mc now colored correctly

[k8sterm.git] / src / sterm.c

/* See LICENSE for licence details. */
#ifdef _XOPEN_SOURCE
# undef _XOPEN_SOURCE
#endif
#define _XOPEN_SOURCE 600

#include <alloca.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <locale.h>
#include <pty.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/cursorfont.h>
#include <X11/keysym.h>

#include "dbglog.h"


#define MOUSE_REPORTING_ALWAYS
#define DUMP_PROG_OUTPUT
#define DUMP_PROG_INPUT


////////////////////////////////////////////////////////////////////////////////
#define USAGE \
  "sterm " VERSION " (c) 2010-2012 st engineers\n" \
  "usage: sterm [-t title] [-c class] [-w windowid] [-T termname] [-v] [-e command...]\n"


////////////////////////////////////////////////////////////////////////////////
/* XEMBED messages */
#define XEMBED_FOCUS_IN   (4)
#define XEMBED_FOCUS_OUT  (5)

/* Arbitrary sizes */
#define ESC_TITLE_SIZ  (256)
#define ESC_BUF_SIZ    (256)
#define ESC_ARG_SIZ    (16)
#define DRAW_BUF_SIZ   (2048)
#define UTF_SIZ        (4)
#define XK_NO_MOD      UINT_MAX
#define XK_ANY_MOD     (0)

#define SELECT_TIMEOUT  (20*1000) /* 20 ms */
#define DRAW_TIMEOUT    30 /* 30 ms */

#define SERRNO            strerror(errno)
#define MIN(a, b)         ((a) < (b) ? (a) : (b))
#define MAX(a, b)         ((a) < (b) ? (b) : (a))
#define LEN(a)            (sizeof(a)/sizeof(a[0]))
#define DEFAULT(a, b)     (a) = (a) ? (a) : (b)
#define BETWEEN(x, a, b)  ((a) <= (x) && (x) <= (b))
#define LIMIT(x, a, b)    (x) = (x) < (a) ? (a) : (x) > (b) ? (b) : (x)
#define ATTRCMP(a, b)     ((a).mode != (b).mode || (a).fg != (b).fg || (a).bg != (b).bg)
#define IS_SET(flag)      (term.mode & (flag))
#define TIMEDIFF(t1, t2)  ((t1.tv_sec-t2.tv_sec)*1000+(t1.tv_usec-t2.tv_usec)/1000)
#define X2COL(x)          (((x)-BORDER)/xw.cw)
#define Y2ROW(y)          (((y)-BORDER)/xw.ch)


////////////////////////////////////////////////////////////////////////////////
enum glyph_attribute {
  ATTR_NULL      = 0x00,
  ATTR_REVERSE   = 0x01,
  ATTR_UNDERLINE = 0x02,
  ATTR_BOLD      = 0x04,
  ATTR_GFX       = 0x08,
};

enum cursor_movement {
  CURSOR_UP,
  CURSOR_DOWN,
  CURSOR_LEFT,
  CURSOR_RIGHT,
  CURSOR_SAVE,
  CURSOR_LOAD
};

enum cursor_state {
  CURSOR_DEFAULT  = 0,
  CURSOR_HIDE     = 1,
  CURSOR_WRAPNEXT = 2
};

enum glyph_state {
  GLYPH_SET   = 0x01, /* for selection only */
  GLYPH_DIRTY = 0x02,
};


enum term_mode {
  MODE_WRAP        = 0x01,
  MODE_INSERT      = 0x02,
  MODE_APPKEYPAD   = 0x04,
  MODE_ALTSCREEN   = 0x08,
  MODE_CRLF        = 0x10,
  MODE_MOUSEBTN    = 0x20,
  MODE_MOUSEMOTION = 0x40,
  MODE_MOUSE       = 0x20|0x40,
  MODE_REVERSE     = 0x80,
};

enum escape_state {
  ESC_START      = 0x01,
  ESC_CSI        = 0x02,
  ESC_OSC        = 0x04,
  ESC_TITLE      = 0x08,
  ESC_ALTCHARSET = 0x10,
  ESC_HASH       = 0x20,
  ESC_PERCENT    = 0x40,
};

enum window_state {
  WIN_VISIBLE = 0x01,
  WIN_REDRAW  = 0x02,
  WIN_FOCUSED = 0x04,
};

/* bit macro */
#undef B0
enum { B0=1, B1=2, B2=4, B3=8, B4=16, B5=32, B6=64, B7=128 };


////////////////////////////////////////////////////////////////////////////////
typedef unsigned char uchar;
typedef unsigned int uint;
typedef unsigned long ulong;
typedef unsigned short ushort;


typedef struct {
  char c[UTF_SIZ]; /* character code */
  uchar mode;      /* attribute flags */
  ushort fg;       /* foreground */
  ushort bg;       /* background */
  uchar state;     /* state flags */
} Glyph;


typedef Glyph *Line;

typedef struct {
  Glyph attr; /* current char attributes */
  int x;
  int y;
  char state;
} TCursor;


/* CSI Escape sequence structs */
/* ESC '[' [[ [<priv>] <arg> [;]] <mode>] */
typedef struct {
  char buf[ESC_BUF_SIZ]; /* raw string */
  int len;  /* raw string length */
  char priv;
  int arg[ESC_ARG_SIZ];
  int narg; /* nb of args */
  char mode;
} CSIEscape;


/* Internal representation of the screen */
typedef struct {
  int row;     /* nb row */
  int col;     /* nb col */
  Line *line;  /* screen */
  Line *alt;   /* alternate screen */
  bool *dirty; /* dirtyness of lines */
  TCursor c;   /* cursor */
  int top;     /* top    scroll limit */
  int bot;     /* bottom scroll limit */
  int mode;    /* terminal mode flags */
  int esc;     /* escape state flags */
  char title[ESC_TITLE_SIZ];
  int titlelen;
} Term;


/* Purely graphic info */
typedef struct {
  Display *dpy;
  Colormap cmap;
  Window win;
  Pixmap buf;
  Atom xembed;
  XIM xim;
  XIC xic;
  int scr;
  int w;      /* window width */
  int h;      /* window height */
  int bufw;   /* pixmap width */
  int bufh;   /* pixmap height */
  int ch;     /* char height */
  int cw;     /* char width */
  char state; /* focus, redraw, visible */
  struct timeval lastdraw;
} XWindow;


typedef struct {
  KeySym k;
  uint mask;
  char s[ESC_BUF_SIZ];
} Key;


/* TODO: use better name for vars... */
typedef struct {
  int mode;
  int bx, by;
  int ex, ey;
  struct { int x, y; } b, e;
  char *clip;
  Atom xtarget;
  struct timeval tclick1;
  struct timeval tclick2;
} Selection;


#include "config.h"


/* Drawing Context */
typedef struct {
  ulong col[LEN(colorname) < 256 ? 256 : LEN(colorname)];
  GC gc;
  struct {
    int ascent;
    int descent;
    short lbearing;
    short rbearing;
    XFontSet set;
  } font, bfont;
} DC;


////////////////////////////////////////////////////////////////////////////////
static void die (const char*, ...);
static void draw (void);
static void drawregion (int, int, int, int);
static void execsh (void);
static void sigchld (int);
static void run (void);
static bool last_draw_too_old (void);

static void csidump (void);
static void csihandle (void);
static void csiparse (void);
static void csireset (void);

static void tclearregion (int, int, int, int);
static void tcursor (int);
static void tdeletechar (int);
static void tdeleteline (int);
static void tinsertblank (int);
static void tinsertblankline (int);
static void tmoveto (int, int);
static void tnew (int, int);
static void tnewline (int);
static void tputtab (void);
static void tputc (const char *);
static void treset (void);
static int tresize (int, int);
static void tscrollup (int, int);
static void tscrolldown (int, int);
static void tsetattr (int*, int);
static void tsetchar (const char *);
static void tsetscroll (int, int);
static void tswapscreen (void);
static void tsetdirt (int, int);
static void tfulldirt (void);

static void ttynew (void);
static void ttyread (void);
static void ttyresize (int, int);
static void ttywrite (const char *, size_t);

static void xdraws (char *, const Glyph *, int, int, int, int);
static void xhints (void);
static void xclear (int, int, int, int);
static void xcopy (int, int, int, int);
static void xdrawcursor (void);
static void xinit (void);
static void xloadcols (void);
static void xseturgency (int);
static void xsetsel (char *);
static void xresize (int, int);

static void expose (XEvent *);
static void visibility (XEvent *);
static void unmap (XEvent *);
static const char *kmap (KeySym, uint);
static void kpress (XEvent *);
static void cmessage (XEvent *);
static void resize (XEvent *);
static void focus (XEvent *);
static void brelease (XEvent *);
static void bpress (XEvent *);
static void bmotion (XEvent *);
static void selnotify (XEvent *);
static void selrequest (XEvent *);

static void selinit (void);
static inline bool selected (int, int);
static void selcopy (void);
static void selpaste ();
static void selscroll (int, int);

static int utf8decode (const char *, long *);
static int utf8encode (const long *, char *);
static int utf8size (const char *);
static int isfullutf8 (const char *, int);


////////////////////////////////////////////////////////////////////////////////
static void (*handler[LASTEvent])(XEvent *) = {
  [KeyPress] = kpress,
  [ClientMessage] = cmessage,
  [ConfigureNotify] = resize,
  [VisibilityNotify] = visibility,
  [UnmapNotify] = unmap,
  [Expose] = expose,
  [FocusIn] = focus,
  [FocusOut] = focus,
  [MotionNotify] = bmotion,
  [ButtonPress] = bpress,
  [ButtonRelease] = brelease,
  [SelectionNotify] = selnotify,
  [SelectionRequest] = selrequest,
};


////////////////////////////////////////////////////////////////////////////////
/* Globals */
static DC dc;
static XWindow xw;
static Term term;
static CSIEscape escseq;
static int cmdfd;
static pid_t pid;
static Selection sel;
static char **opt_cmd  = NULL;
static char *opt_title = NULL;
static char *opt_embed = NULL;
static char *opt_class = NULL;
static char *opt_term = NULL;


static int tty_last_write_ms = 0;


