stash.c

/*
 *      stash.c - this file is part of Geany, a fast and lightweight IDE
 *
 *      Copyright 2008-2012 Nick Treleaven <nick(dot)treleaven(at)btinternet(dot)com>
 *      Copyright 2008-2012 Enrico Tröger <enrico(dot)troeger(at)uvena(dot)de>
 *
 *      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., 51 Franklin Street, Fifth Floor, Boston,
 *      MA 02110-1301, USA.
 */

/**
 * @file stash.h
 * Lightweight library for reading/writing @c GKeyFile settings and synchronizing widgets with
 * C variables.
 *
 * Note: Stash should only depend on GLib and GTK, but currently has some minor
 * dependencies on Geany's utils.c.
 *
 * @section Terms
 * 'Setting' is used only for data stored on disk or in memory.
 * 'Pref' can also include visual widget information.
 *
 * @section Memory Usage
 * Stash will not duplicate strings if they are normally static arrays, such as
 * keyfile group names and key names, string default values, widget_id names, property names.
 *
 * @section String Settings
 * String settings and other dynamically allocated settings will be initialized to NULL when
 * added to a StashGroup (so they can safely be reassigned later).
 *
 * @section Widget Support
 * Widgets very commonly used in configuration dialogs will be supported with their own function.
 * Widgets less commonly used such as @c GtkExpander or widget settings that aren't commonly needed
 * to be persistent won't be directly supported, to keep the library lightweight. However, you can
 * use stash_group_add_widget_property() to also save these settings for any read/write widget
 * property. Macros could be added for common widget properties such as @c GtkExpander:"expanded".
 *
 * @section settings-example Settings Example
 * Here we have some settings for how to make a cup - whether it should be made of china
 * and who's going to make it. (Yes, it's a stupid example).
 * @include stash-example.c
 * @note You might want to handle the warning/error conditions differently from above.
 *
 * @section prefs-example GUI Prefs Example
 * For prefs, it's the same as the above example but you tell Stash to add widget prefs instead of
 * just data settings.
 *
 * This example uses lookup strings for widgets as they are more flexible than widget pointers.
 * Code to load and save the settings is omitted - see the first example instead.
 *
 * Here we show a dialog with a toggle button for whether the cup should have a handle.
 * @include stash-gui-example.c
 * @note This example should also work for other widget containers besides dialogs, e.g. popup menus.
 */

/* Implementation Note
 * We dynamically allocate prefs. It would be more efficient for user code to declare
 * a static array of StashPref structs, but we don't do this because:
 *
 * * It would be more ugly (lots of casts and NULLs).
 * * Less type checking.
 * * The API & ABI would have to break when adding/changing fields.
 *
 * Usually the prefs code isn't what user code will spend most of its time doing, so this
 * should be efficient enough.
 */


#include "geany.h"		/* necessary for utils.h, otherwise use gtk/gtk.h */
#include <stdlib.h>		/* only for atoi() */
#include "support.h"	/* only for _("text") */
#include "utils.h"		/* only for foreach_*, utils_get_setting_*(). Stash should not depend on Geany. */

#include "stash.h"


struct StashPref
{
	GType setting_type;			/* e.g. G_TYPE_INT */
	gpointer setting;			/* Address of a variable */
	const gchar *key_name;
	gpointer default_value;		/* Default value, e.g. (gpointer)1 */
	GType widget_type;			/* e.g. GTK_TYPE_TOGGLE_BUTTON */
	StashWidgetID widget_id;	/* (GtkWidget*) or (gchar*) */
	union
	{
		struct EnumWidget *radio_buttons;
		const gchar *property_name;
	} extra;	/* extra fields depending on widget_type */
};

typedef struct StashPref StashPref;

struct StashGroup
{
	const gchar *name;			/* group name to use in the keyfile */
	GPtrArray *entries;			/* array of (StashPref*) */
	gboolean various;		/* mark group for display/edit in stash treeview */
	gboolean use_defaults;		/* use default values if there's no keyfile entry */
};

typedef struct EnumWidget
{
	StashWidgetID widget_id;
	gint enum_id;
}
EnumWidget;


typedef enum SettingAction
{
	SETTING_READ,
	SETTING_WRITE
}
SettingAction;

typedef enum PrefAction
{
	PREF_DISPLAY,
	PREF_UPDATE
}
PrefAction;


static void handle_boolean_setting(StashGroup *group, StashPref *se,
		GKeyFile *config, SettingAction action)
{
	gboolean *setting = se->setting;

	switch (action)
	{
		case SETTING_READ:
			*setting = utils_get_setting_boolean(config, group->name, se->key_name,
				GPOINTER_TO_INT(se->default_value));
			break;
		case SETTING_WRITE:
			g_key_file_set_boolean(config, group->name, se->key_name, *setting);
			break;
	}
}


