From: Mikko Rasa <tdb@tdb.fi>
Date: Wed, 31 Aug 2016 08:17:33 +0000 (+0300)
Subject: Refactor the traversal logic out of List::check_view_range
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=db2a069cd5ec4c8809c2ba6ddeec2ddcd32d49ef;p=libs%2Fgltk.git

Refactor the traversal logic out of List::check_view_range

It'll be useful for other things as well.
---

diff --git a/source/list.cpp b/source/list.cpp
index 0f887f3..b971342 100644
--- a/source/list.cpp
+++ b/source/list.cpp
@@ -254,29 +254,39 @@ void List::item_autosize_changed(Item *item)
 	rebuild();
 }
 
-void List::check_view_range()
+unsigned List::last_to_first(unsigned last) const
 {
 	if(!style)
-		return;
+		return last;
 
-	unsigned h = geom.h;
+	unsigned view_h = geom.h;
 	if(const Part *items_part = style->get_part("items"))
 	{
 		const Sides &margin = items_part->get_margin();
-		h -= margin.top+margin.bottom;
+		view_h -= margin.top+margin.bottom;
 	}
 
-	max_scroll = items.size();
-	for(unsigned i=items.size(); i-->0; )
+	unsigned items_h = 0;
+	for(unsigned i=last; i<items.size(); --i)
 	{
-		unsigned ih = items[i]->get_geometry().h;
-		if(ih<=h)
-		{
-			h -= ih;
-			--max_scroll;
-		}
+		items_h += items[i]->get_geometry().h;
+		if(items_h>view_h)
+			return min(i+1, last);
 	}
 
+	return 0;
+}
+
+void List::check_view_range()
+{
+	if(!style)
+		return;
+
+	if(items.empty())
+		max_scroll = 0;
+	else
+		max_scroll = last_to_first(items.size()-1);
+
 	if(first>max_scroll)
 		first = max_scroll;
 
diff --git a/source/list.h b/source/list.h
index 246a729..ad12786 100644
--- a/source/list.h
+++ b/source/list.h
@@ -193,6 +193,7 @@ public:
 
 private:
 	void item_autosize_changed(Item *);
+	unsigned last_to_first(unsigned) const;
 	void check_view_range();
 	void slider_value_changed(double);
 };