to_null),
                        (GtkObject *) &current_fontsel_box);

        gtk_font_selection_dialog_set_font_name(current_fontsel_box,
                                                option->value);

        gtk_signal_connect(GTK_OBJECT(current_fontsel_box), "response",
                        GTK_SIGNAL_FUNC(font_chosen), option);

        gtk_widget_show(GTK_WIDGET(current_fontsel_box));
}

/* These are used during parsing... */
static xmlDocPtr options_doc = NULL;

#define DATA(node) (xmlNodeListGetString(options_doc, node->xmlChildrenNode, 1))

static void may_add_tip(GtkWidget *widget, xmlNode *element)
{
        guchar  *data, *tip;

        data = DATA(element);
        if (!data)
                return;

        tip = g_strstrip(g_strdup(data));
        g_free(data);
        if (*tip)
                OPTION_TIP(widget, _(tip));
        g_free(tip);
}

static int get_int(xmlNode *node, guchar *attr)
{
        guchar *txt;
        int     retval;

        txt = xmlGetProp(node, attr);
        if (!txt)
                return 0;

        retval = atoi(txt);
        g_free(txt);

        return retval;
}

static GtkWidget *build_radio(xmlNode *radio, GtkWidget *prev)
{
        GtkWidget       *button;
        GtkRadioButton  *prev_button = (GtkRadioButton *) prev;
        guchar          *label;

        label = xmlGetProp(radio, "label");

        button = gtk_radio_button_new_with_label(
                        prev_button ? gtk_radio_button_group(prev_button)
                                    : NULL,
                        _(label));
        g_free(label);

        may_add_tip(button, radio);

        gtk_object_set_data(GTK_OBJECT(button), "value",
                        xmlGetProp(radio, "value"));

        return button;
}

static void build_menu_item(xmlNode *node, GtkWidget *option_menu)
{
        GtkWidget       *item, *menu;
        guchar          *label;

        g_return_if_fail(strcmp(node->name, "item") == 0);

        label = xmlGetProp(node, "label");
        item = gtk_menu_item_new_with_label(_(label));
        g_free(label);

        menu = gtk_option_menu_get_menu(GTK_OPTION_MENU(option_menu));
        gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);
        gtk_widget_show_all(menu);

        gtk_object_set_data(GTK_OBJECT(item),
                                "value", xmlGetProp(node, "value"));
}

static void build_widget(xmlNode *widget, GtkWidget *box)
{
        const char *name = widget->name;
        OptionBuildFn builder;
        guchar  *oname;
        Option  *option;
        guchar  *label;

        if (strcmp(name, "label") == 0)
        {
                GtkWidget *label;
                guchar *text;

                text = DATA(widget);
                label = gtk_label_new(_(text));
                g_free(text);

                gtk_misc_set_alignment(GTK_MISC(label), 0, 1);
                gtk_label_set_justify(GTK_LABEL(label), GTK_JUSTIFY_LEFT);
                gtk_label_set_line_wrap(GTK_LABEL(label), TRUE);
                gtk_box_pack_start(GTK_BOX(box), label, FALSE, TRUE, 0);
                return;
        }
        else if (strcmp(name, "spacer") == 0)
        {
                GtkWidget *eb;

                eb = gtk_event_box_new();
                gtk_widget_set_usize(eb, 12, 12);
                gtk_box_pack_start(GTK_BOX(box), eb, FALSE, TRUE, 0);
                return;
        }

        label = xmlGetProp(widget, "label");

        if (strcmp(name, "hbox") == 0 || strcmp(name, "vbox") == 0)
        {
                GtkWidget *nbox;
                xmlNode   *hw;

                if (name[0] == 'h')
                        nbox = gtk_hbox_new(FALSE, 4);
                else
                        nbox = gtk_vbox_new(FALSE, 4);

                if (label)
                        gtk_box_pack_start(GTK_BOX(nbox),
                                gtk_label_new(_(label)), FALSE, TRUE, 4);
                gtk_box_pack_start(GTK_BOX(box), nbox, FALSE, TRUE, 0);

                for (hw = widget->xmlChildrenNode; hw; hw = hw->next)
                {
                        if (hw->type == XML_ELEMENT_NODE)
                                build_widget(hw, nbox);
                }

                g_free(label);
                return;
        }

        oname = xmlGetProp(widget, "name");

        if (oname)
        {
                option = g_hash_table_lookup(option_hash, oname);