static void handle_integer_setting(StashGroup *group, StashPref *se,
		GKeyFile *config, SettingAction action)
{
	gint *setting = se->setting;

	switch (action)
	{
		case SETTING_READ:
			*setting = utils_get_setting_integer(config, group->name, se->key_name,
				GPOINTER_TO_INT(se->default_value));
			break;
		case SETTING_WRITE:
			g_key_file_set_integer(config, group->name, se->key_name, *setting);
			break;
	}
}


static void handle_string_setting(StashGroup *group, StashPref *se,
		GKeyFile *config, SettingAction action)
{
	gchararray *setting = se->setting;

	switch (action)
	{
		case SETTING_READ:
			g_free(*setting);
			*setting = utils_get_setting_string(config, group->name, se->key_name,
				se->default_value);
			break;
		case SETTING_WRITE:
			g_key_file_set_string(config, group->name, se->key_name,
				*setting ? *setting : "");
			break;
	}
}


static void handle_strv_setting(StashGroup *group, StashPref *se,
		GKeyFile *config, SettingAction action)
{
	gchararray **setting = se->setting;

	switch (action)
	{
		case SETTING_READ:
			g_strfreev(*setting);
			*setting = g_key_file_get_string_list(config, group->name, se->key_name,
				NULL, NULL);
			if (*setting == NULL)
				*setting = g_strdupv(se->default_value);
			break;

		case SETTING_WRITE:
		{
			/* don't try to save a NULL string vector */
			const gchar *dummy[] = { "", NULL };
			const gchar **strv = *setting ? (const gchar **)*setting : dummy;

			g_key_file_set_string_list(config, group->name, se->key_name,
				strv, g_strv_length((gchar **)strv));
			break;
		}
	}
}


static void keyfile_action(SettingAction action, StashGroup *group, GKeyFile *keyfile)
{
	StashPref *entry;
	guint i;

	foreach_ptr_array(entry, i, group->entries)
	{
		/* don't override settings with default values */
		if (!group->use_defaults && action == SETTING_READ &&
			!g_key_file_has_key(keyfile, group->name, entry->key_name, NULL))
			continue;

		switch (entry->setting_type)
		{
			case G_TYPE_BOOLEAN:
				handle_boolean_setting(group, entry, keyfile, action); break;
			case G_TYPE_INT:
				handle_integer_setting(group, entry, keyfile, action); break;
			case G_TYPE_STRING:
				handle_string_setting(group, entry, keyfile, action); break;
			default:
				/* Note: G_TYPE_STRV is not a constant, can't use case label */
				if (entry->setting_type == G_TYPE_STRV)
					handle_strv_setting(group, entry, keyfile, action);
				else
					g_warning("Unhandled type for %s::%s in %s()!", group->name, entry->key_name,
						G_STRFUNC);
		}
	}
}


/** Reads key values from @a keyfile into the group settings.
 * @note You should still call this even if the keyfile couldn't be loaded from disk
 * so that all Stash settings are initialized to defaults.
 * @param group .
 * @param keyfile Usually loaded from a configuration file first. */
void stash_group_load_from_key_file(StashGroup *group, GKeyFile *keyfile)
{
	keyfile_action(SETTING_READ, group, keyfile);
}


/** Writes group settings into key values in @a keyfile.
 * @a keyfile is usually written to a configuration file afterwards.
 * @param group .
 * @param keyfile . */
void stash_group_save_to_key_file(StashGroup *group, GKeyFile *keyfile)
{
	keyfile_action(SETTING_WRITE, group, keyfile);
}


/** Reads group settings from a configuration file using @c GKeyFile.
 * @note Stash settings will be initialized to defaults if the keyfile
 * couldn't be loaded from disk.
 * @param group .
 * @param filename Filename of the file to read, in locale encoding.
 * @return @c TRUE if a key file could be loaded.
 * @see stash_group_load_from_key_file().
 **/
gboolean stash_group_load_from_file(StashGroup *group, const gchar *filename)
{
	GKeyFile *keyfile;
	gboolean ret;

	keyfile = g_key_file_new();
	ret = g_key_file_load_from_file(keyfile, filename, 0, NULL);
	/* even on failure we load settings to apply defaults */
	stash_group_load_from_key_file(group, keyfile);

	g_key_file_free(keyfile);
	return ret;
}


/** Writes group settings to a configuration file using @c GKeyFile.
 *
 * @param group .
 * @param filename Filename of the file to write, in locale encoding.
 * @param flags Keyfile options - @c G_KEY_FILE_NONE is the most efficient.
 * @return 0 if the file was successfully written, otherwise the @c errno of the
 *         failed operation is returned.
 * @see stash_group_save_to_key_file().
 **/
gint stash_group_save_to_file(StashGroup *group, const gchar *filename,
		GKeyFileFlags flags)
{
	GKeyFile *keyfile;
	gchar *data;
	gint ret;

	keyfile = g_key_file_new();
	/* if we need to keep comments or translations, try to load first */
	if (flags)
		g_key_file_load_from_file(keyfile, filename, flags, NULL);

	stash_group_save_to_key_file(group, keyfile);
	data = g_key_file_to_data(keyfile, NULL, NULL);
	ret = utils_write_file(filename, data);
	g_free(data);
	g_key_file_free(keyfile);
	return ret;
}


