Add support for backspace and a cursor to NxConsole

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4546 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/ChangeLog

@@ -2612,3 +2612,6 @@
 	  VT100 escape sequence definitions.
 	* graphics/nxconsole/nxcon_vt100.c:  Add add framework to support VT100 escape
 	  sequences in NxConsole.
+	* fs/fs_read.c:  Fix read() return value for attempt to read from write-only
+	  file or device.  Was returning EBADF, should return EACCES.
+	* graphics/nxconsole.c:  NxConsole now supports backspace and a cursor.

nuttx/Documentation/NXGraphicsSubsystem.html

@@ -3360,6 +3360,8 @@ int nxf_convert_32bpp(FAR uint32_t *dest, uint16_t height,
       <dd>Currently, NxConsole supports only a single pixel depth.
       This configuration setting must be provided to support that single pixel depth.
       Default: The smallest enabled pixel depth. (see <code>CONFIG_NX_DISABLE_*BPP</code>)
+    <dt><code>CONFIG_NXCONSOLE_CURSORCHAR</code>:
+      <dd>The bitmap code to use as the cursor.  Default '_'
     <dt><code>CONFIG_NXCONSOLE_NOGETRUN</code>:
       <dd>NxConsole needs to know if it can read from the LCD or not.
       If reading from the LCD is supported, then NxConsole can do more efficient scrolling.

nuttx/graphics/README.txt

@@ -328,6 +328,8 @@ CONFIG_NXCONSOLE_BPP
   Currently, NxConsole supports only a single pixel depth. This
   configuration setting must be provided to support that single pixel depth.
   Default: The smallest enabled pixel depth. (see CONFIG_NX_DISABLE_*BPP)
+CONFIG_NXCONSOLE_CURSORCHAR
+  The bitmap code to use as the cursor.  Default '_'
 CONFIG_NXCONSOLE_NOGETRUN
   NxConsole needs to know if it can read from the LCD or not. If reading
   from the LCD is supported, then NxConsole can do more efficient

nuttx/graphics/nxconsole/nxcon_driver.c

@@ -142,6 +142,10 @@ static ssize_t nxcon_write(FAR struct file *filep, FAR const char *buffer,
       return ret;
     }
 
+  /* Hide the cursor while we update the display */
+
+  nxcon_hidecursor(priv);
+
   /* Loop writing each character to the display */
 
   for (remaining = (ssize_t)buflen; remaining > 0; remaining--)
@@ -217,6 +221,9 @@ static ssize_t nxcon_write(FAR struct file *filep, FAR const char *buffer,
       while (state == VT100_ABORT);
     }
 
+  /* Show the cursor at its new position */
+
+  nxcon_showcursor(priv);
   nxcon_sempost(priv);
   return (ssize_t)buflen;
 }

nuttx/graphics/nxconsole/nxcon_font.c

@@ -41,6 +41,7 @@
 
 #include <string.h>
 #include <assert.h>
+#include <errno.h>
 #include <debug.h>
 
 #include <nuttx/kmalloc.h>
@@ -441,6 +442,88 @@ nxcon_addchar(NXHANDLE hfont, FAR struct nxcon_state_s *priv, uint8_t ch)
   return bm;
 }
 
+/****************************************************************************
+ * Name: nxcon_hidechar
+ *
+ * Description:
+ *   Erase a character from the window.
+ *
+ ****************************************************************************/
+int nxcon_hidechar(FAR struct nxcon_state_s *priv,
+                   FAR const struct nxcon_bitmap_s *bm)
+{
+  struct nxgl_rect_s bounds;
+  struct nxgl_size_s fsize;
+  int ret;
+
+  /* Get the size of the font glyph.  If nxcon_fontsize, then the
+   * character will have been rendered as a space, and no display
+   * modification is required (not an error).
+   */
+
+  ret = nxcon_fontsize(priv->font, bm->code, &fsize);
+  if (ret < 0)
+    {
+      /* It was rendered as a space. */
+
+      return OK;
+    }
+
+  /* Construct a bounding box for the glyph */
+
+  bounds.pt1.x = bm->pos.x;
+  bounds.pt1.y = bm->pos.y;
+  bounds.pt2.x = bm->pos.x + fsize.w - 1;
+  bounds.pt2.y = bm->pos.y + fsize.h - 1;
+
+  /* Fill the bitmap region with the background color, erasing the
+   * character from the display.  NOTE:  This region might actually
+   * be obscured... NX will handle that case.
+   */
+
+  return priv->ops->fill(priv, &bounds, priv->wndo.wcolor);
+}
+
+/****************************************************************************
+ * Name: nxcon_backspace
+ *
+ * Description:
+ *   Remove the last character from the window.
+ *
+ ****************************************************************************/
+
+int nxcon_backspace(FAR struct nxcon_state_s *priv)
+{
+  FAR struct nxcon_bitmap_s *bm;
+  int ndx;
+  int ret = -ENOENT;
+
+  /* Is there a character on the display? */
+
+  if (priv->nchars > 0)
+    {
+      /* Yes.. Get the index to the last bitmap on the display */
+
+      ndx = priv->nchars - 1;
+      bm  = &priv->bm[ndx];
+
+      /* Erase the character from the display */
+
+      ret = nxcon_hidechar(priv, bm);
+
+      /* The current position to the location where the last character was */
+    
+      priv->fpos.x = bm->pos.x;
+      priv->fpos.y = bm->pos.y;
+
+      /* Decrement nchars to discard this character */
+
+      priv->nchars = ndx;
+    }
+
+  return ret;
+}
+
 /****************************************************************************
  * Name: nxcon_home
  *

nuttx/graphics/nxconsole/nxcon_internal.h

@@ -162,6 +162,7 @@ struct nxcon_state_s
 
   /* Font cache data storage */
 
+  struct nxcon_bitmap_s cursor;
   struct nxcon_bitmap_s bm[CONFIG_NXCONSOLE_MXCHARS];
 