////////////////////////////////////////////////////////////////////////////////
// UTF-8
static int utf8decode (const char *s, long *u) {
  uchar c;
  int i, n, rtn;
  //
  rtn = 1;
  c = *s;
  if (~c & B7) { /* 0xxxxxxx */
    *u = c;
    return rtn;
  } else if ((c & (B7|B6|B5)) == (B7|B6)) { /* 110xxxxx */
    *u = c&(B4|B3|B2|B1|B0);
    n = 1;
  } else if ((c & (B7|B6|B5|B4)) == (B7|B6|B5)) { /* 1110xxxx */
    *u = c&(B3|B2|B1|B0);
    n = 2;
  } else if ((c & (B7|B6|B5|B4|B3)) == (B7|B6|B5|B4)) { /* 11110xxx */
    *u = c & (B2|B1|B0);
    n = 3;
  } else {
    goto invalid;
  }
  for (i = n, ++s; i > 0; --i, ++rtn, ++s) {
    c = *s;
    if ((c & (B7|B6)) != B7) goto invalid; /* 10xxxxxx */
    *u <<= 6;
    *u |= c & (B5|B4|B3|B2|B1|B0);
  }
  if ((n == 1 && *u < 0x80) ||
      (n == 2 && *u < 0x800) ||
      (n == 3 && *u < 0x10000) ||
      (*u >= 0xD800 && *u <= 0xDFFF)) {
    goto invalid;
  }
  return rtn;
invalid:
  *u = 0xFFFD;
  return rtn;
}


static int utf8encode (const long *u, char *s) {
  uchar *sp;
  ulong uc;
  int i, n;
  //
  sp = (uchar *)s;
  uc = *u;
  if (uc < 0x80) {
    *sp = uc; /* 0xxxxxxx */
    return 1;
  } else if (*u < 0x800) {
    *sp = (uc >> 6) | (B7|B6); /* 110xxxxx */
    n = 1;
  } else if (uc < 0x10000) {
    *sp = (uc >> 12) | (B7|B6|B5); /* 1110xxxx */
    n = 2;
  } else if (uc <= 0x10FFFF) {
    *sp = (uc >> 18) | (B7|B6|B5|B4); /* 11110xxx */
    n = 3;
  } else {
    goto invalid;
  }
  for (i = n, ++sp; i > 0; --i, ++sp) *sp = ((uc >> 6*(i-1)) & (B5|B4|B3|B2|B1|B0)) | B7; /* 10xxxxxx */
  return n+1;
invalid:
  /* U+FFFD */
  *s++ = '\xEF';
  *s++ = '\xBF';
  *s = '\xBD';
  return 3;
}


/* use this if your buffer is less than UTF_SIZ, it returns 1 if you can decode
   UTF-8 otherwise return 0 */
static int isfullutf8 (const char *s, int b) {
  uchar *c1, *c2, *c3;
  //
  c1 = (uchar *) s;
  c2 = (uchar *) ++s;
  c3 = (uchar *) ++s;
  if (b < 1) return 0;
  if ((*c1&(B7|B6|B5)) == (B7|B6) && b == 1) return 0;
  if ((*c1&(B7|B6|B5|B4)) == (B7|B6|B5) && (b == 1 || (b == 2 && (*c2&(B7|B6)) == B7))) return 0;
  if ((*c1&(B7|B6|B5|B4|B3)) == (B7|B6|B5|B4) && (b == 1 || (b == 2 && (*c2&(B7|B6)) == B7) || (b == 3 && (*c2&(B7|B6)) == B7 && (*c3&(B7|B6)) == B7))) return 0;
  return 1;
}


static int utf8size (const char *s) {
  uchar c = *s;
  //
  if (~c&B7) return 1;
  if ((c&(B7|B6|B5)) == (B7|B6)) return 2;
  if ((c&(B7|B6|B5|B4)) == (B7|B6|B5)) return 3;
  return 4;
}


////////////////////////////////////////////////////////////////////////////////
// utilities
static char *SPrintfVA (const char *fmt, va_list vaorig) {
  char *buf = NULL;
  int olen, len = 128;
  //
  buf = malloc(len);
  if (buf == NULL) { fprintf(stderr, "\nFATAL: out of memory!\n"); abort(); }
  for (;;) {
    char *nb;
    va_list va;
    //
    va_copy(va, vaorig);
    olen = vsnprintf(buf, len, fmt, va);
    va_end(va);
    if (olen >= 0 && olen < len) return buf;
    if (olen < 0) olen = len*2-1;
    nb = realloc(buf, olen+1);
    if (nb == NULL) { fprintf(stderr, "\nFATAL: out of memory!\n"); abort(); }
    buf = nb;
    len = olen+1;
  }
}


static __attribute__((format(printf,1,2))) char *SPrintf (const char *fmt, ...) {
  char *buf = NULL;
  va_list va;
  //
  va_start(va, fmt);
  buf = SPrintfVA(fmt, va);
  va_end(va);
  return buf;
}


static __attribute__((noreturn)) __attribute__((format(printf,1,2))) void die (const char *errstr, ...) {
  va_list ap;
  //
  va_start(ap, errstr);
  vfprintf(stderr, errstr, ap);
  va_end(ap);
  exit(EXIT_FAILURE);
}


static __attribute__((noreturn)) void execsh (void) {
  char **args;
  char *envshell = getenv("SHELL");
  char *term = SPrintf("TERM=%s", opt_term ? opt_term : TNAME);
  //
  DEFAULT(envshell, SHELL);
  putenv(term);
  free(term);
  args = opt_cmd ? opt_cmd : (char*[]){envshell, "-i", NULL};
  execvp(args[0], args);
  exit(EXIT_FAILURE);
}


static __attribute__((noreturn)) void sigchld (int a) {
  int stat = 0;
  if (waitpid(pid, &stat, 0) < 0) die("Waiting for pid %hd failed: %s\n", pid, SERRNO);
  if (WIFEXITED(stat)) exit(WEXITSTATUS(stat));
  exit(EXIT_FAILURE);
}


////////////////////////////////////////////////////////////////////////////////
// getticks
static struct timespec mclk_sttime; // starting time of monotonic clock


static void mclock_init (void) {
  clock_gettime(CLOCK_MONOTONIC_RAW, &mclk_sttime);
}


static int mclock_ticks (void) {
  struct timespec tp;
  //
  clock_gettime(CLOCK_MONOTONIC_RAW, &tp);
  tp.tv_sec -= mclk_sttime.tv_sec;
  return tp.tv_sec*1000+(tp.tv_nsec/1000000);
}


////////////////////////////////////////////////////////////////////////////////
// selection
static void selinit (void) {
  memset(&sel.tclick1, 0, sizeof(sel.tclick1));
  memset(&sel.tclick2, 0, sizeof(sel.tclick2));
  sel.mode = 0;
  sel.bx = -1;
  sel.clip = NULL;
  sel.xtarget = XInternAtom(xw.dpy, "UTF8_STRING", 0);
  if (sel.xtarget == None) sel.xtarget = XA_STRING;
}


static inline bool selected (int x, int y) {
  if (sel.ey == y && sel.by == y) {
    int bx = MIN(sel.bx, sel.ex);
    int ex = MAX(sel.bx, sel.ex);
    return BETWEEN(x, bx, ex);
  }
  return
    ((sel.b.y < y && y < sel.e.y) || (y == sel.e.y && x <= sel.e.x)) ||
    (y == sel.b.y && x >= sel.b.x && (x <= sel.e.x || sel.b.y != sel.e.y));
}


static void getbuttoninfo (XEvent *e, int *b, int *x, int *y) {
  if (b) *b = e->xbutton.button;
  *x = X2COL(e->xbutton.x);
  *y = Y2ROW(e->xbutton.y);
  sel.b.x = sel.by < sel.ey ? sel.bx : sel.ex;
  sel.b.y = MIN(sel.by, sel.ey);
  sel.e.x = sel.by < sel.ey ? sel.ex : sel.bx;
  sel.e.y = MAX(sel.by, sel.ey);
}


static void mousereport (XEvent *e) {
  int x = X2COL(e->xbutton.x);
  int y = Y2ROW(e->xbutton.y);
  int button = e->xbutton.button;
  int state = e->xbutton.state;
  char buf[] = { '\033', '[', 'M', 0, 32+x+1, 32+y+1 };
  static int ob, ox, oy;
  //
  /* from urxvt */
  if (e->xbutton.type == MotionNotify) {
    if (!IS_SET(MODE_MOUSEMOTION) || (x == ox && y == oy)) return;
    button = ob + 32;
    ox = x, oy = y;
  } else if (e->xbutton.type == ButtonRelease || button == AnyButton) {
    button = 3;
  } else {
    button -= Button1;
    if (button >= 3) button += 64-3;
    if (e->xbutton.type == ButtonPress) {
      ob = button;
      ox = x, oy = y;
    }
  }
  buf[3] = 32+button+(state & ShiftMask ? 4 : 0)+(state & Mod4Mask ? 8 : 0)+(state & ControlMask ? 16 : 0);
  ttywrite(buf, sizeof(buf));
}


static void bpress (XEvent *e) {
  if (IS_SET(MODE_MOUSE)) mousereport(e);
  else if (e->xbutton.button == Button1) {
    if (sel.bx != -1) tsetdirt(sel.b.y, sel.e.y);
    sel.mode = 1;
    sel.ex = sel.bx = X2COL(e->xbutton.x);
    sel.ey = sel.by = Y2ROW(e->xbutton.y);
  }
}


static void selcopy (void) {
  char *str, *ptr;
  int x, y, bufsize, is_selected = 0;
  //
  if (sel.bx == -1) {
    str = NULL;
  } else {
    bufsize = (term.col+1) * (sel.e.y-sel.b.y+1) * UTF_SIZ;
    ptr = str = malloc(bufsize);
    /* append every set & selected glyph to the selection */
    for (y = 0; y < term.row; ++y) {
      for (x = 0; x < term.col; ++x) {
        is_selected = selected(x, y);
        if ((term.line[y][x].state & GLYPH_SET) && is_selected) {
          int size = utf8size(term.line[y][x].c);
          memcpy(ptr, term.line[y][x].c, size);
          ptr += size;
        }
      }
      /* \n at the end of every selected line except for the last one */
      if (is_selected && y < sel.e.y) *ptr++ = '\n';
    }
    *ptr = 0;
  }
  xsetsel(str);
}


