/* vi:set ts=8 sts=4 sw=4 noet:
 *
 * VIM - Vi IMproved	by Bram Moolenaar
 *
 * Do ":help uganda"  in Vim to read a list of people who contributed.
 * Do ":help credits" in Vim to see a list of people who contributed.
 * See README.txt for an overview of the Vim source code.
 */

/*
 * Implementation of popup windows.  See ":help popup".
 */

#include "vim.h"

#ifdef FEAT_TEXT_PROP

typedef struct {
    char	*pp_name;
    poppos_T	pp_val;
} poppos_entry_T;

static poppos_entry_T poppos_entries[] = {
    {"botleft", POPPOS_BOTLEFT},
    {"topleft", POPPOS_TOPLEFT},
    {"botright", POPPOS_BOTRIGHT},
    {"topright", POPPOS_TOPRIGHT},
    {"center", POPPOS_CENTER}
};

/*
 * Get option value for "key", which is "line" or "col".
 * Handles "cursor+N" and "cursor-N".
 */
    static int
popup_options_one(dict_T *dict, char_u *key)
{
    dictitem_T	*di;
    char_u	*val;
    char_u	*s;
    char_u	*endp;
    int		n = 0;

    di = dict_find(dict, key, -1);
    if (di == NULL)
	return 0;

    val = tv_get_string(&di->di_tv);
    if (STRNCMP(val, "cursor", 6) != 0)
	return dict_get_number_check(dict, key);

    setcursor_mayforce(TRUE);
    s = val + 6;
    if (*s != NUL)
    {
	endp = s;
	if (*skipwhite(s) == '+' || *skipwhite(s) == '-')
	    n = strtol((char *)s, (char **)&endp, 10);
	if (endp != NULL && *skipwhite(endp) != NUL)
	{
	    semsg(_(e_invexpr2), val);
	    return 0;
	}
    }

    if (STRCMP(key, "line") == 0)
	n = screen_screenrow() + 1 + n;
    else // "col"
	n = screen_screencol() + 1 + n;

    if (n < 1)
	n = 1;
    return n;
}

    static void
get_pos_options(win_T *wp, dict_T *dict)
{
    char_u	*str;
    int		nr;
    dictitem_T	*di;

    nr = popup_options_one(dict, (char_u *)"line");
    if (nr > 0)
	wp->w_wantline = nr;
    nr = popup_options_one(dict, (char_u *)"col");
    if (nr > 0)
	wp->w_wantcol = nr;

    di = dict_find(dict, (char_u *)"fixed", -1);
    if (di != NULL)
	wp->w_popup_fixed = dict_get_number(dict, (char_u *)"fixed") != 0;

    str = dict_get_string(dict, (char_u *)"pos", FALSE);
    if (str != NULL)
    {
	for (nr = 0;
		nr < (int)(sizeof(poppos_entries) / sizeof(poppos_entry_T));
									  ++nr)
	    if (STRCMP(str, poppos_entries[nr].pp_name) == 0)
	    {
		wp->w_popup_pos = poppos_entries[nr].pp_val;
		nr = -1;
		break;
	    }
	if (nr != -1)
	    semsg(_(e_invarg2), str);
    }
}

    static void
set_padding_border(dict_T *dict, int *array, char *name, int max_val)
{
    dictitem_T	*di;

    di = dict_find(dict, (char_u *)name, -1);
    if (di != NULL)
    {
	if (di->di_tv.v_type != VAR_LIST)
	    emsg(_(e_listreq));
	else
	{
	    list_T	*list = di->di_tv.vval.v_list;
	    listitem_T	*li;
	    int		i;
	    int		nr;

	    for (i = 0; i < 4; ++i)
		array[i] = 1;
	    if (list != NULL)
		for (i = 0, li = list->lv_first; i < 4 && i < list->lv_len;
							 ++i, li = li->li_next)
		{
		    nr = (int)tv_get_number(&li->li_tv);
		    if (nr >= 0)
			array[i] = nr > max_val ? max_val : nr;
		}
	}
    }
}

/*
 * Used when popup options contain "moved": set default moved values.
 */
    static void
set_moved_values(win_T *wp)
{
    wp->w_popup_curwin = curwin;
    wp->w_popup_lnum = curwin->w_cursor.lnum;
    wp->w_popup_mincol = curwin->w_cursor.col;
    wp->w_popup_maxcol = curwin->w_cursor.col;
}

/*
 * Used when popup options contain "moved" with "word" or "WORD".
 */
    static void
set_moved_columns(win_T *wp, int flags)
{
    char_u	*ptr;
    int		len = find_ident_under_cursor(&ptr, flags | FIND_NOERROR);

    if (len > 0)
    {
	wp->w_popup_mincol = (int)(ptr - ml_get_curline());
	wp->w_popup_maxcol = wp->w_popup_mincol + len - 1;
    }
}

/*
 * Used when popup options contain "mousemoved": set default moved values.
 */
    static void
set_mousemoved_values(win_T *wp)
{
    wp->w_popup_mouse_row = mouse_row;
    wp->w_popup_mouse_mincol = mouse_col;
    wp->w_popup_mouse_maxcol = mouse_col;
}

/*
 * Used when popup options contain "moved" with "word" or "WORD".
 */
    static void
set_mousemoved_columns(win_T *wp, int flags)
{
    win_T	*textwp;
    char_u	*text;
    int		col;
    pos_T	pos;
    colnr_T	mcol;

    if (find_word_under_cursor(mouse_row, mouse_col, TRUE, flags,
				  &textwp, &pos.lnum, &text, NULL, &col) == OK)
    {
	// convert text column to mouse column
	pos.col = col;
	pos.coladd = 0;
	getvcol(textwp, &pos, &mcol, NULL, NULL);
	wp->w_popup_mouse_mincol = mcol;

	pos.col = col + (colnr_T)STRLEN(text) - 1;
	getvcol(textwp, &pos, NULL, NULL, &mcol);
	wp->w_popup_mouse_maxcol = mcol;
	vim_free(text);
    }
}

/*
 * Return TRUE if "row"/"col" is on the border of the popup.
 * The values are relative to the top-left corner.
 */
    int
popup_on_border(win_T *wp, int row, int col)
{
    return (row == 0 && wp->w_popup_border[0] > 0)
	    || (row == popup_height(wp) - 1 && wp->w_popup_border[2] > 0)
	    || (col == 0 && wp->w_popup_border[3] > 0)
	    || (col == popup_width(wp) - 1 && wp->w_popup_border[1] > 0);
}

/*
 * Return TRUE if "row"/"col" is on the "X" button of the popup.
 * The values are relative to the top-left corner.
 * Caller should check w_popup_close is POPCLOSE_BUTTON.
 */
    int
popup_on_X_button(win_T *wp, int row, int col)
{
    return row == 0 && col == popup_width(wp) - 1;
}

// Values set when dragging a popup window starts.
static int drag_start_row;
static int drag_start_col;
static int drag_start_wantline;
static int drag_start_wantcol;

/*
 * Mouse down on border of popup window: start dragging it.
 * Uses mouse_col and mouse_row.
 */
    void
popup_start_drag(win_T *wp)
{
    drag_start_row = mouse_row;
    drag_start_col = mouse_col;
    // TODO: handle using different corner
    if (wp->w_wantline == 0)
	drag_start_wantline = wp->w_winrow + 1;
    else
	drag_start_wantline = wp->w_wantline;
    if (wp->w_wantcol == 0)
	drag_start_wantcol = wp->w_wincol + 1;
    else
	drag_start_wantcol = wp->w_wantcol;

    // Stop centering the popup
    if (wp->w_popup_pos == POPPOS_CENTER)
	wp->w_popup_pos = POPPOS_TOPLEFT;
}

/*
 * Mouse moved while dragging a popup window: adjust the window popup position.
 */
    void
popup_drag(win_T *wp)
{
    // The popup may be closed before dragging stops.
    if (!win_valid_popup(wp))
	return;

    wp->w_wantline = drag_start_wantline + (mouse_row - drag_start_row);
    if (wp->w_wantline < 1)
	wp->w_wantline = 1;
    if (wp->w_wantline > Rows)
	wp->w_wantline = Rows;
    wp->w_wantcol = drag_start_wantcol + (mouse_col - drag_start_col);
    if (wp->w_wantcol < 1)
	wp->w_wantcol = 1;
    if (wp->w_wantcol > Columns)
	wp->w_wantcol = Columns;

    popup_adjust_position(wp);
}

/*
 * Set w_firstline to match the current "wp->w_topline".
 */
    void
popup_set_firstline(win_T *wp)
{
    int	    height = wp->w_height;

    wp->w_firstline = wp->w_topline;
    popup_adjust_position(wp);

    // we don't want the popup to get smaller, decrement the first line
    // until it doesn't
    while (wp->w_firstline > 1 && wp->w_height < height)
    {
	--wp->w_firstline;
	popup_adjust_position(wp);
    }
}

/*
 * Handle a click in a popup window, if it is in the scrollbar.
 */
    void
popup_handle_scrollbar_click(win_T *wp, int row, int col)
{
    int	    height = popup_height(wp);
    int	    old_topline = wp->w_topline;

    if (wp->w_has_scrollbar == 0)
	return;
    if (row >= wp->w_popup_border[0]
	    && row < height - wp->w_popup_border[2]
	    && col == popup_width(wp) - 1)
    {
	if (row >= height / 2)
	{
	    // Click in lower half, scroll down.
	    if (wp->w_topline < wp->w_buffer->b_ml.ml_line_count)
		++wp->w_topline;
	}
	else if (wp->w_topline > 1)
	    // click on upper half, scroll up.
	    --wp->w_topline;
	if (wp->w_topline != old_topline)
	{
	    popup_set_firstline(wp);
	    redraw_win_later(wp, NOT_VALID);
	}
    }
}

#if defined(FEAT_TIMERS)
    static void
popup_add_timeout(win_T *wp, int time)
{
    char_u	    cbbuf[50];
    char_u	    *ptr = cbbuf;
    typval_T	    tv;

    vim_snprintf((char *)cbbuf, sizeof(cbbuf),
				       "{_ -> popup_close(%d)}", wp->w_id);
    if (get_lambda_tv(&ptr, &tv, TRUE) == OK)
    {
	wp->w_popup_timer = create_timer(time, 0);
	wp->w_popup_timer->tr_callback = get_callback(&tv);
	clear_tv(&tv);
    }
}
#endif

