--- a/src/X_supp.c	Mon Jul 19 15:44:49 2010 +0800
+++ b/src/X_supp.c	Wed Dec 01 12:25:56 2010 +0800
@@ -1,18 +1,36 @@
+// -*- indent-tabs-mode: t; tab-width: 8; c-basic-offset: 4; -*-
+// vim: sw=4:ts=8:sts=4
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
+#include <cairo-xlib.h>
 #include "mb_graph_engine.h"
 #include "mb_redraw_man.h"
 #include "mb_timer.h"
 #include "mb_X_supp.h"
+#include "mb_backend.h"
+#include "mb_backend_utils.h"
+#include "config.h"
+
+#ifdef XSHM
+/* \sa http://www.xfree86.org/current/mit-shm.html */
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <X11/extensions/XShm.h>
+static void XSHM_update(X_supp_runtime_t *xmb_rt);
+#endif
 
 #define ERR -1
 #define OK 0
 
+#define ASSERT(x)
+
 #define ONLY_MOUSE_MOVE_RAW 1
 
+static mb_timer_factory_t *_timer_factory = &tman_timer_factory;
+
 /*! \ingroup xkb
  * @{
  */
@@ -21,18 +39,12 @@
     int ksym_per_code;
     KeySym *syms;
     subject_t *kbevents;
-    ob_factory_t *ob_factory;
+    observer_factory_t *observer_factory;
 };
 
 /* @} */
-#define MAX_MONITORS 200
-typedef struct {
-    int type;
-    int fd;
-    mb_eventcb_t f;
-    void *arg;
-}  monitor_t;
-struct _X_MB_runtime {
+
+struct _X_supp_runtime {
     Display *display;
     Window win;
     Visual *visual;
@@ -40,20 +52,221 @@
     mbe_pattern_t *surface_ptn;
     mbe_t *cr, *backend_cr;
     redraw_man_t *rdman;
-    mb_tman_t *tman;
     mb_img_ldr_t *img_ldr;
     int w, h;
 
     X_kb_info_t kbinfo;
-    monitor_t monitors[MAX_MONITORS];
-    int n_monitor;
+    mb_IO_man_t *io_man;
+    mb_timer_man_t *timer_man;
 
 #ifndef ONLY_MOUSE_MOVE_RAW
     /* States */
     shape_t *last;
 #endif
+
+#ifdef XSHM
+    XImage *ximage;
+    XShmSegmentInfo shminfo;
+#endif
+
+    /* For handle connection */
+    int io_hdl;
+
+    /*
+     * Following variables are used by handle_single_x_event()
+     */
+    int last_evt_type;	       /* Type of last event */
+    int eflag;
+    int ex1, ey1, ex2, ey2;    /* Aggregate expose events */
+    int mflag;
+    int mx, my;		       /* Position of last motion event */
+    int mbut_state;	       /* Button state of last motion event */
 };
 
