RFR: 8291625: DialogPane without header nor headerText nor graphic node adds padding to the left of the content pane

[Ajit Ghaisas]

On Tue, 2 Aug 2022 10:45:54 GMT, Jose Pereda <jpereda at openjdk.org> wrote:

> This PR fixes an issue when there is a DialogPane that has no header and no graphic is set, by adding the `graphic-container` styleclass only when there is a non-null graphic applied, preventing the padding that otherwise the graphic container will keep.
> 
> Two tests have been added, to verify that the padding is 0 when there is no graphic (this test fails without this PR) and to verify that the padding is correct when there is a graphic to the left of the content area.
> 
> As part of this PR or as possible follow-up, it could be also discussed that the right/bottom padding of the graphic container shouldn't be 0 when there is no header and the graphic is laid out to the left of the content area.

Fix looks good to me.

-------------

Marked as reviewed by aghaisas (Reviewer).

PR: https://git.openjdk.org/jfx/pull/859