Squashed commit of the following:

libs/libnx/nxme:  Add front-end, client, message handling needed for cursor support.  Still actual cursor logic yet, just message handling.

    graphics/nxmu and graphics/nxbe:  Add back-end message handling needed for cursor support.  No actual cursor logic yet, just message handling.

graphics/nxbe/Make.defs

@@ -44,6 +44,12 @@ ifeq ($(CONFIG_NX_RAMBACKED),y)
 CSRCS += nxbe_flush.c
 endif
 
+ifeq ($(CONFIG_NX_HWCURSOR),y)
+CSRCS += nxbe_cursor.c
+else ifeq ($(CONFIG_NX_SWCURSOR),y)
+CSRCS += nxbe_cursor.c
+endif
+
 DEPPATH += --dep-path nxbe
 CFLAGS += ${shell $(INCDIR) $(INCDIROPT) "$(CC)" $(TOPDIR)/graphics/nxbe}
 VPATH += :nxbe

graphics/nxbe/nxbe.h

@@ -188,12 +188,25 @@ struct nxbe_clipops_s
 
 struct nxbe_state_s
 {
-  uint8_t flags;                    /* NXBE_STATE_* flags */
+  uint8_t flags;                     /* NXBE_STATE_* flags */
+
+#if defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
+  /* Cursor support */
+
+  struct
+  {
+    bool visible;                    /* True: the cursor is visible */
+    struct cursor_pos_s pos;         /* The current cursor position */
+#ifdef CONFIG_NX_SWCURSOR
+    FAR struct cursor_image_s image; /* Cursor image */
+#endif
+  } cursor;
+#endif
 
   /* The window list (with the background window always at the bottom) */
 
-  FAR struct nxbe_window_s *topwnd; /* The window at the top of the display */
+  FAR struct nxbe_window_s *topwnd;  /* The window at the top of the display */
-  struct nxbe_window_s bkgd;        /* The background window is always at the bottom */
+  struct nxbe_window_s bkgd;         /* The background window is always at the bottom */
 
   /* At present, only a solid colored background is supported for refills.  The
    * following provides the background color.  It would be nice to support
@@ -254,6 +267,65 @@ int nxbe_colormap(FAR NX_DRIVERTYPE *dev);
 
 int nxbe_configure(FAR NX_DRIVERTYPE *dev, FAR struct nxbe_state_s *be);
 
+#if defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
+/****************************************************************************
+ * Name: nxbe_cursor_enable
+ *
+ * Description:
+ *   Enable/disable presentation of the cursor
+ *
+ * Input Parameters:
+ *   be  - The back-end state structure instance
+ *   enable - True: show the cursor, false: hide the cursor.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void nxbe_cursor_enable(FAR struct nxbe_state_s *be, bool enable);
+
+/****************************************************************************
+ * Name: nxbe_cursor_setimage
+ *
+ * Description:
+ *   Set the cursor image
+ *
+ * Input Parameters:
+ *   be  - The back-end state structure instance
+ *   image - Describes the cursor image in the expected format.  For a
+ *           software cursor, this is the format used with the display.  The
+ *           format may be different if a hardware cursor is used.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NX_HWCURSORIMAGE) || defined(CONFIG_NX_SWCURSOR)
+void nxbe_cursor_setimage(FAR struct nxbe_state_s *be,
+                          FAR struct cursor_image_s *image);
+#endif
+
+/****************************************************************************
+ * Name: nxcursor_setposition
+ *
+ * Description:
+ *   Move the cursor to the specified position
+ *
+ * Input Parameters:
+ *   be  - The back-end state structure instance
+ *   pos - The new cursor position
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void nxcursor_setposition(FAR struct nxbe_state_s *be,
+                          FAR const struct cursor_pos_s *pos);
+#endif /* CONFIG_NX_SWCURSOR || CONFIG_NX_HWCURSOR */
+
 /****************************************************************************
  * Name: nxbe_closewindow
  *

