[Gtk-sharp-list] Treeview question (controlling the model using a TreeModel)

[Milton Pividori]

Here is an example. I think I understood your problem:

------
using System;
using Gtk;

public partial class MainWindow: Gtk.Window
{	
	public MainWindow (): base (Gtk.WindowType.Toplevel)
	{
		Build ();
 
		Gtk.TreeViewColumn artistColumn = new Gtk.TreeViewColumn ();
		artistColumn.Title = "Artist";
 
		Gtk.CellRendererText artistNameCell = new Gtk.CellRendererText ();
		
		artistColumn.PackStart (artistNameCell, true);
 
		Gtk.TreeViewColumn songColumn = new Gtk.TreeViewColumn ();
		songColumn.Title = "Song Title";
 
		Gtk.CellRendererText songTitleCell = new Gtk.CellRendererText ();
		songColumn.PackStart (songTitleCell, true);
 
		tree.AppendColumn (artistColumn);
		tree.AppendColumn (songColumn);
 
		artistColumn.SetCellDataFunc(artistNameCell,
		                             new TreeCellDataFunc(this.RenderArtistName));
		songColumn.SetCellDataFunc(songTitleCell,
		                           new TreeCellDataFunc(this.RenderSongTitle));
		
		/* I save the song and genre */
		Gtk.TreeStore musicListStore = new Gtk.TreeStore (typeof (Song),
		                                                  typeof(string));
		
		Gtk.TreeIter iter = musicListStore.AppendValues(null, "Dance");
		musicListStore.AppendValues (iter, new Song("Fannypack",
		                                            "Nu Nu (Yeah Yeah) (double j and haze radio edit)"));
 
		iter = musicListStore.AppendValues (null, "Hip-hop");
		musicListStore.AppendValues (iter,
		                             new Song("Nelly", "Country Grammer"));
 
		tree.Model = musicListStore;
	}
	
	private void RenderArtistName (Gtk.TreeViewColumn column,
	                               Gtk.CellRenderer cell, Gtk.TreeModel model,
	                               Gtk.TreeIter iter)
	{
		Song song = model.GetValue (iter, 0) as Song;
		
		/* If song is null, then this is the parent iter */
		if (song == null) {
			string s = model.GetValue(iter, 1).ToString();
			(cell as Gtk.CellRendererText).Text = s;
		}
		else
			(cell as Gtk.CellRendererText).Text = song.Artist;
	}
	
	private void RenderSongTitle (Gtk.TreeViewColumn column,
	                              Gtk.CellRenderer cell, Gtk.TreeModel model,
	                              Gtk.TreeIter iter)
	{
		Song song = model.GetValue (iter, 0) as Song;
		
		if (song == null)
			(cell as Gtk.CellRendererText).Text = "";
		else
			(cell as Gtk.CellRendererText).Text = song.Title;
	}
	
	protected void OnDeleteEvent (object sender, DeleteEventArgs a)
	{
		Application.Quit ();
		a.RetVal = true;
	}
}

public class Song
{
	public Song (string artist, string title)
	{
		this.Artist = artist;
		this.Title = title;
	}
 
	public string Artist;
	public string Title;
}
------

Is this what you want to do?


On Wed, 2008-01-02 at 16:56 +0000, Paul Bourke wrote:
> I pasted the code badly.. maybe I can simplify my question a little as
> would really like to get this working:
> Basically if you check out the piece of the tutorial here:
> http://www.mono-project.com/GtkSharp_TreeView_Tutorial#Controlling_how_the_model_is_used
>  it describes how to set up a TreeView so that it is bound to an
> object containing your data.  When the data in your object changes, so
> does the TreeView thus allowing you to update the data easily.
> My problem is that the example uses a ListModel rather than a
> TreeModel as in the previous section
> (http://www.mono-project.com/GtkSharp_TreeView_Tutorial#Your_first_TreeView).
> If anyone has any examples of how to do this above using a TreeModel I
> would greatly appreciate it.
> 
> On 31/12/2007, Michael Hutchinson <m.j.hutchinson at gmail.com> wrote:
> > On Dec 30, 2007 6:01 PM, Paul Bourke <pauldbourke at gmail.com> wrote:
> > ...
> > > System.InvalidCastException: Cannot cast from source type to destination type.
> > >   at GRapid.MainWindow.RenderURLColumn (Gtk.TreeViewColumn column,
> > ...
> > > TreeStore myTreeStore = new TreeStore (typeof(string), typeof (MyClass));
> > ...
> > The two store columns have type string and MyClass,
> >
> > >     DownloadItem d = (DownloadItem) model.GetValue (iter, 0);
> >
> > but you're trying to cast the string to a DownloadItem.
> >
> > --
> > Michael Hutchinson
> > http://mjhutchinson.com
> >
> _______________________________________________
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-- 
Milton Pividori
Blog: http://www.miltonpividori.com.ar
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