added custom render interface for checkboxes

include/gwin/checkbox.h

@@ -104,6 +104,17 @@ void gwinCheckboxDraw(GHandle gh);
  */
 void gwinCheckboxSetEnabled(GHandle gh, bool_t enabled);
 
+/**
+ * @brief	Set the callback routine to perform a custom drawing.
+ *
+ * @param[in] gh		The window handle (must be a checkbox window)
+ * @param[in] fn		The function to use to draw the checkbox
+ * @param[in] param		A parameter to pass to the checkbox drawing function
+ *
+ * @api
+ */
+void gwinCheckboxSetCustom(GHandle gh, GCheckboxDrawFunction fn, void *param);
+
 /**
  * @brief Enable a checkbox
  *

src/gwin/checkbox.c

@@ -122,6 +122,19 @@ GHandle gwinCheckboxCreate(GCheckboxObject *gb, coord_t x, coord_t y, coord_t wi
 	return (GHandle)gb;
 }
 
+void gwinCheckboxSetCustom(GHandle gh, GCheckboxDrawFunction fn, void *param) {
+	#define gcw		((GCheckboxObject *)gh)
+
+	if (gh->type != GW_CHECKBOX)
+		return;
+
+	gcw->fn = fn;
+	gcw->param = param;
+
+	#undef gcw	
+}
+
+
 void gwinCheckboxSetEnabled(GHandle gh, bool_t enabled) {
 	if (gh->type != GW_CHECKBOX)
 		return;
@@ -136,7 +149,7 @@ void gwinCheckboxDraw(GHandle gh) {
 		return;
 
 	#if GDISP_NEED_CLIP
-		gdispSetClip(gh->x, gh->y, gh->width, gh->height);
+		//gdispSetClip(gh->x, gh->y, gh->width, gh->height);
 	#endif
 
 	gcw->fn(gh,