graphics/nxbe/nxbe_cursor.c

@@ -0,0 +1,117 @@
+/****************************************************************************
+ * graphics/nxbe/nxbe_cursor.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+
+#include "nxbe.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+#if defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
+/****************************************************************************
+ * Name: nxbe_cursor_enable
+ *
+ * Description:
+ *   Enable/disable presentation of the cursor
+ *
+ * Input Parameters:
+ *   be  - The back-end state structure instance
+ *   enable - True: show the cursor, false: hide the cursor.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void nxbe_cursor_enable(FAR struct nxbe_state_s *be, bool enable)
+{
+#warning Missing logic
+}
+
+/****************************************************************************
+ * Name: nxbe_cursor_setimage
+ *
+ * Description:
+ *   Set the cursor image
+ *
+ * Input Parameters:
+ *   be  - The back-end state structure instance
+ *   image - Describes the cursor image in the expected format.  For a
+ *           software cursor, this is the format used with the display.  The
+ *           format may be different if a hardware cursor is used.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NX_HWCURSORIMAGE) || defined(CONFIG_NX_SWCURSOR)
+void nxbe_cursor_setimage(FAR struct nxbe_state_s *be,
+                          FAR struct cursor_image_s *image);
+{
+#warning Missing logic
+}
+#endif
+
+/****************************************************************************
+ * Name: nxcursor_setposition
+ *
+ * Description:
+ *   Move the cursor to the specified position
+ *
+ * Input Parameters:
+ *   be  - The back-end state structure instance
+ *   pos - The new cursor position
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void nxcursor_setposition(FAR struct nxbe_state_s *be,
+                          FAR const struct cursor_pos_s *pos)
+{
+#warning Missing logic
+}
+
+#endif /* CONFIG_NX_SWCURSOR || CONFIG_NX_HWCURSOR */

graphics/nxmu/nxmu_server.c

@@ -376,6 +376,30 @@ int nx_runinstance(FAR const char *mqname, FAR NX_DRIVERTYPE *dev)
            }
            break;
 
+#if defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
+         case NX_SVRMSG_CURSOR_ENABLE: /* Enable/disable cursor */
+           {
+             FAR struct nxsvrmsg_curenable_s *enabmsg = (FAR struct nxsvrmsg_curenable_s *)buffer;
+             nxbe_cursor_enable(&nxwm.be, enabmsg->enable);
+           }
+           break;
+
+#if defined(CONFIG_NX_HWCURSORIMAGE) || defined(CONFIG_NX_SWCURSOR)
+         case NX_SVRMSG_CURSOR_IMAGE: /* Set cursor image */
+           {
+             FAR struct nxsvrmsg_curimage_s *imgmsg = (FAR struct nxsvrmsg_curimage_s *)buffer;
+             nxbe_cursor_setimage(&nxwm.be, imgmsg->image);
+           }
+           break;
+#endif
+         case NX_SVRMSG_CURSOR_SETPOS: /* Set cursor position */
+           {
+             FAR struct nxsvrmsg_curpos_s *posmsg = (FAR struct nxsvrmsg_curpos_s *)buffer;
+             nxbe_cursor_setposition(&nxwm.be, &posmsg->pos);
+           }
+           break;
+#endif
+
          case NX_SVRMSG_REQUESTBKGD: /* Give access to the background window */
            {
              FAR struct nxsvrmsg_requestbkgd_s *rqbgmsg = (FAR struct nxsvrmsg_requestbkgd_s *)buffer;

include/nuttx/nx/nxcursor.h

@@ -50,18 +50,6 @@
 
 #ifndef defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
 
-/****************************************************************************
- * Pre-processor Definitions
- ****************************************************************************/
-
-/****************************************************************************
- * Public Types
- ****************************************************************************/
-
-/****************************************************************************
- * Public Data
- ****************************************************************************/
-
 #undef EXTERN
 #if defined(__cplusplus)
 #define EXTERN extern "C"
@@ -86,17 +74,21 @@ extern "C"
  *   enable - True: show the cursor, false: hide the cursor.
  *
  * Returned Value:
- *   None
+ *   OK on success; ERROR on failure with errno set appropriately
  *
  ****************************************************************************/
 
-void nxcursor_enable(NXHANDLE hnd, bool enable);
+int nxcursor_enable(NXHANDLE hnd, bool enable);
 
 /****************************************************************************
- * Name: nxcursor_set_image
+ * Name: nxcursor_setimage
  *
  * Description:
- *   Set the cursor image
+ *   Set the cursor image.
+ *
+ *   NOTE: The NX logic will reference the user image buffer repeatedly.
+ *   That image buffer must persist for as long as the NX server connection
+ *   persists.
  *
  * Input Parameters:
  *   hnd   - The server handle returned by nx_connect()
@@ -105,30 +97,30 @@ void nxcursor_enable(NXHANDLE hnd, bool enable);
  *           format may be different if a hardware cursor is used.
  *
  * Returned Value:
- *   None
+ *   OK on success; ERROR on failure with errno set appropriately
  *
  ****************************************************************************/
 
