//
// Definition of X11 Screen interface
//
// Copyright 1998-2025 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//


#include <config.h>
#include "Fl_X11_Screen_Driver.H"
#include "Fl_X11_Window_Driver.H"
#include "../../Fl_Scalable_Graphics_Driver.H"
#include "../Posix/Fl_Posix_System_Driver.H"
#include <FL/Fl.H>
#include <FL/platform.H>
#include <FL/fl_ask.H>
#include <FL/Fl_Box.H>
#include <FL/Fl_Image_Surface.H>
#include <FL/Fl_Tooltip.H>
#include <FL/filename.H>
#include <sys/time.h>

#include "../../Fl_Timeout.h"
#include "../../flstring.h"

#if HAVE_XINERAMA
#  include <X11/extensions/Xinerama.h>
#endif

#  include <X11/Xutil.h>
#  ifdef __sgi
#    include <X11/extensions/readdisplay.h>
#  else
#    include <stdlib.h>
#  endif // __sgi

#ifdef DEBUG
#  include <stdio.h>
#endif // DEBUG

extern Atom fl_NET_WORKAREA;

// these are set by Fl::args() and FL_OVERRIDE any system colors: from Fl_get_system_colors.cxx
extern const char *fl_fg;
extern const char *fl_bg;
extern const char *fl_bg2;
// end of extern additions workaround

#if !(USE_XFT || FLTK_USE_CAIRO)
extern char *fl_get_font_xfld(int fnum, int size);
#endif

XIM Fl_X11_Screen_Driver::xim_im = 0;

XIC Fl_X11_Screen_Driver::xim_ic = 0;

int Fl_X11_Screen_Driver::fl_spotf = -1;
int Fl_X11_Screen_Driver::fl_spots = -1;
XRectangle Fl_X11_Screen_Driver::fl_spot;
char Fl_X11_Screen_Driver::fl_is_over_the_spot = 0;

Window Fl_X11_Screen_Driver::xim_win = 0;

Fl_X11_Screen_Driver::Fl_X11_Screen_Driver() : Fl_Unix_Screen_Driver() {
  // X11 screen driver does not use a key table
  key_table = NULL;
  key_table_size = 0;
}

void Fl_X11_Screen_Driver::display(const char *d) {
  if (!d) return;
  // Issue #937:
  // setenv() is available since POSIX.1-2001
  // https://pubs.opengroup.org/onlinepubs/009604499/functions/setenv.html
#if HAVE_SETENV
  setenv("DISPLAY", d, 1);
#else  // HAVE_SETENV
  // Use putenv() for old systems (similar to FLTK 1.3)
  static char e[1024];
  strcpy(e, "DISPLAY=");
  strlcat(e, d, sizeof(e));
  char *c;
  for (c = e + 8; *c != ':'; c++) {
    if (!*c) {
      strlcat(e,":0.0",sizeof(e));
      break;
    }
  }
  putenv(e);
#endif  // HAVE_SETENV
}

void fl_x11_use_display(Display *d) {
  fl_display = d;
}

int Fl_X11_Screen_Driver::XParseGeometry(const char* string, int* x, int* y,
                                         unsigned int* width, unsigned int* height) {
  return ::XParseGeometry(string, x, y, width, height);
}


void Fl_X11_Screen_Driver::own_colormap() {
  fl_open_display();
#if USE_COLORMAP
  switch (fl_visual->c_class) {
  case GrayScale :
  case PseudoColor :
  case DirectColor :
    break;
  default:
    return; // don't do anything for non-colormapped visuals
  }
  int i;
  XColor colors[16];
  // Get the first 16 colors from the default colormap...
  for (i = 0; i < 16; i ++) colors[i].pixel = i;
  XQueryColors(fl_display, fl_colormap, colors, 16);
  // Create a new colormap...
  fl_colormap = XCreateColormap(fl_display,
                                RootWindow(fl_display,fl_screen),
                                fl_visual->visual, AllocNone);
  // Copy those first 16 colors to our own colormap:
  for (i = 0; i < 16; i ++)
    XAllocColor(fl_display, fl_colormap, colors + i);
#endif // USE_COLORMAP
}


const char *Fl_X11_Screen_Driver::shortcut_add_key_name(unsigned key, char *p, char *buf, const char **eom)
{
  const char* q;
  if (key == FL_Enter || key == '\r') q = "Enter";  // don't use Xlib's "Return":
  else if (key > 32 && key < 0x100) q = 0;
  else q = XKeysymToString(key);
  if (!q) {
    p += fl_utf8encode(fl_toupper(key), p);
    *p = 0;
    return buf;
  }
  if (p > buf) {
    strcpy(p,q);
    return buf;
  } else {
    if (eom) *eom = q;
    return q;
  }
}