/** Creates a new group.
 * @param name Name used for @c GKeyFile group.
 * @return Group. */
StashGroup *stash_group_new(const gchar *name)
{
	StashGroup *group = g_new0(StashGroup, 1);

	group->name = name;
	group->entries = g_ptr_array_new();
	group->use_defaults = TRUE;
	return group;
}


/** Frees the memory allocated for setting values in a group.
 * Useful e.g. to avoid freeing strings individually.
 * @note This is *not* called by stash_group_free().
 * @param group . */
void stash_group_free_settings(StashGroup *group)
{
	StashPref *entry;
	guint i;

	foreach_ptr_array(entry, i, group->entries)
	{
		if (entry->setting_type == G_TYPE_STRING)
			g_free(*(gchararray *) entry->setting);
		else if (entry->setting_type == G_TYPE_STRV)
			g_strfreev(*(gchararray **) entry->setting);
		else
			continue;

		*(gpointer**) entry->setting = NULL;
	}
}


/** Frees a group.
 * @param group . */
void stash_group_free(StashGroup *group)
{
	StashPref *entry;
	guint i;

	foreach_ptr_array(entry, i, group->entries)
	{
		if (entry->widget_type == GTK_TYPE_RADIO_BUTTON)
		{
			g_free(entry->extra.radio_buttons);
		}
		g_slice_free(StashPref, entry);
	}
	g_ptr_array_free(group->entries, TRUE);
	g_free(group);
}


/* Used for selecting groups passed to stash_tree_setup().
 * @c FALSE by default. */
void stash_group_set_various(StashGroup *group, gboolean various)
{
	group->various = various;
}


/* When @c FALSE, Stash doesn't change the setting if there is no keyfile entry, so it
 * remains whatever it was initialized/set to by user code.
 * @c TRUE by default. */
void stash_group_set_use_defaults(StashGroup *group, gboolean use_defaults)
{
	group->use_defaults = use_defaults;
}


static StashPref *
add_pref(StashGroup *group, GType type, gpointer setting,
		const gchar *key_name, gpointer default_value)
{
	StashPref init = {type, setting, key_name, default_value, G_TYPE_NONE, NULL, {NULL}};
	StashPref *entry = g_slice_new(StashPref);

	*entry = init;

	/* init any pointer settings to NULL so they can be freed later */
	if (type == G_TYPE_STRING ||
		type == G_TYPE_STRV)
		if (group->use_defaults)
			*(gpointer**)setting = NULL;

	g_ptr_array_add(group->entries, entry);
	return entry;
}


/** Adds boolean setting.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading. */
void stash_group_add_boolean(StashGroup *group, gboolean *setting,
		const gchar *key_name, gboolean default_value)
{
	add_pref(group, G_TYPE_BOOLEAN, setting, key_name, GINT_TO_POINTER(default_value));
}


/** Adds integer setting.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading. */
void stash_group_add_integer(StashGroup *group, gint *setting,
		const gchar *key_name, gint default_value)
{
	add_pref(group, G_TYPE_INT, setting, key_name, GINT_TO_POINTER(default_value));
}


/** Adds string setting.
 * The contents of @a setting will be initialized to @c NULL.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value String to copy if the key doesn't exist when loading, or @c NULL. */
void stash_group_add_string(StashGroup *group, gchar **setting,
		const gchar *key_name, const gchar *default_value)
{
	add_pref(group, G_TYPE_STRING, setting, key_name, (gpointer)default_value);
}


/** Adds string vector setting (array of strings).
 * The contents of @a setting will be initialized to @c NULL.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Vector to copy if the key doesn't exist when loading. Usually @c NULL. */
void stash_group_add_string_vector(StashGroup *group, gchar ***setting,
		const gchar *key_name, const gchar **default_value)
{
	add_pref(group, G_TYPE_STRV, setting, key_name, (gpointer)default_value);
}