+static void _x_supp_handle_x_event(X_supp_runtime_t *rt);
+
+/*! \defgroup x_supp_io IO manager for X.
+ * @{
+ */
+#define MAX_MONITORS 200
+
+typedef struct {
+    int type;
+    int fd;
+    mb_IO_cb_t cb;
+    void *data;
+}  monitor_t;
+
+struct _X_supp_IO_man {
+    mb_IO_man_t io_man;
+    monitor_t monitors[MAX_MONITORS];
+    int n_monitor;
+};
+
+static int _x_supp_io_man_reg(struct _mb_IO_man *io_man,
+			      int fd, MB_IO_TYPE type,
+			      mb_IO_cb_t cb, void *data);
+static void _x_supp_io_man_unreg(struct _mb_IO_man *io_man, int io_hdl);
+static mb_IO_man_t *_x_supp_io_man_new(void);
+static void _x_supp_io_man_free(mb_IO_man_t *io_man);
+
+static mb_IO_factory_t _X_supp_default_io_factory = {
+    _x_supp_io_man_new,
+    _x_supp_io_man_free
+};
+static mb_IO_factory_t *_io_factory = &_X_supp_default_io_factory;
+
+static struct _X_supp_IO_man _default_io_man = {
+    {_x_supp_io_man_reg, _x_supp_io_man_unreg},
+    {},			/* monitors */
+    0			/* n_monitor */
+};
+
+static mb_IO_man_t *
+_x_supp_io_man_new(void) {
+    return (mb_IO_man_t *)&_default_io_man;
+}
+
+static void
+_x_supp_io_man_free(mb_IO_man_t *io_man) {
+}
+
+static int
+_x_supp_io_man_reg(struct _mb_IO_man *io_man,
+		   int fd, MB_IO_TYPE type, mb_IO_cb_t cb, void *data) {
+    struct _X_supp_IO_man *xmb_io_man = (struct _X_supp_IO_man *)io_man;
+    int i;
+
+    for(i = 0; i < xmb_io_man->n_monitor; i++) {
+        if (xmb_io_man->monitors[i].type == MB_IO_DUMMY)
+	    break;
+    }
+    if (i == MAX_MONITORS)
+	return ERR;
+    
+    xmb_io_man->monitors[i].type = type;
+    xmb_io_man->monitors[i].fd = fd;
+    xmb_io_man->monitors[i].cb = cb;
+    xmb_io_man->monitors[i].data = data;
+    i++;
+    if(i > xmb_io_man->n_monitor)
+	xmb_io_man->n_monitor = i;
+    return i - 1;
+}
+
+static void
+_x_supp_io_man_unreg(struct _mb_IO_man *io_man, int io_hdl) {
+    struct _X_supp_IO_man *xmb_io_man = (struct _X_supp_IO_man *)io_man;
+    
+    ASSERT(io_hdl < xmb_io_man->n_monitor);
+    xmb_io_man->monitors[io_hdl].type = MB_IO_DUMMY;
+}
+
+/*! \brief Handle connection coming data and timeout of timers.
+ *
+ * \param display is a Display returned by XOpenDisplay().
+ * \param rdman is a redraw manager.
+ * \param tman is a timer manager.
+ *
+ * The display is managed by specified rdman and tman.  rdman draws
+ * on the display, and tman trigger actions according timers.
+ */
+static void
+_x_supp_event_loop(mb_rt_t *rt) {
+    struct _X_supp_runtime *xmb_rt = (struct _X_supp_runtime *)rt;
+    struct _X_supp_IO_man *io_man = (struct _X_supp_IO_man *)xmb_rt->io_man;
+    mb_timer_man_t *timer_man = (mb_timer_man_t *)xmb_rt->timer_man;
+    redraw_man_t *rdman;
+    mb_tman_t *tman = tman_timer_man_get_tman(timer_man);
+    mb_timeval_t now, tmo;
+    struct timeval tv;
+    fd_set rfds, wfds;
+    int nfds = 0;
+    int r, r1,i;
+
+    rdman = mb_runtime_rdman(rt);
+    
+    _x_supp_handle_x_event(xmb_rt);
+
+    while(1) {
+	FD_ZERO(&rfds);
+	FD_ZERO(&wfds);
+        for(i = 0; i < io_man->n_monitor; i++) {
+	    if(io_man->monitors[i].type == MB_IO_R ||
+	       io_man->monitors[i].type == MB_IO_RW) {
+		FD_SET(io_man->monitors[i].fd, &rfds);
+		nfds = MB_MAX(nfds, io_man->monitors[i].fd + 1);
+	    }
+	    if(io_man->monitors[i].type == MB_IO_W ||
+	       io_man->monitors[i].type == MB_IO_RW) {
+		FD_SET(io_man->monitors[i].fd, &wfds);
+		nfds = MB_MAX(nfds, io_man->monitors[i].fd + 1);
+	    }
+        }
+
+	get_now(&now);
+	r = mb_tman_next_timeout(tman, &now, &tmo);
+
+	if(r == 0) {
+	    tv.tv_sec = MB_TIMEVAL_SEC(&tmo);
+	    tv.tv_usec = MB_TIMEVAL_USEC(&tmo);
+	    r1 = select(nfds, &rfds, NULL, NULL, &tv);
+	} else
+	    r1 = select(nfds, &rfds, NULL, NULL, NULL);
+
+	if(r1 == -1) {
+	    perror("select");
+	    break;
+	}
+
+	if(r1 == 0) {
+	    get_now(&now);
+	    mb_tman_handle_timeout(tman, &now);
+	    rdman_redraw_changed(rdman);
+#ifdef XSHM
+	    XSHM_update(xmb_rt);
+#endif
+	    XFlush(xmb_rt->display);
+	} else {
+            for(i = 0; i < io_man->n_monitor; i++) {
+	        if(io_man->monitors[i].type == MB_IO_R ||
+		   io_man->monitors[i].type == MB_IO_RW) {
+		    if(FD_ISSET(io_man->monitors[i].fd, &rfds))
+		    	io_man->monitors[i].cb(i, io_man->monitors[i].fd,
+					       MB_IO_R,
+					       io_man->monitors[i].data);
+		}
+		if(io_man->monitors[i].type == MB_IO_W ||
+		   io_man->monitors[i].type == MB_IO_RW) {
+		    if(FD_ISSET(io_man->monitors[i].fd, &wfds))
+			io_man->monitors[i].cb(i, io_man->monitors[i].fd,
+					       MB_IO_W,
+					       io_man->monitors[i].data);
+		}
+            }
+	}
+    }
+}
+
+/* @} */
+
+#ifdef XSHM
+static void
+XSHM_update(X_supp_runtime_t *xmb_rt) {
+    GC gc;
+
+    gc = DefaultGC(xmb_rt->display, DefaultScreen(xmb_rt->display));
+    if(xmb_rt->ximage) {	/* support XSHM */
+	XShmPutImage(xmb_rt->display,
+		     xmb_rt->win,
+		     gc,
+		     xmb_rt->ximage,
+		     0, 0, 0, 0,
+		     xmb_rt->w, xmb_rt->h, 0);
+    }
+}
+#endif
+
 /*! \defgroup xkb X Keyboard Handling
  *
  * Accept keyboard events from X server and delivery it to
@@ -73,7 +286,7 @@
 static int X_kb_init(X_kb_info_t *kbinfo, Display *display,
 		     redraw_man_t *rdman) {
     int n_syms;
-    ob_factory_t *factory;
+    observer_factory_t *factory;
     int r;
 
     r = XDisplayKeycodes(display,
@@ -89,12 +302,12 @@
     if(kbinfo->syms == NULL)
 	return ERR;
 
-    factory = rdman_get_ob_factory(rdman);
+    factory = rdman_get_observer_factory(rdman);
     kbinfo->kbevents = subject_new(factory, kbinfo, OBJT_KB);
     if(kbinfo->kbevents == NULL)
 	return ERR;
-    /*! \todo Make sure ob_factory is still need. */
-    kbinfo->ob_factory = factory;
+    /*! \todo Make sure observer_factory is still need. */
+    kbinfo->observer_factory = factory;
 
     return OK;
 }
@@ -104,7 +317,8 @@
     XFree(kbinfo->syms);
 }
 
-/*! \brief Accept X keyboard events from handle_x_event() and dispatch it.
+/*! \brief Accept X keyboard events from _x_supp_handle_x_event() and
+ *         dispatch it.
  */
 static void X_kb_handle_event(X_kb_info_t *kbinfo, XKeyEvent *xkey) {
     unsigned int code;
@@ -123,7 +337,6 @@
 
     subject_notify(kbinfo->kbevents, &event.event);
 }
-
 /* @} */
 
 static unsigned int get_button_state(unsigned int state) {
@@ -135,7 +348,7 @@
 	but |= MOUSE_BUT2;
     if(state & Button3Mask)
 	but |= MOUSE_BUT3;
-    
+
     return but;
 }
 