static void selnotify (XEvent *e) {
  ulong nitems, ofs, rem;
  int format;
  uchar *data;
  Atom type;
  //
  ofs = 0;
  do {
    if (XGetWindowProperty(xw.dpy, xw.win, XA_PRIMARY, ofs, BUFSIZ/4, False, AnyPropertyType, &type, &format, &nitems, &rem, &data)) {
      fprintf(stderr, "Clipboard allocation failed\n");
      return;
    }
    ttywrite((const char *)data, nitems*format/8);
    XFree(data);
    /* number of 32-bit chunks returned */
    ofs += nitems*format/32;
  } while (rem > 0);
}


static void selpaste (void) {
  XConvertSelection(xw.dpy, XA_PRIMARY, sel.xtarget, XA_PRIMARY, xw.win, CurrentTime);
}


void selrequest (XEvent *e) {
  XSelectionRequestEvent *xsre;
  XSelectionEvent xev;
  Atom xa_targets;
  //
  xsre = (XSelectionRequestEvent *)e;
  xev.type = SelectionNotify;
  xev.requestor = xsre->requestor;
  xev.selection = xsre->selection;
  xev.target = xsre->target;
  xev.time = xsre->time;
  /* reject */
  xev.property = None;
  xa_targets = XInternAtom(xw.dpy, "TARGETS", 0);
  if (xsre->target == xa_targets) {
    /* respond with the supported type */
    Atom string = sel.xtarget;
    XChangeProperty(xsre->display, xsre->requestor, xsre->property, XA_ATOM, 32, PropModeReplace, (uchar *)&string, 1);
    xev.property = xsre->property;
  } else if (xsre->target == sel.xtarget && sel.clip != NULL) {
    XChangeProperty(xsre->display, xsre->requestor, xsre->property, xsre->target, 8, PropModeReplace, (uchar *)sel.clip, strlen(sel.clip));
    xev.property = xsre->property;
  }
  /* all done, send a notification to the listener */
  if (!XSendEvent(xsre->display, xsre->requestor, True, 0, (XEvent *) &xev)) fprintf(stderr, "Error sending SelectionNotify event\n");
}


static void xsetsel (char *str) {
  /* register the selection for both the clipboard and the primary */
  Atom clipboard;
  //
  free(sel.clip);
  sel.clip = str;
  XSetSelectionOwner(xw.dpy, XA_PRIMARY, xw.win, CurrentTime);
  clipboard = XInternAtom(xw.dpy, "CLIPBOARD", 0);
  XSetSelectionOwner(xw.dpy, clipboard, xw.win, CurrentTime);
  XFlush(xw.dpy);
}


static void brelease (XEvent *e) {
  if (IS_SET(MODE_MOUSE)) {
    mousereport(e);
    return;
  }
  if (e->xbutton.button == Button2) {
    selpaste();
  } else if (e->xbutton.button == Button1) {
    sel.mode = 0;
    getbuttoninfo(e, NULL, &sel.ex, &sel.ey);
    term.dirty[sel.ey] = 1;
    if (sel.bx == sel.ex && sel.by == sel.ey) {
      struct timeval now;
      sel.bx = -1;
      gettimeofday(&now, NULL);
      if (TIMEDIFF(now, sel.tclick2) <= TRIPLECLICK_TIMEOUT) {
        /* triple click on the line */
        sel.b.x = sel.bx = 0;
        sel.e.x = sel.ex = term.col;
        sel.b.y = sel.e.y = sel.ey;
        selcopy();
      } else if (TIMEDIFF(now, sel.tclick1) <= DOUBLECLICK_TIMEOUT) {
        /* double click to select word */
        sel.bx = sel.ex;
        while (sel.bx > 0 && term.line[sel.ey][sel.bx-1].state & GLYPH_SET && term.line[sel.ey][sel.bx-1].c[0] != ' ') --sel.bx;
        sel.b.x = sel.bx;
        while (sel.ex < term.col-1 && term.line[sel.ey][sel.ex+1].state & GLYPH_SET && term.line[sel.ey][sel.ex+1].c[0] != ' ') ++sel.ex;
        sel.e.x = sel.ex;
        sel.b.y = sel.e.y = sel.ey;
        selcopy();
      }
    } else {
      selcopy();
    }
  }
  memcpy(&sel.tclick2, &sel.tclick1, sizeof(struct timeval));
  gettimeofday(&sel.tclick1, NULL);
  draw();
}


static void bmotion (XEvent *e) {
  if (IS_SET(MODE_MOUSE)) {
    mousereport(e);
    return;
  }
  if (sel.mode) {
    int oldey = sel.ey, oldex = sel.ex;
    //
    getbuttoninfo(e, NULL, &sel.ex, &sel.ey);
    if (oldey != sel.ey || oldex != sel.ex) {
      int starty = MIN(oldey, sel.ey);
      int endy = MAX(oldey, sel.ey);
      //
      tsetdirt(starty, endy);
      draw();
    }
  }
}


////////////////////////////////////////////////////////////////////////////////
// tty init
/*
static void dump (char c) {
  static int col;
  //
  fprintf(stderr, " %02x '%c' ", c, isprint(c)?c:'.');
  if (++col % 10 == 0) fprintf(stderr, "\n");
}
*/


static void ttynew (void) {
  int m, s;
  struct winsize w = {term.row, term.col, 0, 0};
  //
  if (openpty(&m, &s, NULL, NULL, &w) < 0) die("openpty failed: %s\n", SERRNO);
  switch (pid = fork()) {
    case -1:
      die("fork failed\n");
      break;
    case 0:
      setsid(); /* create a new process group */
      dup2(s, STDIN_FILENO);
      dup2(s, STDOUT_FILENO);
      dup2(s, STDERR_FILENO);
      if (ioctl(s, TIOCSCTTY, NULL) < 0) die("ioctl TIOCSCTTY failed: %s\n", SERRNO);
      close(s);
      close(m);
      execsh();
      break;
    default:
      close(s);
      cmdfd = m;
      signal(SIGCHLD, sigchld);
  }
}


////////////////////////////////////////////////////////////////////////////////
// tty r/w
static int ttycanread (void) {
  for (;;) {
    fd_set rfd;
    struct timeval timeout = {0};
    //
    FD_ZERO(&rfd);
    FD_SET(cmdfd, &rfd);
    if (select(cmdfd+1, &rfd, NULL, NULL, &timeout) < 0) {
      if (errno == EINTR) continue;
      die("select failed: %s\n", SERRNO);
    }
    if (FD_ISSET(cmdfd, &rfd)) return 1;
    break;
  }
  return 0;
}


static int ttycanwrite (void) {
  for (;;) {
    fd_set wfd;
    struct timeval timeout = {0};
    //
    FD_ZERO(&wfd);
    FD_SET(cmdfd, &wfd);
    if (select(cmdfd+1, NULL, &wfd, NULL, &timeout) < 0) {
      if (errno == EINTR) continue;
      die("select failed: %s\n", SERRNO);
    }
    if (FD_ISSET(cmdfd, &wfd)) return 1;
    break;
  }
  return 0;
}


static void ttyread (void) {
  static char buf[BUFSIZ];
  static int buflen = 0, obuflen = 0;
  //
  char *ptr;
  int left;
  //
  /* append read bytes to unprocessed bytes */
  obuflen = buflen;
  left = LEN(buf)-buflen;
  //dlogf("0: ttyread before: free=%d, used=%d", left, buflen);
  while (left > 0 && ttycanread()) {
    int ret;
    //
    //if ((ret = read(cmdfd, buf+buflen, 1)) < 0) die("Couldn't read from shell: %s\n", SERRNO);
    if ((ret = read(cmdfd, buf+buflen, left)) < 0) die("Couldn't read from shell: %s\n", SERRNO);
    buflen += ret;
    left -= ret;
  }
  //dlogf("1: ttyread after: free=%d, used=%d", left, buflen);
  /* process every complete utf8 char */
#ifdef DUMP_PROG_OUTPUT
  {
    FILE *fo = fopen("zlogo.log", "ab");
    if (fo) {
      fwrite(buf+obuflen, buflen-obuflen, 1, fo);
      fclose(fo);
    }
  }
#endif
  ptr = buf;
  while (buflen >= UTF_SIZ || isfullutf8(ptr, buflen)) {
    long utf8c;
    char s[UTF_SIZ];
    int charsize = utf8decode(ptr, &utf8c); /* returns size of utf8 char in bytes */
    //
    utf8encode(&utf8c, s);
    tputc(s);
    ptr += charsize;
    buflen -= charsize;
  }
  //dlogf("2: ttyread afterproc: used=%d", buflen);
  /* keep any uncomplete utf8 char for the next call */
  if (buflen > 0) memmove(buf, ptr, buflen);
}


#define WRBUF_SIZE  (1024)
static char tty_wrbuf[WRBUF_SIZE];
static int tty_wrbufsize = WRBUF_SIZE, tty_wrbufused = 0, tty_wrbufpos = 0;


static void ttyflushwrbuf (void) {
  if (tty_wrbufpos >= tty_wrbufused) {
    tty_wrbufpos = tty_wrbufused = 0;
    return;
  }
  //dlogf("0: ttyflushwrbuf before: towrite=%d", tty_wrbufused-tty_wrbufpos);
  while (tty_wrbufpos < tty_wrbufused && ttycanwrite()) {
    int ret;
    //
    if ((ret = write(cmdfd, tty_wrbuf+tty_wrbufpos, tty_wrbufused-tty_wrbufpos)) == -1) die("write error on tty: %s\n", SERRNO);
    tty_wrbufpos += ret;
  }
  if (tty_wrbufpos > 0) {
    int left = tty_wrbufused-tty_wrbufpos;
    //
    if (left < 1) {
      // write buffer is empty
      tty_wrbufpos = tty_wrbufused = 0;
    } else {
      memmove(tty_wrbuf, tty_wrbuf+tty_wrbufpos, left);
      tty_wrbufpos = 0;
      tty_wrbufused = left;
    }
  }
  //dlogf("1: ttyflushwrbuf after: towrite=%d", tty_wrbufused-tty_wrbufpos);
}


static void ttywrite (const char *s, size_t n) {
#ifdef DUMP_PROG_INPUT
  if (s != NULL && n > 0) {
    FILE *fo = fopen("zlogw.log", "ab");
    if (fo) {
      fwrite(s, n, 1, fo);
      fclose(fo);
    }
  }
#endif
  ttyflushwrbuf();
  if (s != NULL && n > 0) {
    while (n > 0) {
      while (tty_wrbufused >= tty_wrbufsize) {
        //FIXME: make write buffer dynamic?
        // force write at least one char
        //dlogf("ttywrite: forced write");
        if (write(cmdfd, tty_wrbuf+tty_wrbufpos, 1) == -1) die("write error on tty: %s\n", SERRNO);
        ++tty_wrbufpos;
        ttyflushwrbuf(); // make room for char
      }
      tty_wrbuf[tty_wrbufused++] = *s++;
      --n;
    }
  }
}


