Propagate Layer changes via Style command on-the-fly.

[fvwm.git] / libs / FScreen.c

/* -*-c-*- */
/* This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*
 *  FScreen.c
 *    Xinerama abstraction support for window manager.
 *
 *  This module is all original code
 *  by Dmitry Yu. Bolkhovityanov <bolkhov@inp.nsk.su>
 *  Copyright 2001, Dmitry Bolkhovityanov
 *     You may use this code for any purpose, as long as the original
 *     copyright remains in the source code and all documentation
 */

/*
 * Brief description of used concept:
 *
 *   This code is always used by client, regardless of if Xinerama is
 *   available or not (either because -lXinerama was missing or
 *   because Xinerama extension is missing on display).
 *
 *   If Xinerama is available, this module maintains a list of screens,
 *   from [1] to [num_screens].  screens[0] is always the "global" screen,
 *   so if Xinerama is unavailable or disabled, the module performs
 *   all checks on screens[0] instead of screens[1..num_screens].
 *
 *   The client should first call the FScreenInit(), passing
 *   it the opened display descriptor.  During this call the list of
 *   Xinerama screens is retrieved and 'dpy' is saved for future
 *   reference.
 *
 *   If the client wishes to hard-disable Xinerama support (e.g. if
 *   Xinerama extension is present but is broken on display), it should
 *   call FScreenDisable() *before* FScreenInit().
 *
 *   Using real Xinerama screens info may be switched on/off "on the
 *   fly" by calling FScreenSetState(0=off/else=on).
 *
 *   Modules with Xinerama support should listen to the XineramaEnable
 *   and XineramaDisable strings coming over the module pipe as
 *   M_CONFIG_INFO packets and call FScreenEnable() or
 *   FScreenDisable in response.
 *
 */

#include "config.h"

#include <stdio.h>
#include <ctype.h>

#include "defaults.h"
#include "fvwmlib.h"
#include "Parse.h"
#include "FScreen.h"
#include "PictureBase.h"

#ifdef HAVE_XINERAMA
# undef FSCREEN_NEED_SCREENINFO
# define FScreenHaveXinerama 1
# ifdef HAVE_SOLARIS_XINERAMA
#  define FScreenHaveSolarisXinerama 1
#  ifdef HAVE_SOLARIS_XINERAMA_H
#   include <X11/extensions/xinerama.h>
#  else
#   define FSCREEN_NEED_SOLARIS_PROTOTYPES
#  endif
#  define FSCREEN_NEED_SCREENINFO
# else
#  define FScreenHaveSolarisXinerama 0
#  include <X11/extensions/Xinerama.h>
# endif
#else
# define FSCREEN_NEED_SCREENINFO
# define FScreenHaveXinerama 0
# define FScreenHaveSolarisXinerama 0
#endif

#ifdef FSCREEN_NEED_SCREENINFO
typedef struct
{
        int   screen_number;
        short x_org;
        short y_org;
        unsigned short width;
        unsigned short height;
} XineramaScreenInfo;
#endif

#ifdef FSCREEN_NEED_SOLARIS_PROTOTYPES
/* Copied from Solaris 9's X11/extensions/xinerama.h */
Bool XineramaGetState(Display*, int);
Status XineramaGetInfo(Display*, int, XRectangle*, unsigned char*, int*);
Status XineramaGetCenterHint(Display*, int, int*, int*);
#endif

#if FScreenHaveSolarisXinerama == 0
#define XineramaGetInfo(a,b,c,d,e) 0
#endif

#if FScreenHaveXinerama
# if FScreenHaveSolarisXinerama
#  define XineramaQueryExtension(d,b,c) 1 /* Lie, for now */
#  define XineramaIsActive(d) XineramaGetState((d),0)
#  define XineramaQueryScreens(d,s) (*(s)) = 0, NULL
# endif
#else
# define XineramaQueryExtension(da, b, c) 0
# define XineramaIsActive(a) 0
# define XineramaQueryScreens(d,s) (*(s)) = 0, NULL
#endif

#ifndef MAXFRAMEBUFFERS
#define MAXFRAMEBUFFERS 16
#endif


#ifdef USE_XINERAMA_EMULATION
#define FScreenXineramaEmulation 1
#else
#define FScreenXineramaEmulation 0
#endif

#if 0
#ifdef HAVE_RANDR
#include <X11/Xproto.h>
#include <X11/extensions/Xrandr.h>
#endif
#endif

enum
{
        /* Replace with FSCREEN_GLOBAL to restore default behaviour */
        DEFAULT_GEOMETRY_SCREEN = FSCREEN_PRIMARY
};

/* In fact, only corners matter -- there will never be GRAV_NONE */
enum {GRAV_POS = 0, GRAV_NONE = 1, GRAV_NEG = 2};
static int grav_matrix[3][3] =
{
        { NorthWestGravity, NorthGravity,  NorthEastGravity },
        { WestGravity,      CenterGravity, EastGravity },
        { SouthWestGravity, SouthGravity,  SouthEastGravity }
};
#define DEFAULT_GRAVITY NorthWestGravity


static Display            *disp              = NULL;
static Bool                is_xinerama_enabled = DEFAULT_XINERAMA_ENABLED;
static Bool                is_sls_enabled    = False;
static Bool                have_sls_screen_list = False;
static XineramaScreenInfo *screens;
static XineramaScreenInfo *screens_xi;
static XineramaScreenInfo *screens_sls       = NULL;
/* # of Xinerama screens, *not* counting the global, 0 if disabled */
static int                 num_screens       = 0;
/* # of Xinerama screens, *not* counting the global */
static int                 total_screens     = 0;
static int                 total_screens_xi  = 0;
static int                 total_screens_sls = 1;
static int                 total_sls_width   = 1;
static int                 total_sls_height  = 1;
static int                 first_to_check    = 0;
static int                 last_to_check     = 0;
static int                 default_geometry_scr = FSCREEN_PRIMARY;
/* only to be accessed vie the set/get functions! */
static int                 primary_scr       = DEFAULT_PRIMARY_SCREEN;

