Bug 450448

Summary: Scrolling with touchscreen does not work consistently
Product: [Plasma] plasmashell Reporter: Patrick Silva <bugseforuns>
Component: Application Launcher (Kickoff)Assignee: Plasma Bugs List <plasma-bugs>
Status: RESOLVED FIXED    
Severity: normal CC: mikel5764, nate, noahadvs, personalizedrefrigerator, qydwhotmail
Priority: NOR Keywords: regression, usability
Version: 5.25.0   
Target Milestone: 1.0   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed In: 5.25.5
Sentry Crash Report:

Description Patrick Silva 2022-02-17 12:16:41 UTC
STEPS TO REPRODUCE
1. open kickoff
2. tap on 'All applications'
3. try to scroll the applications list with the touchscreen

OBSERVED RESULT
sometimes the apps list scrolls a few pixels, but scrolling fails completely almost always

EXPECTED RESULT
scrolling with touchscreen should work consistently

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.24.80
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3
Graphics Platform: Wayland
Comment 1 Nate Graham 2022-02-17 23:17:54 UTC
Can reproduce.
Comment 2 Fushan Wen 2022-02-17 23:54:40 UTC
Can reproduce in 5.24.0
Comment 3 Patrick Silva 2022-07-14 12:16:43 UTC
*** Bug 456708 has been marked as a duplicate of this bug. ***
Comment 4 Nate Graham 2022-08-11 22:37:28 UTC
Looks like it works if you drag on a header (using either a touchscreen or a pointing device, interestingly), but if you do it on an item, it eats the event and treats it as an attempt to activate the item.
Comment 5 Nate Graham 2022-08-12 01:41:04 UTC
Looks like it's the embedded MouseArea in each delegate that blocks events from reaching the scrollable view.
Comment 6 Nate Graham 2022-08-12 02:58:31 UTC
We could port them to *Handler items, but there's sort of a conceptual incompatibility between touch-scrolling and touch-dragging, for views where items are draggable. We currently have press-and-hold bound to "show context menu," so we would have to re-arrange the UI a bit probably, to make press-and-hold-and-drag re-arrange items, while press-and-hold-and-release-without-moving opens a context menu.
Comment 7 Bug Janitor Service 2022-08-16 01:20:18 UTC
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/1094
Comment 8 Noah Davis 2022-08-16 03:05:12 UTC
Git commit 66507b5df163071128a90983d10f699aa1a9b3cf by Noah Davis.
Committed on 16/08/2022 at 03:01.
Pushed by ndavis into branch 'master'.

Disable Drag and Drop for touch, fix drag and drop icons

Drag and drop conflicted with drag/flick scrolling and drag and drop was
deemed less important than scrolling or opening the context menu for
touch. Maybe in the future we can have a way to at least rearrange
favorites with touch input.

Drag and drop icons seem to have been broken by commit
0868a5ae8154d10ccc7488034bc5b6e458a17968 and are now fixed.

M  +15   -12   applets/kickoff/package/contents/ui/AbstractKickoffItemDelegate.qml
M  +3    -0    applets/kickoff/package/contents/ui/KickoffGridDelegate.qml
M  +2    -0    applets/kickoff/package/contents/ui/KickoffListDelegate.qml

https://invent.kde.org/plasma/plasma-desktop/commit/66507b5df163071128a90983d10f699aa1a9b3cf
Comment 9 Noah Davis 2022-08-17 14:57:22 UTC
Git commit b31aeb62f739c8e948acc4d687895f32e86aa986 by Noah Davis.
Committed on 17/08/2022 at 00:13.
Pushed by ngraham into branch 'Plasma/5.25'.

Disable Drag and Drop for touch, fix drag and drop icons

Drag and drop conflicted with drag/flick scrolling and drag and drop was
deemed less important than scrolling or opening the context menu for
touch. Maybe in the future we can have a way to at least rearrange
favorites with touch input.

This commit does the same thing as
66507b5df163071128a90983d10f699aa1a9b3cf, but that one couldn't be
cherry-picked.

M  +12   -11   applets/kickoff/package/contents/ui/KickoffItemDelegate.qml

https://invent.kde.org/plasma/plasma-desktop/commit/b31aeb62f739c8e948acc4d687895f32e86aa986