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.

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
-#define __INCLUDE_NUTTX_VIDIO_CURSOR_H
+#ifndef __INCLUDE_NUTTX_VIDEO_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
-#define __INCLUDE_NUTTX_VIDIO_FB_H
+#ifndef __INCLUDE_NUTTX_VIDEO_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 */