   /* Glyph cache data storage */
@@ -204,12 +205,18 @@ enum nxcon_vt100state_e nxcon_vt100(FAR struct nxcon_state_s *priv, char ch);
 
 void nxcon_home(FAR struct nxcon_state_s *priv);
 void nxcon_newline(FAR struct nxcon_state_s *priv);
-void nxcon_putc(FAR struct nxcon_state_s *priv, uint8_t ch);
 FAR const struct nxcon_bitmap_s *nxcon_addchar(NXHANDLE hfont,
     FAR struct nxcon_state_s *priv, uint8_t ch);
+int nxcon_hidechar(FAR struct nxcon_state_s *priv,
+    FAR const struct nxcon_bitmap_s *bm);
+int nxcon_backspace(FAR struct nxcon_state_s *priv);
 void nxcon_fillchar(FAR struct nxcon_state_s *priv,
     FAR const struct nxgl_rect_s *rect, FAR const struct nxcon_bitmap_s *bm);
 
+void nxcon_putc(FAR struct nxcon_state_s *priv, uint8_t ch);
+void nxcon_showcursor(FAR struct nxcon_state_s *priv);
+void nxcon_hidecursor(FAR struct nxcon_state_s *priv);
+
 /* Scrolling support */
 
 void nxcon_scroll(FAR struct nxcon_state_s *priv, int scrollheight);

nuttx/graphics/nxconsole/nxcon_putc.c

@@ -39,6 +39,8 @@
 
 #include <nuttx/config.h>
 
+#include <nuttx/ascii.h>
+
 #include "nxcon_internal.h"
 
 /****************************************************************************
@@ -85,6 +87,14 @@ void nxcon_putc(FAR struct nxcon_state_s *priv, uint8_t ch)
       return;
     }
 
+  /* Handle backspace (treating both BS and DEL as backspace) */
+
+  if (ch == ASCII_BS || ch == ASCII_DEL)
+    {
+      nxcon_backspace(priv);
+      return;
+    }
+
   /* Will another character fit on this line? */
 
   if (priv->fpos.x + priv->fwidth > priv->wndo.wsize.w)
@@ -138,3 +148,56 @@ void nxcon_putc(FAR struct nxcon_state_s *priv, uint8_t ch)
       nxcon_fillchar(priv, NULL, bm);
     }
 }
+
+/****************************************************************************
+ * Name: nxcon_showcursor
+ *
+ * Description:
+ *   Render the cursor character at the current display position.
+ *
+ ****************************************************************************/
+
+void nxcon_showcursor(FAR struct nxcon_state_s *priv)
+{
+  int lineheight;
+
+  /* Will another character fit on this line? */
+
+  if (priv->fpos.x + priv->fwidth > priv->wndo.wsize.w)
+    {
+#ifndef CONFIG_NXCONSOLE_NOWRAP
+      /* No.. move to the next line */
+
+      nxcon_newline(priv);
+#else
+      return;
+#endif
+    }
+
+  /* Check if we need to scroll up */
+
+  lineheight = (priv->fheight + CONFIG_NXCONSOLE_LINESEPARATION);
+  while (priv->fpos.y >= priv->wndo.wsize.h - lineheight)
+    {
+      nxcon_scroll(priv, lineheight);
+    }
+
+  /* Render the cursor glyph onto the display. */
+
+  priv->cursor.pos.x = priv->fpos.x;
+  priv->cursor.pos.y = priv->fpos.y;
+  nxcon_fillchar(priv, NULL, &priv->cursor);
+}
+
+/****************************************************************************
+ * Name: nxcon_hidecursor
+ *
+ * Description:
+ *   Render the cursor cursor character from the display.
+ *
+ ****************************************************************************/
+
+void nxcon_hidecursor(FAR struct nxcon_state_s *priv)
+{
+  (void)nxcon_hidechar(priv, &priv->cursor);
+}

nuttx/graphics/nxconsole/nxcon_register.c

@@ -132,6 +132,11 @@ FAR struct nxcon_state_s *
 
   nxcon_home(priv);
 
+  /* Show the cursor */
+
+  priv->cursor.code = CONFIG_NXCONSOLE_CURSORCHAR;
+  nxcon_showcursor(priv);
+
   /* Register the driver */
 
   snprintf(devname, NX_DEVNAME_SIZE, NX_DEVNAME_FORMAT, minor);

nuttx/include/nuttx/nx/nxconsole.h

@@ -69,6 +69,8 @@
  *   Currently, NxConsole supports only a single pixel depth. This
  *   configuration setting must be provided to support that single pixel depth.
  *   Default: The smallest enabled pixel depth. (see CONFIG_NX_DISABLE_*BPP)
+ * CONFIG_NXCONSOLE_CURSORCHAR
+ *   The bitmap code to use as the cursor.  Default '_'
  * CONFIG_NXCONSOLE_NOGETRUN
  *   NxConsole needs to know if it can read from the LCD or not. If reading
  *   from the LCD is supported, then NxConsole can do more efficient
@@ -95,6 +97,12 @@
  *   that the text is simply truncated until a new line is  encountered.
  */
 
+/* Cursor character */
+
+#ifndef CONFIG_NXCONSOLE_CURSORCHAR
+#  define CONFIG_NXCONSOLE_CURSORCHAR '_'
+#endif
+
 /* The maximum number of characters that can be remembered */
 
 #ifndef CONFIG_NXCONSOLE_MXCHARS