Hack for font background when we cannot read from the LCD; Candidate fix for ILI9325 LCD

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@4763 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog.txt

@@ -144,3 +144,11 @@
   example.
 * NXWidgets::CNxTkWindow:  Back out height adjustment in the getSize()
   method.  The code was correct as it was before.
+* NXWidgets::CButtonArray and NXWidgets::CGraphicsPort:  There is
+  a kludge in there to handle the case where we cannot read the
+  background data because the LCD does not support read operations.
+  In that case, we just use the default background color.  However,
+  that doesn't work either for the case where the background color
+  changes when the widget is selected.  Thenthe background color
+  in the font is wrong.  Fixed in CButtonArrary, but the problem
+  probably exists in other places as well.

TODO.txt

@@ -127,3 +127,18 @@ o Platform specific issues
                The fixed version is available in SVN but won't be in a released
                version until NuttX-6.198 is released.
   Priorioty:   Low, but really annoying.
+
+  Title:       BUGS WHEN CANNOT READ FROM LCD
+  Description: There is a kludge in there to handle the case where we cannot
+               read the background data because the LCD does not support read
+               operations.  You cannot read from the STM3240G-EVAL LCD right
+               now (it might be possible, but I have not figured out how yet).
+
+               In that case, we just use the default background color.  However,
+               that doesn't work either for the case where the background color
+               changes when the widget is selected.  Then the background color
+               in the font is wrong.  There is a hack in in CButtonArrary that
+               fixed this problem, but the problem certainly exists in other
+               places as well and begs for a better solution.
+  Status:      Open
+  Priority:    Medium-Low

libnxwidgets/include/cgraphicsport.hxx

@@ -151,6 +151,36 @@ namespace NXWidgets
 
     const nxgl_coord_t getY(void) const;
 
+    /**
+     * Get the background color that will be used to fill in the spaces
+     * when rendering fonts.  This background color is ONLY used if the
+     * LCD device does not support reading GRAM contents.
+     *
+     * @return.  The current background color being used.
+     */
+
+#ifdef CONFIG_NX_WRITEONLY
+    nxgl_mxpixel_t getBackColor(void) const
+    {
+       return m_backColor;
+    }
+#endif
+
+    /**
+     * Set the background color that will be used to fill in the spaces
+     * when rendering fonts.  This background color is ONLY used if the
+     * LCD device does not support reading GRAM contents.
+     *
+     * @return.  The current background color being used.
+     */
+
+#ifdef CONFIG_NX_WRITEONLY
+    void setBackColor(nxgl_mxpixel_t backColor)
+    {
+       m_backColor = backColor;
+    }
+#endif
+
     /**
      * Draw a pixel into the window.
      *

libnxwidgets/src/cbuttonarray.cxx

@@ -519,9 +519,25 @@ void CButtonArray::drawButton(CGraphicsPort *port, int column, int row, bool use
   pos.x = x + alignX;
   pos.y = y + alignY;
 
-  // And draw the button text
+  // Set the CGraphicsControl background to match the selected background color.
+  // This is only necessary if we cannot read from the LCD.  If we cannot read
+  // from then the font background is set to this background color.
+  // REVISIT:  This begs for a more generalized solution.
+
+#ifdef CONFIG_NX_WRITEONLY
+  nxgl_mxpixel_t saveColor = port->getBackColor();
+  port->setBackColor(backColor);
+#endif
+
+  // And draw the button text.
 
   port->drawText(&pos, &rect, getFont(), *text, 0, text->getLength(), textColor);
+
+  // Restore the default background color
+
+#ifdef CONFIG_NX_WRITEONLY
+  port->setBackColor(saveColor);
+#endif
 }
 
 /**