static int test_visual(XVisualInfo& v, int flags) {
  if (v.screen != fl_screen) return 0;
#if USE_COLORMAP
  if (!(flags & FL_INDEX)) {
    if (v.c_class != StaticColor && v.c_class != TrueColor) return 0;
    if (v.depth <= 8) return 0; // fltk will work better in colormap mode
  }
  if (flags & FL_RGB8) {
    if (v.depth < 24) return 0;
  }
  // for now, fltk does not like colormaps of more than 8 bits:
  if ((v.c_class&1) && v.depth > 8) return 0;
#else
  // simpler if we can't use colormapped visuals at all:
  if (v.c_class != StaticColor && v.c_class != TrueColor) return 0;
#endif
  return 1;
}


int Fl_X11_Screen_Driver::visual(int flags)
{
  if (flags & FL_DOUBLE) return 0;
  open_display();
  // always use default if possible:
  if (test_visual(*fl_visual, flags)) return 1;
  // get all the visuals:
  XVisualInfo vTemplate;
  int num;
  XVisualInfo *visualList = XGetVisualInfo(fl_display, 0, &vTemplate, &num);
  // find all matches, use the one with greatest depth:
  XVisualInfo *found = 0;
  int i;
  for (i =0; i<num; i++) if (test_visual(visualList[i], flags)) {
    if (!found || found->depth < visualList[i].depth)
      found = &visualList[i];
  }
  if (!found) {XFree((void*)visualList); return 0;}
  fl_visual = found;
  fl_colormap = XCreateColormap(fl_display, RootWindow(fl_display,fl_screen),
                                fl_visual->visual, AllocNone);
  return 1;
}


static int fl_workarea_xywh[4] = { -1, -1, -1, -1 };


void Fl_X11_Screen_Driver::init_workarea()
{
  Atom actual;
  unsigned long count, remaining;
  int format;
  long *xywh = 0;

  /* If there are several screens, the _NET_WORKAREA property
   does not give the work area of the main screen, but that of all screens together.
   Therefore, we use this property only when there is a single screen,
   and fall back to the main screen full area when there are several screens.
   */
  if (Fl::screen_count() > 1 || XGetWindowProperty(fl_display, RootWindow(fl_display, fl_screen),
                         fl_NET_WORKAREA, 0, 4, False,
                         XA_CARDINAL, &actual, &format, &count, &remaining,
                         (unsigned char **)&xywh) || !xywh || !xywh[2] ||
                         !xywh[3])
  {
    fl_workarea_xywh[0] = screens[0].x_org;
    fl_workarea_xywh[1] = screens[0].y_org;
    fl_workarea_xywh[2] = screens[0].width;
    fl_workarea_xywh[3] = screens[0].height;
  }
  else
  {
    fl_workarea_xywh[0] = xywh[0];
    fl_workarea_xywh[1] = xywh[1];
    fl_workarea_xywh[2] = xywh[2];
    fl_workarea_xywh[3] = xywh[3];
  }
  if ( xywh ) { XFree(xywh); xywh = 0; }
}


int Fl_X11_Screen_Driver::x() {
  if (!fl_display) open_display();
  return fl_workarea_xywh[0]
#if USE_XFT || FLTK_USE_CAIRO
  / screens[0].scale
#endif
  ;
}

int Fl_X11_Screen_Driver::y() {
  if (!fl_display) open_display();
  return fl_workarea_xywh[1]
#if USE_XFT || FLTK_USE_CAIRO
  / screens[0].scale
#endif
  ;
}

int Fl_X11_Screen_Driver::w() {
  if (!fl_display) open_display();
  return fl_workarea_xywh[2]
#if USE_XFT || FLTK_USE_CAIRO
      / screens[0].scale
#endif
  ;
}

int Fl_X11_Screen_Driver::h() {
  if (!fl_display) open_display();
  return fl_workarea_xywh[3]
#if USE_XFT || FLTK_USE_CAIRO
  / screens[0].scale
#endif
  ;
}

#define USE_XRANDR (HAVE_DLSYM && HAVE_DLFCN_H) // means attempt to dynamically load libXrandr.so
#if USE_XRANDR
#include <dlfcn.h>
typedef struct {
  int    width, height;
  int    mwidth, mheight;
} XRRScreenSize;
typedef XRRScreenSize* (*XRRSizes_type)(Display *dpy, int screen, int *nsizes);
#endif // USE_XRANDR

void Fl_X11_Screen_Driver::init() {
  if (!fl_display) open_display();

  int dpi_by_randr = 0;
  float dpih = 0.0f, dpiv = 0.0f;

#if USE_XRANDR

  static XRRSizes_type XRRSizes_f = NULL;
  if (!XRRSizes_f) {
    XRRSizes_f = (XRRSizes_type)Fl_Posix_System_Driver::dlopen_or_dlsym("libXrandr", "XRRSizes");
  }
  if (XRRSizes_f) {
    int nscreens;
    XRRScreenSize *ssize = XRRSizes_f(fl_display, fl_screen, &nscreens);