#if 0
#ifdef HAVE_RANDR
static Bool                randr_disabled    = 0;
static Bool                randr_active      = 0;
static int                 randr_event_base  = -1;
static int                 randr_error_base  = -1;
#endif
#endif

static Window blank_w, vert_w, blank2_w, blank3_w;

static int FScreenParseScreenBit(char *arg, char default_screen);
static int FindScreenOfXY(int x, int y);

static XineramaScreenInfo *
solaris_XineramaQueryScreens(Display *d, int *nscreens)
{
        if (FScreenHaveSolarisXinerama)
        {
                XineramaScreenInfo *screens = NULL;
                XRectangle monitors[MAXFRAMEBUFFERS];
                unsigned char hints[16];
                int result;

                /* dummy instructions to keep -Wall happy */
                hints[0] = hints[0];
                result = XineramaGetInfo(
                        d, DefaultScreen(d), monitors, hints, nscreens);
                if (result)
                {
                        int m;

                        /* Note, malloced area later freed by XFree() */
                        screens = (XineramaScreenInfo *)malloc(
                                sizeof(XineramaScreenInfo) * (*nscreens));
                        for (m = 0; m < *nscreens; ++m)
                        {
                                screens[m].screen_number = m;
                                screens[m].x_org = monitors[m].x;
                                screens[m].y_org = monitors[m].y;
                                screens[m].width = monitors[m].width;
                                screens[m].height = monitors[m].height;
                        }
                }
                else
                {
                        fprintf(
                                stderr,
                                "Error getting Xinerama information\n");
                        *nscreens = 0;
                }

                return screens;
        }
        else
        {
                return NULL;
        }
}

static XineramaScreenInfo *FXineramaQueryScreens(Display *d, int *nscreens)
{
        if (FScreenHaveXinerama == 0)
        {
                *nscreens = 0;

                return NULL;
        }
        if (FScreenHaveSolarisXinerama == 1)
        {
                return solaris_XineramaQueryScreens(d, nscreens);
        }
        else
        {
                return XineramaQueryScreens(d, nscreens);
        }
}

static void GetMouseXY(XEvent *eventp, int *x, int *y)
{
        if (!is_xinerama_enabled || last_to_check == first_to_check)
        {
                /* We use .x_org,.y_org because nothing prevents a screen to be
                 * not at (0,0) */
                *x = screens[first_to_check].x_org;
                *y = screens[first_to_check].y_org;
        }
        else
        {
                XEvent e;

                if (eventp == NULL)
                {
                        eventp = &e;
                        e.type = 0;
                }
                fev_get_evpos_or_query(
                        disp, DefaultRootWindow(disp), eventp, x, y);
        }

        return;
}

Bool FScreenIsEnabled(void)
{
        return (!is_xinerama_enabled || num_screens == 0) ? False : True;
}

Bool FScreenIsSLSEnabled(void)
{
        return is_sls_enabled;
}

static void FScreenUpdateEmulationMapState(void)
{
        static Bool is_mapped = False;

        if (!FScreenXineramaEmulation)
        {
                return;
        }

        if (is_xinerama_enabled && !is_sls_enabled)
        {
                if (!is_mapped)
                {
                        XMapRaised(disp, blank_w);
                        XMapRaised(disp, blank2_w);
                        XMapRaised(disp, blank3_w);
                        XMapRaised(disp, vert_w);
                        is_mapped = True;
                }
        }
        else
        {
                if (is_mapped)
                {
                        XUnmapWindow(disp, blank_w);
                        XUnmapWindow(disp, blank2_w);
                        XUnmapWindow(disp, blank3_w);
                        XUnmapWindow(disp, vert_w);
                        is_mapped = False;
                }
        }
}

static void FScreenSetState(Bool do_enable)
{
        is_xinerama_enabled = do_enable;
        if (do_enable && total_screens > 0)
        {
                num_screens = total_screens;
                first_to_check = 1;
                last_to_check  = total_screens;
        }
        else
        {
                num_screens = 0;
                first_to_check = 0;
                last_to_check = 0;
        }
        FScreenUpdateEmulationMapState();
}


void FScreenInit(Display *dpy)
{
        static Bool is_initialised = False;
        int dummy_rc;

        if (is_initialised)
        {
                return;
        }
        dummy_rc = 0;
        is_initialised = True;
        disp = dpy;
        if (FScreenXineramaEmulation)
        {
                int count;
                int w;
                int h;
                int ws;
                unsigned long scr;
                Window root;
                XSetWindowAttributes attributes;

                scr = DefaultScreen(disp);
                root = RootWindow(disp, scr);