/*
 * Shared between popup_create() and f_popup_move().
 */
    static void
apply_move_options(win_T *wp, dict_T *d)
{
    int nr;

    if ((nr = dict_get_number(d, (char_u *)"minwidth")) > 0)
	wp->w_minwidth = nr;
    if ((nr = dict_get_number(d, (char_u *)"minheight")) > 0)
	wp->w_minheight = nr;
    if ((nr = dict_get_number(d, (char_u *)"maxwidth")) > 0)
	wp->w_maxwidth = nr;
    if ((nr = dict_get_number(d, (char_u *)"maxheight")) > 0)
	wp->w_maxheight = nr;
    get_pos_options(wp, d);
}

    static void
handle_moved_argument(win_T *wp, dictitem_T *di, int mousemoved)
{
    if (di->di_tv.v_type == VAR_STRING && di->di_tv.vval.v_string != NULL)
    {
	char_u  *s = di->di_tv.vval.v_string;
	int	flags = 0;

	if (STRCMP(s, "word") == 0)
	    flags = FIND_IDENT | FIND_STRING;
	else if (STRCMP(s, "WORD") == 0)
	    flags = FIND_STRING;
	else if (STRCMP(s, "expr") == 0)
	    flags = FIND_IDENT | FIND_STRING | FIND_EVAL;
	else if (STRCMP(s, "any") != 0)
	    semsg(_(e_invarg2), s);
	if (flags != 0)
	{
	    if (mousemoved)
		set_mousemoved_columns(wp, flags);
	    else
		set_moved_columns(wp, flags);
	}
    }
    else if (di->di_tv.v_type == VAR_LIST
	    && di->di_tv.vval.v_list != NULL
	    && di->di_tv.vval.v_list->lv_len == 2)
    {
	list_T	*l = di->di_tv.vval.v_list;
	int	mincol = tv_get_number(&l->lv_first->li_tv);
	int	maxcol = tv_get_number(&l->lv_first->li_next->li_tv);

	if (mousemoved)
	{
	    wp->w_popup_mouse_mincol = mincol;
	    wp->w_popup_mouse_maxcol = maxcol;
	}
	else
	{
	    wp->w_popup_mincol = mincol;
	    wp->w_popup_maxcol = maxcol;
	}
    }
    else
	semsg(_(e_invarg2), tv_get_string(&di->di_tv));
}

    static void
check_highlight(dict_T *dict, char *name, char_u **pval)
{
    dictitem_T  *di;
    char_u	*str;

    di = dict_find(dict, (char_u *)name, -1);
    if (di != NULL)
    {
	if (di->di_tv.v_type != VAR_STRING)
	    semsg(_(e_invargval), name);
	else
	{
	    str = tv_get_string(&di->di_tv);
	    if (*str != NUL)
		*pval = vim_strsave(str);
	}
    }
}

/*
 * Shared between popup_create() and f_popup_setoptions().
 */
    static void
apply_general_options(win_T *wp, dict_T *dict)
{
    dictitem_T	*di;
    int		nr;
    char_u	*str;

    // TODO: flip

    di = dict_find(dict, (char_u *)"firstline", -1);
    if (di != NULL)
	wp->w_firstline = dict_get_number(dict, (char_u *)"firstline");
    if (wp->w_firstline < 1)
	wp->w_firstline = 1;

    di = dict_find(dict, (char_u *)"scrollbar", -1);
    if (di != NULL)
	wp->w_want_scrollbar = dict_get_number(dict, (char_u *)"scrollbar");

    str = dict_get_string(dict, (char_u *)"title", FALSE);
    if (str != NULL)
    {
	vim_free(wp->w_popup_title);
	wp->w_popup_title = vim_strsave(str);
    }

    di = dict_find(dict, (char_u *)"wrap", -1);
    if (di != NULL)
    {
	nr = dict_get_number(dict, (char_u *)"wrap");
	wp->w_p_wrap = nr != 0;
    }

    di = dict_find(dict, (char_u *)"drag", -1);
    if (di != NULL)
	wp->w_popup_drag = dict_get_number(dict, (char_u *)"drag");

    di = dict_find(dict, (char_u *)"close", -1);
    if (di != NULL)
    {
	int ok = TRUE;

	if (di->di_tv.v_type == VAR_STRING && di->di_tv.vval.v_string != NULL)
	{
	    char_u  *s = di->di_tv.vval.v_string;

	    if (STRCMP(s, "none") == 0)
		wp->w_popup_close = POPCLOSE_NONE;
	    else if (STRCMP(s, "button") == 0)
		wp->w_popup_close = POPCLOSE_BUTTON;
	    else if (STRCMP(s, "click") == 0)
		wp->w_popup_close = POPCLOSE_CLICK;
	    else
		ok = FALSE;
	}
	else
	    ok = FALSE;
	if (!ok)
	    semsg(_(e_invargNval), "close", tv_get_string(&di->di_tv));
    }

    str = dict_get_string(dict, (char_u *)"highlight", FALSE);
    if (str != NULL)
	set_string_option_direct_in_win(wp, (char_u *)"wincolor", -1,
						   str, OPT_FREE|OPT_LOCAL, 0);

    set_padding_border(dict, wp->w_popup_padding, "padding", 999);
    set_padding_border(dict, wp->w_popup_border, "border", 1);

    di = dict_find(dict, (char_u *)"borderhighlight", -1);
    if (di != NULL)
    {
	if (di->di_tv.v_type != VAR_LIST)
	    emsg(_(e_listreq));
	else
	{
	    list_T	*list = di->di_tv.vval.v_list;
	    listitem_T	*li;
	    int		i;

	    if (list != NULL)
		for (i = 0, li = list->lv_first; i < 4 && i < list->lv_len;
							 ++i, li = li->li_next)
		{
		    str = tv_get_string(&li->li_tv);
		    if (*str != NUL)
			wp->w_border_highlight[i] = vim_strsave(str);
		}
	    if (list->lv_len == 1 && wp->w_border_highlight[0] != NULL)
		for (i = 1; i < 4; ++i)
			wp->w_border_highlight[i] =
					vim_strsave(wp->w_border_highlight[0]);
	}
    }

    di = dict_find(dict, (char_u *)"borderchars", -1);
    if (di != NULL)
    {
	if (di->di_tv.v_type != VAR_LIST)
	    emsg(_(e_listreq));
	else
	{
	    list_T	*list = di->di_tv.vval.v_list;
	    listitem_T	*li;
	    int		i;

	    if (list != NULL)
		for (i = 0, li = list->lv_first; i < 8 && i < list->lv_len;
							 ++i, li = li->li_next)
		{
		    str = tv_get_string(&li->li_tv);
		    if (*str != NUL)
			wp->w_border_char[i] = mb_ptr2char(str);
		}
	    if (list->lv_len == 1)
		for (i = 1; i < 8; ++i)
		    wp->w_border_char[i] = wp->w_border_char[0];
	    if (list->lv_len == 2)
	    {
		for (i = 4; i < 8; ++i)
		    wp->w_border_char[i] = wp->w_border_char[1];
		for (i = 1; i < 4; ++i)
		    wp->w_border_char[i] = wp->w_border_char[0];
	    }
	}
    }

    check_highlight(dict, "scrollbarhighlight", &wp->w_scrollbar_highlight);
    check_highlight(dict, "thumbhighlight", &wp->w_thumb_highlight);

    di = dict_find(dict, (char_u *)"zindex", -1);
    if (di != NULL)
    {
	wp->w_zindex = dict_get_number(dict, (char_u *)"zindex");
	if (wp->w_zindex < 1)
	    wp->w_zindex = POPUPWIN_DEFAULT_ZINDEX;
	if (wp->w_zindex > 32000)
	    wp->w_zindex = 32000;
    }

    di = dict_find(dict, (char_u *)"mask", -1);
    if (di != NULL)
    {
	int ok = TRUE;

	if (di->di_tv.v_type != VAR_LIST)
	    ok = FALSE;
	else if (di->di_tv.vval.v_list != NULL)
	{
	    listitem_T *li;

	    for (li = di->di_tv.vval.v_list->lv_first; li != NULL;
							      li = li->li_next)
	    {
		if (li->li_tv.v_type != VAR_LIST
			|| li->li_tv.vval.v_list == NULL
			|| li->li_tv.vval.v_list->lv_len != 4)
		{
		    ok = FALSE;
		    break;
		}
	    }
	}
	if (ok)
	{
	    wp->w_popup_mask = di->di_tv.vval.v_list;
	    ++wp->w_popup_mask->lv_refcount;
	}
	else
	    semsg(_(e_invargval), "mask");
    }

#if defined(FEAT_TIMERS)
    // Add timer to close the popup after some time.
    nr = dict_get_number(dict, (char_u *)"time");
    if (nr > 0)
	popup_add_timeout(wp, nr);
#endif

    di = dict_find(dict, (char_u *)"moved", -1);
    if (di != NULL)
    {
	set_moved_values(wp);
	handle_moved_argument(wp, di, FALSE);
    }

    di = dict_find(dict, (char_u *)"mousemoved", -1);
    if (di != NULL)
    {
	set_mousemoved_values(wp);
	handle_moved_argument(wp, di, TRUE);
    }

    di = dict_find(dict, (char_u *)"filter", -1);
    if (di != NULL)
    {
	callback_T	callback = get_callback(&di->di_tv);

	if (callback.cb_name != NULL)
	{
	    free_callback(&wp->w_filter_cb);
	    set_callback(&wp->w_filter_cb, &callback);
	}
    }

    di = dict_find(dict, (char_u *)"callback", -1);
    if (di != NULL)
    {
	callback_T	callback = get_callback(&di->di_tv);

	if (callback.cb_name != NULL)
	{
	    free_callback(&wp->w_close_cb);
	    set_callback(&wp->w_close_cb, &callback);
	}
    }
}

/*
 * Go through the options in "dict" and apply them to popup window "wp".
 */
    static void
apply_options(win_T *wp, dict_T *dict)
{
    int		nr;

    apply_move_options(wp, dict);
    apply_general_options(wp, dict);

    nr = dict_get_number(dict, (char_u *)"hidden");
    if (nr > 0)
    {
	wp->w_popup_flags |= POPF_HIDDEN;
	--wp->w_buffer->b_nwindows;
    }

    popup_mask_refresh = TRUE;
}

/*
 * Add lines to the popup from a list of strings.
 */
    static void
add_popup_strings(buf_T *buf, list_T *l)
{
    listitem_T  *li;
    linenr_T    lnum = 0;
    char_u	*p;

    for (li = l->lv_first; li != NULL; li = li->li_next)
	if (li->li_tv.v_type == VAR_STRING)
	{
	    p = li->li_tv.vval.v_string;
	    ml_append_buf(buf, lnum++,
			       p == NULL ? (char_u *)"" : p, (colnr_T)0, TRUE);
	}
}

/*
 * Add lines to the popup from a list of dictionaries.
 */
    static void
add_popup_dicts(buf_T *buf, list_T *l)
{
    listitem_T  *li;
    listitem_T  *pli;
    linenr_T    lnum = 0;
    char_u	*p;
    dict_T	*dict;