                if (!option)
                {
                        g_warning("No Option for '%s'!\n", oname);
                        g_free(oname);
                        return;
                }

                g_free(oname);
        }
        else
                option = NULL;

        builder = g_hash_table_lookup(widget_builder, name);
        if (builder)
        {
                GList *widgets, *next;

                if (option && option->widget)
                        g_warning("Widget for option already exists!");

                widgets = builder(option, widget, label);

                for (next = widgets; next; next = next->next)
                {
                        GtkWidget *w = (GtkWidget *) next->data;
                        gtk_box_pack_start(GTK_BOX(box), w, FALSE, TRUE, 0);
                }
                g_list_free(widgets);
        }
        else
                g_warning("Unknown option type '%s'\n", name);

        g_free(label);
}

static void build_sections(xmlNode *options, GtkWidget *sections_box)
{
        xmlNode *section = options->xmlChildrenNode;

        g_return_if_fail(strcmp(options->name, "options") == 0);

        for (; section; section = section->next)
        {
                guchar          *title;
                GtkWidget       *page, *scrolled_area;
                xmlNode         *widget;

                if (section->type != XML_ELEMENT_NODE)
                        continue;

                title = xmlGetProp(section, "title");
                page = gtk_vbox_new(FALSE, 0);
                gtk_container_set_border_width(GTK_CONTAINER(page), 4);

                scrolled_area = gtk_scrolled_window_new(NULL, NULL);
                gtk_scrolled_window_set_policy(
                                        GTK_SCROLLED_WINDOW(scrolled_area),
                                        GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);

                gtk_scrolled_window_add_with_viewport(
                                        GTK_SCROLLED_WINDOW(scrolled_area),
                                        page);

                gtk_notebook_append_page(GTK_NOTEBOOK(sections_box),
                                        scrolled_area,
                                        gtk_label_new(_(title)));

                widget = section->xmlChildrenNode;
                for (; widget; widget = widget->next)
                {
                        if (widget->type == XML_ELEMENT_NODE)
                                build_widget(widget, page);
                }

                g_free(title);
        }
}

/* Parse <app_dir>/Options.xml to create the options window.
 * Sets the global 'window' variable.
 */
static void build_options_window(void)
{
        GtkWidget *sections_box;
        xmlDocPtr options_doc;
        gchar     *path;

        sections_box = build_frame();
        
        path = g_strconcat(app_dir, "/Options.xml", NULL);
        options_doc = xmlParseFile(path);

        if (!options_doc)
        {
                report_error("Internal error: %s unreadable", path);
                g_free(path);
                return;
        }

        g_free(path);

        build_sections(xmlDocGetRootElement(options_doc), sections_box);

        xmlFreeDoc(options_doc);
        options_doc = NULL;
}

static void null_widget(gpointer key, gpointer value, gpointer data)
{
        Option  *option = (Option *) value;

        g_return_if_fail(option->widget != NULL);

        option->widget = NULL;
}

static void options_destroyed(GtkWidget *widget, gpointer data)
{
        if (current_csel_box)
                gtk_widget_destroy(GTK_WIDGET(current_csel_box));
        if (current_fontsel_box)
                gtk_widget_destroy(GTK_WIDGET(current_fontsel_box));
        
        if (widget == window)
        {
                window = NULL;

                g_hash_table_foreach(option_hash, null_widget, NULL);
        }
}

/* Creates the window and adds the various buttons to it.
 * Returns the vbox to add sections to and sets the global
 * 'window'.
 */
static GtkWidget *build_frame(void)
{
        GtkWidget       *sections_box;
        GtkWidget       *tl_vbox;
        GtkWidget       *actions, *button;
        char            *string, *save_path;

        window = gtk_window_new(GTK_WINDOW_TOPLEVEL);

        gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
        gtk_window_set_title(GTK_WINDOW(window), _("Options"));
        gtk_signal_connect(GTK_OBJECT(window), "destroy",
                        GTK_SIGNAL_FUNC(options_destroyed), NULL);
        gtk_container_set_border_width(GTK_CONTAINER(window), 4);
        gtk_window_set_default_size(GTK_WINDOW(window), -1, 400);

        tl_vbox = gtk_vbox_new(FALSE, 4);
        gtk_container_add(GTK_CONTAINER(window), tl_vbox);