/* *** GTK-related functions *** */

static void handle_toggle_button(GtkWidget *widget, gboolean *setting,
		PrefAction action)
{
	switch (action)
	{
		case PREF_DISPLAY:
			gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(widget), *setting);
			break;
		case PREF_UPDATE:
			*setting = gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(widget));
			break;
	}
}


static void handle_spin_button(GtkWidget *widget, StashPref *entry,
		PrefAction action)
{
	gint *setting = entry->setting;

	g_assert(entry->setting_type == G_TYPE_INT);	/* only int spin prefs */

	switch (action)
	{
		case PREF_DISPLAY:
			gtk_spin_button_set_value(GTK_SPIN_BUTTON(widget), *setting);
			break;
		case PREF_UPDATE:
			/* if the widget is focussed, the value might not be updated */
			gtk_spin_button_update(GTK_SPIN_BUTTON(widget));
			*setting = gtk_spin_button_get_value_as_int(GTK_SPIN_BUTTON(widget));
			break;
	}
}


static void handle_combo_box(GtkWidget *widget, StashPref *entry,
		PrefAction action)
{
	gint *setting = entry->setting;

	switch (action)
	{
		case PREF_DISPLAY:
			gtk_combo_box_set_active(GTK_COMBO_BOX(widget), *setting);
			break;
		case PREF_UPDATE:
			*setting = gtk_combo_box_get_active(GTK_COMBO_BOX(widget));
			break;
	}
}


static void handle_entry(GtkWidget *widget, StashPref *entry,
		PrefAction action)
{
	gchararray *setting = entry->setting;

	switch (action)
	{
		case PREF_DISPLAY:
			gtk_entry_set_text(GTK_ENTRY(widget), *setting);
			break;
		case PREF_UPDATE:
			g_free(*setting);
			*setting = g_strdup(gtk_entry_get_text(GTK_ENTRY(widget)));
			break;
	}
}


static void handle_combo_box_entry(GtkWidget *widget, StashPref *entry,
		PrefAction action)
{
	widget = gtk_bin_get_child(GTK_BIN(widget));
	handle_entry(widget, entry, action);
}


/* taken from Glade 2.x generated support.c */
static GtkWidget*
lookup_widget(GtkWidget *widget, const gchar *widget_name)
{
	GtkWidget *parent, *found_widget;

	g_return_val_if_fail(widget != NULL, NULL);
	g_return_val_if_fail(widget_name != NULL, NULL);

	for (;;)
	{
		if (GTK_IS_MENU(widget))
			parent = gtk_menu_get_attach_widget(GTK_MENU(widget));
		else
			parent = widget->parent;
		if (parent == NULL)
			parent = (GtkWidget*) g_object_get_data(G_OBJECT(widget), "GladeParentKey");
		if (parent == NULL)
			break;
		widget = parent;
	}

	found_widget = (GtkWidget*) g_object_get_data(G_OBJECT(widget), widget_name);
	if (G_UNLIKELY(found_widget == NULL))
		g_warning("Widget not found: %s", widget_name);
	return found_widget;
}


static GtkWidget *
get_widget(GtkWidget *owner, StashWidgetID widget_id)
{
	GtkWidget *widget;

	if (owner)
		widget = lookup_widget(owner, (const gchar *)widget_id);
	else
		widget = (GtkWidget *)widget_id;

	if (!GTK_IS_WIDGET(widget))
	{
		g_warning("Unknown widget in %s()!", G_STRFUNC);
		return NULL;
	}
	return widget;
}


static void handle_radio_button(GtkWidget *widget, gint enum_id, gboolean *setting,
		PrefAction action)
{
	switch (action)
	{
		case PREF_DISPLAY:
			if (*setting == enum_id)
				gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(widget), TRUE);
			break;
		case PREF_UPDATE:
			if (gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(widget)))
				*setting = enum_id;
			break;
	}
}


static void handle_radio_buttons(GtkWidget *owner, StashPref *entry,
		PrefAction action)
{
	EnumWidget *field = entry->extra.radio_buttons;
	gsize count = 0;
	GtkWidget *widget = NULL;

	while (1)
	{
		widget = get_widget(owner, field->widget_id);

		if (!widget)
			continue;

		count++;
		handle_radio_button(widget, field->enum_id, entry->setting, action);
		field++;
		if (!field->widget_id)
			break;
	}
	if (g_slist_length(gtk_radio_button_get_group(GTK_RADIO_BUTTON(widget))) != count)
		g_warning("Missing/invalid radio button widget IDs found!");
}


static void handle_widget_property(GtkWidget *widget, StashPref *entry,
		PrefAction action)
{
	GObject *object = G_OBJECT(widget);
	const gchar *name = entry->extra.property_name;

	switch (action)
	{
		case PREF_DISPLAY:
			g_object_set(object, name, entry->setting, NULL);
			break;
		case PREF_UPDATE:
			if (entry->setting_type == G_TYPE_STRING)
				g_free(entry->setting);
			/* TODO: Which other types need freeing here? */

			g_object_get(object, name, entry->setting, NULL);
			break;
	}
}


static void pref_action(PrefAction action, StashGroup *group, GtkWidget *owner)
{
	StashPref *entry;
	guint i;

	foreach_ptr_array(entry, i, group->entries)
	{
		GtkWidget *widget;

