Bug: JList does not always show the right selection

Question

I have a JList (Navigator model!) on my form which contains the data of a certain view. The view consists of several attributes but the navigator model always only shows the value of one field. The field I have choosen hasn't an unique value but that's no problem for what I want to do with the JList.
When I select another row in the view object useing it's key the row is selected in the view object (which I can check looking at the primary key attribute of the currently selected row), but in the JList sometimes the wrong row is selected. I noticed that if there is another row with the same value for the visible attribute (in my case an attribute called "name") as the row which is selected in the view object sometimes this wrong row is selected in the JList. This occurs if the wrong row with the same visible value (name) is at a higher position in the list. So it looks like the BC4J framework checks what the value is of the visible attribute of the currently selected row in the view object and used this value to select the first row in the JList that has this value. This doesn't necessarily mean it's the right row!!!
E.g.
The initial view object:
PK | Name
1 | test
2 | another test <-- currently selected row
3 | test
The initial JList:
| test |
| another test | <-- currently selected row
| test |
Now I tell the view object that I want to select the row with primary key value "3".
Now my view object looks like this:
PK | Name
1 | test
2 | another test
3 | test <-- currently selected row
But my JList now looks like this:
| test | <-- currently selected row
| another test |
| test |
I hope this is sufficient information to trace the bug, if not feel free to contact me (by sending a response to this message). I'm useing JDeveloper 9.0.3 preview!
Regards,
Peter

Answer 1

Well, how should the list resolve the difference between two "displayed values" that are same?Well, if I select a certain value in the list the connected record in the ViewObject is selected. In other words the JList seems to know enough about the ViewObject to select the correct record (it doesn't select the first record in the ViewObject with the display value!). So if "it" knows how to do it one way, why not the other way?When you select by index then the object corresponding to that index is selected and that means the right row (if you are able to figure out which row by simply having the knowledge of the row index though even though the displayed values are duplicate - but I won't say that's realistic). The other way, it only has a value - string that it has to match with a set of values in the list and that logic has no clues which of the "duplicate" entries would be the right one.
To resolve such conflicts you could add another "displayed attribute" in the list which is going to make the attribute-set unique in the list.I did do that already, but then my list becomes read-only (not selectable) because the attribute I added is a primary key attribute which is a DBSequence field what may not be changed once it has been inserted. The weird thing is, you can't change the value when you select it from the list, so why does it behave like this? (In other words why is a list with a read only display attribute also read only? because selecting something in a navigator list doesn't mean something get's changed in the selected attribute value!). I'd chase this one. This definitely sounds like a bug. Readonly-ness should not be derived from "displayed" attributes but "updateable" attributes.