On Tue, 25 Mar 2025 17:08:02 GMT, Andy Goryachev <ango...@openjdk.org> wrote:
>> This PR will forward more Label calculations to LabeledSkinBase, as they are
>> quite complex, especially when a Graphic is involved which is a full-fledged
>> `Node`. More specifically, this solves issues with TitledPane when the
>> graphic is resizable (ie. an HBox is placed as Graphic in the titled pane's
>> title area). Before, the calculations would only look at the preferred size
>> of the graphic, and use these regardless of available space, even if the
>> maximum size allowed for the graphic to be larger. After this fix, the more
>> extensive LabeledSkinBase calculations are used.
>>
>> This PR also simplifies the layout calculation. Instead of manually
>> calculating where the label should be positioned (according to alignment),
>> this is left to `layoutLabelInArea` which will do this automatically when
>> its provided with the available space for the label instead of the label's
>> width.
>>
>> See the ticket for a sample program; take a look at the graphic-only case
>> where an HBox is used to put a label + gap + button as the graphic of the
>> titled pane.
>
> modules/javafx.controls/src/main/java/javafx/scene/control/skin/TitledPaneSkin.java
> line 160:
>
>> 158: registerChangeListener(titleRegion.alignmentProperty(), e ->
>> pos = titleRegion.getAlignment());
>> 159:
>> 160: // NOTE: Listening to two different alignment properties, and
>> using the last value of either is likely a bug!
>
> I agree: it is definitely a bug. I think we should remove it along with the
> possibility of specifying conflicting alignment via CSS. The control must be
> in control.
Yeah, the reason I was hesitant to change this is that currently you can set
the alignment from CSS in two ways:
.titled-pane {
-fx-alignment: RIGHT;
}
Or:
.titled-pane > .title {
-fx-alignment: RIGHT;
}
Both will work at the moment. I'm not sure which one is more correct.
A titled pane naturally has two major regions; its title area, and its content
area. The top level alignment could apply to either or none in theory. The
top level alignment setting is "inherited" from being a Labeled control, which
only has a single alignment to worry about (this also shows using this kind of
inheritance is just a bad idea). It would have been much more clear to have a
`titleAlignment` and `contentAlignment` property.
At the "top" level there is nothing to align, since a titled pane always fill
its width.
-------------
PR Review Comment: https://git.openjdk.org/jfx/pull/1742#discussion_r2014914945