    // first add the text lines
    for (li = l->lv_first; li != NULL; li = li->li_next)
    {
	if (li->li_tv.v_type != VAR_DICT)
	{
	    emsg(_(e_dictreq));
	    return;
	}
	dict = li->li_tv.vval.v_dict;
	p = dict == NULL ? NULL
			      : dict_get_string(dict, (char_u *)"text", FALSE);
	ml_append_buf(buf, lnum++,
			       p == NULL ? (char_u *)"" : p, (colnr_T)0, TRUE);
    }

    // add the text properties
    lnum = 1;
    for (li = l->lv_first; li != NULL; li = li->li_next, ++lnum)
    {
	dictitem_T	*di;
	list_T		*plist;

	dict = li->li_tv.vval.v_dict;
	di = dict_find(dict, (char_u *)"props", -1);
	if (di != NULL)
	{
	    if (di->di_tv.v_type != VAR_LIST)
	    {
		emsg(_(e_listreq));
		return;
	    }
	    plist = di->di_tv.vval.v_list;
	    if (plist != NULL)
	    {
		for (pli = plist->lv_first; pli != NULL; pli = pli->li_next)
		{
		    if (pli->li_tv.v_type != VAR_DICT)
		    {
			emsg(_(e_dictreq));
			return;
		    }
		    dict = pli->li_tv.vval.v_dict;
		    if (dict != NULL)
		    {
			int col = dict_get_number(dict, (char_u *)"col");

			prop_add_common( lnum, col, dict, buf, NULL);
		    }
		}
	    }
	}
    }
}

/*
 * Get the padding plus border at the top, adjusted to 1 if there is a title.
 */
    static int
popup_top_extra(win_T *wp)
{
    int	extra = wp->w_popup_border[0] + wp->w_popup_padding[0];

    if (extra == 0 && wp->w_popup_title != NULL && *wp->w_popup_title != NUL)
	return 1;
    return extra;
}

/*
 * Return the height of popup window "wp", including border and padding.
 */
    int
popup_height(win_T *wp)
{
    return wp->w_height
	+ popup_top_extra(wp)
	+ wp->w_popup_padding[2] + wp->w_popup_border[2];
}

/*
 * Return the width of popup window "wp", including border, padding and
 * scrollbar.
 */
    int
popup_width(win_T *wp)
{
    return wp->w_width + wp->w_leftcol
	+ wp->w_popup_padding[3] + wp->w_popup_border[3]
	+ wp->w_popup_padding[1] + wp->w_popup_border[1]
	+ wp->w_has_scrollbar
	+ wp->w_popup_rightoff;
}

/*
 * Adjust the position and size of the popup to fit on the screen.
 */
    void
popup_adjust_position(win_T *wp)
{
    linenr_T	lnum;
    int		wrapped = 0;
    int		maxwidth;
    int		maxspace;
    int		center_vert = FALSE;
    int		center_hor = FALSE;
    int		allow_adjust_left = !wp->w_popup_fixed;
    int		top_extra = popup_top_extra(wp);
    int		right_extra = wp->w_popup_border[1] + wp->w_popup_padding[1];
    int		bot_extra = wp->w_popup_border[2] + wp->w_popup_padding[2];
    int		left_extra = wp->w_popup_border[3] + wp->w_popup_padding[3];
    int		extra_height = top_extra + bot_extra;
    int		extra_width = left_extra + right_extra;
    int		org_winrow = wp->w_winrow;
    int		org_wincol = wp->w_wincol;
    int		org_width = wp->w_width;
    int		org_height = wp->w_height;
    int		org_leftcol = wp->w_leftcol;
    int		org_leftoff = wp->w_popup_leftoff;
    int		minwidth;

    wp->w_winrow = 0;
    wp->w_wincol = 0;
    wp->w_leftcol = 0;
    wp->w_popup_leftoff = 0;
    wp->w_popup_rightoff = 0;
    if (wp->w_popup_pos == POPPOS_CENTER)
    {
	// center after computing the size
	center_vert = TRUE;
	center_hor = TRUE;
    }
    else
    {
	if (wp->w_wantline == 0)
	    center_vert = TRUE;
	else if (wp->w_popup_pos == POPPOS_TOPLEFT
		|| wp->w_popup_pos == POPPOS_TOPRIGHT)
	{
	    wp->w_winrow = wp->w_wantline - 1;
	    if (wp->w_winrow >= Rows)
		wp->w_winrow = Rows - 1;
	}

	if (wp->w_wantcol == 0)
	    center_hor = TRUE;
	else if (wp->w_popup_pos == POPPOS_TOPLEFT
		|| wp->w_popup_pos == POPPOS_BOTLEFT)
	{
	    wp->w_wincol = wp->w_wantcol - 1;
	    if (wp->w_wincol >= Columns - 3)
		wp->w_wincol = Columns - 3;
	}
    }

    // When centering or right aligned, use maximum width.
    // When left aligned use the space available, but shift to the left when we
    // hit the right of the screen.
    maxspace = Columns - wp->w_wincol - left_extra;
    maxwidth = maxspace;
    if (wp->w_maxwidth > 0 && maxwidth > wp->w_maxwidth)
    {
	allow_adjust_left = FALSE;
	maxwidth = wp->w_maxwidth;
    }

    // start at the desired first line
    wp->w_topline = wp->w_firstline;
    if (wp->w_topline > wp->w_buffer->b_ml.ml_line_count)
	wp->w_topline = wp->w_buffer->b_ml.ml_line_count;

    // Compute width based on longest text line and the 'wrap' option.
    // Use a minimum width of one, so that something shows when there is no
    // text.
    // TODO: more accurate wrapping
    wp->w_width = 1;
    for (lnum = wp->w_topline; lnum <= wp->w_buffer->b_ml.ml_line_count; ++lnum)
    {
	// count Tabs for what they are worth
	int len = win_linetabsize(wp, ml_get_buf(wp->w_buffer, lnum, FALSE),
							      (colnr_T)MAXCOL);

	if (wp->w_p_wrap)
	{
	    while (len > maxwidth)
	    {
		++wrapped;
		len -= maxwidth;
		wp->w_width = maxwidth;
	    }
	}
	else if (len > maxwidth
		&& allow_adjust_left
		&& (wp->w_popup_pos == POPPOS_TOPLEFT
		    || wp->w_popup_pos == POPPOS_BOTLEFT))
	{
	    // adjust leftwise to fit text on screen
	    int shift_by = len - maxwidth;

	    if (shift_by > wp->w_wincol)
	    {
		int truncate_shift = shift_by - wp->w_wincol;

		len -= truncate_shift;
		shift_by -= truncate_shift;
	    }

	    wp->w_wincol -= shift_by;
	    maxwidth += shift_by;
	    wp->w_width = maxwidth;
	}
	if (wp->w_width < len)
	    wp->w_width = len;
	// do not use the width of lines we're not going to show
	if (wp->w_maxheight > 0
		       && lnum - wp->w_topline + 1 + wrapped > wp->w_maxheight)
	    break;
    }

    wp->w_has_scrollbar = wp->w_want_scrollbar
	   && (wp->w_topline > 1 || lnum <= wp->w_buffer->b_ml.ml_line_count);

    minwidth = wp->w_minwidth;
    if (wp->w_popup_title != NULL && *wp->w_popup_title != NUL)
    {
	int title_len = vim_strsize(wp->w_popup_title) + 2 - extra_width;

	if (minwidth < title_len)
	    minwidth = title_len;
    }

    if (minwidth > 0 && wp->w_width < minwidth)
	wp->w_width = minwidth;
    if (wp->w_width > maxwidth)
    {
	if (wp->w_width > maxspace)
	    // some columns cut off on the right
	    wp->w_popup_rightoff = wp->w_width - maxspace;
	wp->w_width = maxwidth;
    }
    if (center_hor)
    {
	wp->w_wincol = (Columns - wp->w_width - extra_width) / 2;
	if (wp->w_wincol < 0)
	    wp->w_wincol = 0;
    }
    else if (wp->w_popup_pos == POPPOS_BOTRIGHT
	    || wp->w_popup_pos == POPPOS_TOPRIGHT)
    {
	int leftoff = wp->w_wantcol - (wp->w_width + extra_width);

	// Right aligned: move to the right if needed.
	// No truncation, because that would change the height.
	if (leftoff >= 0)
	    wp->w_wincol = leftoff;
	else if (wp->w_popup_fixed)
	{
	    // "col" specifies the right edge, but popup doesn't fit, skip some
	    // columns when displaying the window, minus left border and
	    // padding.
	    if (-leftoff > left_extra)
		wp->w_leftcol = -leftoff - left_extra;
	    wp->w_width -= wp->w_leftcol;
	    wp->w_popup_leftoff = -leftoff;
	    if (wp->w_width < 0)
		wp->w_width = 0;
	}
    }

    wp->w_height = wp->w_buffer->b_ml.ml_line_count - wp->w_topline
								 + 1 + wrapped;
    if (wp->w_minheight > 0 && wp->w_height < wp->w_minheight)
	wp->w_height = wp->w_minheight;
    if (wp->w_maxheight > 0 && wp->w_height > wp->w_maxheight)
	wp->w_height = wp->w_maxheight;
    if (wp->w_height > Rows - wp->w_winrow)
	wp->w_height = Rows - wp->w_winrow;

    if (center_vert)
    {
	wp->w_winrow = (Rows - wp->w_height - extra_height) / 2;
	if (wp->w_winrow < 0)
	    wp->w_winrow = 0;
    }
    else if (wp->w_popup_pos == POPPOS_BOTRIGHT
	    || wp->w_popup_pos == POPPOS_BOTLEFT)
    {
	if ((wp->w_height + extra_height) <= wp->w_wantline)
	    // bottom aligned: may move down
	    wp->w_winrow = wp->w_wantline - (wp->w_height + extra_height);
	else
	    // not enough space, make top aligned
	    wp->w_winrow = wp->w_wantline + 1;
    }

    wp->w_popup_last_changedtick = CHANGEDTICK(wp->w_buffer);

    // Need to update popup_mask if the position or size changed.
    // And redraw windows that were behind the popup.
    if (org_winrow != wp->w_winrow
	    || org_wincol != wp->w_wincol
	    || org_leftcol != wp->w_leftcol
	    || org_leftoff != wp->w_popup_leftoff
	    || org_width != wp->w_width
	    || org_height != wp->w_height)
    {
	redraw_all_later(VALID);
	popup_mask_refresh = TRUE;
    }
}

typedef enum
{
    TYPE_NORMAL,
    TYPE_ATCURSOR,
    TYPE_BEVAL,
    TYPE_NOTIFICATION,
    TYPE_DIALOG,
    TYPE_MENU
} create_type_T;

/*
 * Make "buf" empty and set the contents to "text".
 * Used by popup_create() and popup_settext().
 */
    static void
popup_set_buffer_text(buf_T *buf, typval_T text)
{
    int	    lnum;