    //for (int i=0; i<nscreens; i++)
    //  printf("width=%d height=%d mwidth=%d mheight=%d\n",
    //         ssize[i].width,ssize[i].height,ssize[i].mwidth,ssize[i].mheight);

    if (nscreens > 0) { // Note: XRRSizes() *may* return nscreens == 0, see docs
      int mm = ssize[0].mwidth;
      dpih = mm ? ssize[0].width*25.4f/mm : 0.0f;
      mm = ssize[0].mheight;
      dpiv = mm ? ssize[0].height*25.4f/mm : 0.0f;
      dpi_by_randr = 1;
    }
  }

#endif // USE_XRANDR

  int i;

#if HAVE_XINERAMA

  if (XineramaIsActive(fl_display)) {
    XineramaScreenInfo *xsi = XineramaQueryScreens(fl_display, &num_screens);
    if (num_screens > MAX_SCREENS) num_screens = MAX_SCREENS;

    /* There's no way to use different DPI for different Xinerama screens. */
    for (i =0; i<num_screens; i++) {
      screens[i].x_org = xsi[i].x_org;
      screens[i].y_org = xsi[i].y_org;
      screens[i].width = xsi[i].width;
      screens[i].height = xsi[i].height;
      if (dpi_by_randr) {
        dpi[i][0] = dpih;
        dpi[i][1] = dpiv;
      } else {
        int mm = DisplayWidthMM(fl_display, fl_screen);
        dpi[i][0] = mm ? screens[i].width*25.4f/mm : 0.0f;
        mm = DisplayHeightMM(fl_display, fl_screen);
        dpi[i][1] = mm ? screens[i].height*25.4f/mm : 0.0f;
      }
    }
    if (xsi) XFree(xsi);
  } else

#endif // HAVE_XINERAMA

  { // ! HAVE_XINERAMA || ! XineramaIsActive()
    num_screens = ScreenCount(fl_display);
    if (num_screens > MAX_SCREENS) num_screens = MAX_SCREENS;

    for (i =0; i<num_screens; i++) {
      screens[i].x_org = 0;
      screens[i].y_org = 0;
      screens[i].width = DisplayWidth(fl_display, i);
      screens[i].height = DisplayHeight(fl_display, i);
#if USE_XFT || FLTK_USE_CAIRO
      screens[i].scale = 1;
#endif
      if (dpi_by_randr) {
        dpi[i][0] = dpih;
        dpi[i][1] = dpiv;
      } else {
        int mm = DisplayWidthMM(fl_display, i);
        dpi[i][0] = mm ? screens[i].width*25.4f/mm : 0.0f;
        mm = DisplayHeightMM(fl_display, fl_screen);
        dpi[i][1] = mm ? screens[i].height*25.4f/mm : 0.0f;
      }
    }
  }
  init_workarea();
}


void Fl_X11_Screen_Driver::screen_work_area(int &X, int &Y, int &W, int &H, int n)
{
  if (num_screens < 0) init();
  if (n < 0 || n >= num_screens) n = 0;
  if (n == 0) { // for the main screen, these return the work area
    X = Fl::x();
    Y = Fl::y();
    W = Fl::w();
    H = Fl::h();
  } else { // for other screens, work area is full screen,
    screen_xywh(X, Y, W, H, n);
  }
}


void Fl_X11_Screen_Driver::screen_xywh(int &X, int &Y, int &W, int &H, int n)
{
  if (num_screens < 0) init();

  if ((n < 0) || (n >= num_screens))
    n = 0;

  if (num_screens > 0) {
#if USE_XFT || FLTK_USE_CAIRO
    float s = screens[n].scale;
#else
    float s = 1;
#endif
    X = screens[n].x_org / s;
    Y = screens[n].y_org / s;
    W = screens[n].width / s;
    H = screens[n].height / s;
  }
}


void Fl_X11_Screen_Driver::screen_dpi(float &h, float &v, int n)
{
  if (num_screens < 0) init();
  h = v = 0.0f;

  if (n >= 0 && n < num_screens) {
    h = dpi[n][0];
    v = dpi[n][1];
  }
}


// Implements fl_beep(). See documentation in src/fl_ask.cxx.
void Fl_X11_Screen_Driver::beep(int type)
{
  int vol;
  switch (type) {
    case FL_BEEP_ERROR :
      vol = 100;
      break;
    case FL_BEEP_DEFAULT :
    default :
      vol = 0;
      break;
  }
  if (!fl_display) open_display();
  XBell(fl_display, vol);
}