@@ -171,35 +384,193 @@
     mouse_event.y = y;
     mouse_event.but_state = state;
     mouse_event.button = button;
-    
+
     if(IS_MBO_SHAPES(obj))
 	subject = sh_get_mouse_event_subject((shape_t *)obj);
     else
 	subject = coord_get_mouse_event((coord_t *)obj);
+
+    subject_notify(subject, (event_t *)&mouse_event);
+}
+
+/*! \brief Handle motion event.
+ */
+static void
+handle_motion_event(X_supp_runtime_t *rt) {
+    redraw_man_t *rdman = rt->rdman;
+    int x, y;
+    int state;
+    shape_t *shape;
+    coord_t *root;
+    int in_stroke;
     
-    subject_notify(subject, (event_t *)&mouse_event);
+    x = rt->mx;
+    y = rt->my;
+    state = rt->mbut_state;
+    
+    shape = find_shape_at_pos(rdman, x, y,
+			      &in_stroke);
+#ifdef ONLY_MOUSE_MOVE_RAW
+    if(shape != NULL) {
+	notify_coord_or_shape(rdman, (mb_obj_t *)shape,
+			      x, y, EVT_MOUSE_MOVE_RAW, state, 0);
+    } else {
+	root = rdman_get_root(rdman);
+	notify_coord_or_shape(rdman, (mb_obj_t *)root,
+			      x, y, EVT_MOUSE_MOVE_RAW, state, 0);
+    }
+#else
+    if(shape != NULL) {
+	if(rt->last != shape) {
+	    if(rt->last)
+		notify_coord_or_shape(rdman, rt->last, x, y,
+				      EVT_MOUSE_OUT, state, 0);
+	    notify_coord_or_shape(rdman, shape, x, y,
+				  EVT_MOUSE_OVER, state, 0);
+	    rt->last = shape;
+	} else
+	    notify_coord_or_shape(rdman, shape, x, y,
+				  EVT_MOUSE_MOVE, state, 0);
+    } else {
+	if(rt->last) {
+	    notify_coord_or_shape(rdman, rt->last, x, y,
+				  EVT_MOUSE_OUT, state, 0);
+	    rt->last = NULL;
+	}
+    }
+#endif
+    
+    rt->mflag = 0;
+}
+
+/*! \brief Redraw exposed area.
+ */
+static void
+handle_expose_event(X_supp_runtime_t *rt) {
+    redraw_man_t *rdman = rt->rdman;
+    int ex1, ey1, ex2, ey2;
+
+    ex1 = rt->ex1;
+    ey1 = rt->ey1;
+    ex2 = rt->ex2;
+    ey2 = rt->ey2;
+    
+    rdman_redraw_area(rdman, ex1, ey1, (ex2 - ex1), (ey2 - ey1));
+    
+    rt->eflag = 0;
+}
+
+/*! \brief Handle single X event and maintain internal states.
+ *
+ * It keeps internal state in rt to improve performance.
+ */
+static void
+handle_single_x_event(X_supp_runtime_t *rt, XEvent *evt) {
+    redraw_man_t *rdman = rt->rdman;
+    XMotionEvent *mevt;
+    XButtonEvent *bevt;
+    XExposeEvent *eevt;
+    XKeyEvent *xkey;
+    int x, y, w, h;
+
+    shape_t *shape;
+
+    unsigned int state, button;
+    int in_stroke;
+
+    if(evt->type != MotionNotify && rt->mflag)
+	handle_motion_event(rt);
+
+    switch(evt->type) {
+    case ButtonPress:
+	bevt = (XButtonEvent *)evt;
+	x = bevt->x;
+	y = bevt->y;
+	state = get_button_state(bevt->state);
+	button = get_button(bevt->button);
+
+	shape = find_shape_at_pos(rdman, x, y,
+				  &in_stroke);
+	if(shape)
+	    notify_coord_or_shape(rdman, (mb_obj_t *)shape,
+				  x, y, EVT_MOUSE_BUT_PRESS,
+				  state, button);
+	break;
+
+    case ButtonRelease:
+	bevt = (XButtonEvent *)evt;
+	x = bevt->x;
+	y = bevt->y;
+	state = get_button_state(bevt->state);
+	button = get_button(bevt->button);
+
+	shape = find_shape_at_pos(rdman, x, y,
+				  &in_stroke);
+	if(shape)
+	    notify_coord_or_shape(rdman, (mb_obj_t *)shape,
+				  x, y, EVT_MOUSE_BUT_RELEASE,
+				  state, button);
+	break;
+
+    case MotionNotify:
+	mevt = (XMotionEvent *)evt;
+	rt->mx = mevt->x;
+	rt->my = mevt->y;
+	rt->mbut_state = get_button_state(mevt->state);
+	rt->mflag = 1;
+	break;
+
+    case KeyPress:
+    case KeyRelease:
+	xkey = &evt->xkey;
+	X_kb_handle_event(&rt->kbinfo, xkey);
+	break;
+
+    case Expose:
+	eevt = &evt->xexpose;
+	x = eevt->x;
+	y = eevt->y;
+	w = eevt->width;
+	h = eevt->height;
+
+	if(rt->eflag) {
+	    if(x < rt->ex1)
+		rt->ex1 = x;
+	    if(y < rt->ey1)
+		rt->ey1 = y;
+	    if((x + w) > rt->ex2)
+		rt->ex2 = x + w;
+	    if((y + h) > rt->ey2)
+		rt->ey2 = y + h;
+	} else {
+	    rt->ex1 = x;
+	    rt->ey1 = y;
+	    rt->ex2 = x + w;
+	    rt->ey2 = y + h;
+	    rt->eflag = 1;
+	}
+	break;
+    }
+}
+
+/*! \brief Call when no more event in an event iteration.
+ *
+ * No more event means event queue is emplty.  This function will
+ * perform some actions according current internal state.
+ */
+static void
+no_more_event(X_supp_runtime_t *rt) {
+    if(rt->mflag)
+	handle_motion_event(rt);
+    if(rt->eflag)
+	handle_expose_event(rt);
 }
 