////////////////////////////////////////////////////////////////////////////////
// tty resize ioctl
static void ttyresize (int x, int y) {
  struct winsize w;
  //
  w.ws_row = term.row;
  w.ws_col = term.col;
  w.ws_xpixel = w.ws_ypixel = 0;
  if (ioctl(cmdfd, TIOCSWINSZ, &w) < 0) fprintf(stderr, "Couldn't set window size: %s\n", SERRNO);
}


////////////////////////////////////////////////////////////////////////////////
// tty utilities
static void tsetdirt (int top, int bot) {
  int i;
  //
  LIMIT(top, 0, term.row-1);
  LIMIT(bot, 0, term.row-1);
  for (i = top; i <= bot; ++i) term.dirty[i] = 1;
}


static void tfulldirt (void) {
  tsetdirt(0, term.row-1);
}


static void tcursor (int mode) {
  static TCursor c;
  //
  if (mode == CURSOR_SAVE) {
    c = term.c;
  } else if (mode == CURSOR_LOAD) {
    term.c = c;
    tmoveto(c.x, c.y);
  }
}


static void treset (void) {
  term.c = (TCursor){{
    .mode = ATTR_NULL,
    .fg = DefaultFG,
    .bg = DefaultBG
  }, .x = 0, .y = 0, .state = CURSOR_DEFAULT};
  //
  term.top = 0, term.bot = term.row-1;
  term.mode = MODE_WRAP;
#ifdef MOUSE_REPORTING_ALWAYS
  term.mode = MODE_MOUSEBTN;
#endif
  tclearregion(0, 0, term.col-1, term.row-1);
}


static void tnew (int col, int row) {
  /* set screen size */
  term.row = row, term.col = col;
  term.line = malloc(term.row*sizeof(Line));
  term.alt = malloc(term.row*sizeof(Line));
  term.dirty = malloc(term.row*sizeof(*term.dirty));
  for (row = 0; row < term.row; ++row) {
    term.line[row] = malloc(term.col*sizeof(Glyph));
    term.alt[row] = malloc(term.col*sizeof(Glyph));
    term.dirty[row] = 0;
  }
  /* setup screen */
  treset();
  tswapscreen();
  treset();
}


static void tswapscreen (void) {
  Line *tmp = term.line;
  //
  term.line = term.alt;
  term.alt = tmp;
  term.mode ^= MODE_ALTSCREEN;
  tfulldirt();
}


static void tscrolldown (int orig, int n) {
  int i;
  Line temp;
  //
  LIMIT(n, 0, term.bot-orig+1);
  tclearregion(0, term.bot-n+1, term.col-1, term.bot);
  for (i = term.bot; i >= orig+n; --i) {
    temp = term.line[i];
    term.line[i] = term.line[i-n];
    term.line[i-n] = temp;
    term.dirty[i] = 1;
    term.dirty[i-n] = 1;
  }
  selscroll(orig, n);
}


static void tscrollup (int orig, int n) {
  int i;
  Line temp;
  //
  LIMIT(n, 0, term.bot-orig+1);
  tclearregion(0, orig, term.col-1, orig+n-1);
  for (i = orig; i <= term.bot-n; ++i) {
     temp = term.line[i];
     term.line[i] = term.line[i+n];
     term.line[i+n] = temp;
     term.dirty[i] = 1;
     term.dirty[i+n] = 1;
  }
  selscroll(orig, -n);
}


static void selscroll (int orig, int n) {
  if (sel.bx == -1) return;
  if (BETWEEN(sel.by, orig, term.bot) || BETWEEN(sel.ey, orig, term.bot)) {
    if ((sel.by += n) > term.bot || (sel.ey += n) < term.top) {
      sel.bx = -1;
      return;
    }
    if (sel.by < term.top) {
      sel.by = term.top;
      sel.bx = 0;
    }
    if (sel.ey > term.bot) {
      sel.ey = term.bot;
      sel.ex = term.col;
    }
    sel.b.y = sel.by, sel.b.x = sel.bx;
    sel.e.y = sel.ey, sel.e.x = sel.ex;
  }
}


static void tnewline (int first_col) {
  int y = term.c.y;
  if (y == term.bot) tscrollup(term.top, 1); else ++y;
  tmoveto(first_col ? 0 : term.c.x, y);
}


static void csiparse (void) {
  /* int noarg = 1; */
  char *p = escseq.buf;
  escseq.narg = 0;
  if (*p == '?') { escseq.priv = 1; ++p; }
  while (p < escseq.buf+escseq.len) {
    while (isdigit(*p)) {
      escseq.arg[escseq.narg] *= 10;
      escseq.arg[escseq.narg] += *p++ - '0'/*, noarg = 0 */;
    }
    if (*p == ';' && escseq.narg+1 < ESC_ARG_SIZ) {
      ++escseq.narg;
      ++p;
    } else {
      escseq.mode = *p;
      ++escseq.narg;
      return;
    }
  }
}


static void tmoveto (int x, int y) {
  LIMIT(x, 0, term.col-1);
  LIMIT(y, 0, term.row-1);
  term.c.state &= ~CURSOR_WRAPNEXT;
  term.c.x = x;
  term.c.y = y;
}


static void tsetchar (const char *c) {
  term.dirty[term.c.y] = 1;
  term.line[term.c.y][term.c.x] = term.c.attr;
  memcpy(term.line[term.c.y][term.c.x].c, c, UTF_SIZ);
  term.line[term.c.y][term.c.x].state |= GLYPH_SET;
}


/*
static void tsetchar1b (char c) {
  term.dirty[term.c.y] = 1;
  term.line[term.c.y][term.c.x] = term.c.attr;
  memset(term.line[term.c.y][term.c.x].c, 0, UTF_SIZ);
  term.line[term.c.y][term.c.x].c[0] = c;
  term.line[term.c.y][term.c.x].state |= GLYPH_SET;
}
*/


static void tclearregion (int x1, int y1, int x2, int y2) {
  int temp;
  //
  if (x1 > x2) { temp = x1; x1 = x2; x2 = temp; }
  if (y1 > y2) { temp = y1; y1 = y2; y2 = temp; }
  LIMIT(x1, 0, term.col-1);
  LIMIT(x2, 0, term.col-1);
  LIMIT(y1, 0, term.row-1);
  LIMIT(y2, 0, term.row-1);
  for (int y = y1; y <= y2; ++y) {
    term.dirty[y] = 1;
    for (int x = x1; x <= x2; ++x) {
      term.line[y][x] = term.c.attr;
      term.line[y][x].state = 0;
      term.line[y][x].mode &= ATTR_GFX;
      term.line[y][x].c[0] = ' ';
    }
  }
}


static void tfillregionwithE (int x1, int y1, int x2, int y2) {
  int temp;
  //
  if (x1 > x2) { temp = x1; x1 = x2; x2 = temp; }
  if (y1 > y2) { temp = y1; y1 = y2; y2 = temp; }
  LIMIT(x1, 0, term.col-1);
  LIMIT(x2, 0, term.col-1);
  LIMIT(y1, 0, term.row-1);
  LIMIT(y2, 0, term.row-1);
  for (int y = y1; y <= y2; ++y) {
    term.dirty[y] = 1;
    for (int x = x1; x <= x2; ++x) {
      term.line[y][x].state = /*GLYPH_SET |*/ GLYPH_DIRTY;
      term.line[y][x].c[0] = 'E';
      term.line[y][x].mode = ATTR_NULL;
    }
  }
}


static void tdeletechar (int n) {
  int src = term.c.x+n;
  int dst = term.c.x;
  int size = term.col-src;
  //
  term.dirty[term.c.y] = 1;
  if (src >= term.col) {
    tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
    return;
  }
  memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src], size*sizeof(Glyph));
  tclearregion(term.col-n, term.c.y, term.col-1, term.c.y);
}


static void tinsertblank (int n) {
  int src = term.c.x;
  int dst = src+n;
  int size = term.col-dst;
  //
  term.dirty[term.c.y] = 1;
  if (dst >= term.col) {
    tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
    return;
  }
  memmove(&term.line[term.c.y][dst], &term.line[term.c.y][src], size*sizeof(Glyph));
  tclearregion(src, term.c.y, dst-1, term.c.y);
}


static void tinsertblankline (int n) {
  if (term.c.y < term.top || term.c.y > term.bot) return;
  tscrolldown(term.c.y, n);
}


static void tdeleteline (int n) {
  if (term.c.y < term.top || term.c.y > term.bot) return;
  tscrollup(term.c.y, n);
}


static void tsetattr (int *attr, int l) {
  int i;
  //
  for (i = 0; i < l; ++i) {
    switch (attr[i]) {
    case 0:
      term.c.attr.mode &= ~(ATTR_REVERSE | ATTR_UNDERLINE | ATTR_BOLD);
      term.c.attr.fg = DefaultFG;
      term.c.attr.bg = DefaultBG;
      break;
    case 1:
      term.c.attr.mode |= ATTR_BOLD;
      break;
    case 4:
      term.c.attr.mode |= ATTR_UNDERLINE;
      break;
    case 7:
      term.c.attr.mode |= ATTR_REVERSE;
      break;
    case 22:
      term.c.attr.mode &= ~ATTR_BOLD;
      break;
    case 24:
      term.c.attr.mode &= ~ATTR_UNDERLINE;
      break;
    case 27:
      term.c.attr.mode &= ~ATTR_REVERSE;
      break;
    case 38:
      if (i + 2 < l && attr[i + 1] == 5) {
        i += 2;
        if (BETWEEN(attr[i], 0, 255)) {
          term.c.attr.fg = attr[i];
        } else {
          fprintf(stderr, "erresc: bad fgcolor %d\n", attr[i]);
        }
      } else {
        fprintf(stderr, "erresc: gfx attr %d unknown\n", attr[i]);
      }
      break;
    case 39:
      term.c.attr.fg = DefaultFG;
      break;
    case 48:
      if (i + 2 < l && attr[i + 1] == 5) {
        i += 2;
        if (BETWEEN(attr[i], 0, 255)) {
          term.c.attr.bg = attr[i];
        } else {
          fprintf(stderr, "erresc: bad bgcolor %d\n", attr[i]);
        }
      } else {
        fprintf(stderr, "erresc: gfx attr %d unknown\n", attr[i]);
      }
      break;
    case 49:
      term.c.attr.bg = DefaultBG;
      break;
    default:
      if (BETWEEN(attr[i], 30, 37)) term.c.attr.fg = attr[i]-30;
      else if (BETWEEN(attr[i], 40, 47)) term.c.attr.bg = attr[i]-40;
      else if (BETWEEN(attr[i], 90, 97)) term.c.attr.fg = attr[i]-90+8;
      else if (BETWEEN(attr[i], 100, 107)) term.c.attr.fg = attr[i]-100+8;
      else { fprintf(stderr, "erresc: gfx attr %d unknown\n", attr[i]); csidump(); }
      break;
    }
  }
}


static void tsetscroll (int t, int b) {
  int temp;
  //
  LIMIT(t, 0, term.row-1);
  LIMIT(b, 0, term.row-1);
  if (t > b) {
    temp = t;
    t = b;
    b = temp;
  }
  term.top = t;
  term.bot = b;
}