                /* xinerama emulation simulates xinerama on a single screen:
                 *
                 * actual screen
                 * +---------------------+--------------+
                 * |                     |              |
                 * |                     |              |
                 * |                     |              |
                 * |                     |  simulated   |
                 * |                     |  screen 2    |
                 * |  simulated screen 1 |              |
                 * |                     |              |
                 * |                     |              |
                 * |                     |              |
                 * |                     |              |
                 * +---------------------+              |
                 * |   blank area        |              |
                 * |                     |              |
                 * +---------------------+--------------+
                 */
                count = 2;
                total_screens_xi = count;
                screens_xi = (XineramaScreenInfo *)
                        safemalloc(sizeof(XineramaScreenInfo) * (1 + count));
                /* calculate the faked sub screen dimensions */
                w = DisplayWidth(disp, scr);
                ws = 3 * w / 5;
                h = DisplayHeight(disp, scr);
                screens_xi[1].screen_number = 0;
                screens_xi[1].x_org         = 0;
                screens_xi[1].y_org         = h / 16;
                screens_xi[1].width         = ws;
                screens_xi[1].height        = 7 * h / 8;
                screens_xi[2].screen_number = 1;
                screens_xi[2].x_org         = ws;
                screens_xi[2].y_org         = 0;
                screens_xi[2].width         = w - ws;
                screens_xi[2].height        = 7 * h / 8;
                /* add delimiter */
                attributes.background_pixel = PictureWhitePixel();
                attributes.override_redirect = True;
                blank_w = XCreateWindow(
                        disp, root, 0, screens_xi[1].y_org - 1,
                        screens_xi[1].width, 2, 0, CopyFromParent,
                        CopyFromParent, CopyFromParent,
                        CWBackPixel|CWOverrideRedirect, &attributes);
                blank2_w = XCreateWindow(
                        disp, root, 0,
                        screens_xi[1].y_org + screens_xi[1].height - 1,
                        screens_xi[1].width, 2, 0, CopyFromParent,
                        CopyFromParent, CopyFromParent,
                        CWBackPixel|CWOverrideRedirect, &attributes);
                blank3_w = XCreateWindow(
                        disp, root, screens_xi[2].x_org,
                        screens_xi[2].height - 1, w - screens_xi[2].x_org, 2,
                        0, CopyFromParent, CopyFromParent, CopyFromParent,
                        CWBackPixel|CWOverrideRedirect, &attributes);
                vert_w = XCreateWindow(
                        disp, root, screens_xi[2].x_org - 1, 0, 2, h, 0,
                        CopyFromParent, CopyFromParent, CopyFromParent,
                        CWBackPixel|CWOverrideRedirect, &attributes);
        }
        else if (FScreenHaveXinerama &&
                 XineramaQueryExtension(disp, &dummy_rc, &dummy_rc) &&
                 XineramaIsActive(disp))
        {
                int count;
                XineramaScreenInfo *info;

                info = FXineramaQueryScreens(disp, &count);
                total_screens_xi = count;
                screens_xi = (XineramaScreenInfo *)
                        safemalloc(sizeof(XineramaScreenInfo) *
                                   (1 + count));
                memcpy(screens_xi + 1, info,
                       sizeof(XineramaScreenInfo) * count);
                XFree(info);
        }
        else
        {
                total_screens_xi = 0;
                screens_xi =
                        (XineramaScreenInfo *)safemalloc(
                                sizeof(XineramaScreenInfo)*1);
        }
        total_screens = total_screens_xi;
        screens = screens_xi;

        /* Now, fill screens[0] with global screen parameters */
        screens_xi[0].screen_number = -1;
        screens_xi[0].x_org         = 0;
        screens_xi[0].y_org         = 0;
        screens_xi[0].width         = DisplayWidth (disp, DefaultScreen(disp));
        screens_xi[0].height        = DisplayHeight(disp, DefaultScreen(disp));

        /* Fill in the screen range */
        FScreenSetState(is_xinerama_enabled);

        return;
}

void FScreenOnOff(Bool do_enable)
{
        FScreenSetState(do_enable);
}

void FScreenSLSOnOff(Bool do_enable)
{
        is_sls_enabled = do_enable;
        if (do_enable)
        {
                total_screens = total_screens_sls;
                if (!screens_sls)
                {
                        /* Sls not configured yet, use whole screen by default
                         */
                        FScreenConfigureSLSSize(1, 1);
                }
                screens = screens_sls;
        }
        else
        {
                total_screens = total_screens_xi;
                screens = screens_xi;
        }
        FScreenSetState(is_xinerama_enabled);
}

Bool FScreenConfigureSLSSize(int width, int height)
{
        unsigned long scr = DefaultScreen(disp);
        int w = DisplayWidth(disp, scr);
        int h = DisplayHeight(disp, scr);

        if (width <= 1)
        {
                width = 1;
        }
        else if (width > w)
        {
                width = w;
        }
        if (height <= 1)
        {
                height = 1;
        }
        else if (height > h)
        {
                height = h;
        }
        if (total_sls_width == width && total_sls_height == height &&
            screens_sls)
        {
                return False;
        }
        if (screens_sls)
        {
                free(screens_sls);
                screens_sls = NULL;
        }
        /* calculate the screens */
        {
                int row, col, sn;
                int ws;
                int hs;

                total_screens_sls = width * height;
                total_sls_width = width;
                total_sls_height = height;
                ws = w / total_sls_width;
                hs = h / total_sls_height;
                screens_sls = (XineramaScreenInfo *)
                        safemalloc(sizeof(XineramaScreenInfo) *
                                   (1 + total_screens_sls));
                /* calculate the faked sub screen dimensions */
                screens_sls[0] = screens_xi[0];
                sn = 1;
                for (row = 0; row < total_sls_height; row++)
                {
                        for (col = 0; col < total_sls_width; col++, sn++)
                        {
                                screens_sls[sn].screen_number = sn - 1;
                                screens_sls[sn].x_org         = col * ws;
                                screens_sls[sn].y_org         = row * hs;
                                screens_sls[sn].width         = ws;
                                screens_sls[sn].height        = hs;
                        }
                }
        }
        have_sls_screen_list = False;
        FScreenSLSOnOff(is_sls_enabled);