void Fl_X11_Screen_Driver::flush()
{
  if (fl_display)
    XFlush(fl_display);
}


extern void fl_fix_focus(); // in Fl.cxx


void Fl_X11_Screen_Driver::grab(Fl_Window* win)
{
  const char *p;
  static bool using_kde =
    ( p = getenv("XDG_CURRENT_DESKTOP") , (p && (strcmp(p, "KDE") == 0)) );
  Fl_Window *fullscreen_win = NULL;
  Fl_Window *W;
  for (W = Fl::first_window(); W; W = Fl::next_window(W)) {
    if (W->fullscreen_active()) {
      fullscreen_win = W;
      break;
    }
  }
  if (win) {
    if (!Fl::grab()) {
      Window xid = fullscreen_win ? fl_xid(fullscreen_win) : fl_xid(Fl::first_window());
      XGrabPointer(fl_display,
                   xid,
                   1,
                   ButtonPressMask|ButtonReleaseMask|
                   ButtonMotionMask|PointerMotionMask,
                   GrabModeAsync,
                   GrabModeAsync,
                   None,
                   0,
                   fl_event_time);
      if (!using_kde) { // grabbing tends to stick with KDE (#904)
        XGrabKeyboard(fl_display,
                      xid,
                      1,
                      GrabModeAsync,
                      GrabModeAsync,
                      fl_event_time);
      }
    }
    Fl::grab_ = win;    // FIXME: Fl::grab_ "should be private", but we need
                        // a way to *set* the variable from the driver!
  } else {
    if (Fl::grab()) {
      // We must keep the grab in the non-EWMH fullscreen case
      if (!fullscreen_win || ewmh_supported()) {
        XUngrabKeyboard(fl_display, fl_event_time);
      }
      XUngrabPointer(fl_display, fl_event_time);
      // this flush is done in case the picked menu item goes into
      // an infinite loop, so we don't leave the X server locked up:
      XFlush(fl_display);
      Fl::grab_ = 0;    // FIXME: Fl::grab_ "should be private", but we need
                        // a way to *set* the variable from the driver!
      fl_fix_focus();
    }
  }
}


// Wrapper around XParseColor...
int Fl_X11_Screen_Driver::parse_color(const char* p, uchar& r, uchar& g, uchar& b)
{
  // before w open the display, we try interpreting this ourselves
  // "None" will ultimately always return 0
  if (   (fl_ascii_strcasecmp(p, "none") == 0)
      || (fl_ascii_strcasecmp(p, "#transparent") == 0) )
    return 0;
  // if it's #rgb, we can do that ourselves
  if (Fl_Screen_Driver::parse_color(p, r, g, b))
    return 1;
  // it's neither "None" nor hex, so finally open the diplay and ask X11
  XColor x;
  if (!fl_display) open_display();
  if (XParseColor(fl_display, fl_colormap, p, &x)) {
    r = (uchar)(x.red>>8);
    g = (uchar)(x.green>>8);
    b = (uchar)(x.blue>>8);
    return 1;
  } else return 0;
}


// Read colors that KDE writes to the xrdb database.

// XGetDefault does not do the expected thing: it does not like
// periods in either word. Therefore it cannot match class.Text.background.
// However *.Text.background is matched by pretending the program is "Text".
// But this will also match *.background if there is no *.Text.background
// entry, requiring users to put in both (unless they want the text fields
// the same color as the windows).

static void set_selection_color(uchar r, uchar g, uchar b)
{
  Fl::set_color(FL_SELECTION_COLOR,r,g,b);
}

static void getsyscolor(const char *key1, const char* key2, const char *arg, const char *defarg, void (*func)(uchar,uchar,uchar))
{
  if (!arg) {
    arg = XGetDefault(fl_display, key1, key2);
    if (!arg) arg = defarg;
  }
  XColor x;
  if (!XParseColor(fl_display, fl_colormap, arg, &x))
    Fl::error("Unknown color: %s", arg);
  else
    func(x.red>>8, x.green>>8, x.blue>>8);
}


void Fl_X11_Screen_Driver::get_system_colors()
{
  open_display();
  const char* key1 = 0;
  if (Fl::first_window()) key1 = Fl::first_window()->xclass();
  if (!key1) key1 = "fltk";
  if (!bg2_set)
    getsyscolor("Text","background",    fl_bg2, "#ffffff", Fl::background2);
  if (!fg_set)
    getsyscolor(key1,  "foreground",    fl_fg,  "#000000", Fl::foreground);
  if (!bg_set)
    getsyscolor(key1,  "background",    fl_bg,  "#c0c0c0", Fl::background);
  getsyscolor("Text", "selectBackground", 0, "#000080", set_selection_color);
}


const char *Fl_X11_Screen_Driver::get_system_scheme()
{
  const char *s = 0L;
  if ((s = fl_getenv("FLTK_SCHEME")) == NULL) {
    const char* key = 0;
    if (Fl::first_window()) key = Fl::first_window()->xclass();
    if (!key) key = "fltk";
    open_display();
    s = XGetDefault(fl_display, key, "scheme");
  }
  return s;
}


int Fl_X11_Screen_Driver::compose(int& del) {
  int condition;
  unsigned char ascii = (unsigned char)Fl::e_text[0];
  condition = (Fl::e_state & (FL_ALT | FL_META | FL_CTRL)) && !(ascii & 128) ;
  if (condition) { del = 0; return 0;} // this stuff is to be treated as a function key
  del = Fl::compose_state;
  Fl::compose_state = 0;
  // Only insert non-control characters:
  if ( (!Fl::compose_state) && ! (ascii & ~31 && ascii!=127)) { return 0; }
  return 1;
}

void Fl_X11_Screen_Driver::compose_reset()
{
  Fl::compose_state = 0;
  if (xim_ic) XmbResetIC(xim_ic);
}

int Fl_X11_Screen_Driver::text_display_can_leak() const {
#if USE_XFT || FLTK_USE_CAIRO
  return 1;
#else
  return 0;
#endif
}