 /*! \brief Dispatch all X events in the queue.
  */
-static void handle_x_event(X_MB_runtime_t *rt) {
+static void _x_supp_handle_x_event(X_supp_runtime_t *rt) {
     Display *display = rt->display;
-    redraw_man_t *rdman = rt->rdman;
-    XEvent evt, peek_evt;
-    XMotionEvent *mevt;
-    XButtonEvent *bevt;
-    XExposeEvent *eevt;
-    XKeyEvent *xkey;
-    co_aix x, y, w, h;
-
-    int eflag = 0;
-    int ex1=0, ey1=0, ex2=0, ey2=0;
-
-    shape_t *shape;
-    coord_t *root;
-
-    unsigned int state, button;
-    int in_stroke;
+    XEvent evt;
     int r;
 
     /* XXX: For some unknown reason, it causes a segmentation fault to
@@ -211,200 +582,23 @@
 	if(r == -1)
 	    break;
 
-	switch(evt.type) {
-	case ButtonPress:
-	    bevt = (XButtonEvent *)&evt;
-	    x = bevt->x;
-	    y = bevt->y;
-	    state = get_button_state(bevt->state);
-	    button = get_button(bevt->button);
-
-	    shape = find_shape_at_pos(rdman, x, y,
-				      &in_stroke);
-	    if(shape)
-		notify_coord_or_shape(rdman, (mb_obj_t *)shape,
-				      x, y, EVT_MOUSE_BUT_PRESS,
-				      state, button);
-	    break;
-
-	case ButtonRelease:
-	    bevt = (XButtonEvent *)&evt;
-	    x = bevt->x;
-	    y = bevt->y;
-	    state = get_button_state(bevt->state);
-	    button = get_button(bevt->button);
-
-	    shape = find_shape_at_pos(rdman, x, y,
-				      &in_stroke);
-	    if(shape)
-		notify_coord_or_shape(rdman, (mb_obj_t *)shape,
-			      x, y, EVT_MOUSE_BUT_RELEASE,
-			      state, button);
-	    break;
-
-	case MotionNotify:
-	    while(XEventsQueued(display, QueuedAfterReading) > 0) {
-		r = XPeekEvent(display, &peek_evt);
-		if(r == -1)
-		    break;
-		if(peek_evt.type != MotionNotify)
-		    break;
-		XNextEvent(display, &evt);
-	    }
-	    if(r == -1)
-		break;
-	    
-	    mevt = (XMotionEvent *)&evt;
-	    x = mevt->x;
-	    y = mevt->y;
-	    state = get_button_state(mevt->state);
-
-	    shape = find_shape_at_pos(rdman, x, y,
-				      &in_stroke);
-#ifdef ONLY_MOUSE_MOVE_RAW
-	    if(shape != NULL) {
-		notify_coord_or_shape(rdman, (mb_obj_t *)shape,
-			      x, y, EVT_MOUSE_MOVE_RAW, state, 0);
-	    } else {
-		root = rdman_get_root(rdman);
-		notify_coord_or_shape(rdman, (mb_obj_t *)root,
-			      x, y, EVT_MOUSE_MOVE_RAW, state, 0);
-	    }
-#else
-	    if(shape != NULL) {
-		if(rt->last != shape) {
-		    if(rt->last)
-			notify_coord_or_shape(rdman, rt->last, x, y,
-				      EVT_MOUSE_OUT, state, 0);
-		    notify_coord_or_shape(rdman, shape, x, y,
-				  EVT_MOUSE_OVER, state, 0);
-		    rt->last = shape;
-		} else
-		    notify_coord_or_shape(rdman, shape, x, y,
-				  EVT_MOUSE_MOVE, state, 0);
-	    } else {
-		if(rt->last) {
-		    notify_coord_or_shape(rdman, rt->last, x, y,
-				  EVT_MOUSE_OUT, state, 0);
-		    rt->last = NULL;
-		}
-	    }
+	handle_single_x_event(rt, &evt);
+    }
+    no_more_event(rt);
+    
+#ifdef XSHM
+    XSHM_update(rt);
 #endif
-	    break;
-
-	case KeyPress:
-	case KeyRelease:
-	    xkey = &evt.xkey;
-	    X_kb_handle_event(&rt->kbinfo, xkey);
-	    break;
-
-	case Expose:
-	    eevt = &evt.xexpose;
-	    x = eevt->x;
-	    y = eevt->y;
-	    w = eevt->width;
-	    h = eevt->height;
-
-	    if(eflag) {
-		if(x < ex1)
-		    ex1 = x;
-		if(y < ey1)
-		    ey1 = y;
-		if((x + w) > ex2)
-		    ex2 = x + w;
-		if((y + h) > ey2)
-		    ey2 = y + h;
-	    } else {
-		ex1 = x;
-		ey1 = y;
-		ex2 = x + w;
-		ey2 = y + h;
-		eflag = 1;
-	    }
-	    break;
-	}
-    }
-    if(eflag) {
-	rdman_redraw_area(rdman, ex1, ey1, (ex2 - ex1), (ey2 - ey1));
-	eflag = 0;
-    }
     XFlush(display);
 }
 
