Let's discuss JDK-8338952

[Andy Goryachev]

Redundant?  Not really: to get the cell value from an item, one needs a pointer to the column.  Since the existing machinery already computes the value, we just pass it along with (what is missing now) a pointer to the item.  I think it's more "convenient", and one could possibly reuse the sort policy for multiple columns.

I don't know whether the column pointer needs to be passed - probably not, but perhaps I don't see scenarios where it might be needed, and it makes the policy more complicated since we now have to have separate policies for TableView and TreeTableView.

Example:

public interface SortPolicy<ITEM,VALUE> {
    public int compare(Tree/TableColumn column, ITEM itemA, VALUE valueA, ITEM itemB, VALUE valueB);
}

What do everyone think?

-andy


From: openjfx-dev <openjfx-dev-retn at openjdk.org> on behalf of PavelTurk <pavelturk2000 at gmail.com>
Date: Monday, May 19, 2025 at 17:21
To: openjfx-dev at openjdk.org <openjfx-dev at openjdk.org>
Subject: Re: Let's discuss JDK-8338952
Andy, I think this is a good solution because it provides everything needed for sorting.
Moreover, it complies with the generics of TableColumn.

For example,

var column = new TableColumn<Person, String>("First Name");
SortPolicy<Person, String> sortPolicy = ...
column.setSortPolicy(sortPolicy);

But don't you think the VALUE parameters are redundant since they can be obtained directly from ITEM?

Best regards, Pavel
On 5/19/25 22:28, Andy Goryachev wrote:
One possible solution would be to deprecate the comparator property (not for removal, keep it for backward compatibility), and add a new property 'sortPolicy' which will use an interface that can be evolved, as opposed to a naive callback.

public interface SortPolicy<ITEM,VALUE> {
    public int compare(ITEM itemA, VALUE valueA, ITEM itemB, VALUE valueB);
}

when set, the new property will override the comparator property.

What do you think?

-andy

From: openjfx-dev <openjfx-dev-retn at openjdk.org><mailto:openjfx-dev-retn at openjdk.org> on behalf of PavelTurk <pavelturk2000 at gmail.com><mailto:pavelturk2000 at gmail.com>
Date: Monday, May 19, 2025 at 00:59
To: openjfx-dev at openjdk.org<mailto:openjfx-dev at openjdk.org> <openjfx-dev at openjdk.org><mailto:openjfx-dev at openjdk.org>
Subject: Let's discuss JDK-8338952
About six months ago, I opened JDK-8338952 with a proposal to add an item comparator to (Tree)TableView.

The reason for this issue is that when using non-standard sorting — for example, when there is a "Total"
row in the table — the standard API becomes insufficient. One has to reinvent the wheel, and the code
quickly becomes extremely messy. Given that tables are one of the core UI components, this becomes
a serious problem.

To address this, I proposed adding an item comparator, which I believe would be very simple to implement.
I suggest we at least discuss this issue so we can start moving toward a solution.

Best regards, Pavel

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