//
// 'fl_subimage_offsets()' - Calculate subimage offsets for an axis
static inline int
fl_subimage_offsets(int a, int aw, int b, int bw, int &obw)
{
  int off;
  int ob;

  if (b >= a) {
    ob = b;
    off = 0;
  } else {
    ob = a;
    off = a - b;
  }

  bw -= off;

  if (ob + bw <= a + aw) {
    obw = bw;
  } else {
    obw = (a + aw) - ob;
  }

  return off;
}

// this handler will catch and ignore exceptions during XGetImage
// to avoid an application crash
extern "C" {
  static int xgetimageerrhandler(Display *display, XErrorEvent *error) {
    return 0;
  }
}


// When capturing window decoration, w is negative and X,Y,w and h are in pixels;
// otherwise X,Y,w and h are in FLTK units.
//
Fl_RGB_Image *Fl_X11_Screen_Driver::read_win_rectangle(int X, int Y, int w, int h, Fl_Window *win, bool may_capture_subwins, bool *did_capture_subwins)
{
  XImage        *image;         // Captured image
  int           i, maxindex;    // Looping vars
  int           x, y;           // Current X & Y in image
  unsigned char *line,          // Array to hold image row
                *line_ptr;      // Pointer to current line image
  unsigned char *pixel;         // Current color value
  XColor        colors[4096];   // Colors from the colormap...
  unsigned char cvals[4096][3]; // Color values from the colormap...
  unsigned      index_mask,
                index_shift,
                red_mask,
                red_shift,
                green_mask,
                green_shift,
                blue_mask,
                blue_shift;
  //
  // Under X11 we have the option of the XGetImage() interface or SGI's
  // ReadDisplay extension which does all of the really hard work for
  // us...
  //
  int allow_outside = w < 0;    // negative w allows negative X or Y, that is, window frame
  if (w < 0) w = - w;
  Window xid;
  if (win && !allow_outside) {
    if (win->as_double_window()) { // read from the window's offscreen buffer
      xid = Fl_X11_Window_Driver::driver(win)->other_xid->offscreen();
      win = NULL;
    } else xid = fl_xid(win);
  } else xid = fl_window;

  float s = allow_outside ? 1 : Fl_Surface_Device::surface()->driver()->scale();
  int Xs = Fl_Scalable_Graphics_Driver::floor(X, s);
  int Ys = Fl_Scalable_Graphics_Driver::floor(Y, s);
  int ws = Fl_Scalable_Graphics_Driver::floor(X+w, s) - Xs;
  int hs = Fl_Scalable_Graphics_Driver::floor(Y+h, s) - Ys;

#  ifdef __sgi
  if (XReadDisplayQueryExtension(fl_display, &i, &i)) {
    image = XReadDisplay(fl_display, xid, Xs, Ys, ws, hs, 0, NULL);
  } else
#  else
    image = 0;
#  endif // __sgi

  if (!image) {
    // fetch absolute coordinates
    int dx = 0, dy = 0, sx = 0, sy = 0, sw = 0, sh = 0;
    Window child_win;

    if (win) {
      XTranslateCoordinates(fl_display, xid,
                            RootWindow(fl_display, fl_screen), Xs, Ys, &dx, &dy, &child_win);
      // screen dimensions
      int ns = Fl_Window_Driver::driver(win)->screen_num();
      sx = screens[ns].x_org;
      sy = screens[ns].y_org;
      sw = screens[ns].width;
      sh = screens[ns].height;
    }
#if ! HAVE_XRENDER
    if (win && !allow_outside && int(s) != s) {
      ws = (w+1) * s; // approximates what Fl_Graphics_Driver::cache_size() does
      hs = (h+1) * s;
     }
#endif
    if (!allow_outside && win && Xs + ws > int(win->w()*s)) ws = win->w()*s - Xs;
    if (!allow_outside && win && Ys + hs > int(win->h()*s)) hs = win->h()*s - Ys;
    if (ws < 1) ws = 1;
    if (hs < 1) hs = 1;
    if (!win || (dx >= sx && dy >= sy && dx + ws <= sx+sw && dy + hs <= sy+sh) ) {
      // the image is fully contained, we can use the traditional method
      // however, if the window is obscured etc. the function will still fail. Make sure we
      // catch the error and continue, otherwise an exception will be thrown.
      XErrorHandler old_handler = XSetErrorHandler(xgetimageerrhandler);
      image = XGetImage(fl_display, xid, Xs, Ys, ws, hs, AllPlanes, ZPixmap);
      XSetErrorHandler(old_handler);
    } else {
      // image is crossing borders, determine visible region
      int nw, nh, noffx, noffy;
      noffx = fl_subimage_offsets(sx, sw, dx, ws, nw);
      noffy = fl_subimage_offsets(sy, sh, dy, hs, nh);
      if (nw <= 0 || nh <= 0) return 0;

