fix hardware dc visible function.

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@417 bbd45198-f89e-11dd-88c7-29a3b14d5316

rtgui/common/dc_hw.c

@@ -423,9 +423,11 @@ static rt_int32_t rtgui_dc_hw_get_textalign(struct rtgui_dc* self)
 	return dc->owner->gc.textalign;
 }
 
-static rt_bool_t rtgui_dc_hw_get_visible(struct rtgui_dc* dc)
+static rt_bool_t rtgui_dc_hw_get_visible(struct rtgui_dc* self)
 {
-	return RT_TRUE;
+	struct rtgui_dc_hw* dc = (struct rtgui_dc_hw*)self;
+
+	return dc->visible;
 }
 
 static void rtgui_dc_hw_get_rect(struct rtgui_dc* self, rtgui_rect_t* rect)