    // Clear the buffer, then replace the lines.
    curbuf = buf;
    for (lnum = buf->b_ml.ml_line_count; lnum > 0; --lnum)
	ml_delete(lnum, FALSE);
    curbuf = curwin->w_buffer;

    // Add text to the buffer.
    if (text.v_type == VAR_STRING)
    {
	// just a string
	ml_append_buf(buf, 0, text.vval.v_string, (colnr_T)0, TRUE);
    }
    else
    {
	list_T *l = text.vval.v_list;

	if (l->lv_len > 0)
	{
	    if (l->lv_first->li_tv.v_type == VAR_STRING)
		// list of strings
		add_popup_strings(buf, l);
	    else
		// list of dictionaries
		add_popup_dicts(buf, l);
	}
    }

    // delete the line that was in the empty buffer
    curbuf = buf;
    ml_delete(buf->b_ml.ml_line_count, FALSE);
    curbuf = curwin->w_buffer;
}

/*
 * popup_create({text}, {options})
 * popup_atcursor({text}, {options})
 */
    static win_T *
popup_create(typval_T *argvars, typval_T *rettv, create_type_T type)
{
    win_T	*wp;
    tabpage_T	*tp = NULL;
    int		tabnr;
    int		new_buffer;
    buf_T	*buf = NULL;
    dict_T	*d;
    int		nr;
    int		i;

    // Check arguments look OK.
    if (argvars[0].v_type == VAR_NUMBER)
    {
	buf = buflist_findnr( argvars[0].vval.v_number);
	if (buf == NULL)
	{
	    semsg(_(e_nobufnr), argvars[0].vval.v_number);
	    return NULL;
	}
    }
    else if (!(argvars[0].v_type == VAR_STRING
		    && argvars[0].vval.v_string != NULL)
		&& !(argvars[0].v_type == VAR_LIST
		    && argvars[0].vval.v_list != NULL))
    {
	emsg(_(e_listreq));
	return NULL;
    }
    if (argvars[1].v_type != VAR_DICT || argvars[1].vval.v_dict == NULL)
    {
	emsg(_(e_dictreq));
	return NULL;
    }
    d = argvars[1].vval.v_dict;

    if (dict_find(d, (char_u *)"tabpage", -1) != NULL)
	tabnr = (int)dict_get_number(d, (char_u *)"tabpage");
    else if (type == TYPE_NOTIFICATION)
	tabnr = -1;  // notifications are global by default
    else
	tabnr = 0;
    if (tabnr > 0)
    {
	tp = find_tabpage(tabnr);
	if (tp == NULL)
	{
	    semsg(_("E997: Tabpage not found: %d"), tabnr);
	    return NULL;
	}
    }

    // Create the window and buffer.
    wp = win_alloc_popup_win();
    if (wp == NULL)
	return NULL;
    rettv->vval.v_number = wp->w_id;
    wp->w_popup_pos = POPPOS_TOPLEFT;
    wp->w_popup_flags = POPF_IS_POPUP;

    if (buf != NULL)
    {
	// use existing buffer
	new_buffer = FALSE;
	win_init_popup_win(wp, buf);
	buffer_ensure_loaded(buf);
    }
    else
    {
	// create a new buffer associated with the popup
	new_buffer = TRUE;
	buf = buflist_new(NULL, NULL, (linenr_T)0,
						 BLN_NEW|BLN_LISTED|BLN_DUMMY);
	if (buf == NULL)
	    return NULL;
	ml_open(buf);

	win_init_popup_win(wp, buf);

	set_local_options_default(wp);
	set_string_option_direct_in_buf(buf, (char_u *)"buftype", -1,
				     (char_u *)"popup", OPT_FREE|OPT_LOCAL, 0);
	set_string_option_direct_in_buf(buf, (char_u *)"bufhidden", -1,
				      (char_u *)"hide", OPT_FREE|OPT_LOCAL, 0);
	buf->b_p_ul = -1;	// no undo
	buf->b_p_swf = FALSE;   // no swap file
	buf->b_p_bl = FALSE;    // unlisted buffer
	buf->b_locked = TRUE;
	wp->w_p_wrap = TRUE;	// 'wrap' is default on

	// Avoid that 'buftype' is reset when this buffer is entered.
	buf->b_p_initialized = TRUE;
    }

    if (tp != NULL)
    {
	// popup on specified tab page
	wp->w_next = tp->tp_first_popupwin;
	tp->tp_first_popupwin = wp;
    }
    else if (tabnr == 0)
    {
	// popup on current tab page
	wp->w_next = curtab->tp_first_popupwin;
	curtab->tp_first_popupwin = wp;
    }
    else // (tabnr < 0)
    {
	win_T *prev = first_popupwin;

	// Global popup: add at the end, so that it gets displayed on top of
	// older ones with the same zindex. Matters for notifications.
	if (first_popupwin == NULL)
	    first_popupwin = wp;
	else
	{
	    while (prev->w_next != NULL)
		prev = prev->w_next;
	    prev->w_next = wp;
	}
    }

    if (new_buffer)
	popup_set_buffer_text(buf, argvars[0]);

    if (type == TYPE_ATCURSOR)
    {
	wp->w_popup_pos = POPPOS_BOTLEFT;
	setcursor_mayforce(TRUE);
	wp->w_wantline = curwin->w_winrow + curwin->w_wrow;
	if (wp->w_wantline == 0)  // cursor in first line
	{
	    wp->w_wantline = 2;
	    wp->w_popup_pos = POPPOS_TOPLEFT;
	}
	wp->w_wantcol = curwin->w_wincol + curwin->w_wcol + 1;
	set_moved_values(wp);
	set_moved_columns(wp, FIND_STRING);
    }

    if (type == TYPE_BEVAL)
    {
	wp->w_popup_pos = POPPOS_BOTLEFT;

	// by default use the mouse position
	wp->w_wantline = mouse_row;
	if (wp->w_wantline <= 0)  // mouse on first line
	{
	    wp->w_wantline = 2;
	    wp->w_popup_pos = POPPOS_TOPLEFT;
	}
	wp->w_wantcol = mouse_col + 1;
	set_mousemoved_values(wp);
	set_mousemoved_columns(wp, FIND_IDENT + FIND_STRING + FIND_EVAL);
    }

    // set default values
    wp->w_zindex = POPUPWIN_DEFAULT_ZINDEX;
    wp->w_popup_close = POPCLOSE_NONE;

    if (type == TYPE_NOTIFICATION)
    {
	win_T  *twp, *nextwin;
	int	height = buf->b_ml.ml_line_count + 3;

	// Try to not overlap with another global popup.  Guess we need 3
	// more screen lines than buffer lines.
	wp->w_wantline = 1;
	for (twp = first_popupwin; twp != NULL; twp = nextwin)
	{
	    nextwin = twp->w_next;
	    if (twp != wp
		    && twp->w_zindex == POPUPWIN_NOTIFICATION_ZINDEX
		    && twp->w_winrow <= wp->w_wantline - 1 + height
		    && twp->w_winrow + popup_height(twp) > wp->w_wantline - 1)
	    {
		// move to below this popup and restart the loop to check for
		// overlap with other popups
		wp->w_wantline = twp->w_winrow + popup_height(twp) + 1;
		nextwin = first_popupwin;
	    }
	}
	if (wp->w_wantline + height > Rows)
	{
	    // can't avoid overlap, put on top in the hope that message goes
	    // away soon.
	    wp->w_wantline = 1;
	}

	wp->w_wantcol = 10;
	wp->w_zindex = POPUPWIN_NOTIFICATION_ZINDEX;
	wp->w_minwidth = 20;
	wp->w_popup_drag = 1;
	wp->w_popup_close = POPCLOSE_CLICK;
	for (i = 0; i < 4; ++i)
	    wp->w_popup_border[i] = 1;
	wp->w_popup_padding[1] = 1;
	wp->w_popup_padding[3] = 1;

	nr = syn_name2id((char_u *)"PopupNotification");
	set_string_option_direct_in_win(wp, (char_u *)"wincolor", -1,
		(char_u *)(nr == 0 ? "WarningMsg" : "PopupNotification"),
		OPT_FREE|OPT_LOCAL, 0);
    }

    if (type == TYPE_DIALOG || type == TYPE_MENU)
    {
	wp->w_popup_pos = POPPOS_CENTER;
	wp->w_zindex = POPUPWIN_DIALOG_ZINDEX;
	wp->w_popup_drag = 1;
	for (i = 0; i < 4; ++i)
	{
	    wp->w_popup_border[i] = 1;
	    wp->w_popup_padding[i] = 1;
	}
    }

    if (type == TYPE_MENU)
    {
	typval_T	tv;
	callback_T	callback;

	tv.v_type = VAR_STRING;
	tv.vval.v_string = (char_u *)"popup_filter_menu";
	callback = get_callback(&tv);
	if (callback.cb_name != NULL)
	    set_callback(&wp->w_filter_cb, &callback);

	wp->w_p_wrap = 0;
    }

    for (i = 0; i < 4; ++i)
	VIM_CLEAR(wp->w_border_highlight[i]);
    for (i = 0; i < 8; ++i)
	wp->w_border_char[i] = 0;
    wp->w_want_scrollbar = 1;
    wp->w_popup_fixed = 0;

    // Deal with options.
    apply_options(wp, argvars[1].vval.v_dict);

#ifdef FEAT_TIMERS
    if (type == TYPE_NOTIFICATION && wp->w_popup_timer == NULL)
	popup_add_timeout(wp, 3000);
#endif

    popup_adjust_position(wp);

    wp->w_vsep_width = 0;

    redraw_all_later(NOT_VALID);
    popup_mask_refresh = TRUE;

    return wp;
}

/*
 * popup_clear()
 */
    void
f_popup_clear(typval_T *argvars UNUSED, typval_T *rettv UNUSED)
{
    close_all_popups();
}

/*
 * popup_create({text}, {options})
 */
    void
f_popup_create(typval_T *argvars, typval_T *rettv)
{
    popup_create(argvars, rettv, TYPE_NORMAL);
}

/*
 * popup_atcursor({text}, {options})
 */
    void
f_popup_atcursor(typval_T *argvars, typval_T *rettv)
{
    popup_create(argvars, rettv, TYPE_ATCURSOR);
}

/*
 * popup_beval({text}, {options})
 */
    void
f_popup_beval(typval_T *argvars, typval_T *rettv)
{
    popup_create(argvars, rettv, TYPE_BEVAL);
}