      // allocate the image
      int bpp = fl_visual->depth + ((fl_visual->depth / 8) % 2) * 8;
      char* buf = (char*)malloc((bpp / 8) * ws * hs);
      image = XCreateImage(fl_display, fl_visual->visual,
                           fl_visual->depth, ZPixmap, 0, buf, ws, hs, bpp, 0);
      if (!image) {
        if (buf) free(buf);
        return 0;
      }

      XErrorHandler old_handler = XSetErrorHandler(xgetimageerrhandler);
      XImage *subimg = XGetSubImage(fl_display, xid, Xs + noffx, Ys + noffy,
                                    nw, nh, AllPlanes, ZPixmap, image, noffx, noffy);
      XSetErrorHandler(old_handler);
      if (!subimg) {
        XDestroyImage(image);
        return 0;
      }
    }
  }

  if (!image) return 0;
  if (s != 1) {
    w = ws;
    h = hs;
  }

#ifdef DEBUG
  printf("width            = %d\n", image->width);
  printf("height           = %d\n", image->height);
  printf("xoffset          = %d\n", image->xoffset);
  printf("format           = %d\n", image->format);
  printf("data             = %p\n", image->data);
  printf("byte_order       = %d\n", image->byte_order);
  printf("bitmap_unit      = %d\n", image->bitmap_unit);
  printf("bitmap_bit_order = %d\n", image->bitmap_bit_order);
  printf("bitmap_pad       = %d\n", image->bitmap_pad);
  printf("depth            = %d\n", image->depth);
  printf("bytes_per_line   = %d\n", image->bytes_per_line);
  printf("bits_per_pixel   = %d\n", image->bits_per_pixel);
  printf("red_mask         = %08x\n", image->red_mask);
  printf("green_mask       = %08x\n", image->green_mask);
  printf("blue_mask        = %08x\n", image->blue_mask);
  printf("map_entries      = %d\n", fl_visual->visual->map_entries);
#endif // DEBUG

  const int d = 3; // Depth of image
  uchar *p = NULL;
  // Allocate the image data array as needed...
  p = new uchar[w * h * d];

  // Initialize the default colors/alpha in the whole image...
  memset(p, 0, w * h * d);

  // Check that we have valid mask/shift values...
  if (!image->red_mask && image->bits_per_pixel > 12) {
    // Greater than 12 bits must be TrueColor...
    image->red_mask   = fl_visual->visual->red_mask;
    image->green_mask = fl_visual->visual->green_mask;
    image->blue_mask  = fl_visual->visual->blue_mask;

#ifdef DEBUG
    // Defined in Fl_Xlib_Graphics_Driver_color.cxx
    extern uchar fl_redmask, fl_greenmask, fl_bluemask;
    extern int fl_redshift, fl_greenshift, fl_blueshift;
    puts("\n---- UPDATED ----");
    printf("fl_redmask       = %08x\n", fl_redmask);
    printf("fl_redshift      = %d\n", fl_redshift);
    printf("fl_greenmask     = %08x\n", fl_greenmask);
    printf("fl_greenshift    = %d\n", fl_greenshift);
    printf("fl_bluemask      = %08x\n", fl_bluemask);
    printf("fl_blueshift     = %d\n", fl_blueshift);
    printf("red_mask         = %08x\n", image->red_mask);
    printf("green_mask       = %08x\n", image->green_mask);
    printf("blue_mask        = %08x\n", image->blue_mask);
#endif // DEBUG
  }

  // Check if we have colormap image...
  if (!image->red_mask) {
    // Get the colormap entries for this window...
    maxindex = fl_visual->visual->map_entries;

    for (i = 0; i < maxindex; i ++) colors[i].pixel = i;

    XQueryColors(fl_display, fl_colormap, colors, maxindex);

    for (i = 0; i < maxindex; i ++) {
      cvals[i][0] = colors[i].red >> 8;
      cvals[i][1] = colors[i].green >> 8;
      cvals[i][2] = colors[i].blue >> 8;
    }

    // Read the pixels and output an RGB image...
    for (y = 0; y < image->height; y ++) {
      pixel = (unsigned char *)(image->data + y * image->bytes_per_line);
      line  = p + y * w * d;

      switch (image->bits_per_pixel) {
        case 1 :
          for (x = image->width, line_ptr = line, index_mask = 128;
               x > 0;
               x --, line_ptr += d) {
            if (*pixel & index_mask) {
              line_ptr[0] = cvals[1][0];
              line_ptr[1] = cvals[1][1];
              line_ptr[2] = cvals[1][2];
            } else {
              line_ptr[0] = cvals[0][0];
              line_ptr[1] = cvals[0][1];
              line_ptr[2] = cvals[0][2];
            }

            if (index_mask > 1) {
              index_mask >>= 1;
            } else {
              index_mask = 128;
              pixel ++;
            }
          }
          break;

        case 2 :
          for (x = image->width, line_ptr = line, index_shift = 6;
               x > 0;
               x --, line_ptr += d) {
            i = (*pixel >> index_shift) & 3;