        sections_box = gtk_notebook_new();
        gtk_notebook_set_scrollable(GTK_NOTEBOOK(sections_box), TRUE);
        gtk_notebook_set_tab_pos(GTK_NOTEBOOK(sections_box), GTK_POS_LEFT);
        gtk_box_pack_start(GTK_BOX(tl_vbox), sections_box, TRUE, TRUE, 0);
        
        actions = gtk_hbutton_box_new();
        gtk_button_box_set_layout(GTK_BUTTON_BOX(actions),
                                  GTK_BUTTONBOX_END);
        gtk_button_box_set_spacing(GTK_BUTTON_BOX(actions), 10);

        save_path = choices_find_path_save("...", PROJECT, FALSE);
        if (save_path)
                gtk_box_pack_start(GTK_BOX(tl_vbox), actions, FALSE, TRUE, 0);
        else
        {
                GtkWidget *hbox;

                hbox = gtk_hbox_new(FALSE, 0);
                gtk_box_pack_start(GTK_BOX(tl_vbox), hbox, FALSE, TRUE, 0);
                gtk_box_pack_start(GTK_BOX(hbox),
                        gtk_label_new(_("(saving disabled by CHOICESPATH)")),
                        FALSE, FALSE, 0);
                gtk_box_pack_start(GTK_BOX(hbox), actions, TRUE, TRUE, 0);
        }
        
        button = button_new_mixed(GTK_STOCK_UNDO, "_Revert");
        GTK_WIDGET_SET_FLAGS(button, GTK_CAN_DEFAULT);
        gtk_box_pack_start(GTK_BOX(actions), button, FALSE, TRUE, 0);
        gtk_signal_connect(GTK_OBJECT(button), "clicked",
                        GTK_SIGNAL_FUNC(revert_options), NULL);
        gtk_tooltips_set_tip(option_tooltips, button,
                        _("Restore all choices to how they were when the "
                          "Options box was opened."), NULL);

        button = button_new_mixed(GTK_STOCK_APPLY, "_OK");
        GTK_WIDGET_SET_FLAGS(button, GTK_CAN_DEFAULT);
        gtk_box_pack_start(GTK_BOX(actions), button, FALSE, TRUE, 0);
        gtk_signal_connect_object(GTK_OBJECT(button), "clicked",
                GTK_SIGNAL_FUNC(gtk_widget_destroy), GTK_OBJECT(window));

        if (save_path)
        {
                button = gtk_button_new_from_stock(GTK_STOCK_SAVE);
                gtk_box_pack_start(GTK_BOX(actions), button, FALSE, TRUE, 0);
                gtk_signal_connect_object(GTK_OBJECT(button), "clicked",
                        GTK_SIGNAL_FUNC(save_options), NULL);

                string = g_strdup_printf(_("Choices will be saved as:\n%s"),
                                        save_path);
                gtk_tooltips_set_tip(option_tooltips, button, string, NULL);
                g_free(save_path);
                g_free(string);
                GTK_WIDGET_SET_FLAGS(button, GTK_CAN_DEFAULT);
                gtk_widget_grab_default(button);
                gtk_widget_grab_focus(button);
        }

        return sections_box;
}

/* Given the last radio button in the group, select whichever
 * radio button matches the given value.
 */
static void radio_group_set_value(GtkRadioButton *last, guchar *value)
{       
        GSList  *next;

        next = gtk_radio_button_group(last);
        while (next)
        {
                GtkToggleButton *button = (GtkToggleButton *) next->data;
                guchar  *val;

                val = gtk_object_get_data(GTK_OBJECT(button), "value");
                g_return_if_fail(val != NULL);

                if (strcmp(val, value) == 0)
                {
                        gtk_toggle_button_set_active(button, TRUE);
                        return;
                }
                
                next = next->next;
        }

        g_warning("Can't find radio button with value %s\n", value);
}

/* Given the last radio button in the group, return a copy of the
 * value for the selected radio item.
 */
static guchar *radio_group_get_value(GtkRadioButton *last)
{
        GSList  *next;

        next = gtk_radio_button_group(last);
        while (next)
        {
                GtkToggleButton *button = (GtkToggleButton *) next->data;

                if (gtk_toggle_button_get_active(button))
                {
                        guchar  *val;

                        val = gtk_object_get_data(GTK_OBJECT(button), "value");
                        g_return_val_if_fail(val != NULL, NULL);