        return True;
}

Bool FScreenConfigureSLSScreens(int nscreens, char *args)
{
        int sn;
        char *next;

        if (nscreens == 0 || args == NULL)
        {
                return FScreenConfigureSLSSize(1, 1);
        }
        if (nscreens == 1 && screens_sls)
        {
                return False;
        }
        if (screens_sls)
        {
                free(screens_sls);
                screens_sls = NULL;
        }
        screens_sls = (XineramaScreenInfo *)
                safemalloc(sizeof(XineramaScreenInfo) * (nscreens + 1));
        screens_sls[0] = screens_xi[0];
        for (sn = 1; sn <= nscreens; sn++, args = next)
        {
                char *token;
                int val[4];

                /* read next screen spec */
                token = PeekToken(args, &next);
                if (!token)
                {
                        break;
                }
                if (XParseGeometry(token, &val[0], &val[1],
                                   (unsigned int *)&val[2],
                                   (unsigned int *)&val[3]) ==
                    (XValue|YValue|WidthValue|HeightValue) ||
                    GetIntegerArguments(args, &next, val, 4) == 4)
                {
                        if (val[0] < 0 || val[1] < 0 || val[2] < 1 ||
                            val[3] < 1)
                        {
                                /* illegal spec */
                                break;
                        }
                        screens_sls[sn].screen_number = sn - 1;
                        screens_sls[sn].x_org = val[0];
                        screens_sls[sn].y_org = val[1];
                        screens_sls[sn].width = val[2];
                        screens_sls[sn].height = val[3];
                }
                else
                {
                        /* illegal spec */
                        break;
                }
        }
        total_screens_sls = sn - 1;
        have_sls_screen_list = True;
        FScreenSLSOnOff(is_sls_enabled);

        return True;
}

#if 0
void FScreenDisableRandR(void)
{
        if (disp != NULL)
        {
                fprintf(stderr, "FScreen: WARNING: FScreenDisableRandR()"
                        " called after FScreenInit()!\n");
        }
        randr_disabled = 1;

        return;
}
#endif

static int FScreenGetPrimaryScreen(XEvent *ev)
{
        if (!is_xinerama_enabled)
        {
                return 0;
        }
        if (primary_scr == FSCREEN_GLOBAL)
        {
                return 0;
        }
        else if (primary_scr == FSCREEN_CURRENT)
        {
                int mx;
                int my;

                /* use current screen as primary screen */
                GetMouseXY(ev, &mx, &my);
                return FindScreenOfXY(mx, my);
        }
        else if (primary_scr < 0 || primary_scr >= last_to_check)
        {
                /* out of range */
                return 0;
        }

        return primary_scr + 1;
}

void FScreenSetPrimaryScreen(int scr)
{
        primary_scr = scr;
}

/* Intended to be called by modules.  Simply pass in the parameter from the
 * config string sent by fvwm. */
void FScreenConfigureModule(char *args)
{
        int val[6];
        int n;
        char *next;

        n = GetIntegerArguments(args, &next, val, 4);
        if (n != 4)
        {
                /* ignore broken line */
                return;
        }
        FScreenSetPrimaryScreen(val[1]);

        if (val[3])
        {
                /* SLS screen coordinates follow */
                n = GetIntegerArguments(next, &next, val + 4, 1);
                if (n != 1)
                {
                        /* ignore broken line */
                        return;
                }
                FScreenConfigureSLSScreens(val[4], next);
        }
        else
        {
                /* simple SLS line */
                n = GetIntegerArguments(next, NULL, val + 4, 2);
                if (n != 2)
                {
                        /* ignore broken line */
                        return;
                }
                FScreenConfigureSLSSize(val[4], val[5]);
        }

        FScreenSLSOnOff(val[2]);
        FScreenOnOff(val[0]);

        return;
}

/* Here's the function used by fvwm to generate the string which
 * FScreenConfigureModule expects to receive back as its argument.
 */
const char *FScreenGetConfiguration(void)
{
        int i;
        int l;
        int l2;
        static char msg[MAX_MODULE_INPUT_TEXT_LEN];
        char buf[64];

        sprintf(
                msg, XINERAMA_CONFIG_STRING" %d %d %d %d",
                FScreenIsEnabled(), primary_scr,
                FScreenIsSLSEnabled(), have_sls_screen_list);
        l = strlen(msg);
        if (have_sls_screen_list)
        {
                sprintf(msg + l, " %d", total_screens_sls);
                for (i = 0; i < total_screens_sls; i++)
                {
                        sprintf(buf, " %d %d %d %d", screens_sls[i].x_org,
                                screens_sls[i].y_org, screens_sls[i].width,
                                screens_sls[i].height);
                        l2 = strlen(buf);
                        if (l + l2 > MAX_MODULE_INPUT_TEXT_LEN)
                        {
                                break;
                        }
                        strcat(msg + l, buf);
                        l += l2;
                }
        }
        else
        {
                sprintf(msg + l, " %d %d", total_sls_width, total_sls_height);
        }

