/* Public Domain Curses */

#include <curspriv.h>

RCSID("$Id: panel.c,v 1.8 2008/07/14 12:35:23 wmcbrine Exp $")

/*man-start**************************************************************

  Name:                                                         panel

  Synopsis:
        int bottom_panel(PANEL *pan);
        int del_panel(PANEL *pan);
        int hide_panel(PANEL *pan);
        int move_panel(PANEL *pan, int starty, int startx);
        PANEL *new_panel(WINDOW *win);
        PANEL *panel_above(const PANEL *pan);
        PANEL *panel_below(const PANEL *pan);
        int panel_hidden(const PANEL *pan);
        const void *panel_userptr(const PANEL *pan);
        WINDOW *panel_window(const PANEL *pan);
        int replace_panel(PANEL *pan, WINDOW *win);
        int set_panel_userptr(PANEL *pan, const void *uptr);
        int show_panel(PANEL *pan);
        int top_panel(PANEL *pan);
        void update_panels(void);

  Description:
        The panel library is built using the curses library, and any
        program using panels routines must call one of the curses
        initialization routines such as initscr(). A program using these
        routines must be linked with the panels and curses libraries.
        The header <panel.h> includes the header <curses.h>.

        The panels package gives the applications programmer a way to
        have depth relationships between curses windows; a curses window
        is associated with every panel. The panels routines allow curses
        windows to overlap without making visible the overlapped
        portions of underlying windows. The initial curses window,
        stdscr, lies beneath all panels. The set of currently visible
        panels is the 'deck' of panels.

        The panels package allows the applications programmer to create
        panels, fetch and set their associated windows, shuffle panels
        in the deck, and manipulate panels in other ways.

        bottom_panel() places pan at the bottom of the deck. The size, 
        location and contents of the panel are unchanged.

        del_panel() deletes pan, but not its associated winwow.

        hide_panel() removes a panel from the deck and thus hides it 
        from view.

        move_panel() moves the curses window associated with pan, so 
        that its upper lefthand corner is at the supplied coordinates. 
        (Do not use mvwin() on the window.)

        new_panel() creates a new panel associated with win and returns 
        the panel pointer. The new panel is placed at the top of the 
        deck.

        panel_above() returns a pointer to the panel in the deck above 
        pan, or NULL if pan is the top panel. If the value of pan passed 
        is NULL, this function returns a pointer to the bottom panel in 
        the deck.

        panel_below() returns a pointer to the panel in the deck below 
        pan, or NULL if pan is the bottom panel. If the value of pan 
        passed is NULL, this function returns a pointer to the top panel 
        in the deck.

        panel_hidden() returns OK if pan is hidden and ERR if it is not.

        panel_userptr() - Each panel has a user pointer available for 
        maintaining relevant information. This function returns a 
        pointer to that information previously set up by 
        set_panel_userptr().

        panel_window() returns a pointer to the curses window associated 
        with the panel.

        replace_panel() replaces the current window of pan with win.

        set_panel_userptr() - Each panel has a user pointer available 
        for maintaining relevant information. This function sets the 
        value of that information.

        show_panel() makes a previously hidden panel visible and places 
        it back in the deck on top.

        top_panel() places pan on the top of the deck. The size, 
        location and contents of the panel are unchanged.

        update_panels() refreshes the virtual screen to reflect the 
        depth relationships between the panels in the deck. The user 
        must use doupdate() to refresh the physical screen.

  Return Value:
        Each routine that returns a pointer to an object returns NULL if 
        an error occurs. Each panel routine that returns an integer, 
        returns OK if it executes successfully and ERR if it does not.