            line_ptr[0] = cvals[i][0];
            line_ptr[1] = cvals[i][1];
            line_ptr[2] = cvals[i][2];

            if (index_shift > 0) {
              index_shift -= 2;
            } else {
              index_shift = 6;
              pixel ++;
            }
          }
          break;

        case 4 :
          for (x = image->width, line_ptr = line, index_shift = 4;
               x > 0;
               x --, line_ptr += d) {
            if (index_shift == 4) i = (*pixel >> 4) & 15;
            else i = *pixel & 15;

            line_ptr[0] = cvals[i][0];
            line_ptr[1] = cvals[i][1];
            line_ptr[2] = cvals[i][2];

            if (index_shift > 0) {
              index_shift = 0;
            } else {
              index_shift = 4;
              pixel ++;
            }
          }
          break;

        case 8 :
          for (x = image->width, line_ptr = line;
               x > 0;
               x --, line_ptr += d, pixel ++) {
            line_ptr[0] = cvals[*pixel][0];
            line_ptr[1] = cvals[*pixel][1];
            line_ptr[2] = cvals[*pixel][2];
          }
          break;

        case 12 :
          for (x = image->width, line_ptr = line, index_shift = 0;
               x > 0;
               x --, line_ptr += d) {
            if (index_shift == 0) {
              i = ((pixel[0] << 4) | (pixel[1] >> 4)) & 4095;
            } else {
              i = ((pixel[1] << 8) | pixel[2]) & 4095;
            }

            line_ptr[0] = cvals[i][0];
            line_ptr[1] = cvals[i][1];
            line_ptr[2] = cvals[i][2];

            if (index_shift == 0) {
              index_shift = 4;
            } else {
              index_shift = 0;
              pixel += 3;
            }
          }
          break;
      }
    }
  } else {
    // RGB(A) image, so figure out the shifts & masks...
    red_mask  = image->red_mask;
    red_shift = 0;

    while ((red_mask & 1) == 0) {
      red_mask >>= 1;
      red_shift ++;
    }

    green_mask  = image->green_mask;
    green_shift = 0;

    while ((green_mask & 1) == 0) {
      green_mask >>= 1;
      green_shift ++;
    }

    blue_mask  = image->blue_mask;
    blue_shift = 0;

    while ((blue_mask & 1) == 0) {
      blue_mask >>= 1;
      blue_shift ++;
    }

    // Read the pixels and output an RGB image...
    for (y = 0; y < image->height; y ++) {
      pixel = (unsigned char *)(image->data + y * image->bytes_per_line);
      line  = p + y * w * d;

      switch (image->bits_per_pixel) {
        case 8 :
          for (x = image->width, line_ptr = line;
               x > 0;
               x --, line_ptr += d, pixel ++) {
            i = *pixel;

            line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
            line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
            line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
          }
          break;

        case 12 :
          for (x = image->width, line_ptr = line, index_shift = 0;
               x > 0;
               x --, line_ptr += d) {
            if (index_shift == 0) {
              i = ((pixel[0] << 4) | (pixel[1] >> 4)) & 4095;
            } else {
              i = ((pixel[1] << 8) | pixel[2]) & 4095;
            }

            line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
            line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
            line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;

            if (index_shift == 0) {
              index_shift = 4;
            } else {
              index_shift = 0;
              pixel += 3;
            }
          }
          break;

        case 16 :
          if (image->byte_order == LSBFirst) {
            // Little-endian...
            for (x = image->width, line_ptr = line;
                 x > 0;
                 x --, line_ptr += d, pixel += 2) {
              i = (pixel[1] << 8) | pixel[0];

              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
            }
          } else {
            // Big-endian...
            for (x = image->width, line_ptr = line;
                 x > 0;
                 x --, line_ptr += d, pixel += 2) {
              i = (pixel[0] << 8) | pixel[1];

              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
            }
          }
          break;

        case 24 :
          if (image->byte_order == LSBFirst) {
            // Little-endian...
            for (x = image->width, line_ptr = line;
                 x > 0;
                 x --, line_ptr += d, pixel += 3) {
              i = (((pixel[2] << 8) | pixel[1]) << 8) | pixel[0];

              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
            }
          } else {
            // Big-endian...
            for (x = image->width, line_ptr = line;
                 x > 0;
                 x --, line_ptr += d, pixel += 3) {
              i = (((pixel[0] << 8) | pixel[1]) << 8) | pixel[2];

              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
            }
          }
          break;

        case 32 :
          if (image->byte_order == LSBFirst) {
            // Little-endian...
            for (x = image->width, line_ptr = line;
                 x > 0;
                 x --, line_ptr += d, pixel += 4) {
              i = (((((pixel[3] << 8) | pixel[2]) << 8) | pixel[1]) << 8) | pixel[0];

