On Thu, 3 Aug 2023 11:41:30 GMT, Kevin Rushforth <k...@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. > > 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? Yes indeed, leftover from testing. ------------- PR Review Comment: https://git.openjdk.org/jfx/pull/1194#discussion_r1283094443
