Squashed commit of the following:

apps/graphics/twm4nx:  Other toolbar buttons need to be disabled while resizing.  Lots of problems if you decide to iconify or exit while resizing.  CResize now disables all buttons except for the RESIZE button while resizing.

    apps/graphics/twm4nx:  Add an event and logic to support notification of changes in the size of a window to NxTerm.

    Various updates to adapt to change in boardctl() interface.

    apps/graphics/twm4nx:  Correct an error in the NxTerm resize logic

    apps/graphics/twm4nx:  Update debug output when failures to send a message occur.  The returned value of -1 is not interested, need to show the errno value instead.

    apps/graphics/twm4nx:  Correct the maximum size of a message.  Recent changes caused message send failures because a message exceed that previous maximum size.

    apps/graphics/twm4nx:  Fix routing of redraw events.

include/graphics/twm4nx/cnxterm.hxx

@@ -60,16 +60,17 @@
 // Window Events
 
 #define EVENT_NXTERM_REDRAW   (EVENT_RECIPIENT_APP | 0x0000)
+#define EVENT_NXTERM_RESIZE   (EVENT_RECIPIENT_APP | 0x0001)
 #define EVENT_NXTERM_XYINPUT   EVENT_SYSTEM_NOP
 #define EVENT_NXTERM_KBDINPUT  EVENT_SYSTEM_NOP
 
 // Button Events
 
-#define EVENT_NXTERM_CLOSE    (EVENT_RECIPIENT_APP | 0x0001)
+#define EVENT_NXTERM_CLOSE    (EVENT_RECIPIENT_APP | 0x0002)
 
 // Menu Events
 
-#define EVENT_NXTERM_START    (EVENT_RECIPIENT_APP | 0x0002)
+#define EVENT_NXTERM_START    (EVENT_RECIPIENT_APP | 0x0003)
 
 /////////////////////////////////////////////////////////////////////////////
 // Implementation Classes
@@ -113,6 +114,12 @@ namespace Twm4Nx
 
       void redraw(void);
 
+      /**
+       * inform NxTerm of a new window size.
+       */
+
+      void resize(void);
+
       /**
        * This is the close window event handler.  It will stop the NxTerm
        * application trhead.

include/graphics/twm4nx/cwindow.hxx

@@ -110,6 +110,15 @@
 #define WFLAGS_IS_MENU(f)              (((f) & WFLAGS_MENU) != 0)
 #define WFLAGS_IS_HIDDEN(f)            (((f) & WFLAGS_HIDDEN) != 0)
 
+// Buttons can be disabled temporarily while in certain absorbing states
+// (such as resizing the window).
+
+#define DISABLE_NO_BUTTONS        (0)
+#define DISABLE_MENU_BUTTON       (1 << MENU_BUTTON)
+#define DISABLE_DELETE_BUTTON     (1 << DELETE_BUTTON)
+#define DISABLE_RESIZE_BUTTON     (1 << RESIZE_BUTTON)
+#define DISABLE_MINIMIZE_BUTTON   (1 << MINIMIZE_BUTTON)
+
 /////////////////////////////////////////////////////////////////////////////
 // Implementation Classes
 /////////////////////////////////////////////////////////////////////////////
@@ -167,6 +176,7 @@ namespace Twm4Nx
       nxgl_coord_t                m_tbLeftX;     /**< Rightmost position of left buttons */
       nxgl_coord_t                m_tbRightX;    /**< Leftmost position of right buttons */
       uint8_t                     m_tbFlags;     /**< Toolbar button customizations */
+      uint8_t                     m_tbDisables;  /**< Toolbar button disables */
 
       // List of all toolbar button images
 
@@ -849,6 +859,20 @@ namespace Twm4Nx
           }
       }
 
+      /**
+       * Enable/disable toolbar buttons.  Buttons may need to be disabled
+       * temporarily while in certain absorbing states (such as resizing the
+       * window).
+       *
+       * @param disables The set of buttons to enable or disble See
+       *   DISABLE_* definitions.
+       */
+
+      inline void disableToolbarButtons(uint8_t disables)
+      {
+        m_tbDisables = disables;
+      }
+
       /**
        * Check for widget-related toolbar events, typically button presses.
        * This is called by event handling logic for events that require