		/* ignore settings with no widgets */
		if (entry->widget_type == G_TYPE_NONE)
			continue;

		/* radio buttons have several widgets */
		if (entry->widget_type == GTK_TYPE_RADIO_BUTTON)
		{
			handle_radio_buttons(owner, entry, action);
			continue;
		}

		widget = get_widget(owner, entry->widget_id);
		if (!widget)
		{
			g_warning("Unknown widget for %s::%s in %s()!", group->name, entry->key_name,
				G_STRFUNC);
			continue;
		}

		/* note: can't use switch for GTK_TYPE macros */
		if (entry->widget_type == GTK_TYPE_TOGGLE_BUTTON)
			handle_toggle_button(widget, entry->setting, action);
		else if (entry->widget_type == GTK_TYPE_SPIN_BUTTON)
			handle_spin_button(widget, entry, action);
		else if (entry->widget_type == GTK_TYPE_COMBO_BOX)
			handle_combo_box(widget, entry, action);
		else if (entry->widget_type == GTK_TYPE_COMBO_BOX_ENTRY)
			handle_combo_box_entry(widget, entry, action);
		else if (entry->widget_type == GTK_TYPE_ENTRY)
			handle_entry(widget, entry, action);
		else if (entry->widget_type == G_TYPE_PARAM)
			handle_widget_property(widget, entry, action);
		else
			g_warning("Unhandled type for %s::%s in %s()!", group->name, entry->key_name,
				G_STRFUNC);
	}
}


/** Applies Stash settings to widgets, usually called before displaying the widgets.
 * The @a owner argument depends on which type you use for @ref StashWidgetID.
 * @param group .
 * @param owner If non-NULL, used to lookup widgets by name, otherwise
 * widget pointers are assumed.
 * @see stash_group_update(). */
void stash_group_display(StashGroup *group, GtkWidget *owner)
{
	pref_action(PREF_DISPLAY, group, owner);
}


/** Applies widget values to Stash settings, usually called after displaying the widgets.
 * The @a owner argument depends on which type you use for @ref StashWidgetID.
 * @param group .
 * @param owner If non-NULL, used to lookup widgets by name, otherwise
 * widget pointers are assumed.
 * @see stash_group_display(). */
void stash_group_update(StashGroup *group, GtkWidget *owner)
{
	pref_action(PREF_UPDATE, group, owner);
}


static StashPref *
add_widget_pref(StashGroup *group, GType setting_type, gpointer setting,
		const gchar *key_name, gpointer default_value,
		GType widget_type, StashWidgetID widget_id)
{
	StashPref *entry =
		add_pref(group, setting_type, setting, key_name, default_value);

	entry->widget_type = widget_type;
	entry->widget_id = widget_id;
	return entry;
}


/** Adds a @c GtkToggleButton (or @c GtkCheckButton) widget pref.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * @param widget_id @c GtkWidget pointer or string to lookup widget later.
 * @see stash_group_add_radio_buttons(). */
void stash_group_add_toggle_button(StashGroup *group, gboolean *setting,
		const gchar *key_name, gboolean default_value, StashWidgetID widget_id)
{
	add_widget_pref(group, G_TYPE_BOOLEAN, setting, key_name, GINT_TO_POINTER(default_value),
		GTK_TYPE_TOGGLE_BUTTON, widget_id);
}


/** Adds a @c GtkRadioButton widget group pref.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * @param widget_id @c GtkWidget pointer or string to lookup widget later.
 * @param enum_id Enum value for @a widget_id.
 * @param ... pairs of @a widget_id, @a enum_id.
 * Example (using widget lookup strings, but widget pointers can also work):
 * @code
 * enum {FOO, BAR};
 * stash_group_add_radio_buttons(group, &which_one_setting, "which_one", BAR,
 * 	"radio_foo", FOO, "radio_bar", BAR, NULL);
 * @endcode */
void stash_group_add_radio_buttons(StashGroup *group, gint *setting,
		const gchar *key_name, gint default_value,
		StashWidgetID widget_id, gint enum_id, ...)
{
	StashPref *entry =
		add_widget_pref(group, G_TYPE_INT, setting, key_name, GINT_TO_POINTER(default_value),
			GTK_TYPE_RADIO_BUTTON, NULL);
	va_list args;
	gsize count = 1;
	EnumWidget *item, *array;