              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
            }
          } else {
            // Big-endian...
            for (x = image->width, line_ptr = line;
                 x > 0;
                 x --, line_ptr += d, pixel += 4) {
              i = (((((pixel[0] << 8) | pixel[1]) << 8) | pixel[2]) << 8) | pixel[3];

              line_ptr[0] = 255 * ((i >> red_shift) & red_mask) / red_mask;
              line_ptr[1] = 255 * ((i >> green_shift) & green_mask) / green_mask;
              line_ptr[2] = 255 * ((i >> blue_shift) & blue_mask) / blue_mask;
            }
          }
          break;
      }
    }
  }

  // Destroy the X image we've read and return the RGB(A) image...
  XDestroyImage(image);

  Fl_RGB_Image *rgb = new Fl_RGB_Image(p, w, h, d);
  rgb->alloc_array = 1;
  return rgb;
}


void Fl_X11_Screen_Driver::offscreen_size(Fl_Offscreen off, int &width, int &height)
{
  int px, py;
  unsigned w, h, b, d;
  Window root;
  XGetGeometry(fl_display, (Pixmap)off, &root, &px, &py, &w, &h, &b, &d);
  width = (int)w;
  height = (int)h;
}


void Fl_X11_Screen_Driver::reset_spot(void)
{
  fl_spot.x = -1;
  fl_spot.y = -1;
  //if (xim_ic) XUnsetICFocus(xim_ic);
}


void Fl_X11_Screen_Driver::set_spot(int font, int size, int X, int Y, int W, int H, Fl_Window *win)
{
  int change = 0;
  XVaNestedList preedit_attr;
  static XFontSet fs = NULL;
  char **missing_list = NULL;
  int missing_count = 0;
  char *def_string = NULL;
  char *fnt = NULL;
  bool must_free_fnt = true;

  static XIC ic = NULL;

  if (!xim_ic || !fl_is_over_the_spot) return;
  if (Fl::focus()) { // handle case when text widget is inside subwindow
    Fl_Window *focuswin = Fl::focus()->window();
    while (focuswin && focuswin->parent()) {
      X += focuswin->x(); Y += focuswin->y();
      focuswin = focuswin->window();
    }
  }
  // XSetICFocus(xim_ic);
  if (X != fl_spot.x || Y != fl_spot.y) {
    fl_spot.x = X;
    fl_spot.y = Y;
    fl_spot.height = H;
    fl_spot.width = W;
    change = 1;
  }
  if (font != fl_spotf || size != fl_spots) {
    fl_spotf = font;
    fl_spots = size;
    change = 1;
    if (fs) {
      XFreeFontSet(fl_display, fs);
    }
#if USE_XFT || FLTK_USE_CAIRO
    fnt = NULL; // FIXME: missing XFT support here
#else
    fnt = fl_get_font_xfld(font, size);
#endif
    if (!fnt) {
      fnt = (char*)"-misc-fixed-*";
      must_free_fnt = false;
    }
    fs = XCreateFontSet(fl_display, fnt, &missing_list, &missing_count, &def_string);
    if (missing_list)
      XFreeStringList(missing_list);
  }
  if (xim_ic != ic) {
    ic = xim_ic;
    change = 1;
  }

  if (fnt && must_free_fnt) free(fnt);
  if (!change) return;

  float s = Fl_Graphics_Driver::default_driver().scale();
  XRectangle fl_spot_unscaled = { short(fl_spot.x * s), short(fl_spot.y * s),
    (unsigned short)(fl_spot.width * s), (unsigned short)(fl_spot.height * s) };
  preedit_attr = XVaCreateNestedList(0,
                                     XNSpotLocation, &fl_spot_unscaled,
                                     XNFontSet, fs, NULL);
  XSetICValues(xim_ic, XNPreeditAttributes, preedit_attr, NULL);
  XFree(preedit_attr);
}


#if USE_XFT || FLTK_USE_CAIRO
//NOTICE: returns -1 if x,y is not in any screen
int Fl_X11_Screen_Driver::screen_num_unscaled(int x, int y)
{
  int screen = -1;
  if (num_screens < 0) init();

  int i;
  for (i = 0; i < num_screens; i ++) {
    int sx = screens[i].x_org, sy = screens[i].y_org, sw = screens[i].width, sh = screens[i].height;
    if ((x >= sx) && (x < (sx+sw)) && (y >= sy) && (y < (sy+sh))) {
      screen = i;
      break;
    }
  }
  return screen;
}


// set the desktop's default scaling value
void Fl_X11_Screen_Driver::desktop_scale_factor()
{
  if (this->current_xft_dpi == 0.) { // Try getting the Xft.dpi resource value
    char *s = XGetDefault(fl_display, "Xft", "dpi");
    if (s && sscanf(s, "%f", &(this->current_xft_dpi)) == 1) {
      float factor = this->current_xft_dpi / 96.;
      // checks to prevent potential crash (factor <= 0) or very large factors
      // and round nearly 1 or nearly 2 values (issue #1138)
      if (factor < 1.1) factor = 1;
      else if (factor > 1.8 && factor < 2.2) factor = 2;
      else if (factor > 10.0) factor = 10.0;
      int i;
      for (i = 0; i < screen_count(); i++)  scale(i, factor);
    }
  }
}

#endif // USE_XFT || FLTK_USE_CAIRO