////////////////////////////////////////////////////////////////////////////////
// esc processing
#define UPDATE_LASTWRITE  do { tty_last_write_ms = mclock_ticks(); } while (0)


static void csidump (void) {
  int i;
  //
  printf("ESC[");
  for (i = 0; i < escseq.len; ++i) {
    uint c = escseq.buf[i] & 0xff;
    //
    if (isprint(c)) putchar(c);
    else if (c == '\n') printf("(\\n)");
    else if (c == '\r') printf("(\\r)");
    else if (c == 0x1b) printf("(\\e)");
    else printf("(%02x)", c);
  }
  putchar('\n');
}


/*
static void csidumpdbg (void) {
  int i;
  //
  dlogf("ESC[");
  for (i = 0; i < escseq.len; ++i) {
    uint c = escseq.buf[i] & 0xff;
    //
    if (isprint(c)) dlogf(" %c", c);
    else if (c == '\n') dlogf(" (\\n)");
    else if (c == '\r') dlogf(" (\\r)");
    else if (c == 0x1b) dlogf(" (\\e)");
    else dlogf(" (%02x)", c);
  }
  //putchar('\n');
}
*/


static void csihandle (void) {
  switch (escseq.mode) {
    case '@': /* ICH -- Insert <n> blank char */
      DEFAULT(escseq.arg[0], 1);
      tinsertblank(escseq.arg[0]);
      break;
    case 'A': /* CUU -- Cursor <n> Up */
    case 'e':
      DEFAULT(escseq.arg[0], 1);
      tmoveto(term.c.x, term.c.y-escseq.arg[0]);
      break;
    case 'B': /* CUD -- Cursor <n> Down */
      DEFAULT(escseq.arg[0], 1);
      tmoveto(term.c.x, term.c.y+escseq.arg[0]);
      break;
    case 'C': /* CUF -- Cursor <n> Forward */
    case 'a':
      DEFAULT(escseq.arg[0], 1);
      tmoveto(term.c.x+escseq.arg[0], term.c.y);
      break;
    case 'D': /* CUB -- Cursor <n> Backward */
      DEFAULT(escseq.arg[0], 1);
      tmoveto(term.c.x-escseq.arg[0], term.c.y);
      break;
    case 'E': /* CNL -- Cursor <n> Down and first col */
      DEFAULT(escseq.arg[0], 1);
      tmoveto(0, term.c.y+escseq.arg[0]);
      break;
    case 'F': /* CPL -- Cursor <n> Up and first col */
      DEFAULT(escseq.arg[0], 1);
      tmoveto(0, term.c.y-escseq.arg[0]);
      break;
    case 'G': /* CHA -- Move to <col> */
    case '`': /* XXX: HPA -- same? */
      DEFAULT(escseq.arg[0], 1);
      tmoveto(escseq.arg[0]-1, term.c.y);
      break;
    case 'H': /* CUP -- Move to <row> <col> */
    case 'f': /* XXX: HVP -- same? */
      DEFAULT(escseq.arg[0], 1);
      DEFAULT(escseq.arg[1], 1);
      tmoveto(escseq.arg[1]-1, escseq.arg[0]-1);
      break;
    /* XXX: (CSI n I) CHT -- Cursor Forward Tabulation <n> tab stops */
    case 'J': /* ED -- Clear screen */
      sel.bx = -1;
      switch (escseq.arg[0]) {
      case 0: /* below */
        tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
        if (term.c.y < term.row-1) tclearregion(0, term.c.y+1, term.col-1, term.row-1);
        break;
      case 1: /* above */
        if (term.c.y > 1) tclearregion(0, 0, term.col-1, term.c.y-1);
        tclearregion(0, term.c.y, term.c.x, term.c.y);
        break;
      case 2: /* all */
        tclearregion(0, 0, term.col-1, term.row-1);
        break;
      default:
        goto unknown;
      }
      break;
    case 'K': /* EL -- Clear line */
      switch (escseq.arg[0]) {
        case 0: /* right */
          tclearregion(term.c.x, term.c.y, term.col-1, term.c.y);
          break;
        case 1: /* left */
          tclearregion(0, term.c.y, term.c.x, term.c.y);
          break;
        case 2: /* all */
          tclearregion(0, term.c.y, term.col-1, term.c.y);
          break;
      }
      break;
    case 'S': /* SU -- Scroll <n> line up */
      DEFAULT(escseq.arg[0], 1);
      tscrollup(term.top, escseq.arg[0]);
      break;
    case 'T': /* SD -- Scroll <n> line down */
      DEFAULT(escseq.arg[0], 1);
      tscrolldown(term.top, escseq.arg[0]);
      break;
    case 'L': /* IL -- Insert <n> blank lines */
      DEFAULT(escseq.arg[0], 1);
      tinsertblankline(escseq.arg[0]);
      break;
    case 'l': /* RM -- Reset Mode */
      if (escseq.priv) {
        switch (escseq.arg[0]) {
          case 1:
            term.mode &= ~MODE_APPKEYPAD;
            break;
          case 5: /* DECSCNM -- Remove reverse video */
            if (IS_SET(MODE_REVERSE)) {
              term.mode &= ~MODE_REVERSE;
              draw();
            }
            break;
          case 7: /* autowrap off */
            term.mode &= ~MODE_WRAP;
            break;
          case 12: /* att610 -- Stop blinking cursor (IGNORED) */
            break;
          case 20: /* non-standard code? */
            term.mode &= ~MODE_CRLF;
            break;
          case 25: /* hide cursor */
            term.c.state |= CURSOR_HIDE;
            break;
          case 1000: /* disable X11 xterm mouse reporting */
#ifndef MOUSE_REPORTING_ALWAYS
            term.mode &= ~MODE_MOUSEBTN;
#endif
            break;
          case 1002:
#ifndef MOUSE_REPORTING_ALWAYS
            term.mode &= ~MODE_MOUSEMOTION;
#endif
            break;
          case 1049: /* = 1047 and 1048 */
          case 47:
          case 1047:
            if (IS_SET(MODE_ALTSCREEN)) {
              tclearregion(0, 0, term.col-1, term.row-1);
              tswapscreen();
            }
            if (escseq.arg[0] != 1049) break;
          case 1048:
            tcursor(CURSOR_LOAD);
            break;
          default:
            goto unknown;
        }
      } else {
        switch (escseq.arg[0]) {
          case 4:
            term.mode &= ~MODE_INSERT;
            break;
          default:
            goto unknown;
        }
      }
      break;
    case 'M': /* DL -- Delete <n> lines */
      DEFAULT(escseq.arg[0], 1);
      tdeleteline(escseq.arg[0]);
      break;
    case 'X': /* ECH -- Erase <n> char */
      DEFAULT(escseq.arg[0], 1);
      tclearregion(term.c.x, term.c.y, term.c.x + escseq.arg[0], term.c.y);
      break;
    case 'P': /* DCH -- Delete <n> char */
      DEFAULT(escseq.arg[0], 1);
      tdeletechar(escseq.arg[0]);
      break;
    /* XXX: (CSI n Z) CBT -- Cursor Backward Tabulation <n> tab stops */
    case 'd': /* VPA -- Move to <row> */
      DEFAULT(escseq.arg[0], 1);
      tmoveto(term.c.x, escseq.arg[0]-1);
      break;
    case 'h': /* SM -- Set terminal mode */
      if (escseq.priv) {
        switch (escseq.arg[0]) {
          case 1:
            term.mode |= MODE_APPKEYPAD;
            break;
          case 5: /* DECSCNM -- Reverve video */
            if (!IS_SET(MODE_REVERSE)) {
              term.mode |= MODE_REVERSE;
              draw();
            }
            break;
          case 7:
            term.mode |= MODE_WRAP;
            break;
          case 20:
            term.mode |= MODE_CRLF;
            break;
          case 12: /* att610 -- Start blinking cursor (IGNORED) */
            /* fallthrough for xterm cvvis = CSI [ ? 12 ; 25 h */
            if (escseq.narg > 1 && escseq.arg[1] != 25) break;
          case 25:
            term.c.state &= ~CURSOR_HIDE;
            break;
          case 1000: /* 1000,1002: enable xterm mouse report */
#ifndef MOUSE_REPORTING_ALWAYS
            term.mode |= MODE_MOUSEBTN;
#endif
            break;
          case 1002:
#ifndef MOUSE_REPORTING_ALWAYS
            term.mode |= MODE_MOUSEMOTION;
#endif
            break;
          case 1049: /* = 1047 and 1048 */
          case 47:
          case 1047:
            if (IS_SET(MODE_ALTSCREEN)) tclearregion(0, 0, term.col-1, term.row-1); else tswapscreen();
            if (escseq.arg[0] != 1049) break;
          case 1048:
            tcursor(CURSOR_SAVE);
            break;
          default: goto unknown;
        }
      } else {
        switch (escseq.arg[0]) {
          case 4:
            term.mode |= MODE_INSERT;
            break;
          default: goto unknown;
        }
      }
      break;
    case 'm': /* SGR -- Terminal attribute (color) */
      tsetattr(escseq.arg, escseq.narg);
      break;
    case 'r': /* DECSTBM -- Set Scrolling Region */
      if (escseq.priv) {
        goto unknown;
      } else {
        DEFAULT(escseq.arg[0], 1);
        DEFAULT(escseq.arg[1], term.row);
        tsetscroll(escseq.arg[0]-1, escseq.arg[1]-1);
        tmoveto(0, 0);
      }
      break;
    case 's': /* DECSC -- Save cursor position (ANSI.SYS) */
      tcursor(CURSOR_SAVE);
      break;
    case 'u': /* DECRC -- Restore cursor position (ANSI.SYS) */
      tcursor(CURSOR_LOAD);
      break;
    default:
unknown:
      fprintf(stderr, "erresc: unknown csi ");
      csidump();
      /*
      dlogf("erresc: unknown csi ");
      csidumpdbg();
      */
      /* die(""); */
      break;
  }
  UPDATE_LASTWRITE;
}


static void csireset (void) {
  memset(&escseq, 0, sizeof(escseq));
}


static void tputtab (void) {
  int space = TAB-term.c.x%TAB;
  //
  tmoveto(term.c.x+space, term.c.y);
}