        return msg;
}

/* Sets the default screen for ...ParseGeometry if no screen spec is given.
 * Usually this is FSCREEN_SPEC_PRIMARY, but this won't allow modules to appear
 * under the pointer. */
void FScreenSetDefaultModuleScreen(char *scr_spec)
{
        default_geometry_scr =
                FScreenParseScreenBit(scr_spec, FSCREEN_SPEC_PRIMARY);

        return;
}


static int FindScreenOfXY(int x, int y)
{
        int i;

        x = x % screens_xi[0].width;
        while (x < 0)
        {
                x += screens_xi[0].width;
        }
        y = y % screens_xi[0].height;
        while (y < 0)
        {
                y += screens_xi[0].height;
        }
        for (i = first_to_check;  i <= last_to_check;  i++)
        {
                if (x >= screens[i].x_org  &&
                    x < screens[i].x_org + screens[i].width  &&
                    y >= screens[i].y_org  &&
                    y < screens[i].y_org + screens[i].height)
                {
                        return i;
                }
        }

        /* Ouch!  A "black hole" coords?  As for now, return global screen */
        return 0;
}

static int FindScreen(
        fscreen_scr_arg *arg, fscreen_scr_t screen)
{
        fscreen_scr_arg tmp;

        if (num_screens == 0)
        {
                screen = FSCREEN_GLOBAL;
        }
        switch (screen)
        {
        case FSCREEN_GLOBAL:
                screen = 0;
                break;
        case FSCREEN_PRIMARY:
                screen =
                        FScreenGetPrimaryScreen(
                                (arg && arg->mouse_ev) ? arg->mouse_ev : NULL);
                break;
        case FSCREEN_CURRENT:
                /* translate to xypos format */
                if (!arg)
                {
                        tmp.mouse_ev = NULL;
                        arg = &tmp;
                }
                GetMouseXY(arg->mouse_ev, &arg->xypos.x, &arg->xypos.y);
                /* fall through */
        case FSCREEN_XYPOS:
                /* translate to screen number */
                if (!arg)
                {
                        tmp.xypos.x = 0;
                        tmp.xypos.y = 0;
                        arg = &tmp;
                }
                screen = FindScreenOfXY(arg->xypos.x, arg->xypos.y);
                break;
        default:
                /* screen is given counting from 0; translate to counting from
                 * 1 */
                screen++;
                break;
        }

        return screen;
}

/* Returns the specified screens geometry rectangle.  screen can be a screen
 * number or any of the values FSCREEN_GLOBAL, FSCREEN_CURRENT,
 * FSCREEN_PRIMARY or FSCREEN_XYPOS.  The arg union only has a meaning for
 * FSCREEN_CURRENT and FSCREEN_XYARG.  For FSCREEN_CURRENT its mouse_ev member
 * may be given.  It is tried to find out the pointer position from the event
 * first before querying the pointer.  For FSCREEN_XYPOS the xpos member is used
 * to fetch the x/y position of the point on the screen.  If arg is NULL, the
 * position 0 0 is assumed instead.
 *
 * Any of the arguments arg, x, y, w and h may be NULL.
 *
 * FSCREEN_GLOBAL:  return the global screen dimensions
 * FSCREEN_CURRENT: return dimensions of the screen with the pointer
 * FSCREEN_PRIMARY: return the primary screen dimensions
 * FSCREEN_XYPOS:   return dimensions of the screen with the given coordinates
 *
 * The function returns False if the global screen was returned and more than
 * one screen is configured.  Otherwise it returns True.
 */
Bool FScreenGetScrRect(
        fscreen_scr_arg *arg, fscreen_scr_t screen, int *x, int *y,
        int *w, int *h)
{
        screen = FindScreen(arg, screen);
        if (screen < first_to_check || screen > last_to_check)
        {
                screen = 0;
        }
        if (x)
        {
                *x = screens[screen].x_org;
        }
        if (y)
        {
                *y = screens[screen].y_org;
        }
        if (w)
        {
                *w = screens[screen].width;
        }
        if (h)
        {
                *h = screens[screen].height;
        }

        return !(screen == 0 && num_screens > 1);
}

/* returns the screen id */
Bool FScreenGetScrId(
        fscreen_scr_arg *arg, fscreen_scr_t screen)
{
        screen = FindScreen(arg, screen);
        if (screen < 0)
        {
                screen = FSCREEN_GLOBAL;
        }

        return screen;
}

/* Translates the coodinates *x *y from the screen specified by arg_src and
 * screen_src to coordinates on the screen specified by arg_dest and
 * screen_dest. (see FScreenGetScrRect for more details). */
void FScreenTranslateCoordinates(
        fscreen_scr_arg *arg_src, fscreen_scr_t screen_src,
        fscreen_scr_arg *arg_dest, fscreen_scr_t screen_dest,
        int *x, int *y)
{
        int x_src;
        int y_src;
        int x_dest;
        int y_dest;

        FScreenGetScrRect(arg_src, screen_src, &x_src, &y_src, NULL, NULL);
        FScreenGetScrRect(arg_dest, screen_dest, &x_dest, &y_dest, NULL, NULL);

        if (x)
        {
                *x = *x + x_src - x_dest;
        }
        if (y)
        {
                *y = *y + y_src - y_dest;
        }

        return;
}

/* Arguments work exactly like for FScreenGetScrRect() */
int FScreenClipToScreen(
        fscreen_scr_arg *arg, fscreen_scr_t screen, int *x, int *y, int w,
        int h)
{
        int sx;
        int sy;
        int sw;
        int sh;
        int lx = (x) ? *x : 0;
        int ly = (y) ? *y : 0;
        int x_grav = GRAV_POS;
        int y_grav = GRAV_POS;

