mc/lib/widget/scrollbar.c

/*
   Widgets for the Midnight Commander: scrollbar

   Copyright (C) 2014
   The Free Software Foundation, Inc.

   Authors:
   Slava Zanko <slavazanko@gmail.com>, 2014

   This file is part of the Midnight Commander.

   The Midnight Commander 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 3 of the License,
   or (at your option) any later version.

   The Midnight Commander 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 <http://www.gnu.org/licenses/>.
 */

/** \file scrollbar.c
 *  \brief Source: WScrollBar widget
 */

#include <config.h>

#include <stdlib.h>
#include <string.h>

#include "lib/global.h"

#include "lib/tty/tty.h"
#include "lib/tty/color.h"
#include "lib/skin.h"
#include "lib/strutil.h"
#include "lib/widget.h"

/*** global variables ****************************************************************************/

/*** file scope macro definitions ****************************************************************/

#define SKIN_GROUP_NAME "widget-scrollbar"

/*** file scope type declarations ****************************************************************/

/*** file scope variables ************************************************************************/

static struct
{
    char *current_char;

    char *first_vert_char;
    char *last_vert_char;
    char *background_vert_char;

    char *first_horiz_char;
    char *last_horiz_char;
    char *background_horiz_char;
} scrollbar_skin;

/* --------------------------------------------------------------------------------------------- */
/*** file scope functions ************************************************************************/
/* --------------------------------------------------------------------------------------------- */

static void
scrollbar_set_size (WScrollBar * scrollbar)
{
    Widget *w = WIDGET (scrollbar);
    Widget *p = scrollbar->parent;
    Widget *o = WIDGET (p->owner);
    int py = p->y;
    int px = p->x;

    /* There folloing cases are possible here:
       1. Parent is in dialog, scrollbar isn't.
       Parents coordinates are absolute. Scrollbar's coordinate are relative to owner.
       We need relative parent's coordinates here to place scrollbar properly.
       2. Parent and scrollbar are in dialog.
       Parent's and scrollbar's coordinates are absolute. Use them.
       3. Parent and scrollbar aren't in dialog.
       Parent's and scrollbar's coordinates are relative to owner. Use them.
       4. Parent isn't in dialog, scrollbar is.
       This is abnormal and should not happen. */

    if (o != NULL && w->owner == NULL)
    {
        /* Get relative parent's coordinates */
        py -= o->y;
        px -= o->x;
    }

    switch (scrollbar->type)
    {
    case SCROLLBAR_VERTICAL:
        w->y = py;
        w->x = px + p->cols;
        w->lines = p->lines;
        w->cols = 1;
        break;

    default:
        w->x = px;
        w->y = py + p->lines;
        w->cols = p->cols;
        w->lines = 1;
        break;
    }
}

/* --------------------------------------------------------------------------------------------- */

static void
scrollbar_draw_horizontal (WScrollBar * scrollbar)
{
    Widget *w = WIDGET (scrollbar);
    int column = 0;
    int i;

    int start_pos = 0;
    int end_pos = w->cols - 1;
    int total_columns = w->cols;

    if (scrollbar_skin.first_horiz_char != NULL)
    {
        start_pos++;
        total_columns--;

        widget_move (w, 0, 0);
        tty_print_string (scrollbar_skin.first_horiz_char);
    }

    if (scrollbar_skin.last_horiz_char != NULL)
    {
        end_pos--;
        total_columns--;

        widget_move (w, 0, w->cols - 1);
        tty_print_string (scrollbar_skin.last_horiz_char);
    }

    /* Now draw the nice relative pointer */
    if (*scrollbar->total != 0)
        column = *scrollbar->current * total_columns / *scrollbar->total + start_pos;

    for (i = start_pos; i <= end_pos; i++)
    {
        widget_move (w, 0, i);
        if (i != column)
            tty_print_string (scrollbar_skin.background_horiz_char);
        else
            tty_print_string (scrollbar_skin.current_char);
    }
}

/* --------------------------------------------------------------------------------------------- */

static void
scrollbar_draw_vertical (WScrollBar * scrollbar)
{
    Widget *w = WIDGET (scrollbar);
    int line = 0;
    int i;

    int start_pos = 0;
    int end_pos = w->lines - 1;
    int total_lines = w->lines;

    if (scrollbar_skin.first_vert_char != NULL)
    {
        start_pos++;
        total_lines--;

        widget_move (w, 0, 0);
        tty_print_string (scrollbar_skin.first_vert_char);
    }

    if (scrollbar_skin.last_vert_char != NULL)
    {
        end_pos--;
        total_lines--;

        widget_move (w, w->lines - 1, 0);
        tty_print_string (scrollbar_skin.last_vert_char);
    }

    /* Now draw the nice relative pointer */
    if (*scrollbar->total != 0)
        line = *scrollbar->current * total_lines / *scrollbar->total + start_pos;

    for (i = start_pos; i <= end_pos; i++)
    {
        widget_move (w, i, 0);
        if (i != line)
            tty_print_string (scrollbar_skin.background_vert_char);
        else
            tty_print_string (scrollbar_skin.current_char);
    }
}