/*
 * Invoke the close callback for window "wp" with value "result".
 * Careful: The callback may make "wp" invalid!
 */
    static void
invoke_popup_callback(win_T *wp, typval_T *result)
{
    typval_T	rettv;
    int		dummy;
    typval_T	argv[3];

    argv[0].v_type = VAR_NUMBER;
    argv[0].vval.v_number = (varnumber_T)wp->w_id;

    if (result != NULL && result->v_type != VAR_UNKNOWN)
	copy_tv(result, &argv[1]);
    else
    {
	argv[1].v_type = VAR_NUMBER;
	argv[1].vval.v_number = 0;
    }

    argv[2].v_type = VAR_UNKNOWN;

    call_callback(&wp->w_close_cb, -1,
			    &rettv, 2, argv, NULL, 0L, 0L, &dummy, TRUE, NULL);
    if (result != NULL)
	clear_tv(&argv[1]);
    clear_tv(&rettv);
}

/*
 * Close popup "wp" and invoke any close callback for it.
 */
    static void
popup_close_and_callback(win_T *wp, typval_T *arg)
{
    int id = wp->w_id;

    if (wp->w_close_cb.cb_name != NULL)
	// Careful: This may make "wp" invalid.
	invoke_popup_callback(wp, arg);

    popup_close(id);
}

/*
 * Close popup "wp" because of a mouse click.
 */
    void
popup_close_for_mouse_click(win_T *wp)
{
    typval_T res;

    res.v_type = VAR_NUMBER;
    res.vval.v_number = -2;
    popup_close_and_callback(wp, &res);
}

    static void
check_mouse_moved(win_T *wp, win_T *mouse_wp)
{
    // Close the popup when all if these are true:
    // - the mouse is not on this popup
    // - "mousemoved" was used
    // - the mouse is no longer on the same screen row or the mouse column is
    //   outside of the relevant text
    if (wp != mouse_wp
	    && wp->w_popup_mouse_row != 0
	    && (wp->w_popup_mouse_row != mouse_row
		|| mouse_col < wp->w_popup_mouse_mincol
		|| mouse_col > wp->w_popup_mouse_maxcol))
    {
	typval_T res;

	res.v_type = VAR_NUMBER;
	res.vval.v_number = -2;
	// Careful: this makes "wp" invalid.
	popup_close_and_callback(wp, &res);
    }
}

/*
 * Called when the mouse moved: may close a popup with "mousemoved".
 */
    void
popup_handle_mouse_moved(void)
{
    win_T   *wp, *nextwp;
    win_T   *mouse_wp;
    int	    row = mouse_row;
    int	    col = mouse_col;

    // find the window where the mouse is in
    mouse_wp = mouse_find_win(&row, &col, FIND_POPUP);

    for (wp = first_popupwin; wp != NULL; wp = nextwp)
    {
	nextwp = wp->w_next;
	check_mouse_moved(wp, mouse_wp);
    }
    for (wp = curtab->tp_first_popupwin; wp != NULL; wp = nextwp)
    {
	nextwp = wp->w_next;
	check_mouse_moved(wp, mouse_wp);
    }
}

/*
 * In a filter: check if the typed key is a mouse event that is used for
 * dragging the popup.
 */
    static void
filter_handle_drag(win_T *wp, int c, typval_T *rettv)
{
    int	row = mouse_row;
    int	col = mouse_col;

    if (wp->w_popup_drag
	    && is_mouse_key(c)
	    && (wp == popup_dragwin
			  || wp == mouse_find_win(&row, &col, FIND_POPUP)))
	// do not consume the key, allow for dragging the popup
	rettv->vval.v_number = 0;
}

    static void
popup_highlight_curline(win_T *wp)
{
    int	    id;
    char    buf[100];

    match_delete(wp, 1, FALSE);

    id = syn_name2id((char_u *)"PopupSelected");
    vim_snprintf(buf, sizeof(buf), "\\%%%dl.*", (int)wp->w_cursor.lnum);
    match_add(wp, (char_u *)(id == 0 ? "PmenuSel" : "PopupSelected"),
					     (char_u *)buf, 10, 1, NULL, NULL);
}

/*
 * popup_filter_menu({text}, {options})
 */
    void
f_popup_filter_menu(typval_T *argvars, typval_T *rettv)
{
    int		id = tv_get_number(&argvars[0]);
    win_T	*wp = win_id2wp(id);
    char_u	*key = tv_get_string(&argvars[1]);
    typval_T	res;
    int		c;
    linenr_T	old_lnum;

    // If the popup has been closed do not consume the key.
    if (wp == NULL)
	return;

    c = *key;
    if (c == K_SPECIAL && key[1] != NUL)
	c = TO_SPECIAL(key[1], key[2]);

    // consume all keys until done
    rettv->vval.v_number = 1;
    res.v_type = VAR_NUMBER;

    old_lnum = wp->w_cursor.lnum;
    if ((c == 'k' || c == 'K' || c == K_UP) && wp->w_cursor.lnum > 1)
	--wp->w_cursor.lnum;
    if ((c == 'j' || c == 'J' || c == K_DOWN)
		       && wp->w_cursor.lnum < wp->w_buffer->b_ml.ml_line_count)
	++wp->w_cursor.lnum;
    if (old_lnum != wp->w_cursor.lnum)
    {
	popup_highlight_curline(wp);
	return;
    }

    if (c == 'x' || c == 'X' || c == ESC || c == Ctrl_C)
    {
	// Cancelled, invoke callback with -1
	res.vval.v_number = -1;
	popup_close_and_callback(wp, &res);
	return;
    }
    if (c == ' ' || c == K_KENTER || c == CAR || c == NL)
    {
	// Invoke callback with current index.
	res.vval.v_number = wp->w_cursor.lnum;
	popup_close_and_callback(wp, &res);
	return;
    }

    filter_handle_drag(wp, c, rettv);
}

/*
 * popup_filter_yesno({text}, {options})
 */
    void
f_popup_filter_yesno(typval_T *argvars, typval_T *rettv)
{
    int		id = tv_get_number(&argvars[0]);
    win_T	*wp = win_id2wp(id);
    char_u	*key = tv_get_string(&argvars[1]);
    typval_T	res;
    int		c;

    // If the popup has been closed don't consume the key.
    if (wp == NULL)
	return;

    c = *key;
    if (c == K_SPECIAL && key[1] != NUL)
	c = TO_SPECIAL(key[1], key[2]);

    // consume all keys until done
    rettv->vval.v_number = 1;

    if (c == 'y' || c == 'Y')
	res.vval.v_number = 1;
    else if (c == 'n' || c == 'N' || c == 'x' || c == 'X' || c == ESC)
	res.vval.v_number = 0;
    else
    {
	filter_handle_drag(wp, c, rettv);
	return;
    }

    // Invoke callback
    res.v_type = VAR_NUMBER;
    popup_close_and_callback(wp, &res);
}

/*
 * popup_dialog({text}, {options})
 */
    void
f_popup_dialog(typval_T *argvars, typval_T *rettv)
{
    popup_create(argvars, rettv, TYPE_DIALOG);
}

/*
 * popup_menu({text}, {options})
 */
    void
f_popup_menu(typval_T *argvars, typval_T *rettv)
{
    win_T *wp = popup_create(argvars, rettv, TYPE_MENU);

    if (wp != NULL)
	popup_highlight_curline(wp);
}

/*
 * popup_notification({text}, {options})
 */
    void
f_popup_notification(typval_T *argvars, typval_T *rettv)
{
    popup_create(argvars, rettv, TYPE_NOTIFICATION);
}

/*
 * Find the popup window with window-ID "id".
 * If the popup window does not exist NULL is returned.
 * If the window is not a popup window, and error message is given.
 */
    static win_T *
find_popup_win(int id)
{
    win_T *wp = win_id2wp(id);

    if (wp != NULL && !WIN_IS_POPUP(wp))
    {
	semsg(_("E993: window %d is not a popup window"), id);
	return NULL;
    }
    return wp;
}

/*
 * popup_close({id})
 */
    void
f_popup_close(typval_T *argvars, typval_T *rettv UNUSED)
{
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);

    if (wp != NULL)
	popup_close_and_callback(wp, &argvars[1]);
}

/*
 * popup_hide({id})
 */
    void
f_popup_hide(typval_T *argvars, typval_T *rettv UNUSED)
{
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);

    if (wp != NULL && (wp->w_popup_flags & POPF_HIDDEN) == 0)
    {
	wp->w_popup_flags |= POPF_HIDDEN;
	--wp->w_buffer->b_nwindows;
	redraw_all_later(NOT_VALID);
	popup_mask_refresh = TRUE;
    }
}

/*
 * popup_show({id})
 */
    void
f_popup_show(typval_T *argvars, typval_T *rettv UNUSED)
{
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);

    if (wp != NULL && (wp->w_popup_flags & POPF_HIDDEN) != 0)
    {
	wp->w_popup_flags &= ~POPF_HIDDEN;
	++wp->w_buffer->b_nwindows;
	redraw_all_later(NOT_VALID);
	popup_mask_refresh = TRUE;
    }
}

/*
 * popup_settext({id}, {text})
 */
    void
f_popup_settext(typval_T *argvars, typval_T *rettv UNUSED)
{
    int		id = (int)tv_get_number(&argvars[0]);
    win_T	*wp = find_popup_win(id);

    if (wp != NULL)
    {
	if (argvars[1].v_type != VAR_STRING && argvars[1].v_type != VAR_LIST)
	    semsg(_(e_invarg2), tv_get_string(&argvars[1]));
	else
	{
	    popup_set_buffer_text(wp->w_buffer, argvars[1]);
	    popup_adjust_position(wp);
	}
    }
}

    static void
popup_free(win_T *wp)
{
    wp->w_buffer->b_locked = FALSE;
    if (wp->w_winrow + wp->w_height >= cmdline_row)
	clear_cmdline = TRUE;
    win_free_popup(wp);
    redraw_all_later(NOT_VALID);
    popup_mask_refresh = TRUE;
}

/*
 * Close a popup window by Window-id.
 * Does not invoke the callback.
 */
    void
popup_close(int id)
{
    win_T	*wp;
    tabpage_T	*tp;
    win_T	*prev = NULL;

    // go through global popups
    for (wp = first_popupwin; wp != NULL; prev = wp, wp = wp->w_next)
	if (wp->w_id == id)
	{
	    if (prev == NULL)
		first_popupwin = wp->w_next;
	    else
		prev->w_next = wp->w_next;
	    popup_free(wp);
	    return;
	}

    // go through tab-local popups
    FOR_ALL_TABPAGES(tp)
	popup_close_tabpage(tp, id);
}

/*
 * Close a popup window with Window-id "id" in tabpage "tp".
 */
    void
popup_close_tabpage(tabpage_T *tp, int id)
{
    win_T	*wp;
    win_T	**root = &tp->tp_first_popupwin;
    win_T	*prev = NULL;

    for (wp = *root; wp != NULL; prev = wp, wp = wp->w_next)
	if (wp->w_id == id)
	{
	    if (prev == NULL)
		*root = wp->w_next;
	    else
		prev->w_next = wp->w_next;
	    popup_free(wp);
	    return;
	}
}

    void
close_all_popups(void)
{
    while (first_popupwin != NULL)
	popup_close(first_popupwin->w_id);
    while (curtab->tp_first_popupwin != NULL)
	popup_close(curtab->tp_first_popupwin->w_id);
}