        FScreenGetScrRect(arg, screen, &sx, &sy, &sw, &sh);
        if (lx + w > sx + sw)
        {
                lx = sx + sw  - w;
                x_grav = GRAV_NEG;
        }
        if (ly + h > sy + sh)
        {
                ly = sy + sh - h;
                y_grav = GRAV_NEG;
        }
        if (lx < sx)
        {
                lx = sx;
                x_grav = GRAV_POS;
        }
        if (ly < sy)
        {
                ly = sy;
                y_grav = GRAV_POS;
        }
        if (x)
        {
                *x = lx;
        }
        if (y)
        {
                *y = ly;
        }

        return grav_matrix[y_grav][x_grav];
}

/* Arguments work exactly like for FScreenGetScrRect() */
void FScreenCenterOnScreen(
        fscreen_scr_arg *arg, fscreen_scr_t screen, int *x, int *y, int w,
        int h)
{
        int sx;
        int sy;
        int sw;
        int sh;
        int lx;
        int ly;

        FScreenGetScrRect(arg, screen, &sx, &sy, &sw, &sh);
        lx = (sw  - w) / 2;
        ly = (sh - h) / 2;
        if (lx < 0)
                lx = 0;
        if (ly < 0)
                ly = 0;
        lx += sx;
        ly += sy;
        if (x)
        {
                *x = lx;
        }
        if (y)
        {
                *y = ly;
        }

        return;
}

void FScreenGetResistanceRect(
        int wx, int wy, unsigned int ww, unsigned int wh, int *x0, int *y0,
        int *x1, int *y1)
{
        fscreen_scr_arg arg;

        arg.xypos.x = wx + ww / 2;
        arg.xypos.y = wy + wh / 2;
        FScreenGetScrRect(&arg, FSCREEN_XYPOS, x0, y0, x1, y1);
        *x1 += *x0;
        *y1 += *y0;

        return;
}

/* Arguments work exactly like for FScreenGetScrRect() */
Bool FScreenIsRectangleOnScreen(
        fscreen_scr_arg *arg, fscreen_scr_t screen, rectangle *rec)
{
        int sx;
        int sy;
        int sw;
        int sh;

        FScreenGetScrRect(arg, screen, &sx, &sy, &sw, &sh);

        return (rec->x + rec->width > sx && rec->x < sx + sw &&
                rec->y + rec->height > sy && rec->y < sy + sh) ? True : False;
}

void FScreenSpecToString(char *dest, int space, fscreen_scr_t screen)
{
        char s[32];

        if (space <= 0)
        {
                return;
        }
        switch (screen)
        {
        case FSCREEN_GLOBAL:
                strcpy(s, "global screen");
                break;
        case FSCREEN_CURRENT:
                strcpy(s, "current screen");
                break;
        case FSCREEN_PRIMARY:
                strcpy(s, "primary screen");
                break;
        case FSCREEN_XYPOS:
                strcpy(s, "screen specified by xy");
                break;
        default:
                sprintf(s, "%d", screen);
                break;
        }
        strncpy(dest, s, space);
        dest[space - 1] = 0;

        return;
}

static int FScreenParseScreenBit(char *scr_spec, char default_screen)
{
        int scr = default_geometry_scr;
        char c;

        c = (scr_spec) ? tolower(*scr_spec) : tolower(default_screen);
        if (c == FSCREEN_SPEC_GLOBAL)
        {
                scr = FSCREEN_GLOBAL;
        }
        else if (c == FSCREEN_SPEC_CURRENT)
        {
                scr = FSCREEN_CURRENT;
        }
        else if (c == FSCREEN_SPEC_PRIMARY)
        {
                scr = FSCREEN_PRIMARY;
        }
        else if (c == FSCREEN_SPEC_WINDOW)
        {
                scr = FSCREEN_XYPOS;
        }
        else if (isdigit(c))
        {
                scr = atoi(scr_spec);
        }
        else
        {
                c = tolower(default_screen);
                if (c == FSCREEN_SPEC_GLOBAL)
                {
                        scr = FSCREEN_GLOBAL;
                }
                else if (c == FSCREEN_SPEC_CURRENT)
                {
                        scr = FSCREEN_CURRENT;
                }
                else if (c == FSCREEN_SPEC_PRIMARY)
                {
                        scr = FSCREEN_PRIMARY;
                }
                else if (c == FSCREEN_SPEC_WINDOW)
                {
                        scr = FSCREEN_XYPOS;
                }
                else if (isdigit(c))
                {
                        scr = atoi(scr_spec);
                }
        }

        return scr;
}

int FScreenGetScreenArgument(char *scr_spec, fscreen_scr_spec_t default_screen)
{
        while (scr_spec && isspace(*scr_spec))
        {
                scr_spec++;
        }

        return FScreenParseScreenBit(scr_spec, default_screen);
}

/*
 * FScreenParseGeometry
 *     Does the same as XParseGeometry, but handles additional "@scr".
 *     Since it isn't safe to define "ScreenValue" constant (actual values
 *     of other "XXXValue" are specified in Xutil.h, not by us, so there can
 *     be a clash), the screen value is always returned, even if it wasn't
 *     present in `parse_string' (set to default in that case).
 *
 */
int FScreenParseGeometryWithScreen(
        char *parsestring, int *x_return, int *y_return,
        unsigned int *width_return, unsigned int *height_return,
        int *screen_return)
{
        int   ret;
        char *copy, *scr_p;
        int   s_size;
        int   scr;