                        return g_strdup(val);
                }
                
                next = next->next;
        }

        return NULL;
}

/* Select this item with this value */
static void option_menu_set(GtkOptionMenu *om, guchar *value)
{
        GtkWidget *menu;
        GList     *list, *next;
        int       i = 0;

        menu = gtk_option_menu_get_menu(om);
        list = gtk_container_children(GTK_CONTAINER(menu));

        for (next = list; next; next = next->next)
        {
                GtkObject       *item = (GtkObject *) next->data;
                guchar          *data;

                data = gtk_object_get_data(item, "value");
                g_return_if_fail(data != NULL);

                if (strcmp(data, value) == 0)
                {
                        gtk_option_menu_set_history(om, i);
                        break;
                }
                
                i++;
        }

        g_list_free(list);
}

/* Get the value (static) of the selected item */
static guchar *option_menu_get(GtkOptionMenu *om)
{
        GtkWidget *menu, *item;

        menu = gtk_option_menu_get_menu(om);
        item = gtk_menu_get_active(GTK_MENU(menu));

        return gtk_object_get_data(GTK_OBJECT(item), "value");
}

static void restore_backup(gpointer key, gpointer value, gpointer data)
{
        Option *option = (Option *) value;

        g_return_if_fail(option->backup != NULL);

        option->has_changed = strcmp(option->value, option->backup) != 0;
        if (!option->has_changed)
                return;

        g_free(option->value);
        option->value = g_strdup(option->backup);
        option->int_value = atoi(option->value);
}

static void revert_options(GtkWidget *widget, gpointer data)
{
        g_hash_table_foreach(option_hash, restore_backup, NULL);
        options_notify();
        update_option_widgets();
}

static void write_option(gpointer key, gpointer value, gpointer data)
{
        xmlNodePtr doc = (xmlNodePtr) data;
        Option *option = (Option *) value;
        xmlNodePtr tree;

        tree = xmlNewTextChild(doc, NULL, "Option", option->value);
        xmlSetProp(tree, "name", (gchar *) key);
}

/* Save doc as XML as filename, 0 on success or -1 on failure */
static int save_xml_file(xmlDocPtr doc, gchar *filename)
{
#if LIBXML_VERSION > 20400
        if (xmlSaveFormatFileEnc(filename, doc, NULL, 1) < 0)
                return 1;
#else
        FILE *out;
        
        out = fopen(filename, "w");
        if (!out)
                return 1;

        xmlDocDump(out, doc);  /* Some versions return void */

        if (fclose(out))
                return 1;
#endif

        return 0;
}

static void save_options(gpointer unused)
{
        xmlDoc  *doc;
        GList   *next;
        guchar  *save, *save_new;

        save = choices_find_path_save("Options", PROJECT, TRUE);
        if (!save)
        {
                report_error(_("Could not save options: %s"),
                                _("Choices saving is disabled by "
                                        "CHOICESPATH variable"));
                return;
        }

        save_new = g_strconcat(save, ".new", NULL);

        doc = xmlNewDoc("1.0");
        xmlDocSetRootElement(doc, xmlNewDocNode(doc, NULL, "Options", NULL));

        g_hash_table_foreach(option_hash, write_option,
                                xmlDocGetRootElement(doc));

        if (save_xml_file(doc, save_new) || rename(save_new, save))
                report_error(_("Error saving %s: %s"), save, g_strerror(errno));

        g_free(save_new);
        g_free(save);
        xmlFreeDoc(doc);

        for (next = saver_callbacks; next; next = next->next)
        {
                OptionNotify *cb = (OptionNotify *) next->data;
                cb();
        }

        if (window)
                gtk_widget_destroy(window);
}

/* Make the widget reflect the current value of the option */
static void update_cb(gpointer key, gpointer value, gpointer data)
{
        Option *option = (Option *) value;

        g_return_if_fail(option != NULL);
        g_return_if_fail(option->widget != NULL);

        updating_widgets++;
        
        if (option->update_widget)
                option->update_widget(option);

        updating_widgets--;
}

/* Reflect the values in the Option structures by changing the widgets
 * in the Options window.
 */
static void update_option_widgets(void)
{
        g_hash_table_foreach(option_hash, update_cb, NULL);
}