/*
 * popup_move({id}, {options})
 */
    void
f_popup_move(typval_T *argvars, typval_T *rettv UNUSED)
{
    dict_T	*dict;
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);

    if (wp == NULL)
	return;  // invalid {id}

    if (argvars[1].v_type != VAR_DICT || argvars[1].vval.v_dict == NULL)
    {
	emsg(_(e_dictreq));
	return;
    }
    dict = argvars[1].vval.v_dict;

    apply_move_options(wp, dict);

    if (wp->w_winrow + wp->w_height >= cmdline_row)
	clear_cmdline = TRUE;
    popup_adjust_position(wp);
}

/*
 * popup_setoptions({id}, {options})
 */
    void
f_popup_setoptions(typval_T *argvars, typval_T *rettv UNUSED)
{
    dict_T	*dict;
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);
    linenr_T	old_firstline;

    if (wp == NULL)
	return;  // invalid {id}

    if (argvars[1].v_type != VAR_DICT || argvars[1].vval.v_dict == NULL)
    {
	emsg(_(e_dictreq));
	return;
    }
    dict = argvars[1].vval.v_dict;
    old_firstline = wp->w_firstline;

    apply_move_options(wp, dict);
    apply_general_options(wp, dict);

    if (old_firstline != wp->w_firstline)
	redraw_win_later(wp, NOT_VALID);
    popup_mask_refresh = TRUE;
    popup_adjust_position(wp);
}

/*
 * popup_getpos({id})
 */
    void
f_popup_getpos(typval_T *argvars, typval_T *rettv)
{
    dict_T	*dict;
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);
    int		top_extra;
    int		left_extra;

    if (rettv_dict_alloc(rettv) == OK)
    {
	if (wp == NULL)
	    return;  // invalid {id}
	top_extra = popup_top_extra(wp);
	left_extra = wp->w_popup_border[3] + wp->w_popup_padding[3];

	dict = rettv->vval.v_dict;

	dict_add_number(dict, "line", wp->w_winrow + 1);
	dict_add_number(dict, "col", wp->w_wincol + 1);
	dict_add_number(dict, "width", wp->w_width + left_extra
			     + wp->w_popup_border[1] + wp->w_popup_padding[1]);
	dict_add_number(dict, "height", wp->w_height + top_extra
			     + wp->w_popup_border[2] + wp->w_popup_padding[2]);

	dict_add_number(dict, "core_line", wp->w_winrow + 1 + top_extra);
	dict_add_number(dict, "core_col", wp->w_wincol + 1 + left_extra);
	dict_add_number(dict, "core_width", wp->w_width);
	dict_add_number(dict, "core_height", wp->w_height);

	dict_add_number(dict, "scrollbar", wp->w_has_scrollbar);
	dict_add_number(dict, "firstline", wp->w_topline);
	dict_add_number(dict, "visible",
		      win_valid(wp) && (wp->w_popup_flags & POPF_HIDDEN) == 0);
    }
}

/*
 * For popup_getoptions(): add a "border" or "padding" entry to "dict".
 */
    static void
get_padding_border(dict_T *dict, int *array, char *name)
{
    list_T  *list;
    int	    i;

    if (array[0] == 0 && array[1] == 0 && array[2] == 0 && array[3] == 0)
	return;

    list = list_alloc();
    if (list != NULL)
    {
	dict_add_list(dict, name, list);
	if (array[0] != 1 || array[1] != 1 || array[2] != 1 || array[3] != 1)
	    for (i = 0; i < 4; ++i)
		list_append_number(list, array[i]);
    }
}

/*
 * For popup_getoptions(): add a "borderhighlight" entry to "dict".
 */
    static void
get_borderhighlight(dict_T *dict, win_T *wp)
{
    list_T  *list;
    int	    i;

    for (i = 0; i < 4; ++i)
	if (wp->w_border_highlight[i] != NULL)
	    break;
    if (i == 4)
	return;

    list = list_alloc();
    if (list != NULL)
    {
	dict_add_list(dict, "borderhighlight", list);
	for (i = 0; i < 4; ++i)
	    list_append_string(list, wp->w_border_highlight[i], -1);
    }
}

/*
 * For popup_getoptions(): add a "borderchars" entry to "dict".
 */
    static void
get_borderchars(dict_T *dict, win_T *wp)
{
    list_T  *list;
    int	    i;
    char_u  buf[NUMBUFLEN];
    int	    len;

    for (i = 0; i < 8; ++i)
	if (wp->w_border_char[i] != 0)
	    break;
    if (i == 8)
	return;

    list = list_alloc();
    if (list != NULL)
    {
	dict_add_list(dict, "borderchars", list);
	for (i = 0; i < 8; ++i)
	{
	    len = mb_char2bytes(wp->w_border_char[i], buf);
	    list_append_string(list, buf, len);
	}
    }
}

/*
 * For popup_getoptions(): add a "moved" and "mousemoved" entry to "dict".
 */
    static void
get_moved_list(dict_T *dict, win_T *wp)
{
    list_T  *list;

    list = list_alloc();
    if (list != NULL)
    {
	dict_add_list(dict, "moved", list);
	list_append_number(list, wp->w_popup_lnum);
	list_append_number(list, wp->w_popup_mincol);
	list_append_number(list, wp->w_popup_maxcol);
    }
    list = list_alloc();
    if (list != NULL)
    {
	dict_add_list(dict, "mousemoved", list);
	list_append_number(list, wp->w_popup_mouse_row);
	list_append_number(list, wp->w_popup_mouse_mincol);
	list_append_number(list, wp->w_popup_mouse_maxcol);
    }
}

/*
 * popup_getoptions({id})
 */
    void
f_popup_getoptions(typval_T *argvars, typval_T *rettv)
{
    dict_T	*dict;
    int		id = (int)tv_get_number(argvars);
    win_T	*wp = find_popup_win(id);
    tabpage_T	*tp;
    int		i;

    if (rettv_dict_alloc(rettv) == OK)
    {
	if (wp == NULL)
	    return;

	dict = rettv->vval.v_dict;
	dict_add_number(dict, "line", wp->w_wantline);
	dict_add_number(dict, "col", wp->w_wantcol);
	dict_add_number(dict, "minwidth", wp->w_minwidth);
	dict_add_number(dict, "minheight", wp->w_minheight);
	dict_add_number(dict, "maxheight", wp->w_maxheight);
	dict_add_number(dict, "maxwidth", wp->w_maxwidth);
	dict_add_number(dict, "firstline", wp->w_firstline);
	dict_add_number(dict, "scrollbar", wp->w_want_scrollbar);
	dict_add_number(dict, "zindex", wp->w_zindex);
	dict_add_number(dict, "fixed", wp->w_popup_fixed);
	dict_add_string(dict, "title", wp->w_popup_title);
	dict_add_number(dict, "wrap", wp->w_p_wrap);
	dict_add_number(dict, "drag", wp->w_popup_drag);
	dict_add_string(dict, "highlight", wp->w_p_wcr);
	if (wp->w_scrollbar_highlight != NULL)
	    dict_add_string(dict, "scrollbarhighlight",
						    wp->w_scrollbar_highlight);
	if (wp->w_thumb_highlight != NULL)
	    dict_add_string(dict, "thumbhighlight", wp->w_thumb_highlight);

	// find the tabpage that holds this popup
	i = 1;
	FOR_ALL_TABPAGES(tp)
	{
	    win_T *p;

	     for (p = tp->tp_first_popupwin; p != NULL; p = wp->w_next)
		 if (p->w_id == id)
		     break;
	     if (p != NULL)
		 break;
	     ++i;
	}
	if (tp == NULL)
	    i = -1;  // must be global
	else if (tp == curtab)
	    i = 0;
	dict_add_number(dict, "tabpage", i);

	get_padding_border(dict, wp->w_popup_padding, "padding");
	get_padding_border(dict, wp->w_popup_border, "border");
	get_borderhighlight(dict, wp);
	get_borderchars(dict, wp);
	get_moved_list(dict, wp);

	if (wp->w_filter_cb.cb_name != NULL)
	    dict_add_callback(dict, "filter", &wp->w_filter_cb);
	if (wp->w_close_cb.cb_name != NULL)
	    dict_add_callback(dict, "callback", &wp->w_close_cb);

	for (i = 0; i < (int)(sizeof(poppos_entries) / sizeof(poppos_entry_T));
									   ++i)
	    if (wp->w_popup_pos == poppos_entries[i].pp_val)
	    {
		dict_add_string(dict, "pos",
					  (char_u *)poppos_entries[i].pp_name);
		break;
	    }

	dict_add_string(dict, "close", (char_u *)(
		    wp->w_popup_close == POPCLOSE_BUTTON ? "button"
		    : wp->w_popup_close == POPCLOSE_CLICK ? "click" : "none"));

# if defined(FEAT_TIMERS)
	dict_add_number(dict, "time", wp->w_popup_timer != NULL
				 ?  (long)wp->w_popup_timer->tr_interval : 0L);
# endif
    }
}

    int
error_if_popup_window()
{
    if (WIN_IS_POPUP(curwin))
    {
	emsg(_("E994: Not allowed in a popup window"));
	return TRUE;
    }
    return FALSE;
}

/*
 * Reset all the POPF_HANDLED flags in global popup windows and popup windows
 * in the current tab page.
 */
    void
popup_reset_handled()
{
    win_T *wp;

    for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
	wp->w_popup_flags &= ~POPF_HANDLED;
    for (wp = curtab->tp_first_popupwin; wp != NULL; wp = wp->w_next)
	wp->w_popup_flags &= ~POPF_HANDLED;
}

/*
 * Find the next visible popup where POPF_HANDLED is not set.
 * Must have called popup_reset_handled() first.
 * When "lowest" is TRUE find the popup with the lowest zindex, otherwise the
 * popup with the highest zindex.
 */
    win_T *
find_next_popup(int lowest)
{
    win_T   *wp;
    win_T   *found_wp;
    int	    found_zindex;

    found_zindex = lowest ? INT_MAX : 0;
    found_wp = NULL;
    for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
	if ((wp->w_popup_flags & (POPF_HANDLED|POPF_HIDDEN)) == 0
		&& (lowest ? wp->w_zindex < found_zindex
			   : wp->w_zindex > found_zindex))
	{
	    found_zindex = wp->w_zindex;
	    found_wp = wp;
	}
    for (wp = curtab->tp_first_popupwin; wp != NULL; wp = wp->w_next)
	if ((wp->w_popup_flags & (POPF_HANDLED|POPF_HIDDEN)) == 0
		&& (lowest ? wp->w_zindex < found_zindex
			   : wp->w_zindex > found_zindex))
	{
	    found_zindex = wp->w_zindex;
	    found_wp = wp;
	}

    if (found_wp != NULL)
	found_wp->w_popup_flags |= POPF_HANDLED;
    return found_wp;
}