        /* Safety net */
        if (parsestring == NULL  ||  *parsestring == '\0')
        {
                return 0;
        }

        /* Make a local copy devoid of "@scr" */
        s_size = strlen(parsestring) + 1;
        copy = safemalloc(s_size);
        memcpy(copy, parsestring, s_size);
        scr_p = strchr(copy, '@');
        if (scr_p != NULL)
        {
                *scr_p++ = '\0';
        }

        /* Do the parsing */
        ret = XParseGeometry(
                copy, x_return, y_return, width_return, height_return);

        /* Parse the "@scr", if any */
        scr = FScreenParseScreenBit(scr_p, FSCREEN_SPEC_PRIMARY);
        *screen_return = scr;

        /* We don't need the string any more */
        free(copy);

        return ret;
}

/* Same as above, but dump screen return value to keep compatible with the X
 * function. */
int FScreenParseGeometry(
        char *parsestring, int *x_return, int *y_return,
        unsigned int *width_return, unsigned int *height_return)
{
        int scr;
        int rc;
        int mx;
        int my;

        rc = FScreenParseGeometryWithScreen(
                parsestring, x_return, y_return, width_return, height_return,
                &scr);
        if (rc == 0)
        {
                return 0;
        }
        switch (scr)
        {
        case FSCREEN_GLOBAL:
                scr = 0;
                break;
        case FSCREEN_CURRENT:
                GetMouseXY(NULL, &mx, &my);
                scr = FindScreenOfXY(mx, my);
                break;
        case FSCREEN_PRIMARY:
                scr = FScreenGetPrimaryScreen(NULL);
                break;
        default:
                scr++;
                break;
        }
        if (scr <= 0 || scr > last_to_check)
        {
                scr = 0;
        }
        else
        {
                /* adapt geometry to selected screen */
                if (rc & XValue)
                {
                        if (rc & XNegative)
                        {
                                *x_return -=
                                        (screens[0].width -
                                         screens[scr].width -
                                         screens[scr].x_org);
                        }
                        else
                        {
                                *x_return += screens[scr].x_org;
                        }
                }
                if (rc & YValue)
                {
                        if (rc & YNegative)
                        {
                                *y_return -=
                                        (screens[0].height -
                                         screens[scr].height -
                                         screens[scr].y_org);
                        }
                        else
                        {
                                *y_return += screens[scr].y_org;
                        }
                }
        }

        return rc;
}


/*  FScreenGetGeometry
 *      Parses the geometry in a form: XGeometry[@screen], i.e.
 *          [=][<width>{xX}<height>][{+-}<xoffset>{+-}<yoffset>][@<screen>]
 *          where <screen> is either a number or "G" (global) "C" (current)
 *          or "P" (primary)
 *
 *  Args:
 *      parsestring, x_r, y_r, w_r, h_r  the same as in XParseGeometry
 *      hints  window hints structure, may be NULL
 *      flags  bitmask of allowed flags (XValue, WidthValue, XNegative...)
 *
 *  Note1:
 *      hints->width and hints->height will be used to calc negative geometry
 *      if width/height isn't specified in the geometry itself.
 *
 *  Note2:
 *      This function's behaviour is crafted to sutisfy/emulate the
 *      FvwmWinList::MakeMeWindow()'s behaviour.
 *
 *  Note3:
 *      A special value of `flags' when [XY]Value are there but [XY]Negative
 *      aren't, means that in case of negative geometry specification
 *      x_r/y_r values will be promoted to the screen border, but w/h
 *      wouldn't be subtracted, so that the program can do x-=w later
 *      ([XY]Negative *will* be returned, albeit absent in `flags').
 *          This option is supposed for proggies like FvwmButtons, which
 *      receive geometry specification long before they are able to actually
 *      use it (and which calculate w/h themselves).
 *          (The same effect can't be obtained with omitting {Width,Height}Value
 *      in the flags, since the app may wish to get the dimensions but apply
 *      some constraints later (as FvwmButtons do, BTW...).)
 *          This option can be also useful in cases where dimensions are
 *      specified not in pixels but in some other units (e.g., charcells).
 */
int FScreenGetGeometry(
        char *parsestring, int *x_return, int *y_return,
        int *width_return, int *height_return, XSizeHints *hints, int flags)
{
        int   ret;
        int   saved;
        int   x, y;
        unsigned int w = 0, h = 0;
        int   grav, x_grav, y_grav;
        int   scr = default_geometry_scr;
        int   scr_x, scr_y;
        int scr_w, scr_h;

        /* I. Do the parsing and strip off extra bits */
        ret = FScreenParseGeometryWithScreen(parsestring, &x, &y, &w, &h, &scr);
        saved = ret & (XNegative | YNegative);
        ret  &= flags;

        /* II. Get the screen rectangle */
        switch (scr)
        {
        case FSCREEN_GLOBAL:
        case FSCREEN_CURRENT:
        case FSCREEN_PRIMARY:
        case FSCREEN_XYPOS:
                FScreenGetScrRect(NULL, scr, &scr_x, &scr_y, &scr_w, &scr_h);
                break;

        default:
                scr++;
                if (scr < first_to_check  ||  scr > last_to_check)
                        scr = first_to_check;
                scr_x = screens[scr].x_org;
                scr_y = screens[scr].y_org;
                scr_w = screens[scr].width;
                scr_h = screens[scr].height;
        }

