Another JTable Navigation Question

[Avi Abrami]

Hi again,
If a column in a "JTable" has zero width, it is not visible,
as demonstrated in below code snippet:

javax.swing.JFrame frame = new javax.swing.JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
javax.swing.JTable table = new javax.swing.JTable(25, 8);
table.setAutoResizeMode(javax.swing.JTable.AUTO_RESIZE_OFF);
javax.swing.table.TableColumnModel tcm = table.getColumnModel();
javax.swing.table.TableColumn tc = tcm.getColumn(4);
tc.setMaxWidth(0);
tc.setMinWidth(0);
tc.setPreferredWidth(0);
javax.swing.JScrollPane tableScrollPane = new javax.swing.JScrollPane(table);
frame.add(tableScrollPane, java.awt.BorderLayout.CENTER);
frame.pack();
frame.setVisible(true);

However, when using the keyboard navigation keys, like TAB, to navigate
the "JTable" cells, the invisible cell still receives the focus.
When an invisible cell has the focus, there is no visual indication of this
and the user has no idea why suddenly no cell of the table is selected.
My question is: What is a recommended way of ensuring that invisible columns
in a "JTable" do not receive input focus?

Thanks,
Avi.
[ November 04, 2008: Message edited by: Avi Abrami ]

[Maneesh Godbole]

Originally posted by Avi Abrami:

My question is: What is a recommended way of ensuring that invisible columns
in a "JTable" do not receive input focus?
[ November 04, 2008: Message edited by: Avi Abrami ]

Remove the column instead of hiding it by making it 0 width.
In case you do not know how to remove columns, search the forums. There are quite a few recent threads which will tell you how to do it.

[Avi Abrami]

Maneesh,
You said:

Remove the column instead of hiding it by making it 0 width.

Oops, forgot to mention the obvious (to me, anyway :-)
This is not my application, I am just maintaining it.
At this stage, the invisible columns are required and used by the application so removing them is not currently an option.
Hence the question ;-)
Thanks anyway for your prompt and nonetheless helpful reply.

Cheers,
Avi.

[Maneesh Godbole]

You can try tracking the focus.
If your "undesired" column gains focus, you can shift the focus on the previous/next column.

[Avi Abrami]

Maneesh,
Thanks again for your help.
Please pardon my ignorance, but how does one "track the focus"?
I assume I need to add a focus listener, or is there another way?
Method "addFocusListener" is defined in class java.awt.Component.
So which "Component" should I add the focus listener to, since "JTable" is a complex GUI control that involves many different "Component"s.

Also, there appears to be several ways to "shift the focus".
I am hoping that someone reading this will be able to recommend a preferred way of doing this.

Thanks,
Avi.

[Maneesh Godbole]

Are you aware of the "Renderer" concept? Usually you define a Renderer for a Column.
The getTableCellRendererComponent() method returns a Component.
So one of the possible ways is to add a focus listener to the renderer.