/* Each of the following update the widget to make it show the current
 * value of the option.
 */

static void update_toggle(Option *option)
{
        gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(option->widget),
                        option->int_value);
}

static void update_entry(Option *option)
{
        gtk_entry_set_text(GTK_ENTRY(option->widget), option->value);
}

static void update_radio_group(Option *option)
{
        radio_group_set_value(GTK_RADIO_BUTTON(option->widget), option->value);
}

static void update_slider(Option *option)
{
        gtk_adjustment_set_value(
                        gtk_range_get_adjustment(GTK_RANGE(option->widget)),
                        option->int_value);
}

static void update_menu(Option *option)
{
        option_menu_set(GTK_OPTION_MENU(option->widget), option->value);
}

static void update_font(Option *option)
{
        gtk_label_set_text(GTK_LABEL(option->widget), option->value);
}

static void update_colour(Option *option)
{
        GdkColor colour;

        gdk_color_parse(option->value, &colour);
        button_patch_set_colour(option->widget, &colour);
}

/* Each of these read_* calls get the new (string) value of an option
 * from the widget.
 */

static guchar *read_toggle(Option *option)
{
        GtkToggleButton *toggle = GTK_TOGGLE_BUTTON(option->widget);

        return g_strdup_printf("%d", gtk_toggle_button_get_active(toggle));
}

static guchar *read_entry(Option *option)
{
        return gtk_editable_get_chars(GTK_EDITABLE(option->widget), 0, -1);
}

static guchar *read_slider(Option *option)
{
        return g_strdup_printf("%f",
                gtk_range_get_adjustment(GTK_RANGE(option->widget))->value);
}

static guchar *read_radio_group(Option *option)
{
        return radio_group_get_value(GTK_RADIO_BUTTON(option->widget));
}

static guchar *read_menu(Option *option)
{
        return g_strdup(option_menu_get(GTK_OPTION_MENU(option->widget)));
}

static guchar *read_font(Option *option)
{
        return g_strdup(gtk_label_get_text(GTK_LABEL(option->widget)));
}

static guchar *read_colour(Option *option)
{
        GtkStyle *style = GTK_BIN(option->widget)->child->style;

        return g_strdup_printf("#%04x%04x%04x",
                        style->bg[GTK_STATE_NORMAL].red,
                        style->bg[GTK_STATE_NORMAL].green,
                        style->bg[GTK_STATE_NORMAL].blue);
}

static void set_not_changed(gpointer key, gpointer value, gpointer data)
{
        Option  *option = (Option *) value;

        option->has_changed = FALSE;
}

/* These create new widgets in the options window and set the appropriate
 * callbacks.
 */

static GList *build_toggle(Option *option, xmlNode *node, guchar *label)
{
        GtkWidget       *toggle;

        g_return_val_if_fail(option != NULL, NULL);

        toggle = gtk_check_button_new_with_label(_(label));

        may_add_tip(toggle, node);

        option->update_widget = update_toggle;
        option->read_widget = read_toggle;
        option->widget = toggle;

        gtk_signal_connect_object(GTK_OBJECT(toggle), "toggled",
                        GTK_SIGNAL_FUNC(option_check_widget),
                        (GtkObject *) option);

        return g_list_append(NULL, toggle);
}

static GList *build_slider(Option *option, xmlNode *node, guchar *label)
{
        GtkAdjustment *adj;
        GtkWidget *hbox, *slide;
        int     min, max;
        int     fixed;
        int     showvalue;
        guchar  *end;

        g_return_val_if_fail(option != NULL, NULL);

        min = get_int(node, "min");
        max = get_int(node, "max");
        fixed = get_int(node, "fixed");
        showvalue = get_int(node, "showvalue");

        adj = GTK_ADJUSTMENT(gtk_adjustment_new(0,
                                min, max, 1, 10, 0));

        hbox = gtk_hbox_new(FALSE, 4);
        gtk_box_pack_start(GTK_BOX(hbox),
                        gtk_label_new(_(label)),
                        FALSE, TRUE, 0);

        end = xmlGetProp(node, "end");
        if (end)
        {
                gtk_box_pack_end(GTK_BOX(hbox), gtk_label_new(_(end)),
                                 FALSE, TRUE, 0);
                g_free(end);
        }

        slide = gtk_hscale_new(adj);

        if (fixed)
                gtk_widget_set_usize(slide, adj->upper, 24);
        if (showvalue)
        {
                gtk_scale_set_draw_value(GTK_SCALE(slide), TRUE);
                gtk_scale_set_value_pos(GTK_SCALE(slide),
                                GTK_POS_LEFT);
                gtk_scale_set_digits(GTK_SCALE(slide), 0);
        }
        else 
                gtk_scale_set_draw_value(GTK_SCALE(slide), FALSE);
        GTK_WIDGET_UNSET_FLAGS(slide, GTK_CAN_FOCUS);

