On Wed, 2 Aug 2023 22:21:20 GMT, Marius Hanl <mh...@openjdk.org> wrote:
> An IOOBE was thrown when scrolling up via the trough (-> > `VirtualScrollBar#adjustValue`). > This happened only when it has bigger cells than the viewport. > If the the uppermost cell with the index 0 is only visible (although not > completely scrolled to the top) and then an attempt is made to scroll up > again, the `VirtualFlow` will try to scroll to the next cell, subtracting > index 0 by 1, resulting in -1 -> IOOBE. > > The code now guards against any under or overflow. > > This is technically a regression from > https://bugs.openjdk.org/browse/JDK-8173321 > > Note: While testing with very big cells, I found out that scrolling via the > trough may not work after the first time. > This is because the `VirtualFlow` still creates 2 cells, although only one > can be visible at a time (and `VirtualScrollBar` does this check, which will > never be true then: `firstVisibleCell == lastVisibleCell`). This is unrelated > to this fix. I can create a ticket when I have more information. I'll let others who are more familiar with VirtualFlow formally review it, but I left a comment on the fix and test. modules/javafx.controls/src/main/java/com/sun/javafx/scene/control/VirtualScrollBar.java line 144: > 142: index = Math.max(0, index - 1); > 143: } else { > 144: index = Math.max(flow.getCellCount(), index + 1); Shouldn't this be Math.min? modules/javafx.controls/src/test/java/test/javafx/scene/control/skin/VirtualFlowTest.java line 37: > 35: import static org.junit.Assert.assertTrue; > 36: import static org.junit.Assert.fail; > 37: import static org.junit.jupiter.api.Assertions.assertDoesNotThrow; We do not want to mix JUnit 4 and JUnit 5 calls in the same test class. Since converting this class to use JUnit 5 would be out of scope for a bug fix such as this, please rewrite it using JUnit 4 API calls only (which probably means a try/catch with a "fail" if you don't get the expected exception. ------------- PR Review: https://git.openjdk.org/jfx/pull/1194#pullrequestreview-1560899072 PR Review Comment: https://git.openjdk.org/jfx/pull/1194#discussion_r1283076891 PR Review Comment: https://git.openjdk.org/jfx/pull/1194#discussion_r1283074296
