RFR: 8246745: ListCell/Skin: misbehavior on switching skin

[Jeanette Winzenburg]

On Mon, 15 Jun 2020 07:49:24 GMT, Jeanette Winzenburg <fastegal at openjdk.org> wrote:

>> modules/javafx.controls/src/main/java/javafx/scene/control/skin/ListCellSkin.java line 100:
>> 
>>> 99:         double fixedCellSize = getFixedCellSize();
>>> 100:         if (fixedCellSize > 0) {
>>> 101:             return fixedCellSize;
>> 
>> These compute methods get invoked multiple times during each layout pass(10s of times). Fetching the fixed cell size on
>> each call to these methods seems to be repeated and costly operation compared to previous boolean check. I think we
>> should keep the previous way of handling it: registering the change listener to `listView.fixedCellSizeProperty()`.
>
> ehh .. last time I did such micro-optimization was in the 80ies of last century ;)
> 
> Are there any performance measurements anywhere to demonstrate the impact?

a bit less flippant: really interested in the measurements - certainly, they are somewhere but can't find anything. Any
pointer where to look?

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

PR: https://git.openjdk.java.net/jfx/pull/251