  Portability                                X/Open    BSD    SYS V
        bottom_panel                            -       -       Y
        del_panel                               -       -       Y
        hide_panel                              -       -       Y
        move_panel                              -       -       Y
        new_panel                               -       -       Y
        panel_above                             -       -       Y
        panel_below                             -       -       Y
        panel_hidden                            -       -       Y
        panel_userptr                           -       -       Y
        panel_window                            -       -       Y
        replace_panel                           -       -       Y
        set_panel_userptr                       -       -       Y
        show_panel                              -       -       Y
        top_panel                               -       -       Y
        update_panels                           -       -       Y

  Credits:
        Original Author - Warren Tucker <wht@n4hgf.mt-park.ga.us>

**man-end****************************************************************/

#include <panel.h>
#include <stdlib.h>

PANEL *_bottom_panel = (PANEL *)0;
PANEL *_top_panel = (PANEL *)0;
PANEL _stdscr_pseudo_panel = { (WINDOW *)0 };

#ifdef PANEL_DEBUG

static void dPanel(char *text, PANEL *pan)
{
    PDC_LOG(("%s id=%s b=%s a=%s y=%d x=%d", text, pan->user,
             pan->below ? pan->below->user : "--",
             pan->above ? pan->above->user : "--",
             pan->wstarty, pan->wstartx));
}

static void dStack(char *fmt, int num, PANEL *pan)
{
    char s80[80];

    sprintf(s80, fmt, num, pan);
    PDC_LOG(("%s b=%s t=%s", s80, _bottom_panel ? _bottom_panel->user : "--",
             _top_panel    ? _top_panel->user    : "--"));

    if (pan)
        PDC_LOG(("pan id=%s", pan->user));

    pan = _bottom_panel;

    while (pan)
    {
        dPanel("stk", pan);
        pan = pan->above;
    }
}

/* debugging hook for wnoutrefresh */

static void Wnoutrefresh(PANEL *pan)
{
    dPanel("wnoutrefresh", pan);
    wnoutrefresh(pan->win);
}

static void Touchpan(PANEL *pan)
{
    dPanel("Touchpan", pan);
    touchwin(pan->win);
}

static void Touchline(PANEL *pan, int start, int count)
{
    char s80[80];

    sprintf(s80, "Touchline s=%d c=%d", start, count);
    dPanel(s80, pan);
    touchline(pan->win, start, count);
}

#else   /* PANEL_DEBUG */

#define dPanel(text, pan)
#define dStack(fmt, num, pan)
#define Wnoutrefresh(pan) wnoutrefresh((pan)->win)
#define Touchpan(pan) touchwin((pan)->win)
#define Touchline(pan, start, count) touchline((pan)->win, start, count)

#endif  /* PANEL_DEBUG */

static bool _panels_overlapped(PANEL *pan1, PANEL *pan2)
{
    if (!pan1 || !pan2)
        return FALSE;

    return ((pan1->wstarty >= pan2->wstarty && pan1->wstarty < pan2->wendy)
         || (pan2->wstarty >= pan1->wstarty && pan2->wstarty < pan1->wendy))
        && ((pan1->wstartx >= pan2->wstartx && pan1->wstartx < pan2->wendx)
         || (pan2->wstartx >= pan1->wstartx && pan2->wstartx < pan1->wendx));
}

static void _free_obscure(PANEL *pan)
{
    PANELOBS *tobs = pan->obscure;  /* "this" one */
    PANELOBS *nobs;                 /* "next" one */

    while (tobs)
    {
        nobs = tobs->above;
        free((char *)tobs);
        tobs = nobs;
    }
    pan->obscure = (PANELOBS *)0;
}

static void _override(PANEL *pan, int show)
{
    int y;
    PANEL *pan2;
    PANELOBS *tobs = pan->obscure;      /* "this" one */

    if (show == 1)
        Touchpan(pan);
    else if (!show)
    {
        Touchpan(pan);
        Touchpan(&_stdscr_pseudo_panel);
    }
    else if (show == -1)
        while (tobs && (tobs->pan != pan))
            tobs = tobs->above;

    while (tobs)
    {
        if ((pan2 = tobs->pan) != pan)
            for (y = pan->wstarty; y < pan->wendy; y++)
                if ((y >= pan2->wstarty) && (y < pan2->wendy) &&
                   ((is_linetouched(pan->win, y - pan->wstarty)) ||
                    (is_linetouched(stdscr, y))))
                    Touchline(pan2, y - pan2->wstarty, 1);