	/* count pairs of args */
	va_start(args, enum_id);
	while (1)
	{
		if (!va_arg(args, gpointer))
			break;
		va_arg(args, gint);
		count++;
	}
	va_end(args);

	array = g_new0(EnumWidget, count + 1);
	entry->extra.radio_buttons = array;

	va_start(args, enum_id);
	foreach_c_array(item, array, count)
	{
		if (item == array)
		{
			/* first element */
			item->widget_id = widget_id;
			item->enum_id = enum_id;
		}
		else
		{
			item->widget_id = va_arg(args, gpointer);
			item->enum_id = va_arg(args, gint);
		}
	}
	va_end(args);
}


/** Adds a @c GtkSpinButton widget pref.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * @param widget_id @c GtkWidget pointer or string to lookup widget later. */
void stash_group_add_spin_button_integer(StashGroup *group, gint *setting,
		const gchar *key_name, gint default_value, StashWidgetID widget_id)
{
	add_widget_pref(group, G_TYPE_INT, setting, key_name, GINT_TO_POINTER(default_value),
		GTK_TYPE_SPIN_BUTTON, widget_id);
}


/** Adds a @c GtkComboBox widget pref.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * @param widget_id @c GtkWidget pointer or string to lookup widget later.
 * @see stash_group_add_combo_box_entry(). */
void stash_group_add_combo_box(StashGroup *group, gint *setting,
		const gchar *key_name, gint default_value, StashWidgetID widget_id)
{
	add_widget_pref(group, G_TYPE_INT, setting, key_name, GINT_TO_POINTER(default_value),
		GTK_TYPE_COMBO_BOX, widget_id);
}


/** Adds a @c GtkComboBoxEntry widget pref.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * @param widget_id @c GtkWidget pointer or string to lookup widget later. */
/* We could maybe also have something like stash_group_add_combo_box_entry_with_menu()
 * for the history list - or should that be stored as a separate setting? */
void stash_group_add_combo_box_entry(StashGroup *group, gchar **setting,
		const gchar *key_name, const gchar *default_value, StashWidgetID widget_id)
{
	add_widget_pref(group, G_TYPE_STRING, setting, key_name, (gpointer)default_value,
		GTK_TYPE_COMBO_BOX_ENTRY, widget_id);
}


/** Adds a @c GtkEntry widget pref.
 * @param group .
 * @param setting Address of setting variable.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * @param widget_id @c GtkWidget pointer or string to lookup widget later. */
void stash_group_add_entry(StashGroup *group, gchar **setting,
		const gchar *key_name, const gchar *default_value, StashWidgetID widget_id)
{
	add_widget_pref(group, G_TYPE_STRING, setting, key_name, (gpointer)default_value,
		GTK_TYPE_ENTRY, widget_id);
}


static GType object_get_property_type(GObject *object, const gchar *property_name)
{
	GObjectClass *klass = G_OBJECT_GET_CLASS(object);
	GParamSpec *ps;

	ps = g_object_class_find_property(klass, property_name);
	return ps->value_type;
}


/** Adds a widget's read/write property to the stash group.
 * The property will be set when calling
 * stash_group_display(), and read when calling stash_group_update().
 * @param group .
 * @param setting Address of e.g. an integer if using an integer property.
 * @param key_name Name for key in a @c GKeyFile.
 * @param default_value Value to use if the key doesn't exist when loading.
 * Should be cast into a pointer e.g. with @c GINT_TO_POINTER().
 * @param widget_id @c GtkWidget pointer or string to lookup widget later.
 * @param property_name .
 * @param type can be @c 0 if passing a @c GtkWidget as the @a widget_id argument to look it up from the
 * @c GObject data.
 * @warning Currently only string GValue properties will be freed before setting; patch for
 * other types - see @c handle_widget_property(). */
void stash_group_add_widget_property(StashGroup *group, gpointer setting,
		const gchar *key_name, gpointer default_value, StashWidgetID widget_id,
		const gchar *property_name, GType type)
{
	if (!type)
		type = object_get_property_type(G_OBJECT(widget_id), property_name);

	add_widget_pref(group, type, setting, key_name, default_value,
		G_TYPE_PARAM, widget_id)->extra.property_name = property_name;
}


enum
{
	STASH_TREE_NAME,
	STASH_TREE_VALUE,
	STASH_TREE_COUNT
};


struct StashTreeValue
{
	const gchar *group_name;
	StashPref *pref;
	union
	{
		gchararray tree_string;
		gint tree_int;
	} data;
};

typedef struct StashTreeValue StashTreeValue;


static void stash_tree_renderer_set_data(GtkCellLayout *cell_layout, GtkCellRenderer *cell,
	GtkTreeModel *model, GtkTreeIter *iter, gpointer user_data)
{
	GType cell_type = GPOINTER_TO_SIZE(user_data);
	StashTreeValue *value;
	StashPref *pref;
	gboolean matches_type;