        /* III. Interpret and fill in the values */

        /* Fill in dimensions for future negative calculations if
         * omitted/forbidden */
        /* Maybe should use *x_return,*y_return if hints==NULL?
         * Unreliable... */
        if (hints != NULL  &&  hints->flags & PSize)
        {
                if ((ret & WidthValue)  == 0)
                {
                        w = hints->width;
                }
                if ((ret & HeightValue) == 0)
                {
                        h = hints->height;
                }
        }
        else
        {
                /* This branch is required for case when size *is* specified,
                 * but masked off */
                if ((ret & WidthValue)  == 0)
                {
                        w = 0;
                }
                if ((ret & HeightValue) == 0)
                {
                        h = 0;
                }
        }

        /* Advance coords to the screen... */
        x += scr_x;
        y += scr_y;

        /* ...and process negative geometries */
        if (saved & XNegative)
        {
                x += scr_w;
        }
        if (saved & YNegative)
        {
                y += scr_h;
        }
        if (ret & XNegative)
        {
                x -= w;
        }
        if (ret & YNegative)
        {
                y -= h;
        }

        /* Restore negative bits */
        ret |= saved;

        /* Guess orientation */
        x_grav = (ret & XNegative)? GRAV_NEG : GRAV_POS;
        y_grav = (ret & YNegative)? GRAV_NEG : GRAV_POS;
        grav   = grav_matrix[y_grav][x_grav];

        /* Return the values */
        if (ret & XValue)
        {
                *x_return = x;
                if (hints != NULL)
                {
                        hints->x = x;
                }
        }
        if (ret & YValue)
        {
                *y_return = y;
                if (hints != NULL)
                {
                        hints->y = y;
                }
        }
        if (ret & WidthValue)
        {
                *width_return = w;
                if (hints != NULL)
                {
                        hints->width = w;
                }
        }
        if (ret & HeightValue)
        {
                *height_return = h;
                if (hints != NULL)
                {
                        hints->height = h;
                }
        }
        if (1 /*flags & GravityValue*/  &&  grav != DEFAULT_GRAVITY)
        {
                if (hints != NULL  &&  hints->flags & PWinGravity)
                {
                        hints->win_gravity = grav;
                }
        }
        if (hints != NULL  &&  ret & XValue  &&  ret & YValue)
                hints->flags |= USPosition;

        return ret;
}

/*  FScreenMangleScreenIntoUSPosHints
 *      A hack to mangle the screen number into the XSizeHints structure.
 *      If the USPosition flag is set, hints->x is set to the magic number and
 *      hints->y is set to the screen number.  If the USPosition flag is clear,
 *      x and y are set to zero.
 *
 *  Note:  This is a *hack* to allow modules to specify the target screen for
 *  their windows and have the StartsOnScreen style set for them at the same
 *  time.  Do *not* rely on the mechanism described above.
 */
void FScreenMangleScreenIntoUSPosHints(fscreen_scr_t screen, XSizeHints *hints)
{
        if (hints->flags & USPosition)
        {
                hints->x = FSCREEN_MANGLE_USPOS_HINTS_MAGIC;
                hints->y = (short)screen;
        }
        else
        {
                hints->x = 0;
                hints->y = 0;
        }

        return;
}

/*  FScreenMangleScreenIntoUSPosHints
 *      A hack to mangle the screen number into the XSizeHints structure.
 *      If the USPosition flag is set, hints->x is set to the magic number and
 *      hints->y is set to the screen spec.  If the USPosition flag is clear,
 *      x and y are set to zero.
 *
 *  Note:  This is a *hack* to allow modules to specify the target screen for
 *  their windows and have the StartsOnScreen style set for them at the same
 *  time.  Do *not* rely on the mechanism described above.
 */
fscreen_scr_t FScreenFetchMangledScreenFromUSPosHints(XSizeHints *hints)
{
        fscreen_scr_t screen;

        if ((hints->flags & USPosition) &&
            hints->x == FSCREEN_MANGLE_USPOS_HINTS_MAGIC)
        {
                screen = (fscreen_scr_t)(hints->y);
        }
        else
        {
                screen = FSCREEN_GLOBAL;
        }

        return screen;
}


/* no rand_r for now */
# if 0
int  FScreenGetRandrEventType(void)
{
#ifdef HAVE_RANDR
        return randr_active? randr_event_base + RRScreenChangeNotify : 0;
#else
        return 0;
#endif
}

Bool FScreenHandleRandrEvent(
        XEvent *event, int *old_w, int *old_h, int *new_w, int *new_h)
{
#ifndef HAVE_RANDR
        return 0;
#else
        XRRScreenChangeNotifyEvent *ev = (XRRScreenChangeNotifyEvent *)event;
        int nw, nh, tmp;

        if (!randr_active  ||
            event->type != randr_event_base + RRScreenChangeNotify)
        {
                return 0;
        }

        nw = ev->width;
        nh = ev->height;

        /*
         * Note1: this check is not very good, since the right way is to
         *        obtain a list of possible rotations and ...
         *
         * Note2: as to WM's point of view, I'm unsure if rotation should be
         *        treated exactly as resizing (i.e. that it should reposition
         *        windows in the same fashion).
         */
        if (ev->rotation & (1<<1 | 1<<3))
        {
                tmp = nw;
                nw  = nh;
                nh  = tmp;
        }

        *old_w = screens[0].width;
        *old_h = screens[0].height;

        screens[0].width  = nw;
        *new_w = nw;
        screens[0].height = nh;
        *new_h = nh;

        return (nw != *old_w  ||  nh != *old_h);
#endif
}
#endif