        tobs = tobs->above;
    }
}

static void _calculate_obscure(void)
{
    PANEL *pan, *pan2;
    PANELOBS *tobs;     /* "this" one */
    PANELOBS *lobs;     /* last one */

    pan = _bottom_panel;

    while (pan)
    {
        if (pan->obscure)
            _free_obscure(pan);

        lobs = (PANELOBS *)0;
        pan2 = _bottom_panel;

        while (pan2)
        {
            if (_panels_overlapped(pan, pan2))
            {
                if ((tobs = malloc(sizeof(PANELOBS))) == NULL)
                    return;

                tobs->pan = pan2;
                dPanel("obscured", pan2);
                tobs->above = (PANELOBS *)0;

                if (lobs)
                    lobs->above = tobs;
                else
                    pan->obscure = tobs;

                lobs  = tobs;
            }

            pan2 = pan2->above;
        }

        _override(pan, 1);
        pan = pan->above;
    }
}

/* check to see if panel is in the stack */

static bool _panel_is_linked(const PANEL *pan)
{
    PANEL *pan2 = _bottom_panel;

    while (pan2)
    {
        if (pan2 == pan)
            return TRUE;

        pan2 = pan2->above;
    }

    return FALSE;
}

/* link panel into stack at top */

static void _panel_link_top(PANEL *pan)
{
#ifdef PANEL_DEBUG
    dStack("<lt%d>", 1, pan);
    if (_panel_is_linked(pan))
        return;
#endif
    pan->above = (PANEL *)0;
    pan->below = (PANEL *)0;

    if (_top_panel)
    {
        _top_panel->above = pan;
        pan->below = _top_panel;
    }

    _top_panel = pan;

    if (!_bottom_panel)
        _bottom_panel = pan;

    _calculate_obscure();
    dStack("<lt%d>", 9, pan);
}

/* link panel into stack at bottom */

static void _panel_link_bottom(PANEL *pan)
{
#ifdef PANEL_DEBUG
    dStack("<lb%d>", 1, pan);
    if (_panel_is_linked(pan))
        return;
#endif
    pan->above = (PANEL *)0;
    pan->below = (PANEL *)0;

    if (_bottom_panel)
    {
        _bottom_panel->below = pan;
        pan->above = _bottom_panel;
    }

    _bottom_panel = pan;

    if (!_top_panel)
        _top_panel = pan;

    _calculate_obscure();
    dStack("<lb%d>", 9, pan);
}

static void _panel_unlink(PANEL *pan)
{
    PANEL *prev;
    PANEL *next;

#ifdef PANEL_DEBUG
    dStack("<u%d>", 1, pan);
    if (!_panel_is_linked(pan))
        return;
#endif
    _override(pan, 0);
    _free_obscure(pan);

    prev = pan->below;
    next = pan->above;

    /* if non-zero, we will not update the list head */

    if (prev)
    {
        prev->above = next;
        if(next)
            next->below = prev;
    }
    else if (next)
        next->below = prev;

    if (pan == _bottom_panel)
        _bottom_panel = next;

    if (pan == _top_panel)
        _top_panel = prev;

    _calculate_obscure();

    pan->above = (PANEL *)0;
    pan->below = (PANEL *)0;
    dStack("<u%d>", 9, pan);

}

/************************************************************************
 *   The following are the public functions for the panels library.     *
 ************************************************************************/

int bottom_panel(PANEL *pan)
{
    if (!pan)
        return ERR;

    if (pan == _bottom_panel)
        return OK;

    if (_panel_is_linked(pan))
        hide_panel(pan);

    _panel_link_bottom(pan);

    return OK;
}

int del_panel(PANEL *pan)
{
    if (pan)
    {
        if (_panel_is_linked(pan))
            hide_panel(pan);

        free((char *)pan);
        return OK;
    }

    return ERR;
}

int hide_panel(PANEL *pan)
{
    if (!pan)
        return ERR;

    if (!_panel_is_linked(pan))
    {
        pan->above = (PANEL *)0;
        pan->below = (PANEL *)0;
        return ERR;
    }

