Extending Data Models

[kmcculler]

Does anyone know how I can extend an existing model (specifically Im trying for DefaultListModel) to accept a boolean status along with the object in the list?
Im used to programming but new to Java so Im probably just overlooking something simple... Thanks Kris McCuller
Programmer Portiva Corp.
kmcculler@portiva.com

 

[OttSens]

Actually the default list model is basically a vector
with additional code that notifies listDataListeners
when changes occur.

I suspect that what you are really after is a custom
rendering. Take a look at

http://developer.java.sun.com/developer/technicalArticles/InnerWorkings/customjlist/

 

[OttSens]

I would also look at the jList.setCellRenderer method and
writting a custom listCellRenderer which uses a checkbox
as a cellRenderComponent. (I suspect this is what you
are after).

http://java.sun.com/j2se/1.4/docs/api/index.html

 

[kmcculler]

Yes that was what I was after and the page you directed to worked rather well.. Thanks alot...
I still have one issue left however..
Now that I have this CheckBoxList built I can't get it to do anything... the checkboxes seem to be disabled (won't check or uncheck after they are initally set my the data) Any ideas how to fix them so they can be changed by the user?? Kris McCuller
Programmer Portiva Corp.
kmcculler@portiva.com

 

[OttSens]

Add a listener to the listitem object and set the
the state in some event code. ActionPerformed perhaps.

class MyCellRenderer extends MyObject
implements ListCellRenderer,ActionListener {
public MyCellRenderer () {
addActionListener(this);
}

bla...
bla...
bla...
public void actionPerformed(
this.checkbox.setSelected(!(this.checkbox.getSelected()));

bla...
bla...

 

[OttSens]

Sorry that's wrong

It should be the object that you are using as the list
object that implements that ActionLister interface
and the addActionListener(this) should be in the
constructor code for that object not the renderer.
Oops!