/* --------------------------------------------------------------------------------------------- */

static void
scrollbar_draw (WScrollBar * scrollbar)
{
    const int normalc = DISABLED_COLOR;

    if (*scrollbar->total <= scrollbar->parent->lines)
        return;

    tty_setcolor (normalc);

    switch (scrollbar->type)
    {
    case SCROLLBAR_VERTICAL:
        scrollbar_draw_vertical (scrollbar);
        break;
    default:
        scrollbar_draw_horizontal (scrollbar);
    }
}

/* --------------------------------------------------------------------------------------------- */

static cb_ret_t
scrollbar_callback (Widget * w, Widget * sender, widget_msg_t msg, int parm, void *data)
{
    WScrollBar *scrollbar = SCROLLBAR (w);
    cb_ret_t ret = MSG_HANDLED;

    switch (msg)
    {
    case MSG_INIT:
        //        w->pos_flags = WPOS_KEEP_RIGHT | WPOS_KEEP_BOTTOM;
        return MSG_HANDLED;

    case MSG_RESIZE:
        scrollbar_set_size (scrollbar);
        return MSG_HANDLED;

    case MSG_FOCUS:
        return MSG_NOT_HANDLED;

    case MSG_ACTION:
        ret = MSG_NOT_HANDLED;

    case MSG_DRAW:
        scrollbar_draw (scrollbar);
        return ret;

    case MSG_DESTROY:
        return MSG_HANDLED;

    default:
        return widget_default_callback (w, sender, msg, parm, data);
    }
}

/* --------------------------------------------------------------------------------------------- */
/*** public functions ****************************************************************************/
/* --------------------------------------------------------------------------------------------- */
/**
 * Create new WScrollBar object.
 *
 * @param parent parent widget
 * @param type type of scrollbar (vertical or horizontal)
 * @return new WScrollBar object
 */

WScrollBar *
scrollbar_new (Widget * parent, scrollbar_type_t type)
{
    WScrollBar *scrollbar;
    Widget *widget;

    scrollbar = g_new (WScrollBar, 1);
    scrollbar->type = type;

    widget = WIDGET (scrollbar);
    widget_init (widget, 1, 1, 1, 1, scrollbar_callback, NULL);

    scrollbar->parent = parent;
    scrollbar_set_size (scrollbar);

    widget_want_cursor (widget, FALSE);
    widget_want_hotkey (widget, FALSE);

    return scrollbar;
}

/* --------------------------------------------------------------------------------------------- */
/**
 * Set total count of items.
 *
 * @param scrollbar WScrollBar object
 * @param total total count of items
 */

void
scrollbar_set_total (WScrollBar * scrollbar, int *total)
{
    if (scrollbar != NULL)
        scrollbar->total = total;
}

/* --------------------------------------------------------------------------------------------- */

/**
 * Set current position of item.
 *
 * @param scrollbar WScrollBar object
 * @param current current position of item
 */

void
scrollbar_set_current (WScrollBar * scrollbar, int *current)
{
    if (scrollbar != NULL)
        scrollbar->current = current;
}

/* --------------------------------------------------------------------------------------------- */

/**
 * Set position of first displayed item.
 *
 * @param scrollbar WScrollBar object
 * @param first_displayed position of first displayed item
 */

void
scrollbar_set_first_displayed (WScrollBar * scrollbar, int *first_displayed)
{
    if (scrollbar != NULL)
        scrollbar->first_displayed = first_displayed;
}

/* --------------------------------------------------------------------------------------------- */
/**
 * Initialize scrollbars.
 */

void
scrollbar_global_init (void)
{
    scrollbar_skin.current_char = mc_skin_get (SKIN_GROUP_NAME, "current-char", "*");

    scrollbar_skin.first_vert_char = mc_skin_get (SKIN_GROUP_NAME, "first-vert-char", NULL);
    scrollbar_skin.last_vert_char = mc_skin_get (SKIN_GROUP_NAME, "last-vert-char", NULL);
    scrollbar_skin.background_vert_char =
        mc_skin_get (SKIN_GROUP_NAME, "background-vert-char", "|");

    scrollbar_skin.first_horiz_char = mc_skin_get (SKIN_GROUP_NAME, "first-horiz-char", NULL);
    scrollbar_skin.last_horiz_char = mc_skin_get (SKIN_GROUP_NAME, "last-horiz-char", NULL);
    scrollbar_skin.background_horiz_char =
        mc_skin_get (SKIN_GROUP_NAME, "background-horiz-char", "-");
}

/* --------------------------------------------------------------------------------------------- */
/**
 * Deinitialize scrollbars.
 */

void
scrollbar_global_deinit (void)
{
    g_free (scrollbar_skin.current_char);

    g_free (scrollbar_skin.first_vert_char);
    g_free (scrollbar_skin.last_vert_char);
    g_free (scrollbar_skin.background_vert_char);

    g_free (scrollbar_skin.first_horiz_char);
    g_free (scrollbar_skin.last_horiz_char);
    g_free (scrollbar_skin.background_horiz_char);
}

/* --------------------------------------------------------------------------------------------- */