        may_add_tip(slide, node);

        gtk_box_pack_start(GTK_BOX(hbox), slide, !fixed, TRUE, 0);

        option->update_widget = update_slider;
        option->read_widget = read_slider;
        option->widget = slide;

        gtk_signal_connect_object(GTK_OBJECT(adj), "value-changed",
                        GTK_SIGNAL_FUNC(option_check_widget),
                        (GtkObject *) option);

        return g_list_append(NULL, hbox);
}

static GList *build_entry(Option *option, xmlNode *node, guchar *label)
{
        GtkWidget       *hbox;
        GtkWidget       *entry;

        g_return_val_if_fail(option != NULL, NULL);

        hbox = gtk_hbox_new(FALSE, 4);

        gtk_box_pack_start(GTK_BOX(hbox), gtk_label_new(_(label)),
                                FALSE, TRUE, 0);

        entry = gtk_entry_new();
        gtk_box_pack_start(GTK_BOX(hbox), entry, TRUE, TRUE, 0);
        may_add_tip(entry, node);

        option->update_widget = update_entry;
        option->read_widget = read_entry;
        option->widget = entry;

        gtk_signal_connect_object_after(GTK_OBJECT(entry), "changed",
                        GTK_SIGNAL_FUNC(option_check_widget),
                        (GtkObject *) option);

        return g_list_append(NULL, hbox);
}

static GList *build_radio_group(Option *option, xmlNode *node, guchar *label)
{
        GList           *list = NULL;
        GtkWidget       *button = NULL;
        xmlNode         *rn;

        g_return_val_if_fail(option != NULL, NULL);

        for (rn = node->xmlChildrenNode; rn; rn = rn->next)
        {
                if (rn->type == XML_ELEMENT_NODE)
                {
                        button = build_radio(rn, button);
                        gtk_signal_connect_object(GTK_OBJECT(button), "toggled",
                                GTK_SIGNAL_FUNC(option_check_widget),
                                (GtkObject *) option);
                        list = g_list_append(list, button);
                }
        }

        option->update_widget = update_radio_group;
        option->read_widget = read_radio_group;
        option->widget = button;

        return list;
}

static GList *build_colour(Option *option, xmlNode *node, guchar *label)
{
        GtkWidget       *hbox, *da, *button;
        int             lpos;
        
        g_return_val_if_fail(option != NULL, NULL);

        /* lpos gives the position for the label 
         * 0: label comes before the button
         * non-zero: label comes after the button
         */
        lpos = get_int(node, "lpos");

        hbox = gtk_hbox_new(FALSE, 4);
        if (lpos == 0)
                gtk_box_pack_start(GTK_BOX(hbox),
                        gtk_label_new(_(label)),
                        FALSE, TRUE, 0);

        button = gtk_button_new();
        da = gtk_drawing_area_new();
        gtk_drawing_area_size(GTK_DRAWING_AREA(da), 64, 12);
        gtk_container_add(GTK_CONTAINER(button), da);
        gtk_signal_connect(GTK_OBJECT(button), "clicked",
                        GTK_SIGNAL_FUNC(open_coloursel), option);

        may_add_tip(button, node);
        
        gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, TRUE, 0);
        if (lpos)
                gtk_box_pack_start(GTK_BOX(hbox),
                        gtk_label_new(_(label)),
                        FALSE, TRUE, 0);

        option->update_widget = update_colour;
        option->read_widget = read_colour;
        option->widget = button;

        return g_list_append(NULL, hbox);
}

static GList *build_menu(Option *option, xmlNode *node, guchar *label)
{
        GtkWidget       *hbox, *om, *option_menu;
        xmlNode         *item;
        GtkWidget       *menu;
        GList           *list, *kids;
        int             min_w = 4, min_h = 4;

        g_return_val_if_fail(option != NULL, NULL);

        hbox = gtk_hbox_new(FALSE, 4);

        gtk_box_pack_start(GTK_BOX(hbox), gtk_label_new(_(label)),
                        FALSE, TRUE, 0);

        option_menu = gtk_option_menu_new();
        gtk_box_pack_start(GTK_BOX(hbox), option_menu, FALSE, TRUE, 0);