/*
 * Invoke the filter callback for window "wp" with typed character "c".
 * Uses the global "mod_mask" for modifiers.
 * Returns the return value of the filter.
 * Careful: The filter may make "wp" invalid!
 */
    static int
invoke_popup_filter(win_T *wp, int c)
{
    int		res;
    typval_T	rettv;
    int		dummy;
    typval_T	argv[3];
    char_u	buf[NUMBUFLEN];

    // Emergency exit: CTRL-C closes the popup.
    if (c == Ctrl_C)
    {
	rettv.v_type = VAR_NUMBER;
	rettv.vval.v_number = -1;
	popup_close_and_callback(wp, &rettv);
	return 1;
    }

    argv[0].v_type = VAR_NUMBER;
    argv[0].vval.v_number = (varnumber_T)wp->w_id;

    // Convert the number to a string, so that the function can use:
    //	    if a:c == "\<F2>"
    buf[special_to_buf(c, mod_mask, TRUE, buf)] = NUL;
    argv[1].v_type = VAR_STRING;
    argv[1].vval.v_string = vim_strsave(buf);

    argv[2].v_type = VAR_UNKNOWN;

    // NOTE: The callback might close the popup, thus make "wp" invalid.
    call_callback(&wp->w_filter_cb, -1,
			    &rettv, 2, argv, NULL, 0L, 0L, &dummy, TRUE, NULL);
    res = tv_get_number(&rettv);
    vim_free(argv[1].vval.v_string);
    clear_tv(&rettv);
    return res;
}

/*
 * Called when "c" was typed: invoke popup filter callbacks.
 * Returns TRUE when the character was consumed,
 */
    int
popup_do_filter(int c)
{
    int		res = FALSE;
    win_T	*wp;

    popup_reset_handled();

    while (!res && (wp = find_next_popup(FALSE)) != NULL)
	if (wp->w_filter_cb.cb_name != NULL)
	    res = invoke_popup_filter(wp, c);

    return res;
}

/*
 * Called when the cursor moved: check if any popup needs to be closed if the
 * cursor moved far enough.
 */
    void
popup_check_cursor_pos()
{
    win_T *wp;
    typval_T tv;

    popup_reset_handled();
    while ((wp = find_next_popup(TRUE)) != NULL)
	if (wp->w_popup_curwin != NULL
		&& (curwin != wp->w_popup_curwin
		    || curwin->w_cursor.lnum != wp->w_popup_lnum
		    || curwin->w_cursor.col < wp->w_popup_mincol
		    || curwin->w_cursor.col > wp->w_popup_maxcol))
	{
	    tv.v_type = VAR_NUMBER;
	    tv.vval.v_number = -1;
	    popup_close_and_callback(wp, &tv);
	}
}

/*
 * Return TRUE if "col" / "line" matches with an entry in w_popup_mask.
 * "col" and "line" are screen coordinates.
 */
    static int
popup_masked(win_T *wp, int screencol, int screenline)
{
    int		col = screencol - wp->w_wincol + 1 + wp->w_popup_leftoff;
    int		line = screenline - wp->w_winrow + 1;
    listitem_T	*lio, *li;
    int		width, height;

    if (wp->w_popup_mask == NULL)
	return FALSE;
    width = popup_width(wp);
    height = popup_height(wp);

    for (lio = wp->w_popup_mask->lv_first; lio != NULL; lio = lio->li_next)
    {
	int cols, cole;
	int lines, linee;

	li = lio->li_tv.vval.v_list->lv_first;
	cols = tv_get_number(&li->li_tv);
	if (cols < 0)
	    cols = width + cols + 1;
	if (col < cols)
	    continue;
	li = li->li_next;
	cole = tv_get_number(&li->li_tv);
	if (cole < 0)
	    cole = width + cole + 1;
	if (col > cole)
	    continue;
	li = li->li_next;
	lines = tv_get_number(&li->li_tv);
	if (lines < 0)
	    lines = height + lines + 1;
	if (line < lines)
	    continue;
	li = li->li_next;
	linee = tv_get_number(&li->li_tv);
	if (linee < 0)
	    linee = height + linee + 1;
	if (line > linee)
	    continue;
	return TRUE;
    }
    return FALSE;
}

/*
 * Set flags in popup_transparent[] for window "wp" to "val".
 */
    static void
update_popup_transparent(win_T *wp, int val)
{
    if (wp->w_popup_mask != NULL)
    {
	int		width = popup_width(wp);
	int		height = popup_height(wp);
	listitem_T	*lio, *li;
	int		cols, cole;
	int		lines, linee;
	int		col, line;

	for (lio = wp->w_popup_mask->lv_first; lio != NULL; lio = lio->li_next)
	{
	    li = lio->li_tv.vval.v_list->lv_first;
	    cols = tv_get_number(&li->li_tv);
	    if (cols < 0)
		cols = width + cols + 1;
	    li = li->li_next;
	    cole = tv_get_number(&li->li_tv);
	    if (cole < 0)
		cole = width + cole + 1;
	    li = li->li_next;
	    lines = tv_get_number(&li->li_tv);
	    if (lines < 0)
		lines = height + lines + 1;
	    li = li->li_next;
	    linee = tv_get_number(&li->li_tv);
	    if (linee < 0)
		linee = height + linee + 1;

	    --cols;
	    cols -= wp->w_popup_leftoff;
	    if (cols < 0)
		cols = 0;
	    cole -= wp->w_popup_leftoff;
	    --lines;
	    if (lines < 0)
		lines = 0;
	    for (line = lines; line < linee && line < screen_Rows; ++line)
		for (col = cols; col < cole && col < screen_Columns; ++col)
		    popup_transparent[(line + wp->w_winrow) * screen_Columns
						   + col + wp->w_wincol] = val;
	}
    }
}

/*
 * Update "popup_mask" if needed.
 * Also recomputes the popup size and positions.
 * Also updates "popup_visible".
 * Also marks window lines for redrawing.
 */
    void
may_update_popup_mask(int type)
{
    win_T	*wp;
    short	*mask;
    int		line, col;
    int		redraw_all = FALSE;

    // Need to recompute when switching tabs.
    // Also recompute when the type is CLEAR or NOT_VALID, something basic
    // (such as the screen size) must have changed.
    if (popup_mask_tab != curtab || type >= NOT_VALID)
    {
	popup_mask_refresh = TRUE;
	redraw_all = TRUE;
    }
    if (!popup_mask_refresh)
    {
	// Check if any buffer has changed.
	for (wp = first_popupwin; wp != NULL; wp = wp->w_next)
	    if (wp->w_popup_last_changedtick != CHANGEDTICK(wp->w_buffer))
		popup_mask_refresh = TRUE;
	for (wp = curtab->tp_first_popupwin; wp != NULL; wp = wp->w_next)
	    if (wp->w_popup_last_changedtick != CHANGEDTICK(wp->w_buffer))
		popup_mask_refresh = TRUE;
	if (!popup_mask_refresh)
	    return;
    }

    // Need to update the mask, something has changed.
    popup_mask_refresh = FALSE;
    popup_mask_tab = curtab;
    popup_visible = FALSE;

    // If redrawing everything, just update "popup_mask".
    // If redrawing only what is needed, update "popup_mask_next" and then
    // compare with "popup_mask" to see what changed.
    if (type >= SOME_VALID)
	mask = popup_mask;
    else
	mask = popup_mask_next;
    vim_memset(mask, 0, screen_Rows * screen_Columns * sizeof(short));

    // Find the window with the lowest zindex that hasn't been handled yet,
    // so that the window with a higher zindex overwrites the value in
    // popup_mask.
    popup_reset_handled();
    while ((wp = find_next_popup(TRUE)) != NULL)
    {
	int height;
	int width;

	popup_visible = TRUE;

	// Recompute the position if the text changed.
	if (redraw_all
		|| wp->w_popup_last_changedtick != CHANGEDTICK(wp->w_buffer))
	    popup_adjust_position(wp);

	height = popup_height(wp);
	width = popup_width(wp) - wp->w_popup_leftoff;
	for (line = wp->w_winrow;
		line < wp->w_winrow + height && line < screen_Rows; ++line)
	    for (col = wp->w_wincol;
		 col < wp->w_wincol + width && col < screen_Columns; ++col)
		if (!popup_masked(wp, col, line))
		    mask[line * screen_Columns + col] = wp->w_zindex;
    }

    // Only check which lines are to be updated if not already
    // updating all lines.
    if (mask == popup_mask_next)
	for (line = 0; line < screen_Rows; ++line)
	{
	    int	    col_done = 0;

	    for (col = 0; col < screen_Columns; ++col)
	    {
		int off = line * screen_Columns + col;

		if (popup_mask[off] != popup_mask_next[off])
		{
		    popup_mask[off] = popup_mask_next[off];

		    if (line >= cmdline_row)
		    {
			// the command line needs to be cleared if text below
			// the popup is now visible.
			if (!msg_scrolled && popup_mask_next[off] == 0)
			    clear_cmdline = TRUE;
		    }
		    else if (col >= col_done)
		    {
			linenr_T	lnum;
			int		line_cp = line;
			int		col_cp = col;

			// The screen position "line" / "col" needs to be
			// redrawn.  Figure out what window that is and update
			// w_redraw_top and w_redr_bot.  Only needs to be done
			// once for each window line.
			wp = mouse_find_win(&line_cp, &col_cp, IGNORE_POPUP);
			if (wp != NULL)
			{
			    if (line_cp >= wp->w_height)
				// In (or below) status line
				wp->w_redr_status = TRUE;
			    // compute the position in the buffer line from the
			    // position on the screen
			    else if (mouse_comp_pos(wp, &line_cp, &col_cp,
									&lnum))
				// past bottom
				wp->w_redr_status = TRUE;
			    else
				redrawWinline(wp, lnum);

			    // This line is going to be redrawn, no need to
			    // check until the right side of the window.
			    col_done = wp->w_wincol + wp->w_width - 1;
			}
		    }
		}
	    }
	}
}

/*
 * Return a string of "len" spaces in IObuff.
 */
    static char_u *
get_spaces(int len)
{
    vim_memset(IObuff, ' ', (size_t)len);
    IObuff[len] = NUL;
    return IObuff;
}