 #if defined(CONFIG_NX_HWCURSORIMAGE) || defined(CONFIG_NX_SWCURSOR)
-void nxcursor_set_image(NXHANDLE hnd, FAR struct cursor_image_s *image);
+int nxcursor_setimage(NXHANDLE hnd, FAR struct cursor_image_s *image);
 #endif
 
 /****************************************************************************
- * Name: nxcursor_set_position
+ * Name: nxcursor_setposition
  *
  * Description:
  *   Move the cursor to the specified position
  *
  * Input Parameters:
  *   hnd - The server handle returned by nx_connect()
- *   pos -
+ *   pos - The new cursor position
  *
  * Returned Value:
- *   None
+ *   OK on success; ERROR on failure with errno set appropriately
  *
  ****************************************************************************/
 
-void nxcursor_set_position(NXHANDLE hnd, FAR const struct cursor_pos_s *pos);
+int nxcursor_setposition(NXHANDLE hnd, FAR const struct cursor_pos_s *pos);
 
 /****************************************************************************
  * Name: nxcursor_get_position
@@ -146,11 +138,11 @@ void nxcursor_set_position(NXHANDLE hnd, FAR const struct cursor_pos_s *pos);
  *   pos - The location to return the cursor position
  *
  * Returned Value:
- *   None
+ *   OK on success; ERROR on failure with errno set appropriately
  *
  ****************************************************************************/
 
-void nxcursor_get_position(NXHANDLE hnd, FAR struct cursor_pos_s *pos);
+int nxcursor_get_position(NXHANDLE hnd, FAR struct cursor_pos_s *pos);
 
 #undef EXTERN
 #if defined(__cplusplus)

include/nuttx/nx/nxmu.h

@@ -140,6 +140,9 @@ enum nxmsg_e
   NX_SVRMSG_CLOSEWINDOW,      /* Close an existing window */
   NX_SVRMSG_BLOCKED,          /* The window is blocked */
   NX_SVRMSG_SYNCH,            /* Window syncrhonization request */
+  NX_SVRMSG_CURSOR_ENABLE,    /* Enable/disablel cursor presentation */
+  NX_SVRMSG_CURSOR_IMAGE,     /* Set cursor image */
+  NX_SVRMSG_CURSOR_SETPOS,    /* Set cursor position */
   NX_SVRMSG_REQUESTBKGD,      /* Open the background window */
   NX_SVRMSG_RELEASEBKGD,      /* Release the background window */
   NX_SVRMSG_SETPOSITION,      /* Window position has changed */
@@ -295,6 +298,34 @@ struct nxsvrmsg_synch_s
   FAR void *arg;                 /* User argument */
 };
 
+#if defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
+/* Enable/disable cursor */
+
+struct nxsvrmsg_curenable_s
+{
+  uint32_t msgid;                /* NX_SVRMSG_CURSOR_ENABLE */
+  bool enable;                   /* True: show the cursor, false: hide the cursor */
+};
+
+#if defined(CONFIG_NX_HWCURSORIMAGE) || defined(CONFIG_NX_SWCURSOR)
+/* Set cursor image. */
+
+struct nxsvrmsg_curimage_s
+{
+  uint32_t msgid;                  /* NX_SVRMSG_CURSOR_IMAGE */
+  FAR struct cursor_image_s image  /* True: show the cursor, false: hide the cursor */
+};
+#endif
+
+/* Set cursor position. */
+
+struct nxsvrmsg_curpos_s
+{
+  uint32_t msgid;                /* NX_SVRMSG_CURSOR_SETPOS */
+  FAR struct cursor_pos_s pos;   /* The new cursor position */
+};
+#endif
+
 /* This message requests the server to create a new window */
 
 struct nxsvrmsg_requestbkgd_s

include/nuttx/video/cursor.h

@@ -34,8 +34,8 @@
  *
  ****************************************************************************/
 
-#ifndef __INCLUDE_NUTTX_VIDIO_CURSOR_H
+#ifndef __INCLUDE_NUTTX_VIDEO_CURSOR_H
-#define __INCLUDE_NUTTX_VIDIO_CURSOR_H
+#define __INCLUDE_NUTTX_VIDEO_CURSOR_H
 
