GtkSharp/doc/en/Gtk/TreeIterCompareFunc.xml

<Type Name="TreeIterCompareFunc" FullName="Gtk.TreeIterCompareFunc">
  <TypeSignature Language="C#" Maintainer="auto" Value="public delegate int TreeIterCompareFunc(TreeModel model, TreeIter a, TreeIter b);" />
  <AssemblyInfo>
    <AssemblyName>gtk-sharp</AssemblyName>
    <AssemblyVersion>2.12.0.0</AssemblyVersion>
  </AssemblyInfo>
  <ThreadSafetyStatement>Gtk# is thread aware, but not thread safe; See the <link location="node:gtk-sharp/programming/threads">Gtk# Thread Programming</link> for details.</ThreadSafetyStatement>
  <Docs>
    <param name="model">To be added.</param>
    <param name="a">To be added.</param>
    <param name="b">To be added.</param>
    <summary>Delegate function to specify the shape of comparison functions for tree iterators.</summary>
    <remarks>Functions with this call syntax are usually used for comparison between two tree iterators as part of a sort.


<example><code lang="C#">
using System;
using Gtk;

public class SortableTreeView : TreeView	{

	TreeStore ts;
	TreeIter iter;
	TreeViewColumn col0;
	TreeViewColumn col1;

	public SortableTreeView	()	{
		Type[] col_types = {typeof(string), typeof(string)};

		ts = new TreeStore (col_types);
		ts.SetSortFunc (0, col0_compare, IntPtr.Zero, null); // use col0_compare to sort

		iter = new TreeIter ();

		AddRow ("1,1", "1,2");
		AddRow ("2,1", "2,2");
		
		
		this.Model = ts;
		this.HeadersClickable = true;
		this.HeadersVisible = true;

		col0 = new TreeViewColumn ();
		col0.Clickable = true;
		col0.Title = "Column 1";
		CellRendererText col0_renderer = new CellRendererText ();
		col0.PackStart (col0_renderer, true);
		col0.AddAttribute (col0_renderer, "text", 0);
		col0.Clicked += new EventHandler (col0_clicked);
		this.AppendColumn (col0);

		col1 = new TreeViewColumn ();
		col1.Title = "Column 2";
		CellRendererText col1_renderer = new CellRendererText ();
		col1.PackStart (col1_renderer, true);
		col1.AddAttribute (col1_renderer, "text", 1);
		this.AppendColumn (col1);
	}

	public void AddRow (string val1, string val2)	{
		ts.Append (out iter);
		ts.SetValue (iter, 0, val1);
		ts.SetValue (iter, 1, val2);
	}

	public int col0_compare (TreeModel model, TreeIter tia, TreeIter tib)	{
		return String.Compare ((string) model.GetValue (tia, 0),
				(string) model.GetValue (tib, 0));
	}

	private void col0_clicked (object o, EventArgs args)	{
		col0.SortOrder = SetSortOrder (col0); // set order asc or desc
		col0.SortIndicator = true; // turn on sort indicator
		ts.SetSortColumnId (0, col0.SortOrder);
	}

	public SortType SetSortOrder (TreeViewColumn col)	{
		if (col.SortIndicator)  {
			if (col.SortOrder == SortType.Ascending)
				return SortType.Descending;
			else return SortType.Ascending;
		}
		else return SortType.Ascending;
	}

	public static void Main ()	{
		Application.Init ();

		Window win = new Window ("TreeIterCompareFunc Example");
		win.DeleteEvent += new DeleteEventHandler (delete_event);
		win.SetDefaultSize (400, 250);

		ScrolledWindow sw = new ScrolledWindow ();
		win.Add (sw);

		SortableTreeView stv = new SortableTreeView ();
		sw.Add (stv);

		win.ShowAll ();
		Application.Run ();
	}

	private static void delete_event (object o, DeleteEventArgs args)	{
		Application.Quit ();
	}
		
}

  </code></example></remarks>
    <returns>To be added.</returns>
  </Docs>
  <Base>
    <BaseTypeName>System.Delegate</BaseTypeName>
  </Base>
  <Members />
  <Parameters>
    <Parameter Name="model" Type="Gtk.TreeModel" />
    <Parameter Name="a" Type="Gtk.TreeIter" />
    <Parameter Name="b" Type="Gtk.TreeIter" />
  </Parameters>
  <ReturnValue>
    <ReturnType>System.Int32</ReturnType>
  </ReturnValue>
</Type>