RFR: 8323511 Scrollbar Click jumps inconsistent amount of pixels [v2]

[Johan Vos]

On Mon, 15 Jan 2024 08:31:59 GMT, Florian Kirmaier <fkirmaier at openjdk.org> wrote:

>> As seen in the unit test of the PR, when we click on the area above/below the scrollbar the position jumps - but the jump is now not always consistent.
>> In the current version on the last cell - the UI always jumps to the top. In the other cases, the assumed default cell height is used.
>> 
>> With this PR, always the default cell height is used, to determine how much is scrolled.
>> This makes the behavior more consistent.
>> 
>> Especially from the unit-test, it's clear that with this PR the behavior is much more consistent.
>> 
>> This is also related to the following PR: https://github.com/openjdk/jfx/pull/1194
>
> Florian Kirmaier has updated the pull request incrementally with one additional commit since the last revision:
> 
>   JDK-8323511
>   reverted accidental indentation chang

modules/javafx.controls/src/main/java/com/sun/javafx/scene/control/VirtualScrollBar.java line 142:

> 140:                 int index = firstVisibleCell.getIndex();
> 141:                 if (newValue < oldValue) {
> 142:                     index = Math.max(0, index - 1);

Why are the boundary checks (Math.max/min) removed here?

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PR Review Comment: https://git.openjdk.org/jfx/pull/1326#discussion_r1527574978