-/*! \brief Handle connection coming data and timeout of timers.
- *
- * \param display is a Display returned by XOpenDisplay().
- * \param rdman is a redraw manager.
- * \param tman is a timer manager.
- *
- * The display is managed by specified rdman and tman.  rdman draws
- * on the display, and tman trigger actions according timers.
- */
-void X_MB_handle_connection(void *be) {
-    X_MB_runtime_t *rt = (X_MB_runtime_t *) be;
-    Display *display = rt->display;
-    redraw_man_t *rdman = rt->rdman;
-    mb_tman_t *tman = rt->tman;
-    int fd;
-    mb_timeval_t now, tmo;
-    struct timeval tv;
-    fd_set rfds,wfds;
-    int nfds;
-    int r, r1,i;
-
-    handle_x_event(rt);
+static void
+_x_supp_handle_connection(int hdl, int fd, MB_IO_TYPE type, void *data) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *)data;
 
-    fd = XConnectionNumber(display);
-    nfds = fd + 1;
-    while(1) {
-	FD_ZERO(&rfds);
-	FD_ZERO(&wfds);
-	FD_SET(fd, &rfds);
-        for(i=0;i<rt->n_monitor;i++) {
-	    if (rt->monitors[i].type == MONITOR_READ)
-		FD_SET(rt->monitors[i].fd, &rfds);
-	    else if (rt->monitors[i].type == MONITOR_WRITE)
-		FD_SET(rt->monitors[i].fd, &wfds);
-        }
-	
-	get_now(&now);
-	r = mb_tman_next_timeout(tman, &now, &tmo);
-
-	if(r == 0) {
-	    tv.tv_sec = MB_TIMEVAL_SEC(&tmo);
-	    tv.tv_usec = MB_TIMEVAL_USEC(&tmo);
-	    r1 = select(nfds, &rfds, NULL, NULL, &tv);
-	} else
-	    r1 = select(nfds, &rfds, NULL, NULL, NULL);
-
-	if(r1 == -1) {
-	    perror("select");
-	    break;
-	}
-
-	if(r1 == 0) {
-	    get_now(&now);
-	    mb_tman_handle_timeout(tman, &now);
-	    rdman_redraw_changed(rdman);
-	    XFlush(display);
-	} else if(FD_ISSET(fd, &rfds)){
-	    handle_x_event(rt);
-	} else {
-            for(i=0;i<rt->n_monitor;i++) {
-	        if (rt->monitors[i].type == MONITOR_READ)
-		    if (FD_ISSET(rt->monitors[i].fd, &rfds))
-		    	rt->monitors[i].f(rt->monitors[i].fd,rt->monitors[i].arg);
-	        else if (rt->monitors[i].type == MONITOR_WRITE)
-		    if (FD_ISSET(rt->monitors[i].fd, &wfds))
-		    	rt->monitors[i].f(rt->monitors[i].fd,rt->monitors[i].arg);
-            }
-	}
-    }
+    _x_supp_handle_x_event(xmb_rt);
 }
 
-#define ERR -1
-#define OK 0
-
 static int X_init_connection(const char *display_name,
 			     int w, int h,
 			     Display **displayp,
@@ -417,9 +611,27 @@
     XSetWindowAttributes wattr;
     int depth;
     int x, y;
+    int draw_root = 0;
+    const char *disp_name;
+    char disp_buf[32];
+    int cp;
     int r;
 
-    display = XOpenDisplay(display_name);
+    /*
+     * Support drawing on the root window.
+     */
+    disp_name = display_name;
+    if(strstr(display_name, ":root") != NULL) {
+	draw_root = 1;
+	cp = strlen(display_name) - 5;
+	if(cp >= 32)
+	    cp = 31;
+	memcpy(disp_buf, display_name, cp);
+	disp_buf[cp] = 0;
+	disp_name = disp_buf;
+    }
+
+    display = XOpenDisplay(disp_name);
     if(display == NULL)
 	return ERR;
 
@@ -430,15 +642,19 @@
     wattr.override_redirect = False;
     x = 10;
     y = 10;
-    win = XCreateWindow(display, root,
-			 x, y,
-			 w, h,
-			 1, depth, InputOutput, visual,
-			 CWOverrideRedirect, &wattr);
-    r = XMapWindow(display, win);
-    if(r == -1) {
-	XCloseDisplay(display);
-	return ERR;
+    if(draw_root)
+	win = RootWindowOfScreen(ScreenOfDisplay(display, screen));
+    else {
+	win = XCreateWindow(display, root,
+			    x, y,
+			    w, h,
+			    1, depth, InputOutput, visual,
+			    CWOverrideRedirect, &wattr);
+	r = XMapWindow(display, win);
+	if(r == -1) {
+	    XCloseDisplay(display);
+	    return ERR;
+	}
     }
 
     XSelectInput(display, win, PointerMotionMask | ExposureMask |
@@ -453,89 +669,231 @@
     return OK;
 }
 