 /****************************************************************************
  * Included Files
@@ -69,7 +69,7 @@ struct cursor_image_s
 {
   cursor_coord_t width;        /* Width of the cursor image in pixels */
   cursor_coord_t height;       /* Height of the cursor image in pixels */
-  FAR const uint8_t *image;    /* Pointer to image data */
+  FAR const uint8_t *image;    /* Pointer to bitmap image data */
 };
 
 /* The following structure defines the cursor position */
@@ -90,4 +90,4 @@ struct cursor_size_s
   cursor_coord_t w;            /* Width in pixels */
 };
 
-#endif /* __INCLUDE_NUTTX_VIDIO_CURSOR_H */
+#endif /* __INCLUDE_NUTTX_VIDEO_CURSOR_H */

include/nuttx/video/fb.h

@@ -34,8 +34,8 @@
  *
  ****************************************************************************/
 
-#ifndef __INCLUDE_NUTTX_VIDIO_FB_H
+#ifndef __INCLUDE_NUTTX_VIDEO_FB_H
-#define __INCLUDE_NUTTX_VIDIO_FB_H
+#define __INCLUDE_NUTTX_VIDEO_FB_H
 
 /****************************************************************************
  * Included Files
@@ -653,4 +653,4 @@ int fb_register(int display, int plane);
 }
 #endif
 
-#endif /* __INCLUDE_NUTTX_VIDIO_FB_H */
+#endif /* __INCLUDE_NUTTX_VIDEO_FB_H */

libs/libnx/nxmu/Make.defs

@@ -51,6 +51,12 @@ CSRCS += nx_getrectangle.c nx_lower.c nx_modal.c nx_move.c nx_openwindow.c
 CSRCS += nx_raise.c nx_redrawreq.c nx_setpixel.c nx_setposition.c
 CSRCS += nx_setsize.c
 
+ifeq ($(CONFIG_NX_HWCURSOR),y)
+CSRCS += nx_cursor.c
+else ifeq ($(CONFIG_NX_SWCURSOR),y)
+CSRCS += nx_cursor.c
+endif
+
 # Add the nxmu/ directory to the build
 