////////////////////////////////////////////////////////////////////////////////
// put char to output buffer or process command
static void tputc (const char *c) {
  char ascii = *c;
  //
  if (term.esc & ESC_START) {
    if (term.esc & ESC_CSI) {
      escseq.buf[escseq.len++] = ascii;
      if (BETWEEN(ascii, 0x40, 0x7E) || escseq.len >= ESC_BUF_SIZ) {
        term.esc = 0;
        csiparse();
        csihandle();
      }
      /* TODO: handle other OSC */
    } else if (term.esc & ESC_OSC) {
      if (ascii == ';') {
        term.titlelen = 0;
        term.esc = ESC_START | ESC_TITLE;
      }
    } else if (term.esc & ESC_TITLE) {
      if (ascii == '\a' || term.titlelen+1 >= ESC_TITLE_SIZ) {
        term.esc = 0;
        term.title[term.titlelen] = '\0';
        XStoreName(xw.dpy, xw.win, term.title);
      } else {
        term.title[term.titlelen++] = ascii;
      }
    } else if (term.esc & ESC_ALTCHARSET) {
      switch (ascii) {
        case '0': /* Line drawing crap */
          term.c.attr.mode |= ATTR_GFX;
          break;
        case 'B': /* Back to regular text */
          term.c.attr.mode &= ~ATTR_GFX;
          break;
        default:
          fprintf(stderr, "esc unhandled charset: ESC ( %c\n", ascii);
          term.c.attr.mode &= ~ATTR_GFX;
      }
      term.esc = 0;
    } else if (term.esc & ESC_HASH) {
      switch (ascii) {
        case '8': /* DECALN -- DEC screen alignment test -- fill screen with E's */
          tfillregionwithE(0, 0, term.col-1, term.row-1);
          UPDATE_LASTWRITE;
          break;
      }
      term.esc = 0;
    } else if (term.esc & ESC_PERCENT) {
      term.esc = 0;
    } else {
      switch (ascii) {
        case '[':
          term.esc |= ESC_CSI;
          break;
        case ']':
          term.esc |= ESC_OSC;
          break;
        case '(':
          term.esc |= ESC_ALTCHARSET;
          break;
        case '#':
          term.esc |= ESC_HASH;
          break;
        case '%':
          term.esc |= ESC_PERCENT;
          break;
        case 'D': /* IND -- Linefeed */
          if (term.c.y == term.bot) tscrollup(term.top, 1); else tmoveto(term.c.x, term.c.y+1);
          term.esc = 0;
          UPDATE_LASTWRITE;
          break;
        case 'E': /* NEL -- Next line */
          tnewline(1); /* always go to first col */
          term.esc = 0;
          UPDATE_LASTWRITE;
          break;
        case 'M': /* RI -- Reverse linefeed */
          if (term.c.y == term.top) tscrolldown(term.top, 1); else tmoveto(term.c.x, term.c.y-1);
          term.esc = 0;
          UPDATE_LASTWRITE;
          break;
        case 'c': /* RIS -- Reset to inital state */
          treset();
          term.esc = 0;
          UPDATE_LASTWRITE;
          break;
        case '=': /* DECPAM -- Application keypad */
          term.mode |= MODE_APPKEYPAD;
          term.esc = 0;
          break;
        case '>': /* DECPNM -- Normal keypad */
          term.mode &= ~MODE_APPKEYPAD;
          term.esc = 0;
          break;
        case '7': /* DECSC -- Save Cursor */
          /* Save current state (cursor coordinates, attributes, character sets pointed at by G0, G1) */
          //TODO?
          tcursor(CURSOR_SAVE);
          term.esc = 0;
          break;
        case '8': /* DECRC -- Restore Cursor */
          //TODO?
          tcursor(CURSOR_LOAD);
          term.esc = 0;
          UPDATE_LASTWRITE;
          break;
        case 'Z': /* DEC private identification */
          ttywrite("\x1b[?1;2c", 7);
          term.esc = 0;
          break;
/*
        case '\x1b':
          term.esc = 0;
          break;
*/
        default:
          fprintf(stderr, "erresc: unknown sequence ESC 0x%02X '%c'\n", (uchar)ascii, isprint(ascii)?ascii:'.');
          term.esc = 0;
      }
    }
  } else {
    if (sel.bx != -1 && BETWEEN(term.c.y, sel.by, sel.ey)) sel.bx = -1;
    switch (ascii) {
      case '\t':
        tputtab();
        UPDATE_LASTWRITE;
        break;
      case '\b':
        tmoveto(term.c.x-1, term.c.y);
        UPDATE_LASTWRITE;
        break;
      case '\r':
        tmoveto(0, term.c.y);
        UPDATE_LASTWRITE;
        break;
      case '\f':
      case '\v':
      case '\n':
        /* go to first col if the mode is set */
        tnewline(IS_SET(MODE_CRLF));
        UPDATE_LASTWRITE;
        break;
      case '\a':
        //if (!(xw.state & WIN_FOCUSED)) xseturgency(1);
        break;
      case '\033':
        csireset();
        term.esc = ESC_START;
        break;
      default:
        if (term.c.attr.mode&ATTR_GFX) {
          long cc;
          //
          utf8decode(c, &cc);
          if (cc < 32 || cc >= 127) break; //FIXME: nothing at all
        } else {
          if ((unsigned char)ascii < 32 || ascii == 127) break; // seems that this chars are empty too
        }
        if (IS_SET(MODE_WRAP) && term.c.state & CURSOR_WRAPNEXT) tnewline(1); /* always go to first col */
        tsetchar(c);
        if (term.c.x+1 < term.col) tmoveto(term.c.x+1, term.c.y); else term.c.state |= CURSOR_WRAPNEXT;
        UPDATE_LASTWRITE;
        break;
    }
  }
}


////////////////////////////////////////////////////////////////////////////////
// tty resising
static int tresize (int col, int row) {
  int i, x;
  int minrow = MIN(row, term.row);
  int mincol = MIN(col, term.col);
  int slide = term.c.y-row+1;
  //
  if (col < 1 || row < 1) return 0;
  /* free unneeded rows */
  i = 0;
  if (slide > 0) {
    /* slide screen to keep cursor where we expect it -
     * tscrollup would work here, but we can optimize to
     * memmove because we're freeing the earlier lines */
    for (/* i = 0 */; i < slide; ++i) {
      free(term.line[i]);
      free(term.alt[i]);
    }
    memmove(term.line, term.line+slide, row*sizeof(Line));
    memmove(term.alt, term.alt+slide, row*sizeof(Line));
  }
  for (i += row; i < term.row; ++i) {
    free(term.line[i]);
    free(term.alt[i]);
  }
  /* resize to new height */
  term.line = realloc(term.line, row*sizeof(Line));
  term.alt  = realloc(term.alt, row*sizeof(Line));
  term.dirty = realloc(term.dirty, row*sizeof(*term.dirty));
  /* resize each row to new width, zero-pad if needed */
  for (i = 0; i < minrow; ++i) {
    term.dirty[i] = 1;
    term.line[i] = realloc(term.line[i], col*sizeof(Glyph));
    term.alt[i]  = realloc(term.alt[i], col*sizeof(Glyph));
    for (x = mincol; x < col; ++x) {
      term.line[i][x].state = 0;
      term.alt[i][x].state = 0;
    }
  }
  /* allocate any new rows */
  for (/* i == minrow */; i < row; ++i) {
    term.dirty[i] = 1;
    term.line[i] = calloc(col, sizeof(Glyph));
    term.alt[i] = calloc(col, sizeof(Glyph));
  }
  /* update terminal size */
  term.col = col, term.row = row;
  /* make use of the LIMIT in tmoveto */
  tmoveto(term.c.x, term.c.y);
  /* reset scrolling region */
  tsetscroll(0, row-1);
  //
  return (slide > 0);
}


static void xresize (int col, int row) {
  Pixmap newbuf;
  int oldw, oldh;
  //
  oldw = xw.bufw;
  oldh = xw.bufh;
  xw.bufw = MAX(1, col*xw.cw);
  xw.bufh = MAX(1, row*xw.ch);
  newbuf = XCreatePixmap(xw.dpy, xw.win, xw.bufw, xw.bufh, XDefaultDepth(xw.dpy, xw.scr));
  XCopyArea(xw.dpy, xw.buf, newbuf, dc.gc, 0, 0, xw.bufw, xw.bufh, 0, 0);
  XFreePixmap(xw.dpy, xw.buf);
  XSetForeground(xw.dpy, dc.gc, dc.col[DefaultBG]);
  if (xw.bufw > oldw) {
    XFillRectangle(xw.dpy, newbuf, dc.gc, oldw, 0, xw.bufw-oldw, MIN(xw.bufh, oldh));
  } else if (xw.bufw < oldw && (BORDER > 0 || xw.w > xw.bufw)) {
    XClearArea(xw.dpy, xw.win, BORDER+xw.bufw, BORDER, xw.w-xw.bufh-BORDER, BORDER+MIN(xw.bufh, oldh), False);
  }
  if (xw.bufh > oldh) {
    XFillRectangle(xw.dpy, newbuf, dc.gc, 0, oldh, xw.bufw, xw.bufh-oldh);
  } else if (xw.bufh < oldh && (BORDER > 0 || xw.h > xw.bufh)) {
    XClearArea(xw.dpy, xw.win, BORDER, BORDER+xw.bufh, xw.w-2*BORDER, xw.h-xw.bufh-BORDER, False);
  }
  xw.buf = newbuf;
}


