Add gwinPrintg() and fix null pointer handling in sprintg()

2 files changed, 56 insertions, 0 deletions

diff --git a/src/gwin/gwin_widget.c b/src/gwin/gwin_widget.c
index 2965e7c6..483a63b3 100644
--- a/src/gwin/gwin_widget.c
+++ b/src/gwin/gwin_widget.c
@@ -530,6 +530,44 @@ void gwinSetText(GHandle gh, const char *text, bool_t useAlloc) {
 	_gwinUpdate(gh);
 }
 
+#if GFX_USE_GFILE && GFILE_NEED_PRINTG && GFILE_NEED_STRINGS
+	#include <stdarg.h>
+
+	void gwinPrintg(GHandle gh, const char * fmt, ...) {
+		char *str;
+		va_list va;
+		int size;
+		
+		if (!(gh->flags & GWIN_FLG_WIDGET))
+			return;
+
+		// Dispose of the old string
+		if ((gh->flags & GWIN_FLG_ALLOCTXT)) {
+			gh->flags &= ~GWIN_FLG_ALLOCTXT;
+			if (gw->text) {
+				gfxFree((void *)gw->text);
+				gw->text = "";
+			}
+		}
+
+		// Alloc the new text
+		va_start (va, fmt);
+
+		size = vsnprintg(0, 0, fmt, va) + 1;		//determine the buffer size required
+
+		if ((str = gfxAlloc(size))) {
+			gh->flags |= GWIN_FLG_ALLOCTXT;
+			vsnprintg(str, size, fmt, va);
+			gw->text = (const char *)str;
+		} else
+			gw->text = "";
+		
+		va_end (va);
+
+		_gwinUpdate(gh);
+	}
+#endif
+
 const char *gwinGetText(GHandle gh) {
 	if (!(gh->flags & GWIN_FLG_WIDGET))
 		return 0;
diff --git a/src/gwin/gwin_widget.h b/src/gwin/gwin_widget.h
index ceba235b..ece98a06 100644
--- a/src/gwin/gwin_widget.h
+++ b/src/gwin/gwin_widget.h
@@ -231,6 +231,24 @@ void gwinSetText(GHandle gh, const char *text, bool_t useAlloc);
  */
 const char *gwinGetText(GHandle gh);
 
+#if (GFX_USE_GFILE && GFILE_NEED_PRINTG && GFILE_NEED_STRINGS) || defined(__DOXYGEN__)
+	/**
+	 * @brief   Set the text of a widget using a printf style format.
+	 * @pre		GFX_USE_GFILE, GFILE_NEED_PRINTG and GFILE_NEED_STRINGS must all be TRUE
+	 *
+	 * @param[in] gh		The widget handle
+	 * @param[in] fmt		The format string using a printf/g syntax. See @p vsnprintg()
+	 * @param[in] ...		The printg paramters.
+	 *
+	 * @note				The widget is automatically redrawn
+	 * @note				Non-widgets will ignore this call.
+	 * @note				The memory for the text is always allocated by this function.
+	 *
+	 * @api
+	 */
+	void gwinPrintg(GHandle gh, const char * fmt,...);
+#endif
+
 /**
  * @brief	Check whether a handles is a widget handle or not
  *