+#ifdef XSHM
+static void
+xshm_destroy(X_supp_runtime_t *xmb_rt) {
+    XShmSegmentInfo *shminfo;
+
+    shminfo = &xmb_rt->shminfo;
+
+    if(xmb_rt->shminfo.shmaddr) {
+	XShmDetach(xmb_rt->display, shminfo);
+    }
+
+    if(xmb_rt->ximage) {
+	XDestroyImage(xmb_rt->ximage);
+	xmb_rt->ximage = NULL;
+    }
+
+    if(shminfo->shmaddr) {
+	shmdt(shminfo->shmaddr);
+	shminfo->shmaddr = NULL;
+    }
+
+    if(shminfo->shmid) {
+	shmctl(shminfo->shmid, IPC_RMID, 0);
+	shminfo->shmid = 0;
+    }
+}
+
+static void
+xshm_init(X_supp_runtime_t *xmb_rt) {
+    Display *display;
+    Visual *visual;
+    XImage *ximage;
+    int screen;
+    int depth;
+    int support_shm;
+    int mem_sz;
+    XShmSegmentInfo *shminfo;
+    int surf_fmt;
+
+    display = xmb_rt->display;
+    visual = xmb_rt->visual;
+    shminfo = &xmb_rt->shminfo;
+
+    support_shm = XShmQueryExtension(display);
+    if(!support_shm)
+	return;
+
+    screen = DefaultScreen(display);
+    depth = DefaultDepth(display, screen);
+
+    if(depth != 24 && depth != 32)
+	return;
+
+    xmb_rt->ximage = XShmCreateImage(display, visual, depth,
+				     ZPixmap, NULL, shminfo,
+				     xmb_rt->w, xmb_rt->h);
+    ximage = xmb_rt->ximage;
+
+    mem_sz = ximage->bytes_per_line * ximage->height;
+    shminfo->shmid = shmget(IPC_PRIVATE, mem_sz, IPC_CREAT | 0777);
+    if(shminfo->shmid == -1) {
+	xshm_destroy(xmb_rt);
+	return;
+    }
+
+    shminfo->shmaddr = shmat(shminfo->shmid, 0, 0);
+    ximage->data = shminfo->shmaddr;
+
+    shminfo->readOnly = 0;
+
+    XShmAttach(display, shminfo);
+
+    switch(depth) {
+    case 24: surf_fmt = CAIRO_FORMAT_RGB24; break;
+    case 32: surf_fmt = CAIRO_FORMAT_ARGB32; break;
+    }
+
+    xmb_rt->backend_surface =
+	mbe_image_surface_create_for_data((unsigned char *)ximage->data,
+					  surf_fmt,
+					  xmb_rt->w,
+					  xmb_rt->h,
+					  ximage->bytes_per_line);
+    if(xmb_rt->backend_surface == NULL)
+	xshm_destroy(xmb_rt);
+}
+#endif /* XSHM */
+
 /*! \brief Initialize a MadButterfy runtime for Xlib.
  *
- * It setups a runtime environment to run MadButterfly with Xlib.
- * Users should specify width and height of the opening window.
+ * This one is very like _x_supp_init(), except it accepts a
+ * X_supp_runtime_t object initialized with a display connected to a X
+ * server and an opened window.
+ *
+ * Following field of the X_supp_runtime_t object should be initialized.
+ *   - w, h
+ *   - win
+ *   - display
+ *   - visual
  */
-static int X_MB_init(const char *display_name,
-	      int w, int h, X_MB_runtime_t *xmb_rt) {
+static int
+_x_supp_init_with_win_internal(X_supp_runtime_t *xmb_rt) {
     mb_img_ldr_t *img_ldr;
-    
-    memset(xmb_rt, 0, sizeof(X_MB_runtime_t));
+    int w, h;
+    int disp_fd;
 
-    xmb_rt->w = w;
-    xmb_rt->h = h;
-    X_init_connection(display_name, w, h, &xmb_rt->display,
-		      &xmb_rt->visual, &xmb_rt->win);
-#ifdef OPENVG_GRAPH_ENGINE
-    _ge_openvg_disp_id = xmb_rt->display;
+    w = xmb_rt->w;
+    h = xmb_rt->h;
+
+#ifdef XSHM
+    xshm_init(xmb_rt);
 #endif
 
-    mbe_init();
-
     xmb_rt->surface =
 	mbe_image_surface_create(MB_IFMT_ARGB32, w, h);
 
     xmb_rt->surface_ptn =
 	mbe_pattern_create_for_surface(xmb_rt->surface);
-    
-#ifdef OPENVG_GRAPH_ENGINE
-    xmb_rt->backend_surface =
-	mbe_vg_win_surface_create(xmb_rt->display,
-				  xmb_rt->win,
-				  xmb_rt->visual,
-				  w, h);
-#else
-    xmb_rt->backend_surface =
-	mbe_xlib_surface_create(xmb_rt->display,
-				  xmb_rt->win,
-				  xmb_rt->visual,
-				  w, h);
-#endif
+
+    if(xmb_rt->backend_surface == NULL) /* xshm_init() may create one */
+	xmb_rt->backend_surface =
+	    mbe_xlib_surface_create(xmb_rt->display,
+				    xmb_rt->win,
+				    xmb_rt->visual,
+				    w, h);
 
     xmb_rt->cr = mbe_create(xmb_rt->surface);
     xmb_rt->backend_cr = mbe_create(xmb_rt->backend_surface);
 
-    /* TODO: Remove this line.  Since we use mbe_copy_source(), it
-     * will set source for the backend.  So, this line is redundants.
-     * It can be removed.  sourface_ptn can be removed, too.
-     */
     mbe_set_source(xmb_rt->backend_cr, xmb_rt->surface_ptn);
 
     xmb_rt->rdman = (redraw_man_t *)malloc(sizeof(redraw_man_t));
     redraw_man_init(xmb_rt->rdman, xmb_rt->cr, xmb_rt->backend_cr);
-    // FIXME: This is a wired loopback reference. This is inly required when we need 
+    // FIXME: This is a wired loopback reference. This is inly required when we need
     //        to get the xmb_rt->tman for the animation. We should relocate the tman
     //	      to the redraw_man_t instead.
     xmb_rt->rdman->rt = xmb_rt;
-    xmb_rt->rdman->w = w;
-    xmb_rt->rdman->h = h;
 
-    xmb_rt->tman = mb_tman_new();
+    xmb_rt->io_man = mb_io_man_new(_io_factory);
+    xmb_rt->timer_man = mb_timer_man_new(_timer_factory);
 
     img_ldr = simple_mb_img_ldr_new("");
     xmb_rt->img_ldr = img_ldr;
-    rdman_set_img_ldr(xmb_rt->rdman, img_ldr);
-    memset(xmb_rt->monitors,0,sizeof(xmb_rt->monitors));
-    
+    /*! \todo Remove rdman_set_img_ldr() */
+    rdman_set_img_ldr(xmb_rt->rdman, img_ldr); /* this is ncessary? */
+
 #ifndef ONLY_MOUSE_MOVE_RAW
     xmb_rt->last = NULL;
 #endif
 