        om = gtk_menu_new();
        gtk_option_menu_set_menu(GTK_OPTION_MENU(option_menu), om);

        for (item = node->xmlChildrenNode; item; item = item->next)
        {
                if (item->type == XML_ELEMENT_NODE)
                        build_menu_item(item, option_menu);
        }

        menu = gtk_option_menu_get_menu(GTK_OPTION_MENU(option_menu));
        list = kids = gtk_container_children(GTK_CONTAINER(menu));

        while (kids)
        {
                GtkWidget       *item = (GtkWidget *) kids->data;
                GtkRequisition  req;

                gtk_widget_size_request(item, &req);
                if (req.width > min_w)
                        min_w = req.width;
                if (req.height > min_h)
                        min_h = req.height;
                
                kids = kids->next;
        }

        g_list_free(list);

        gtk_widget_set_usize(option_menu,
                        min_w + 50,     /* Else node doesn't work! */
                        min_h + 4);

        option->update_widget = update_menu;
        option->read_widget = read_menu;
        option->widget = option_menu;

        gtk_signal_connect_object_after(GTK_OBJECT(option_menu), "changed",
                        GTK_SIGNAL_FUNC(option_check_widget),
                        (GtkObject *) option);

        return g_list_append(NULL, hbox);
}

static GList *build_font(Option *option, xmlNode *node, guchar *label)
{
        GtkWidget       *hbox, *button;

        g_return_val_if_fail(option != NULL, NULL);

        hbox = gtk_hbox_new(FALSE, 4);

        gtk_box_pack_start(GTK_BOX(hbox), gtk_label_new(_(label)),
                        FALSE, TRUE, 0);

        button = gtk_button_new_with_label("");
        gtk_box_pack_start(GTK_BOX(hbox), button, FALSE, TRUE, 0);

        option->update_widget = update_font;
        option->read_widget = read_font;
        option->widget = GTK_BIN(button)->child;
        may_add_tip(button, node);

        gtk_signal_connect(GTK_OBJECT(button), "clicked",
                        GTK_SIGNAL_FUNC(open_fontsel), (GtkObject *) option);

        return g_list_append(NULL, hbox);
}

static void button_patch_set_colour(GtkWidget *button, GdkColor *colour)
{
        GtkStyle        *style;
        GtkWidget       *patch;

        patch = GTK_BIN(button)->child;

        style = gtk_style_copy(GTK_WIDGET(patch)->style);
        style->bg[GTK_STATE_NORMAL].red = colour->red;
        style->bg[GTK_STATE_NORMAL].green = colour->green;
        style->bg[GTK_STATE_NORMAL].blue = colour->blue;
        gtk_widget_set_style(patch, style);
        gtk_style_unref(style);

        if (GTK_WIDGET_REALIZED(patch))
                gdk_window_clear(patch->window);
}

static void load_options(xmlDoc *doc)
{
        xmlNode *root, *node;

        root = xmlDocGetRootElement(doc);
        
        g_return_if_fail(strcmp(root->name, "Options") == 0);

        for (node = root->xmlChildrenNode; node; node = node->next)
        {
                gchar *value, *name;

                if (node->type != XML_ELEMENT_NODE)
                        continue;
                if (strcmp(node->name, "Option") != 0)
                        continue;
                name = xmlGetProp(node, "name");
                if (!name)
                        continue;

                value = xmlNodeGetContent(node);

                if (g_hash_table_lookup(loading, name))
                        g_warning("Duplicate option found!");

                g_hash_table_insert(loading, name, value);

                /* (don't need to free name or value) */
        }
}

/* Process one line from the options file (\0 term'd).
 * Returns NULL on success, or a pointer to an error message.
 * The line is modified.
 */
static const char *process_option_line(gchar *line)
{
        gchar           *eq, *c;
        gchar           *name = line;

        g_return_val_if_fail(option_hash != NULL, "No registered options!");

        eq = strchr(line, '=');
        if (!eq)
                return _("Missing '='");

        c = eq - 1;
        while (c > line && (*c == ' ' || *c == '\t'))
                c--;
        c[1] = '\0';
        c = eq + 1;
        while (*c == ' ' || *c == '\t')
                c++;

        if (g_hash_table_lookup(loading, name))
                return "Duplicate option found!";

        g_hash_table_insert(loading, g_strdup(name), g_strdup(g_strstrip(c)));

        return NULL;
}