/*
 * Update popup windows.  They are drawn on top of normal windows.
 * "win_update" is called for each popup window, lowest zindex first.
 */
    void
update_popups(void (*win_update)(win_T *wp))
{
    win_T   *wp;
    int	    top_off;
    int	    left_extra;
    int	    total_width;
    int	    total_height;
    int	    top_padding;
    int	    popup_attr;
    int	    border_attr[4];
    int	    border_char[8];
    char_u  buf[MB_MAXBYTES];
    int	    row;
    int	    wincol;
    int	    padcol = 0;
    int	    padwidth = 0;
    int	    i;
    int	    sb_thumb_top = 0;
    int	    sb_thumb_height = 0;
    int	    attr_scroll = 0;
    int	    attr_thumb = 0;

    // Find the window with the lowest zindex that hasn't been updated yet,
    // so that the window with a higher zindex is drawn later, thus goes on
    // top.
    popup_reset_handled();
    while ((wp = find_next_popup(TRUE)) != NULL)
    {
	// This drawing uses the zindex of the popup window, so that it's on
	// top of the text but doesn't draw when another popup with higher
	// zindex is on top of the character.
	screen_zindex = wp->w_zindex;

	// Set flags in popup_transparent[] for masked cells.
	update_popup_transparent(wp, 1);

	// adjust w_winrow and w_wincol for border and padding, since
	// win_update() doesn't handle them.
	top_off = popup_top_extra(wp);
	left_extra = wp->w_popup_padding[3] + wp->w_popup_border[3]
							 - wp->w_popup_leftoff;
	if (wp->w_wincol + left_extra < 0)
	    left_extra = -wp->w_wincol;
	wp->w_winrow += top_off;
	wp->w_wincol += left_extra;

	// Draw the popup text, unless it's off screen.
	if (wp->w_winrow < screen_Rows && wp->w_wincol < screen_Columns)
	    win_update(wp);

	wp->w_winrow -= top_off;
	wp->w_wincol -= left_extra;

	total_width = popup_width(wp);
	total_height = popup_height(wp);
	popup_attr = get_wcr_attr(wp);

	// We can only use these line drawing characters when 'encoding' is
	// "utf-8" and 'ambiwidth' is "single".
	if (enc_utf8 && *p_ambw == 's')
	{
	    border_char[0] = border_char[2] = 0x2550;
	    border_char[1] = border_char[3] = 0x2551;
	    border_char[4] = 0x2554;
	    border_char[5] = 0x2557;
	    border_char[6] = 0x255d;
	    border_char[7] = 0x255a;
	}
	else
	{
	    border_char[0] = border_char[2] = '-';
	    border_char[1] = border_char[3] = '|';
	    for (i = 4; i < 8; ++i)
		border_char[i] = '+';
	}
	for (i = 0; i < 8; ++i)
	    if (wp->w_border_char[i] != 0)
		border_char[i] = wp->w_border_char[i];

	for (i = 0; i < 4; ++i)
	{
	    border_attr[i] = popup_attr;
	    if (wp->w_border_highlight[i] != NULL)
		border_attr[i] = syn_name2attr(wp->w_border_highlight[i]);
	}

	wincol = wp->w_wincol - wp->w_popup_leftoff;
	top_padding = wp->w_popup_padding[0];
	if (wp->w_popup_border[0] > 0)
	{
	    // top border
	    screen_fill(wp->w_winrow, wp->w_winrow + 1,
		    wincol < 0 ? 0 : wincol, wincol + total_width,
		    wp->w_popup_border[3] != 0 && wp->w_popup_leftoff == 0
					     ? border_char[4] : border_char[0],
		    border_char[0], border_attr[0]);
	    if (wp->w_popup_border[1] > 0 && wp->w_popup_rightoff == 0)
	    {
		buf[mb_char2bytes(border_char[5], buf)] = NUL;
		screen_puts(buf, wp->w_winrow,
			       wincol + total_width - 1, border_attr[1]);
	    }
	}
	else if (wp->w_popup_padding[0] == 0 && popup_top_extra(wp) > 0)
	    top_padding = 1;

	if (top_padding > 0 || wp->w_popup_padding[2] > 0)
	{
	    padcol = wincol + wp->w_popup_border[3];
	    padwidth = wp->w_wincol + total_width - wp->w_popup_border[1]
							 - wp->w_has_scrollbar;
	    if (padcol < 0)
	    {
		padwidth += padcol;
		padcol = 0;
	    }
	}
	if (top_padding > 0)
	{
	    // top padding
	    row = wp->w_winrow + wp->w_popup_border[0];
	    screen_fill(row, row + top_padding, padcol, padwidth,
							 ' ', ' ', popup_attr);
	}

	// Title goes on top of border or padding.
	if (wp->w_popup_title != NULL)
	    screen_puts(wp->w_popup_title, wp->w_winrow, wp->w_wincol + 1,
		    wp->w_popup_border[0] > 0 ? border_attr[0] : popup_attr);

	// Compute scrollbar thumb position and size.
	if (wp->w_has_scrollbar)
	{
	    linenr_T linecount = wp->w_buffer->b_ml.ml_line_count;

	    sb_thumb_height = (wp->w_height * wp->w_height + linecount / 2)
								   / linecount;
	    if (sb_thumb_height == 0)
		sb_thumb_height = 1;
	    if (linecount <= wp->w_height)
		// it just fits, avoid divide by zero
		sb_thumb_top = 0;
	    else
		sb_thumb_top = (wp->w_topline - 1
				+ (linecount / wp->w_height) / 2)
				* (wp->w_height - sb_thumb_height)
						  / (linecount - wp->w_height);
	    if (wp->w_scrollbar_highlight != NULL)
		attr_scroll = syn_name2attr(wp->w_scrollbar_highlight);
	    else
		attr_scroll = highlight_attr[HLF_PSB];
	    if (wp->w_thumb_highlight != NULL)
		attr_thumb = syn_name2attr(wp->w_thumb_highlight);
	    else
		attr_thumb = highlight_attr[HLF_PST];
	}

	for (i = wp->w_popup_border[0];
				 i < total_height - wp->w_popup_border[2]; ++i)
	{
	    int	pad_left;
	    // left and right padding only needed next to the body
	    int do_padding =
		    i >= wp->w_popup_border[0] + wp->w_popup_padding[0]
		    && i < total_height - wp->w_popup_border[2]
						 - wp->w_popup_padding[2];

	    row = wp->w_winrow + i;

	    // left border
	    if (wp->w_popup_border[3] > 0 && wincol >= 0)
	    {
		buf[mb_char2bytes(border_char[3], buf)] = NUL;
		screen_puts(buf, row, wincol, border_attr[3]);
	    }
	    if (do_padding && wp->w_popup_padding[3] > 0)
	    {
		int col = wincol + wp->w_popup_border[3];

		// left padding
		pad_left = wp->w_popup_padding[3];
		if (col < 0)
		{
		    pad_left += col;
		    col = 0;
		}
		if (pad_left > 0)
		    screen_puts(get_spaces(pad_left), row, col, popup_attr);
	    }
	    // scrollbar
	    if (wp->w_has_scrollbar)
	    {
		int line = i - top_off;
		int scroll_col = wp->w_wincol + total_width - 1
						       - wp->w_popup_border[1];

		if (line >= 0 && line < wp->w_height)
		    screen_putchar(' ', row, scroll_col,
			    line >= sb_thumb_top
				       && line < sb_thumb_top + sb_thumb_height
						  ? attr_thumb : attr_scroll);
		else
		    screen_putchar(' ', row, scroll_col, popup_attr);
	    }
	    // right border
	    if (wp->w_popup_border[1] > 0)
	    {
		buf[mb_char2bytes(border_char[1], buf)] = NUL;
		screen_puts(buf, row, wincol + total_width - 1, border_attr[1]);
	    }
	    // right padding
	    if (do_padding && wp->w_popup_padding[1] > 0)
		screen_puts(get_spaces(wp->w_popup_padding[1]), row,
			wincol + wp->w_popup_border[3]
			+ wp->w_popup_padding[3] + wp->w_width + wp->w_leftcol,
			popup_attr);
	}

	if (wp->w_popup_padding[2] > 0)
	{
	    // bottom padding
	    row = wp->w_winrow + wp->w_popup_border[0]
				       + wp->w_popup_padding[0] + wp->w_height;
	    screen_fill(row, row + wp->w_popup_padding[2],
				       padcol, padwidth, ' ', ' ', popup_attr);
	}

	if (wp->w_popup_border[2] > 0)
	{
	    // bottom border
	    row = wp->w_winrow + total_height - 1;
	    screen_fill(row , row + 1,
		    wincol < 0 ? 0 : wincol,
		    wincol + total_width,
		    wp->w_popup_border[3] != 0 && wp->w_popup_leftoff == 0
					     ? border_char[7] : border_char[2],
		    border_char[2], border_attr[2]);
	    if (wp->w_popup_border[1] > 0)
	    {
		buf[mb_char2bytes(border_char[6], buf)] = NUL;
		screen_puts(buf, row, wincol + total_width - 1, border_attr[2]);
	    }
	}

	if (wp->w_popup_close == POPCLOSE_BUTTON)
	{
	    // close button goes on top of anything at the top-right corner
	    buf[mb_char2bytes('X', buf)] = NUL;
	    screen_puts(buf, wp->w_winrow, wincol + total_width - 1,
		      wp->w_popup_border[0] > 0 ? border_attr[0] : popup_attr);
	}

	update_popup_transparent(wp, 0);

	// Back to the normal zindex.
	screen_zindex = 0;
    }
}

/*
 * Mark references in callbacks of one popup window.
 */
    static int
set_ref_in_one_popup(win_T *wp, int copyID)
{
    int		abort = FALSE;
    typval_T	tv;

    if (wp->w_close_cb.cb_partial != NULL)
    {
	tv.v_type = VAR_PARTIAL;
	tv.vval.v_partial = wp->w_close_cb.cb_partial;
	abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
    }
    if (wp->w_filter_cb.cb_partial != NULL)
    {
	tv.v_type = VAR_PARTIAL;
	tv.vval.v_partial = wp->w_filter_cb.cb_partial;
	abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
    }
    abort = abort || set_ref_in_list(wp->w_popup_mask, copyID);
    return abort;
}

/*
 * Set reference in callbacks of popup windows.
 */
    int
set_ref_in_popups(int copyID)
{
    int		abort = FALSE;
    win_T	*wp;
    tabpage_T	*tp;

    for (wp = first_popupwin; !abort && wp != NULL; wp = wp->w_next)
	abort = abort || set_ref_in_one_popup(wp, copyID);

    FOR_ALL_TABPAGES(tp)
    {
	for (wp = tp->tp_first_popupwin; !abort && wp != NULL; wp = wp->w_next)
	    abort = abort || set_ref_in_one_popup(wp, copyID);
	if (abort)
	    break;
    }
    return abort;
}
#endif // FEAT_TEXT_PROP