     X_kb_init(&xmb_rt->kbinfo, xmb_rt->display, xmb_rt->rdman);
 
+    disp_fd = XConnectionNumber(xmb_rt->display);
+    xmb_rt->io_hdl = mb_io_man_reg(xmb_rt->io_man, disp_fd,
+				   MB_IO_R,
+				   _x_supp_handle_connection,
+				   xmb_rt);
+
     return OK;
 }
 
-static void X_MB_destroy(X_MB_runtime_t *xmb_rt) {
+/*! \brief Initialize a MadButterfy runtime for Xlib.
+ *
+ * It setups a runtime environment to run MadButterfly with Xlib.
+ * Users should specify width and height of the opening window.
+ */
+static int _x_supp_init(X_supp_runtime_t *xmb_rt, const char *display_name,
+			int w, int h) {
+    int r;
+
+    memset(xmb_rt, 0, sizeof(X_supp_runtime_t));
+
+    xmb_rt->w = w;
+    xmb_rt->h = h;
+    r = X_init_connection(display_name, w, h, &xmb_rt->display,
+			  &xmb_rt->visual, &xmb_rt->win);
+    if(r != OK)
+	return ERR;
+
+    r = _x_supp_init_with_win_internal(xmb_rt);
+
+    return r;
+}
+
+/*! \brief Initialize a MadButterfly runtime for a window of X.
+ *
+ * Runtimes initialized with this function should be destroyed with
+ * x_supp_destroy_keep_win().
+ */
+static int
+_x_supp_init_with_win(X_supp_runtime_t *xmb_rt,
+		      Display *display, Window win) {
+    XWindowAttributes attrs;
+    int r;
+
+    r = XGetWindowAttributes(display, win, &attrs);
+    if(r == 0)
+	return ERR;
+    
+    memset(xmb_rt, 0, sizeof(X_supp_runtime_t));
+
+    xmb_rt->display = display;
+    xmb_rt->win = win;
+    xmb_rt->visual = attrs.visual;
+    xmb_rt->w = attrs.width;
+    xmb_rt->h = attrs.height;
+
+    r = _x_supp_init_with_win_internal(xmb_rt);
+
+    return r;
+}
+
+static void x_supp_destroy(X_supp_runtime_t *xmb_rt) {
     if(xmb_rt->rdman) {
 	redraw_man_destroy(xmb_rt->rdman);
 	free(xmb_rt->rdman);
     }
 
-    if(xmb_rt->tman)
-	mb_tman_free(xmb_rt->tman);
+    if(xmb_rt->io_hdl)
+	mb_io_man_unreg(xmb_rt->io_man, xmb_rt->io_hdl);
+
+    if(xmb_rt->io_man)
+	mb_io_man_free(_io_factory, xmb_rt->io_man);
+    if(xmb_rt->timer_man)
+	mb_timer_man_free(_timer_factory, xmb_rt->timer_man);
 
     if(xmb_rt->img_ldr)
 	MB_IMG_LDR_FREE(xmb_rt->img_ldr);
@@ -558,133 +916,179 @@
     X_kb_destroy(&xmb_rt->kbinfo);
 }
 
-void *X_MB_new(const char *display_name, int w, int h) {
-    X_MB_runtime_t *rt;
+/*! \brief Destroy a MadButterfly runtime initialized with
+ *	_x_supp_init_with_win().
+ *
+ * Destroying a runtime with this function prevent the window and
+ * display associated with the runtime being closed.
+ */
+static void
+x_supp_destroy_keep_win(X_supp_runtime_t *xmb_rt) {
+    Display *display;
+    Window win;
+
+    display = xmb_rt->display;
+    xmb_rt->display = NULL;
+    win = xmb_rt->win;
+    xmb_rt->win = 0;
+
+    x_supp_destroy(xmb_rt);
+    
+    xmb_rt->display = display;
+    xmb_rt->win = win;
+}
+
+static mb_rt_t *
+_x_supp_new(const char *display_name, int w, int h) {
+    X_supp_runtime_t *rt;
     int r;
 
-    rt = O_ALLOC(X_MB_runtime_t);
+    rt = O_ALLOC(X_supp_runtime_t);
     if(rt == NULL)
 	return NULL;
 
-    r = X_MB_init(display_name, w, h, rt);
+    r = _x_supp_init(rt, display_name, w, h);
     if(r != OK) {
 	free(rt);
 	return NULL;
     }
 
-    return rt;
+    return (mb_rt_t *)rt;
 }
 
-void X_MB_free(void *rt) {
-    X_MB_destroy((X_MB_runtime_t *) rt);
+/*! \brief Create a new runtime for existed window for X.
+ *
+ * The object returned by this function must be free with
+ * _x_supp_free_keep_win() to prevent the window from closed.
+ */
+static mb_rt_t *
+_x_supp_new_with_win(MB_DISPLAY display, MB_WINDOW win) {
+    X_supp_runtime_t *rt;
+    int r;
+
+    rt = O_ALLOC(X_supp_runtime_t);
+    if(rt == NULL)
+	return NULL;
+
+    r = _x_supp_init_with_win(rt, display, win);
+    if(r != OK) {
+	free(rt);
+	return NULL;
+    }
+
+    return (mb_rt_t *)rt;
+}
+
+static void
+_x_supp_free(mb_rt_t *rt) {
+    x_supp_destroy((X_supp_runtime_t *) rt);
     free(rt);
 }
 
-subject_t *X_MB_kbevents(void *rt) {
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
+/*! \brief Free runtime created with _x_supp_new_with_win().
+ */
+static void
+_x_supp_free_keep_win(mb_rt_t *rt) {
+    x_supp_destroy_keep_win((X_supp_runtime_t *) rt);
+    free(rt);
+}
+
+static subject_t *
+_x_supp_kbevents(mb_rt_t *rt) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
     return xmb_rt->kbinfo.kbevents;
 }
 