////////////////////////////////////////////////////////////////////////////////
// x11 drawing and utils
static void xloadcols (void) {
  int i, r, g, b;
  XColor color;
  ulong white = WhitePixel(xw.dpy, xw.scr);
  /* load colors [0-15] colors and [256-LEN(colorname)[ (config.h) */
  for (i = 0; i < LEN(colorname); ++i) {
    if (!colorname[i]) continue;
    if (!XAllocNamedColor(xw.dpy, xw.cmap, colorname[i], &color, &color)) {
      dc.col[i] = white;
      fprintf(stderr, "Could not allocate color '%s'\n", colorname[i]);
    } else {
      dc.col[i] = color.pixel;
    }
  }
  /* load colors [16-255] ; same colors as xterm */
  for (i = 16, r = 0; r < 6; ++r) {
    for (g = 0; g < 6; ++g) {
      for (b = 0; b < 6; ++b) {
        color.red = r == 0 ? 0 : 0x3737 + 0x2828 * r;
        color.green = g == 0 ? 0 : 0x3737 + 0x2828 * g;
        color.blue = b == 0 ? 0 : 0x3737 + 0x2828 * b;
        if (!XAllocColor(xw.dpy, xw.cmap, &color)) {
          dc.col[i] = white;
          fprintf(stderr, "Could not allocate color %d\n", i);
        } else {
          dc.col[i] = color.pixel;
        }
        ++i;
      }
    }
  }
  for (r = 0; r < 24; ++r, ++i) {
    color.red = color.green = color.blue = 0x0808+0x0a0a*r;
    if (!XAllocColor(xw.dpy, xw.cmap, &color)) {
      dc.col[i] = white;
      fprintf(stderr, "Could not allocate color %d\n", i);
    } else {
      dc.col[i] = color.pixel;
    }
  }
}


static void xclear (int x1, int y1, int x2, int y2) {
  XSetForeground(xw.dpy, dc.gc, dc.col[IS_SET(MODE_REVERSE) ? DefaultFG : DefaultBG]);
  XFillRectangle(xw.dpy, xw.buf, dc.gc, x1*xw.cw, y1*xw.ch, (x2-x1+1)*xw.cw, (y2-y1+1)*xw.ch);
}


static void xhints (void) {
  XClassHint class = {opt_class ? opt_class : TNAME, TNAME};
  XWMHints wm = {.flags = InputHint, .input = 1};
  XSizeHints size = {
    .flags = PSize | PResizeInc | PBaseSize,
    .height = xw.h,
    .width = xw.w,
    .height_inc = xw.ch,
    .width_inc = xw.cw,
    .base_height = 2*BORDER,
    .base_width = 2*BORDER,
  };
  XSetWMProperties(xw.dpy, xw.win, NULL, NULL, NULL, 0, &size, &wm, &class);
}


static XFontSet xinitfont (const char *fontstr) {
  XFontSet set;
  char *def, **missing;
  int n;
  //
  missing = NULL;
  set = XCreateFontSet(xw.dpy, fontstr, &missing, &n, &def);
  if (missing) {
    while (n--) fprintf(stderr, "st: missing fontset: %s\n", missing[n]);
    XFreeStringList(missing);
  }
  return set;
}


static void xgetfontinfo (XFontSet set, int *ascent, int *descent, short *lbearing, short *rbearing) {
  XFontStruct **xfonts;
  char **font_names;
  int i, n;
  //
  *ascent = *descent = *lbearing = *rbearing = 0;
  n = XFontsOfFontSet(set, &xfonts, &font_names);
  for (i = 0; i < n; ++i) {
    *ascent = MAX(*ascent, (*xfonts)->ascent);
    *descent = MAX(*descent, (*xfonts)->descent);
    *lbearing = MAX(*lbearing, (*xfonts)->min_bounds.lbearing);
    *rbearing = MAX(*rbearing, (*xfonts)->max_bounds.rbearing);
    xfonts++;
  }
}


static void initfonts (char *fontstr, char *bfontstr) {
  if ((dc.font.set = xinitfont(fontstr)) == NULL || (dc.bfont.set = xinitfont(bfontstr)) == NULL) die("Can't load font %s\n", dc.font.set ? BOLDFONT : FONT);
  xgetfontinfo(dc.font.set, &dc.font.ascent, &dc.font.descent, &dc.font.lbearing, &dc.font.rbearing);
  xgetfontinfo(dc.bfont.set, &dc.bfont.ascent, &dc.bfont.descent, &dc.bfont.lbearing, &dc.bfont.rbearing);
}


static void xinit (void) {
  XSetWindowAttributes attrs;
  Cursor cursor;
  Window parent;
  //
  if (!(xw.dpy = XOpenDisplay(NULL))) die("Can't open display\n");
  xw.scr = XDefaultScreen(xw.dpy);
  /* font */
  initfonts(FONT, BOLDFONT);
  /* XXX: Assuming same size for bold font */
  xw.cw = dc.font.rbearing-dc.font.lbearing;
  xw.ch = dc.font.ascent+dc.font.descent;
  /* colors */
  xw.cmap = XDefaultColormap(xw.dpy, xw.scr);
  xloadcols();
  /* window - default size */
  xw.bufh = term.row*xw.ch;
  xw.bufw = term.col*xw.cw;
  xw.h = xw.bufh+2*BORDER;
  xw.w = xw.bufw+2*BORDER;
  attrs.background_pixel = dc.col[DefaultBG];
  attrs.border_pixel = dc.col[DefaultBG];
  attrs.bit_gravity = NorthWestGravity;
  attrs.event_mask = FocusChangeMask | KeyPressMask
    | ExposureMask | VisibilityChangeMask | StructureNotifyMask
    | ButtonMotionMask | ButtonPressMask | ButtonReleaseMask
    | EnterWindowMask | LeaveWindowMask;
  attrs.colormap = xw.cmap;
  parent = opt_embed ? strtol(opt_embed, NULL, 0) : XRootWindow(xw.dpy, xw.scr);
  xw.win = XCreateWindow(xw.dpy, parent, 0, 0,
      xw.w, xw.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput,
      XDefaultVisual(xw.dpy, xw.scr),
      CWBackPixel | CWBorderPixel | CWBitGravity | CWEventMask
      | CWColormap,
      &attrs);
  xw.buf = XCreatePixmap(xw.dpy, xw.win, xw.bufw, xw.bufh, XDefaultDepth(xw.dpy, xw.scr));
  /* input methods */
  xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL);
  xw.xic = XCreateIC(xw.xim, XNInputStyle, XIMPreeditNothing | XIMStatusNothing, XNClientWindow, xw.win, XNFocusWindow, xw.win, NULL);
  /* gc */
  dc.gc = XCreateGC(xw.dpy, xw.win, 0, NULL);
  /* white cursor, black outline */
  cursor = XCreateFontCursor(xw.dpy, XC_xterm);
  XDefineCursor(xw.dpy, xw.win, cursor);
  XRecolorCursor(xw.dpy, cursor,
    &(XColor){.red = 0xffff, .green = 0xffff, .blue = 0xffff},
    &(XColor){.red = 0x0000, .green = 0x0000, .blue = 0x0000});
  xw.xembed = XInternAtom(xw.dpy, "_XEMBED", False);
  XStoreName(xw.dpy, xw.win, opt_title ? opt_title : "sterm");
  XMapWindow(xw.dpy, xw.win);
  xhints();
  XSync(xw.dpy, 0);
}


static void xdraws (char *s, const Glyph *base, int x, int y, int charlen, int bytelen) {
  int fg = base->fg, bg = base->bg, temp;
  int winx = x*xw.cw, winy = y*xw.ch+dc.font.ascent, width = charlen*xw.cw;
  XFontSet fontset = dc.font.set;
  int i;
  int defF = (fg == DefaultFG), defB = (bg == DefaultBG);
  //
  /* only switch default fg/bg if term is in RV mode */
  if (IS_SET(MODE_REVERSE)) {
    if (defF) fg = DefaultBG;
    if (defB) bg = DefaultFG;
  }
  if (base->mode & ATTR_BOLD) {
    if (defF && defB) fg = DefaultBoldFG; else fg += 8;
    fontset = dc.bfont.set;
  }
#ifdef UNDERLINE_COLORED
  if (base->mode & ATTR_UNDERLINE) {
    if (defF && defB) fg = DefaultULFG;
  }
#endif
  //
  if (base->mode & ATTR_REVERSE) { temp = fg; fg = bg; bg = temp; }
  //
  XSetBackground(xw.dpy, dc.gc, dc.col[bg]);
  XSetForeground(xw.dpy, dc.gc, dc.col[fg]);
  //
  if (base->mode & ATTR_GFX) {
    for (i = 0; i < bytelen; ++i) {
      /*char c = gfx[(uint)s[i]%256];
      if (c) s[i] = c;
      else*/
      if ((unsigned char)s[i] > 95) s[i] -= 95;
    }
  }
  //
  XmbDrawImageString(xw.dpy, xw.buf, fontset, dc.gc, winx, winy, s, bytelen);
  //
  if (base->mode & ATTR_UNDERLINE) {
    XDrawLine(xw.dpy, xw.buf, dc.gc, winx, winy+1, winx+width-1, winy+1);
  }
}