	gtk_tree_model_get(model, iter, STASH_TREE_VALUE, &value, -1);
	pref = value->pref;
	matches_type = pref->setting_type == cell_type;
	g_object_set(cell, "visible", matches_type, "sensitive", matches_type,
		cell_type == G_TYPE_BOOLEAN ? "activatable" : "editable", matches_type, NULL);

	if (matches_type)
	{
		switch (pref->setting_type)
		{
			case G_TYPE_BOOLEAN:
				g_object_set(cell, "active", value->data.tree_int, NULL);
				break;
			case G_TYPE_INT:
			{
				gchar *text = g_strdup_printf("%d", value->data.tree_int);
				g_object_set(cell, "text", text, NULL);
				g_free(text);
				break;
			}
			case G_TYPE_STRING:
				g_object_set(cell, "text", value->data.tree_string, NULL);
				break;
		}
	}
}


static void stash_tree_renderer_edited(gchar *path_str, gchar *new_text, GtkTreeModel *model)
{
	GtkTreePath *path;
	GtkTreeIter iter;
	StashTreeValue *value;
	StashPref *pref;

	path = gtk_tree_path_new_from_string(path_str);
	gtk_tree_model_get_iter(model, &iter, path);
	gtk_tree_model_get(model, &iter, STASH_TREE_VALUE, &value, -1);
	pref = value->pref;

	switch (pref->setting_type)
	{
		case G_TYPE_BOOLEAN:
			value->data.tree_int = !value->data.tree_int;
			break;
		case G_TYPE_INT:
			value->data.tree_int = atoi(new_text);
			break;
		case G_TYPE_STRING:
			SETPTR(value->data.tree_string, g_strdup(new_text));
			break;
	}

	gtk_tree_model_row_changed(model, path, &iter);
	gtk_tree_path_free(path);
}


static void stash_tree_boolean_toggled(GtkCellRendererToggle *cell, gchar *path_str,
	GtkTreeModel *model)
{
	stash_tree_renderer_edited(path_str, NULL, model);
}


static void stash_tree_string_edited(GtkCellRenderer *cell, gchar *path_str, gchar *new_text,
	GtkTreeModel *model)
{
	stash_tree_renderer_edited(path_str, new_text, model);
}


static gboolean stash_tree_discard_value(GtkTreeModel *model, GtkTreePath *path,
	GtkTreeIter *iter, gpointer user_data)
{
	StashTreeValue *value;

	gtk_tree_model_get(model, iter, STASH_TREE_VALUE, &value, -1);
	if (value->pref->setting_type == G_TYPE_STRING)
		g_free(value->data.tree_string);
	g_free(value);

	return FALSE;
}


static void stash_tree_destroy_cb(GtkWidget *widget, gpointer user_data)
{
	GtkTreeModel *model = gtk_tree_view_get_model(GTK_TREE_VIEW(widget));
	gtk_tree_model_foreach(model, stash_tree_discard_value, NULL);
}


static void stash_tree_append_pref(StashGroup *group, StashPref *entry, GtkListStore *store,
	PrefAction action)
{
	GtkTreeIter iter;
	StashTreeValue *value;

	value = g_new0(StashTreeValue, 1);

	value->group_name = group->name;
	value->pref = entry;

	gtk_list_store_append(store, &iter);
	gtk_list_store_set(store, &iter, STASH_TREE_NAME, entry->key_name,
		STASH_TREE_VALUE, value, -1);
}


static void stash_tree_append_prefs(GPtrArray *group_array,
	GtkListStore *store, PrefAction action)
{
	StashGroup *group;
	guint i, j;
	StashPref *entry;

	foreach_ptr_array(group, i, group_array)
	{
		if (group->various)
		{
			foreach_ptr_array(entry, j, group->entries)
				stash_tree_append_pref(group, entry, store, action);
		}
	}
}


/* Setups a simple editor for stash preferences based on the widget arguments.
 * group_array - Array of groups which's settings will be edited.
 * tree - GtkTreeView in which to edit the preferences. Must be empty. */
void stash_tree_setup(GPtrArray *group_array, GtkTreeView *tree)
{
	GtkListStore *store;
	GtkTreeModel *model;
	GtkCellRenderer *cell;
	GtkTreeViewColumn *column;
	GtkObject *adjustment;

	store = gtk_list_store_new(STASH_TREE_COUNT, G_TYPE_STRING, G_TYPE_POINTER);
	stash_tree_append_prefs(group_array, store, PREF_DISPLAY);
	gtk_tree_sortable_set_sort_column_id(GTK_TREE_SORTABLE(store), STASH_TREE_NAME,
		GTK_SORT_ASCENDING);

