java-gnome-developer

[Java-gnome-developer] DataColumns and adding TreeView rows

[Spyros S. <fou...@gm...>]

Well, this may sound a little bit silly, however I have a little problem
when it comes to adding a row. I do not know what to put as DataColumn in
the setValue method. But let's take a look to the following piece of code:

public class Whatever{

TreeView list;

public Whatever(){
initTree();
...
...
fillTree();
}

/*Initialize the tree by creating the columns, but NOT filling in the Data*=
/

private void initTree(){
list =3D (TreeView)glade.getWidget("listTreeView");

DataColumn[] dc =3D new DataColumn[4];
for(int i =3D 0; i < 4; i++)
dc[i] =3D new DataColumnString();

ListStore ls =3D new ListStore(dc);
tv.setModel(ls);

TreeViewColumn col0 =3D new TreeViewColumn();
col0.setTitle("ONE");
CellRendererText render0 =3D new CellRendererText();
col0.setResizable(true);
col0.packStart(render0, false);
col0.addAttributeMapping(render0,
org.gnu.gtk.CellRendererText.Attribute.TEXT , (DataColumnString)dc[0]);

TreeViewColumn col1 =3D new TreeViewColumn();
col1.setTitle("TWO");
CellRendererText render1 =3D new CellRendererText();
col1.setResizable(true);
col1.packStart(render1, false);
col1.addAttributeMapping(render1, CellRendererText.Attribute.TEXT,
(DataColumnString)dc[1]);

TreeViewColumn col2 =3D new TreeViewColumn();
col2.setTitle("THREE");
CellRendererText render2 =3D new CellRendererText();
col2.setResizable(true);
col2.packStart(render2, false);
col2.addAttributeMapping(render2, CellRendererText.Attribute.TEXT,
(DataColumnString)dc[2]);

TreeViewColumn col3 =3D new TreeViewColumn();
col3.setTitle("FOUR");
CellRendererText render3 =3D new CellRendererText();
col3.setResizable(true);
col3.packStart(render3, false);
col3.addAttributeMapping(render3, CellRendererText.Attribute.TEXT,
(DataColumnString)dc[3]);

tv.appendColumn(col0);
tv.appendColumn(col1);
tv.appendColumn(col2);
tv.appendColumn(col3);

/* No further data is provided to the TreeView*/

}
}

private void fillTree(){

ListStore ls =3D (ListStore)(list.getModel());
TreeIter it =3D ls.appendRow();
ls.setValue(it, /*WHAT HERE???*/, "Test");

}
}

Well I was not able to find a way to get the DataColumn from the Model, as =
I
would when calling method

ls.setValue(it, (DataColumnString)dc[0], "A String");

from within the method initTree. I mean, there is no dc to use in method
fillTree(). I've read in the docs that this should be done through the
Renderer, however I wasn't able to find a solution to this either. Is there
a way to retrieve the DataColumn of the specified ListStore?

/**
* Sets a value in the data store. To display the data in the widget, you
* need to associate the datablock with the renderer, using methods of the
* {@link TreeViewColumn}.
* @param iter A valid iterator which specifies the row in which the data
* should be set. Iterators can be gained by using methods such as
* {@link #appendRow()}.
* @param dataBlock The data block to store the value in.
* @param value The value to store. This must be of the same type
* for the column as that set in the constructor to the ListStore.
*/
public void setValue( TreeIter iter, DataColumnString dataBlock, String
value){...}

Thnx everyone that might take a look in advance,
Spyros "Foucault" Stathopoulos

Re: [Java-gnome-developer] DataColumns and adding TreeView rows

[Sami W. <swa...@re...>]

Hi Spyros,

There is a very good tutorial on using TreeView on the java-gnome web page
 
   http://java-gnome.sourceforge.net/cgi-bin/bin/view/Main/TreeViewTutorial

But from your email this is probably the most important part of the 
tutorial for you:

    Rather than creating an array of DataColumns, your code will be far
    easier to write if you create separate variables for each column:

DataColumnBoolean ColIsChecked = new DataColumnBoolean();
DataColumnPixbuf  ColFaceImage = new DataColumnPixbuf(); col3.addAttributeMapping(render3, CellRendererText.Attribute.TEXT, (DataColumnString)dc[3]);
DataColumnString ColName = new DataColumnString();
ListStore ls = new ListStore( new DataColumn[] {ColIsChecked, ColFaceImage, ColName} );
  

Then later you can do this:

...
ls.setValue(it, ColName , "Test");
...
  


>   private void initTree(){
>     list = (TreeView)glade.getWidget("listTreeView");
>        
>       DataColumn[] dc = new DataColumn[4];
>       for(int i = 0; i < 4; i++) col3.addAttributeMapping(render3, 
> CellRendererText.Attribute.TEXT, (DataColumnString)dc[3]);
>           dc[i] = new DataColumnString();
>        
>       ListStore ls = new ListStore(dc);
>       tv.setModel(ls);

This probably a mistake that happened when you were writing the email 
but shouldent it be
list.setModel(ls) ?

>      * Sets a value in the data store. To display the data in the 
> widget, you
>      * need to associate the datablock with the renderer, using 
> methods of the
>      * {@link TreeViewColumn}.

This just means calling addAttributeMaping which you already did here:

     col3.addAttributeMapping(render3, CellRendererText.Attribute.TEXT,
    (DataColumnString)dc[3]);

I hope this helps :).
Good luck,
  
   Sami Wagiaalla

Re: [Java-gnome-developer] DataColumns and adding TreeView rows

[Spyros S. <fou...@gm...>]

Thanks Sami, that was helpful indeed; it makes things much clearer. I' ll
try to adjust it to my code, see how it works and mail back if smth goes
wrong.

This probably a mistake that happened when you were writing the email but
> shouldent it be
> list.setModel(ls) ?
>
> True. I' ve changed a bit the code to make it more "mail- compatible", bu=
t
I've forgotten to change tv to list. Anyway you seem to have gotten the
point!.

I've read the tutorial, but I must have missed a few things. I'm still
trying to find out how the whole java- gnome thing works.

Again... thanks.

Spyros "Foucault" Stathopoulos