From f88706e34dbcc9238e63f52200ff535304c9cbe7 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Fri, 15 Nov 2013 23:23:28 +0200
Subject: [PATCH] Add a list item class to manage multiple columns

---
 source/list.cpp | 66 +++++++++++++++++++++++++++++++++++++++++++++++++
 source/list.h   | 10 ++++++++
 2 files changed, 76 insertions(+)

diff --git a/source/list.cpp b/source/list.cpp
index a4550c4..7be9363 100644
--- a/source/list.cpp
+++ b/source/list.cpp
@@ -374,6 +374,72 @@ void List::Item::render_special(const Part &part, GL::Renderer &renderer) const
 }
 
 
+void List::MultiColumnItem::check_widths(vector<unsigned> &widths) const
+{
+	if(widths.size()<children.size())
+		widths.resize(children.size(), 0);
+
+	unsigned n = 0;
+	for(list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i, ++n)
+	{
+		Geometry cgeom;
+		(*i)->widget->autosize(cgeom);
+		// TODO invent a better way to specify spacings
+		widths[n] = max(widths[n], cgeom.w+8);
+	}
+}
+
+void List::MultiColumnItem::set_widths(const vector<unsigned> &widths)
+{
+	if(!style)
+		return;
+
+	const Part *part = style->get_part("children");
+	if(!part)
+		return;
+
+	const Sides &margin = part->get_margin();
+	int x = margin.left;
+	unsigned n = 0;
+	for(list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i, ++n)
+	{
+		(*i)->widget->set_position(x, margin.bottom);
+		x += widths[n];
+	}
+}
+
+void List::MultiColumnItem::on_style_change()
+{
+	if(!style)
+		return;
+
+	for(std::list<Child *>::const_iterator i=children.begin(); i!=children.end(); ++i)
+		(*i)->widget->autosize();
+
+	vector<unsigned> widths;
+	List *list = static_cast<List *>(parent);
+	for(vector<Item *>::const_iterator i=list->items.begin(); i!=list->items.end(); ++i)
+		if(*i!=this)
+			if(MultiColumnItem *mci = dynamic_cast<MultiColumnItem *>(*i))
+				mci->check_widths(widths);
+
+	vector<unsigned> self_widths(widths);
+	check_widths(self_widths);
+	bool update_all = false;
+	for(unsigned i=0; (!update_all && i<widths.size() && i<self_widths.size()); ++i)
+		update_all = self_widths[i]>widths[i];
+
+	if(update_all)
+	{
+		for(vector<Item *>::const_iterator i=list->items.begin(); i!=list->items.end(); ++i)
+			if(MultiColumnItem *mci = dynamic_cast<MultiColumnItem *>(*i))
+				mci->set_widths(self_widths);
+	}
+	else
+		set_widths(widths);
+}
+
+
 List::BasicItem::BasicItem(const string &text):
 	label(text)
 {
diff --git a/source/list.h b/source/list.h
index 0761caf..05ba852 100644
--- a/source/list.h
+++ b/source/list.h
@@ -68,6 +68,16 @@ public:
 		virtual void render_special(const Part &, GL::Renderer &) const;
 	};
 
+	class MultiColumnItem: public Item
+	{
+	protected:
+		virtual void check_widths(std::vector<unsigned> &) const;
+		virtual void set_widths(const std::vector<unsigned> &);
+
+	private:
+		virtual void on_style_change();
+	};
+
 private:
 	class BasicItem: public Item
 	{
-- 
2.45.2