listbox.h

/*
 * Copyright (C) 2021 Mark Hills <mark@xwax.org>
 *
 * This file is part of "xwax".
 *
 * "xwax" is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License, version 3 as
 * published by the Free Software Foundation.
 *
 * "xwax" is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see <https://www.gnu.org/licenses/>.
 *
 */

/*
 * Generic UI listbox widget internals
 */

#ifndef LISTBOX_H
#define LISTBOX_H

/* Managed context of a scrolling window, of a number of fixed-height
 * lines, backed by a list of a known number of entries */

struct listbox {
    int entries, lines, offset, selected;
};

void listbox_init(struct listbox *s);
void listbox_set_lines(struct listbox *s, unsigned int lines);
void listbox_set_entries(struct listbox *s, unsigned int entries);

/* Scroll functions */

void listbox_up(struct listbox *s, unsigned int n);
void listbox_down(struct listbox *s, unsigned int n);
void listbox_first(struct listbox *s);
void listbox_last(struct listbox *s);
void listbox_to(struct listbox *s, unsigned int n);

int listbox_current(const struct listbox *s);
int listbox_map(const struct listbox *s, int row);

#endif