/* copy buffer pixmap to screen pixmap */
static void xcopy (int x, int y, int cols, int rows) {
  int src_x = x*xw.cw, src_y = y*xw.ch, src_w = cols*xw.cw, src_h = rows*xw.ch;
  int dst_x = BORDER+src_x, dst_y = BORDER+src_y;
  //
  XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, src_x, src_y, src_w, src_h, dst_x, dst_y);
}


static void xdrawcursor (void) {
  static int oldx = 0;
  static int oldy = 0;
  int sl;
  Glyph g = {{' '}, ATTR_NULL, DefaultBG, DefaultCS, 0};
  LIMIT(oldx, 0, term.col-1);
  LIMIT(oldy, 0, term.row-1);
  /*if (term.line[term.c.y][term.c.x].state & GLYPH_SET)*/ memcpy(g.c, term.line[term.c.y][term.c.x].c, UTF_SIZ);
  /* remove the old cursor */
  if (/*term.line[oldy][oldx].state & GLYPH_SET*/ 1) {
    sl = utf8size(term.line[oldy][oldx].c);
    xdraws(term.line[oldy][oldx].c, &term.line[oldy][oldx], oldx, oldy, 1, sl);
  } else {
    xclear(oldx, oldy, oldx, oldy);
  }
  xcopy(oldx, oldy, 1, 1);
  /* draw the new one */
  if (!(term.c.state & CURSOR_HIDE)) {
    if (!(xw.state & WIN_FOCUSED)) g.bg = DefaultUCS;
    if (IS_SET(MODE_REVERSE)) g.mode |= ATTR_REVERSE, g.fg = DefaultCS, g.bg = DefaultFG;
    sl = utf8size(g.c);
    xdraws(g.c, &g, term.c.x, term.c.y, 1, sl);
    oldx = term.c.x, oldy = term.c.y;
  }
  xcopy(term.c.x, term.c.y, 1, 1);
}


static void draw (void) {
  drawregion(0, 0, term.col, term.row);
  gettimeofday(&xw.lastdraw, NULL);
}


static void drawregion (int x1, int y1, int x2, int y2) {
  int ic, ib, ox, sl;
  Glyph base, new;
  static char buf[DRAW_BUF_SIZ]; //FIXME! CAUTION
  //
  if (!(xw.state & WIN_VISIBLE)) return;
  //
  for (int y = y1; y < y2; ++y) {
    if (!term.dirty[y]) continue;
    xclear(0, y, term.col, y);
    term.dirty[y] = 0;
    base = term.line[y][0];
    ic = ib = ox = 0;
    for (int x = x1; x < x2; ++x) {
      new = term.line[y][x];
      if (sel.bx != -1 && *(new.c) && selected(x, y)) new.mode ^= ATTR_REVERSE;
      if (ib > 0 && (/*!(new.state & GLYPH_SET) ||*/ ATTRCMP(base, new) || ib >= DRAW_BUF_SIZ-UTF_SIZ)) {
        xdraws(buf, &base, ox, y, ic, ib);
        ic = ib = 0;
      }
      if (/*new.state & GLYPH_SET*/ 1) {
        if (ib == 0) {
          ox = x;
          base = new;
        }
        if (new.mode & ATTR_GFX) {
          sl = 1;
        } else {
          sl = utf8size(new.c);
        }
        memcpy(buf+ib, new.c, sl);
        ib += sl;
        ++ic;
      }
    }
    if (ib > 0) xdraws(buf, &base, ox, y, ic, ib);
    xcopy(0, y, term.col, 1);
  }
  xdrawcursor();
}


static void expose (XEvent *ev) {
  XExposeEvent *e = &ev->xexpose;
  if (xw.state & WIN_REDRAW) {
    if (!e->count) {
      xw.state &= ~WIN_REDRAW;
      xcopy(0, 0, term.col, term.row);
    }
  } else {
    XCopyArea(xw.dpy, xw.buf, xw.win, dc.gc, e->x-BORDER, e->y-BORDER, e->width, e->height, e->x, e->y);
  }
}


static void visibility (XEvent *ev) {
  XVisibilityEvent *e = &ev->xvisibility;
  if (e->state == VisibilityFullyObscured) xw.state &= ~WIN_VISIBLE;
  else if (!(xw.state & WIN_VISIBLE)) xw.state |= WIN_VISIBLE | WIN_REDRAW;
    /* need a full redraw for next Expose, not just a buf copy */
}


static void unmap (XEvent *ev) {
  xw.state &= ~WIN_VISIBLE;
}


static void xseturgency (int add) {
  XWMHints *h = XGetWMHints(xw.dpy, xw.win);
  //
  h->flags = add ? (h->flags | XUrgencyHint) : (h->flags & ~XUrgencyHint);
  XSetWMHints(xw.dpy, xw.win, h);
  XFree(h);
}


static void focus (XEvent *ev) {
  if (ev->type == FocusIn) {
    xw.state |= WIN_FOCUSED;
    xseturgency(0);
  } else {
    xw.state &= ~WIN_FOCUSED;
  }
  draw();
}


////////////////////////////////////////////////////////////////////////////////
// keyboard mapping
static const char *kmap (KeySym k, uint state) {
  state &= ~Mod2Mask;
  for (int i = 0; i < LEN(key); ++i) {
    uint mask = key[i].mask;
    if (key[i].k == k && ((state & mask) == mask || (mask == XK_NO_MOD && !state))) return (char*)key[i].s;
  }
  return NULL;
}


static void kpress (XEvent *ev) {
  XKeyEvent *e = &ev->xkey;
  KeySym ksym;
  char buf[32];
  const char *customkey;
  int len;
  int meta;
  int shift;
  Status status;
  //
  meta = e->state & Mod1Mask;
  shift = e->state & ShiftMask;
  len = XmbLookupString(xw.xic, e, buf, sizeof(buf), &ksym, &status);
  /* 1. custom keys from config.h */
  if ((customkey = kmap(ksym, e->state))) {
    ttywrite(customkey, strlen(customkey));
  /* 2. hardcoded (overrides X lookup) */
  } else {
    switch (ksym) {
      case XK_Up:
      case XK_Down:
      case XK_Left:
      case XK_Right:
        /* XXX: shift up/down doesn't work */
        sprintf(buf, "\033%c%c", IS_SET(MODE_APPKEYPAD) ? 'O' : '[', (shift ? "dacb":"DACB")[ksym - XK_Left]);
        ttywrite(buf, 3);
        break;
      case XK_Insert:
        if (shift) selpaste();
        break;
      case XK_Return:
        if (IS_SET(MODE_CRLF)) ttywrite("\r\n", 2); else ttywrite("\r", 1);
        break;
        /* 3. X lookup  */
      default:
        if (len > 0) {
          if (meta && len == 1) ttywrite("\033", 1);
          ttywrite(buf, len);
        }
        break;
    }
  }
}


////////////////////////////////////////////////////////////////////////////////
// xembed?
static void cmessage (XEvent *e) {
  /* See xembed specs http://standards.freedesktop.org/xembed-spec/xembed-spec-latest.html */
  if (e->xclient.message_type == xw.xembed && e->xclient.format == 32) {
    if (e->xclient.data.l[1] == XEMBED_FOCUS_IN) {
      xw.state |= WIN_FOCUSED;
      xseturgency(0);
    } else if (e->xclient.data.l[1] == XEMBED_FOCUS_OUT) {
      xw.state &= ~WIN_FOCUSED;
    }
    draw();
  }
}


////////////////////////////////////////////////////////////////////////////////
static void resize (XEvent *e) {
  int col, row;
  //
  if (e->xconfigure.width == xw.w && e->xconfigure.height == xw.h) return;
  xw.w = e->xconfigure.width;
  xw.h = e->xconfigure.height;
  col = (xw.w - 2*BORDER) / xw.cw;
  row = (xw.h - 2*BORDER) / xw.ch;
  if (col == term.col && row == term.row) return;
  if (tresize(col, row)) draw();
  ttyresize(col, row);
  xresize(col, row);
}


static bool last_draw_too_old (void) {
/*
  struct timeval now;
  //
  gettimeofday(&now, NULL);
  return TIMEDIFF(now, xw.lastdraw) >= DRAW_TIMEOUT/1000;
*/
  return (mclock_ticks()-tty_last_write_ms >= DRAW_TIMEOUT);
}


////////////////////////////////////////////////////////////////////////////////
// main loop
static void run (void) {
  bool stuff_to_print = 0;
  int xfd = XConnectionNumber(xw.dpy);
  //
  for (;;) {
    XEvent ev;
    fd_set rfd, wfd;
    struct timeval timeout;
    //
    FD_ZERO(&rfd);
    FD_ZERO(&wfd);
    FD_SET(cmdfd, &rfd);
    FD_SET(xfd, &rfd);
    // have something to write?
    if (tty_wrbufpos < tty_wrbufused) FD_SET(cmdfd, &wfd);
    //
    timeout.tv_sec  = 0;
    timeout.tv_usec = SELECT_TIMEOUT;
    if (select(MAX(xfd, cmdfd)+1, &rfd, &wfd, NULL, &timeout) < 0) {
      if (errno == EINTR) continue;
      die("select failed: %s\n", SERRNO);
    }
    //dlogf("after select()");
    //
    if (tty_wrbufpos < tty_wrbufused && FD_ISSET(cmdfd, &wfd)) {
      //dlogf("flushing write buffer");
      ttyflushwrbuf();
      //dlogf("flushing write buffer done");
    }
    //
    if (FD_ISSET(cmdfd, &rfd)) {
      //dlogf("reading from tty");
      ttyread();
      stuff_to_print = 1;
      //dlogf("reading from tty done");
    }
    //
    if (stuff_to_print) {
      if (last_draw_too_old()) {
        //dlogf("drawing");
        stuff_to_print = 0;
        draw();
      } else {
        //dlogf("excess output, not drawing");
      }
    }
    //
    if (XPending(xw.dpy)) {
      //dlogf("X11 events");
      while (XPending(xw.dpy)) {
        XNextEvent(xw.dpy, &ev);
        if (XFilterEvent(&ev, xw.win)) continue;
        if (handler[ev.type]) (handler[ev.type])(&ev);
      }
      //dlogf("X11 events done");
    }
  }
}


////////////////////////////////////////////////////////////////////////////////
int main (int argc, char *argv[]) {
  //dbgLogInit();
  //
  for (int i = 1; i < argc; i++) {
    switch (argv[i][0] != '-' || argv[i][2] ? -1 : argv[i][1]) {
      case 't':
        if (++i < argc) opt_title = argv[i];
        break;
      case 'c':
        if (++i < argc) opt_class = argv[i];
        break;
      case 'w':
        if (++i < argc) opt_embed = argv[i];
        break;
      case 'e':
        /* eat every remaining arguments */
        if (++i < argc) opt_cmd = &argv[i];
        goto run;
      case 'T':
        if (++i < argc) opt_term = argv[i];
        break;
      case 'v':
      case 'h':
      default:
        die(USAGE);
    }
  }
run:
  mclock_init();
  setlocale(LC_CTYPE, "");
  tnew(80, 24);
  ttynew();
  xinit();
  selinit();
  run();
  return 0;
}