	model = GTK_TREE_MODEL(store);
	gtk_tree_view_set_model(tree, model);
	g_object_unref(G_OBJECT(store));
	g_signal_connect(tree, "destroy", G_CALLBACK(stash_tree_destroy_cb), NULL);

	cell = gtk_cell_renderer_text_new();
	column = gtk_tree_view_column_new_with_attributes(_("Name"), cell, "text",
		STASH_TREE_NAME, NULL);
	gtk_tree_view_column_set_sort_column_id(column, STASH_TREE_NAME);
	gtk_tree_view_column_set_sort_indicator(column, TRUE);
	gtk_tree_view_append_column(tree, column);

	column = gtk_tree_view_column_new();
	gtk_tree_view_column_set_title(column, _("Value"));
	gtk_tree_view_append_column(tree, column);
	/* boolean renderer */
	cell = gtk_cell_renderer_toggle_new();
	g_signal_connect(cell, "toggled", G_CALLBACK(stash_tree_boolean_toggled), model);
	gtk_cell_layout_pack_start(GTK_CELL_LAYOUT(column), cell, FALSE);
	gtk_cell_layout_set_cell_data_func(GTK_CELL_LAYOUT(column), cell,
		stash_tree_renderer_set_data, GSIZE_TO_POINTER(G_TYPE_BOOLEAN), NULL);
	/* string renderer */
	cell = gtk_cell_renderer_text_new();
	g_object_set(cell, "ellipsize", PANGO_ELLIPSIZE_END, NULL);
	g_signal_connect(cell, "edited", G_CALLBACK(stash_tree_string_edited), model);
	gtk_cell_layout_pack_start(GTK_CELL_LAYOUT(column), cell, TRUE);
	gtk_cell_layout_set_cell_data_func(GTK_CELL_LAYOUT(column), cell,
		stash_tree_renderer_set_data, GSIZE_TO_POINTER(G_TYPE_STRING), NULL);
	/* integer renderer */
	cell = gtk_cell_renderer_spin_new();
	adjustment = gtk_adjustment_new(0, G_MININT, G_MAXINT, 1, 10, 0);
	g_object_set(cell, "adjustment", adjustment, NULL);
	g_signal_connect(cell, "edited", G_CALLBACK(stash_tree_string_edited), model);
	gtk_cell_layout_pack_start(GTK_CELL_LAYOUT(column), cell, FALSE);
	gtk_cell_layout_set_cell_data_func(GTK_CELL_LAYOUT(column), cell,
		stash_tree_renderer_set_data, GSIZE_TO_POINTER(G_TYPE_INT), NULL);
}


static void stash_tree_display_pref(StashTreeValue *value, StashPref *entry)
{
	switch (entry->setting_type)
	{
		case G_TYPE_BOOLEAN:
			value->data.tree_int = *(gboolean *) entry->setting;
			break;
		case G_TYPE_INT:
			value->data.tree_int = *(gint *) entry->setting;
			break;
		case G_TYPE_STRING:
			SETPTR(value->data.tree_string, g_strdup(*(gchararray *) entry->setting));
			break;
		default:
			g_warning("Unhandled type for %s::%s in %s()!", value->group_name,
				entry->key_name, G_STRFUNC);
	}
}


static void stash_tree_update_pref(StashTreeValue *value, StashPref *entry)
{
	switch (entry->setting_type)
	{
		case G_TYPE_BOOLEAN:
			*(gboolean *) entry->setting = value->data.tree_int;
			break;
		case G_TYPE_INT:
			*(gint *) entry->setting = value->data.tree_int;
			break;
		case G_TYPE_STRING:
		{
			gchararray *text = entry->setting;
			SETPTR(*text, g_strdup(value->data.tree_string));
			break;
		}
		default:
			g_warning("Unhandled type for %s::%s in %s()!", value->group_name,
				entry->key_name, G_STRFUNC);
	}
}


static void stash_tree_action(GtkTreeModel *model, PrefAction action)
{
	GtkTreeIter iter;
	gboolean valid = gtk_tree_model_get_iter_first(model, &iter);
	StashTreeValue *value;

	while (valid)
	{
		gtk_tree_model_get(model, &iter, STASH_TREE_VALUE, &value, -1);

		switch (action)
		{
			case PREF_DISPLAY:
				stash_tree_display_pref(value, value->pref);
				break;
			case PREF_UPDATE:
				stash_tree_update_pref(value, value->pref);
				break;
		}
		valid = gtk_tree_model_iter_next(model, &iter);
	}
}


void stash_tree_display(GtkTreeView *tree)
{
	stash_tree_action(gtk_tree_view_get_model(tree), PREF_DISPLAY);
}


void stash_tree_update(GtkTreeView *tree)
{
	stash_tree_action(gtk_tree_view_get_model(tree), PREF_UPDATE);
}