 DEPPATH += --dep-path nxmu

libs/libnx/nxmu/nx_cursor.c

@@ -0,0 +1,215 @@
+/****************************************************************************
+ * libs/libnx/nxmu/nx_cursor.c
+ *
+ *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <errno.h>
+
+#include <nuttx/video/cursor.h>
+#include <nuttx/nx/nxcursor.h>
+
+#ifndef defined(CONFIG_NX_SWCURSOR) || defined(CONFIG_NX_HWCURSOR)
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: nxcursor_enable
+ *
+ * Description:
+ *   Enable/disable presentation of the cursor
+ *
+ * Input Parameters:
+ *   hnd    - The server handle returned by nx_connect()
+ *   enable - True: show the cursor, false: hide the cursor.
+ *
+ * Returned Value:
+ *   OK on success; ERROR on failure with errno set appropriately
+ *
+ ****************************************************************************/
+
+int nxcursor_enable(NXHANDLE hnd, bool enable)
+{
+  FAR struct nxmu_conn_s *conn = (FAR struct nxmu_conn_s *)handle;
+  struct nxsvrmsg_curenable_s outmsg;
+  int ret;
+
+  /* Send the cursor enable/disable message */
+
+  outmsg.msgid = NX_SVRMSG_CURSOR_ENABLE;
+  outmsg.enable  = enable;
+
+  ret = nxmu_sendserver(conn, &outmsg, sizeof(struct nxsvrmsg_curenable_s));
+  if (ret < 0)
+    {
+      gerr("ERROR: nxmu_sendserver() returned %d\n", ret);
+      set_errno(-ret);
+      return ERROR
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxcursor_setimage
+ *
+ * Description:
+ *   Set the cursor image.
+ *
+ *   NOTE: The NX logic will reference the user image buffer repeatedly.
+ *   That image buffer must persist for as long as the NX server connection
+ *   persists.
+ *
+ * Input Parameters:
+ *   hnd   - The server handle returned by nx_connect()
+ *   image - Describes the cursor image in the expected format.  For a
+ *           software cursor, this is the format used with the display.  The
+ *           format may be different if a hardware cursor is used.
+ *
+ * Returned Value:
+ *   OK on success; ERROR on failure with errno set appropriately
+ *
+ ****************************************************************************/
+
+#if defined(CONFIG_NX_HWCURSORIMAGE) || defined(CONFIG_NX_SWCURSOR)
+int nxcursor_setimage(NXHANDLE hnd, FAR struct cursor_image_s *image)
+{
+  FAR struct nxmu_conn_s *conn = (FAR struct nxmu_conn_s *)handle;
+  struct nxsvrmsg_curimage_s outmsg;
+  int ret;
+
+  DEBUGASSERT(hnd != NULL && image != NULL);
+
+  /* Send the new cursor image to the server */
+
+  outmsg.msgid        = NX_SVRMSG_CURSOR_IMAGE;
+  outmsg.image.width  = image->width;
+  outmsg.image.height = image->height;
+  outmsg.image.image  = image->image;  /* The user pointer is sent, no data */
+
+  /* We will finish the teardown upon receipt of the DISCONNECTED message */
+
+  ret = nxmu_sendserver(conn, &outmsg, sizeof(struct nxsvrmsg_curimage_s));
+  if (ret < 0)
+    {
+      gerr("ERROR: nxmu_sendserver() returned %d\n", ret);
+      set_errno(-ret);
+      return ERROR
+    }
+
+  return OK;
+}
+#endif
+
+/****************************************************************************
+ * Name: nxcursor_setposition
+ *
+ * Description:
+ *   Move the cursor to the specified position
+ *
+ * Input Parameters:
+ *   hnd - The server handle returned by nx_connect()
+ *   pos - The new cursor position
+ *
+ * Returned Value:
+ *   OK on success; ERROR on failure with errno set appropriately
+ *
+ ****************************************************************************/
+
+int nxcursor_setposition(NXHANDLE hnd, FAR const struct cursor_pos_s *pos)
+{
+  FAR struct nxmu_conn_s *conn = (FAR struct nxmu_conn_s *)handle;
+  struct nxsvrmsg_curpos_s outmsg;
+  int ret;
+
+  DEBUGASSERT(hnd != NULL && pos != NULL);
+
+  /* Send the new cursor position to the server */
+
+  outmsg.msgid  = NX_SVRMSG_CURSOR_SETPOS;
+  outmsg.pos.x  = pos->x;
+  outmsg.pos.y  = pos->y;
+
+  /* We will finish the teardown upon receipt of the DISCONNECTED message */
+
+  ret = nxmu_sendserver(conn, &outmsg, sizeof(struct nxsvrmsg_curpos_s));
+  if (ret < 0)
+    {
+      gerr("ERROR: nxmu_sendserver() returned %d\n", ret);
+      set_errno(-ret);
+      return ERROR
+    }
+
+  return OK;
+}
+
+/****************************************************************************
+ * Name: nxcursor_get_position
+ *
+ * Description:
+ *   Return the current cursor position.
+ *
+ *   CAUTION:  The current cursor position is not updated until the display
+ *   is actually changed.  Due to asynchronies caused by queue, the new
+ *   current cursor position may not match the cursor position set until
+ *   the client and server are syncrhonized.
+ *
+ * Input Parameters:
+ *   hnd - The server handle returned by nx_connect()
+ *   pos - The location to return the cursor position
+ *
+ * Returned Value:
+ *   OK on success; ERROR on failure with errno set appropriately
+ *
+ ****************************************************************************/
+
+int nxcursor_get_position(NXHANDLE hnd, FAR struct cursor_pos_s *pos)
+{
+  /* REVISIT:  The cursor position is not accessible from here.  It is in hnd,
+   * be we don't have the definitions exposed to get it.
+   */
+
+#warning Missing logic
+  set_errno(ENOSYS);
+  return ERROR;
+}
+
+#endif /* __INCLUDE_NUTTX_NX_NXCURSOR_H */

libs/libnx/nxmu/nx_fill.c

@@ -75,7 +75,7 @@ int nx_fill(NXWINDOW hwnd, FAR const struct nxgl_rect_s *rect,
   struct nxsvrmsg_fill_s  outmsg;
 
 #ifdef CONFIG_DEBUG_FEATURES
-  if (!wnd || !rect || !color)
+  if (wnd == NULL || rect == NULL || color == NULL)
     {
       set_errno(EINVAL);
       return ERROR;