-redraw_man_t *X_MB_rdman(void *rt) {
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
+static redraw_man_t *
+_x_supp_rdman(mb_rt_t *rt) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
     return xmb_rt->rdman;
 }
 
-mb_tman_t *X_MB_tman(void *rt) {
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
-    return xmb_rt->tman;
+static mb_timer_man_t *
+_x_supp_timer_man(mb_rt_t *rt) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
+    return xmb_rt->timer_man;
 }
 
-ob_factory_t *X_MB_ob_factory(void *rt) {
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
-    ob_factory_t *factory;
+static observer_factory_t *
+_x_supp_observer_factory(mb_rt_t *rt) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
+    observer_factory_t *factory;
 
-    factory = rdman_get_ob_factory(xmb_rt->rdman);
+    factory = rdman_get_observer_factory(xmb_rt->rdman);
     return factory;
 }
 
-mb_img_ldr_t *X_MB_img_ldr(void *rt) {
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
-    X_MB_runtime_t *img_ldr;
+static mb_img_ldr_t *
+_x_supp_img_ldr(mb_rt_t *rt) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
+    mb_img_ldr_t *img_ldr;
 
     img_ldr = xmb_rt->img_ldr;
 
     return img_ldr;
 }
 
-void X_MB_add_event(void *rt, int type, int fd, mb_eventcb_t f,void *arg)
+static int
+_x_supp_add_event(mb_rt_t *rt, int fd, MB_IO_TYPE type,
+	       mb_IO_cb_t cb, void *data)
 {
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
-    int i;
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
+    mb_IO_man_t *io_man = xmb_rt->io_man;
+    int hdl;
 
-    for(i=0;i<xmb_rt->n_monitor;i++) {
-        if (xmb_rt->monitors[i].type == type && xmb_rt->monitors[i].fd == fd) {
-	    xmb_rt->monitors[i].f = f;
-	    xmb_rt->monitors[i].arg = arg;
-	    return;
-	}
-    }
-    for(i=0;i<xmb_rt->n_monitor;i++) {
-        if (xmb_rt->monitors[i].type == 0) {
-	    xmb_rt->monitors[i].type = type;
-	    xmb_rt->monitors[i].fd = fd;
-	    xmb_rt->monitors[i].f = f;
-	    xmb_rt->monitors[i].arg = arg;
-	    return;
-	}
-    }
-    if (i == MAX_MONITORS) return;
-    xmb_rt->monitors[i].type = type;
-    xmb_rt->monitors[i].fd = fd;
-    xmb_rt->monitors[i].f = f;
-    xmb_rt->monitors[i].arg = arg;
-    i++;
-    xmb_rt->n_monitor=i;
+    hdl = mb_io_man_reg(io_man, fd, type, cb, data);
+    return hdl;
+}
+
+static void
+_x_supp_remove_event(mb_rt_t *rt, int hdl)
+{
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
+    mb_IO_man_t *io_man = xmb_rt->io_man;
+
+    mb_io_man_unreg(io_man, hdl);
 }
 
-void X_MB_remove_event(void *rt, int type, int fd)
-{
-    X_MB_runtime_t *xmb_rt = (X_MB_runtime_t *) rt;
-    int i;
-    for(i=0;i<xmb_rt->n_monitor;i++) {
-        if (xmb_rt->monitors[i].type == type && xmb_rt->monitors[i].fd == fd) {
-	    xmb_rt->monitors[i].type = 0;
-	    return;
-	}
-    }
+static int
+_x_supp_flush(mb_rt_t *rt) {
+    X_supp_runtime_t *xmb_rt = (X_supp_runtime_t *) rt;
+    int r;
+
+#ifdef XSHM
+    XSHM_update(xmb_rt);
+#endif
+    r = XFlush(xmb_rt->display);
+    return r == 0? ERR: OK;
 }
-mb_backend_t backend = { X_MB_new,
-			 X_MB_free,
-			 X_MB_add_event,
-			 X_MB_remove_event,
-			 X_MB_handle_connection,
-			 X_MB_kbevents,
-			 X_MB_rdman,
-			 X_MB_tman,
-			 X_MB_ob_factory,
-			 X_MB_img_ldr
-		};
-/*! \defgroup x_supp_nodejs_sup Export functions for supporting nodejs plugin.
- *
- * These functions are for internal using.
- * @{
- */			 
-/*! \brief Exported for nodejs plugin to call handle_x_event.
- */
-void _X_MB_handle_x_event_for_nodejs(void *rt) {
-    handle_x_event((X_MB_runtime_t *)rt);
+
+static void
+_x_supp_reg_IO_factory(mb_IO_factory_t *io_factory) {
+    _io_factory = io_factory;
 }
 
-/*! \brief Get X connect for nodejs plugin.
- */
-int _X_MB_get_x_conn_for_nodejs(void *rt) {
-    return XConnectionNumber(((X_MB_runtime_t *)rt)->display);
+static void
+_x_supp_reg_timer_factory(mb_timer_factory_t *timer_factory) {
+    _timer_factory = timer_factory;
 }
 
-/*! \brief Flush buffer for the X connection of a runtime object.
- */
-int _X_MB_flush_x_conn_for_nodejs(void *rt) {
-    return XFlush(((X_MB_runtime_t *)rt)->display);
-}
+mb_backend_t mb_dfl_backend = { _x_supp_new,
+				_x_supp_new_with_win,
+				
+				_x_supp_free,
+				_x_supp_free_keep_win,
+				_x_supp_add_event,
+				_x_supp_remove_event,
+				_x_supp_event_loop,
+				_x_supp_flush,
+				
+				_x_supp_kbevents,
+				_x_supp_rdman,
+				_x_supp_timer_man,
+				_x_supp_observer_factory,
+				_x_supp_img_ldr,
 
-/* @} */
+				_x_supp_reg_IO_factory,
+				_x_supp_reg_timer_factory,
+};