> But left-to-right is a scroll to up, and down-to-up is a scroll to down. So > you scroll in both direction at the same time.
Whoa, great catch! That's the problem! This is definitively not the right behavior on trackpads; often the user will not scroll exactly horizontally or exactly vertically. And it interacts very badly with the momentum feature of the trackpad; see for instance the video at 1:13, where the viewport is jittering up and down _after_ my fingers have left the trackpad. The "left-to-right is scroll up" feature is not how native apps work on MacOS, so my guess would be it could simply be disabled on MacOS. Note also that when scrolling with the trackpad in native MacOS apps, the OS makes a decision as to whether the scroll is vertical or horizontal, and then scrolls in that direction only. The cut-off is 45 degrees, giving the user plenty of wiggle room. You can never scroll truly diagonally except by zig-zaging. -- Eirik On 1/19/16, 11:50 AM, "Sergey Bylokhov" <sergey.bylok...@oracle.com<mailto:sergey.bylok...@oracle.com>> wrote: I am not sure that this is regression or a bug. In your case you scroll from left-down to right-up. But left-to-right is a scroll to up, and down-to-up is a scroll to down. So you scroll in both direction at the same time. On 19/01/16 19:18, Eirik Bakke wrote: Hi, macos-port-dev. Here's another bug report for Swing on Aqua/MacOS. In recent Java versions (6-12 months, not sure), trackpad scrolling in any JScrollPane has become extremely jittery, as demonstrated in the following video: https://vimeo.com/151843642 The source code for the example app used can be found here: https://gist.github.com/eirikbakke/09a090ab8052d38c8c87 Note that the "implements Scrollable" business is not necessary to trigger the bug, I just did it to set the getScrollableBlockIncrement to something higher than 1 so that you'd see the jitter clearly on a video. This happens in any app that uses a JScrollPane, including the NetBeans IDE's code editor and other scrollable panels, as well as in trivial apps like the linked example. The bug occurs consistently, with or without external monitors attached, at any resolution, and with or without simulated retina mode enabled. I'm on a 13-inch mid-2012 MacBook Air. If no one knows about an existing bug report about this, I'll submit it on http://bugreport.java.com<http://bugreport.java.com/> (I searched bugs.openjdk.java.net ). -- Eirik -- Best regards, Sergey.