    _panel_unlink(pan);

    return OK;
}

int move_panel(PANEL *pan, int starty, int startx)
{
    WINDOW *win;
    int maxy, maxx;

    if (!pan)
        return ERR;

    if (_panel_is_linked(pan))
        _override(pan, 0);

    win = pan->win;

    if (mvwin(win, starty, startx) == ERR)
        return ERR;

    getbegyx(win, pan->wstarty, pan->wstartx);
    getmaxyx(win, maxy, maxx);
    pan->wendy = pan->wstarty + maxy;
    pan->wendx = pan->wstartx + maxx;

    if (_panel_is_linked(pan))
        _calculate_obscure();

    return OK;
}

PANEL *new_panel(WINDOW *win)
{
    PANEL *pan = malloc(sizeof(PANEL));

    if (!_stdscr_pseudo_panel.win)
    {
        _stdscr_pseudo_panel.win = stdscr;
        _stdscr_pseudo_panel.wstarty = 0;
        _stdscr_pseudo_panel.wstartx = 0;
        _stdscr_pseudo_panel.wendy = LINES;
        _stdscr_pseudo_panel.wendx = COLS;
        _stdscr_pseudo_panel.user = "stdscr";
        _stdscr_pseudo_panel.obscure = (PANELOBS *)0;
    }

    if (pan)
    {
        int maxy, maxx;

        pan->win = win;
        pan->above = (PANEL *)0;
        pan->below = (PANEL *)0;
        getbegyx(win, pan->wstarty, pan->wstartx);
        getmaxyx(win, maxy, maxx);
        pan->wendy = pan->wstarty + maxy;
        pan->wendx = pan->wstartx + maxx;
#ifdef PANEL_DEBUG
        pan->user = "new";
#else
        pan->user = (char *)0;
#endif
        pan->obscure = (PANELOBS *)0;
        show_panel(pan);
    }

    return pan;
}

PANEL *panel_above(const PANEL *pan)
{
    return pan ? pan->above : _bottom_panel;
}

PANEL *panel_below(const PANEL *pan)
{
    return pan ? pan->below : _top_panel;
}

int panel_hidden(const PANEL *pan)
{
    if (!pan)
        return ERR;

    return _panel_is_linked(pan) ? ERR : OK;
}

const void *panel_userptr(const PANEL *pan)
{
    return pan ? pan->user : NULL;
}

WINDOW *panel_window(const PANEL *pan)
{
    PDC_LOG(("panel_window() - called\n"));

    return pan->win;
}

int replace_panel(PANEL *pan, WINDOW *win)
{
    int maxy, maxx;

    if (!pan)
        return ERR;

    if (_panel_is_linked(pan))
        _override(pan, 0);

    pan->win = win;
    getbegyx(win, pan->wstarty, pan->wstartx);
    getmaxyx(win, maxy, maxx);
    pan->wendy = pan->wstarty + maxy;
    pan->wendx = pan->wstartx + maxx;

    if (_panel_is_linked(pan))
        _calculate_obscure();

    return OK;
}

int set_panel_userptr(PANEL *pan, const void *uptr)
{
    if (!pan)
        return ERR;

    pan->user = uptr;
    return OK;
}

int show_panel(PANEL *pan)
{
    if (!pan)
        return ERR;

    if (pan == _top_panel)
        return OK;

    if (_panel_is_linked(pan))
        hide_panel(pan);

    _panel_link_top(pan);

    return OK;
}

int top_panel(PANEL *pan)
{
    return show_panel(pan);
}

void update_panels(void)
{
    PANEL *pan;

    PDC_LOG(("update_panels() - called\n"));

    pan = _bottom_panel;

    while (pan)
    {
        _override(pan, -1);
        pan = pan->above;
    }

    if (is_wintouched(stdscr))
        Wnoutrefresh(&_stdscr_pseudo_panel);
    
    pan = _bottom_panel;

    while (pan)
    {
        if (is_wintouched(pan->win) || !pan->above)
            Wnoutrefresh(pan);

        pan = pan->above;
    }
}