RFR: 8218826: TableRowSkinBase: horizontal layout broken if row has padding

[Marius Hanl]

On Tue, 24 May 2022 21:25:23 GMT, Marius Hanl <mhanl at openjdk.org> wrote:

> This PR fixes a problem, where the layout is broken when a `(Tree)TableRow` has padding.
> As also mentioned in the ticket, the `layoutChildren` method in `TableRowSkinBase` is implemented wrong.
> 
> The `layoutChildren` method is responsible for layouting all the `(Tree)TableCells`. 
> When the row has padding, it is subtracted on every `(Tree)TableCell` - which is wrong.
> 
> Instead the `x` and `y` from `layoutChildren` should be used. (E.g. if `x` is 10, then only the first cell should start at 10 and the other cells follow as usual)
> Also the `compute...` methods needs to add the padding as well.
> 
> **Example:**
> _Row padding left right 0:_ 
> [Cell1][Cell2][Cell3]
> _Row padding left right 10:_ 
> [    10    ][Cell1][Cell2][Cell3][    10    ]
> _Same for top bottom._
> 
> When a `fixedCellSize` is set, the padding is currently ignored (also after this PR).
> Therefore, `y` in the `layoutChildren` method is set to 0 for `fixedCellSize`.
> 
> This may can be discussed in the mailing list (Could be a follow up). To support padding also when a `fixedCellSize` is set, the `compute...` methods needs to also add the padding when a `fixedCellSize` is set (in the `if` clauses) and the `VirtualFlow` needs to add the padding to every row instead of using the `fixedCellSize` directly.

modules/javafx.controls/src/test/java/test/javafx/scene/control/skin/TableRowSkinTest.java line 255:

> 253:     private void removedColumnsShouldRemoveCorrespondingCellsInRowImpl() {
> 254:         // Remove the last 2 columns.
> 255:         tableView.getColumns().remove(tableView.getColumns().size() - 2, tableView.getColumns().size());

Note: I added this test in PR: https://github.com/openjdk/jfx/pull/444. While testing this PR I found out that this removes just one column, therefore I fixed it right away.

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PR: https://git.openjdk.java.net/jfx/pull/800