[java-gnome-hackers] big TreeModel API change

[Mark H. <mh...@ti...>]

Hi,
  ListStore and TreeStore (TreeModels) are the model part of the tree
and list widget MVC pattern.

At the moment, they are constructed in the form:
new ListStore( new Type[] {Type.STRING(), Type.INT() ...} );

and used:
listStore.(set|get)Value( iter, 2, 5 );  
  (2 is the dataBlock of the store; 5 is the value)
  (these methods are overloaded for each possible type)

There are two big disadvantages with this:
- It is not easy to keep track of which dataBlock (aka column) relates
to which set of data - methods require an integer argument corresponding
to the order in which the Types were passed to the TreeModel
constructor.
- No type checking is performed. I've found this quite problematic
recently when I had forgotten to call toString() on an object.

I think a good way to solve these problems would be to create new
classes:
Abstract class dataBlock;
dataBlockInt extends dataBlock
dataBlockString
dataBlockObject
dataBlockBoolean

They would then be used in the following way:

private dataBlockString taskName 	= new dataBlockString();
private dataBlockInt 	hours 		= new dataBlockInt();
private dataBlockInt 	remaining 	= new dataBlockInt();
private dataBlockString person 		= new dataBlockString();
...
new ListStore( new dataBlock[] { taskName, hours, remaining, person } );
setValue( iter, taskName, "fix bugs" );
	- type checking would be performed on this. 


I have used the term dataBlock where gtk usually says column. This is
because I was confused when learning about these widgets as you also
need TreeViewColumns, which are used by the views. I would prefer to
keep calling these dataBlocks in the hope that the bindings will be
easier to learn. But I could probably be convinced otherwise...

Any comments?
-- 
  .''`. Mark Howard
 : :' :
 `. `'  http://www.tildemh.com 
   `-   mh...@de... | mh...@ti... | mh...@ca...