include/graphics/twm4nx/cwindowevent.hxx

@@ -68,6 +68,7 @@ namespace Twm4Nx
     FAR void     *eventObj;     /**< Object reference that accompanies events */
     nxgl_coord_t  minWidth;     /**< The minimum width of the window */
     uint16_t      redrawEvent;  /**< Redraw event ID */
+    uint16_t      resizeEvent;  /**< Resize event ID */
     uint16_t      mouseEvent;   /**< Mouse/touchscreen event ID */
     uint16_t      kbdEvent;     /**< Keyboard event ID */
     uint16_t      closeEvent;   /**< Window close event ID */
@@ -283,6 +284,7 @@ namespace Twm4Nx
       {
         m_appEvents.eventObj    = events.eventObj;    // Event object reference
         m_appEvents.redrawEvent = events.redrawEvent; // Redraw event ID
+        m_appEvents.resizeEvent = events.resizeEvent; // Resize event ID
         m_appEvents.mouseEvent  = events.mouseEvent;  // Mouse/touchscreen event ID
         m_appEvents.kbdEvent    = events.kbdEvent;    // Keyboard event ID
         m_appEvents.closeEvent  = events.closeEvent;  // Window close event ID

include/graphics/twm4nx/nxterm_config.hxx

@@ -66,15 +66,15 @@
  */
 
 #ifndef CONFIG_HAVE_CXX
-#  error "C++ support is required (CONFIG_HAVE_CXX)"
+#  error C++ support is required (CONFIG_HAVE_CXX)
 #endif
 
 #ifndef CONFIG_NX
-#  error "NX support is required (CONFIG_NX)"
+#  error NX support is required (CONFIG_NX)
 #endif
 
 #ifndef CONFIG_NXTERM
-#  warning "NxTerm support is required (CONFIG_NXTERM)"
+#  warning NxTerm support is required (CONFIG_NXTERM)
 #endif
 
 // Keyboard input can come from either /dev/console or via Twm4Nx.  If
@@ -84,9 +84,9 @@
 // /dev/console for keyboard input.
 
 #if !defined(CONFIG_TWM4NX_NOKEYBOARD) && !defined(CONFIG_NXTERM_NXKBDIN)
-#  warning "Nxterm needs CONFIG_NXTERM_NXKBDIN for keyboard input"
+#  warning Nxterm needs CONFIG_NXTERM_NXKBDIN for keyboard input
 #elif defined(CONFIG_TWM4NX_NOKEYBOARD) && defined(CONFIG_NXTERM_NXKBDIN)
-#  warning "Nxterm has no keyboard input.  Undefine CONFIG_NXTERM_NXKBDIN
+#  warning Nxterm has no keyboard input.  Undefine CONFIG_NXTERM_NXKBDIN
 #endif
 
 // NxTerm Window /////////////////////////////////////////////////////////////

include/graphics/twm4nx/twm4nx_events.hxx

@@ -52,7 +52,9 @@
 // Preprocessor Definitions
 /////////////////////////////////////////////////////////////////////////////
 
-#define MAX_EVENT_MSGSIZE sizeof(struct SEventMsg)
+// struct SRedrawEventMsg is the largest message as of this writing
+
+#define MAX_EVENT_MSGSIZE sizeof(struct SRedrawEventMsg)
 #define MAX_EVENT_PAYLOAD (MAX_EVENT_MSGSIZE - sizeof(uint16_t))
 
 /////////////////////////////////////////////////////////////////////////////
@@ -197,12 +199,16 @@ namespace Twm4Nx
 
   struct SEventMsg
   {
+    // Common fields
+
     uint16_t eventID;                   /**< Encoded event ID */
     FAR void *obj;                      /**< Context specific reference */
+    FAR void *handler;                  /**< Context specific handler */
+
+    // Event-specific fields
 
     struct nxgl_point_s pos;            /**< X/Y position */
     uint8_t context;                    /**< Button press context */
-    FAR void *handler;                  /**< Context specific handler */
   };
 
   /**
@@ -211,8 +217,13 @@ namespace Twm4Nx
 
   struct SRedrawEventMsg
   {
+    // Common fields
+
     uint16_t eventID;                   /**< Encoded event ID */
     FAR void *obj;                      /**< Context specific reference */
+    FAR void *handler;                  /**< Context specific handler */
+
+    // Event-specific fields
 
     struct nxgl_rect_s rect;            /**< Region to be redrawn */
     bool more;                          /**< True: More redraw requests will follow */
@@ -225,8 +236,13 @@ namespace Twm4Nx
 
   struct SXyInputEventMsg
   {
+    // Common fields
+
     uint16_t eventID;                   /**< Encoded event ID */
     FAR void *obj;                      /**< Context specific reference */
+    FAR void *handler;                  /**< Context specific handler */
+
+    // Event-specific fields
 
     struct nxgl_point_s pos;            /**< X/Y position */
     uint8_t buttons;                    /**< Bit set of button presses */
@@ -239,8 +255,13 @@ namespace Twm4Nx
 
   struct SNxEventMsg
   {
+    // Common fields
+
     uint16_t eventID;                   /**< Encoded event ID */
     FAR void *obj;                      /**< Context specific reference */
+    FAR void *handler;                  /**< Context specific handler */
+
+    // Event-specific fields
 
     FAR CWindowEvent *instance;         /**< X/Y position */
   };