CCDraw: add signals into hide() methode

alows to use slots


Origin commit data
------------------
Commit: 78259c6ec3
Author: Thilo Graf <dbt@novatux.de>
Date: 2016-10-17 (Mon, 17 Oct 2016)

src/gui/components/cc_draw.cpp

@@ -633,6 +633,7 @@ void CCDraw::paintFbItems(bool do_save_bg)
 
 void CCDraw::hide()
 {
+	OnBeforeHide();
 	//restore saved screen background of item if available
 	for(size_t i =0; i< v_fbdata.size() ;i++) {
 		if (v_fbdata[i].fbdata_type == CC_FBDATA_TYPE_BGSCREEN){
@@ -646,6 +647,7 @@ void CCDraw::hide()
 	}
 	is_painted = false;
 	firstPaint = true;
+	OnAfterHide();
 }
 
 //erase or paint over rendered objects