Bug 427122

Summary:	Option to focus unfocused, un-grouped task on scroll
Product:	[Plasma] plasmashell	Reporter:	irchaika
Component:	Task Manager and Icons-Only Task Manager widgets	Assignee:	Eike Hein <hein>
Status:	CONFIRMED ---
Severity:	wishlist	CC:	gabor, nate, plasma-bugs-null
Priority:	NOR
Version First Reported In:	5.19.5
Target Milestone:	1.0
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	patch to change the behavior

Description irchaika 2020-09-29 16:52:48 UTC

SUMMARY
The icon-only task manager has an option to enable scroll-wheel for task switching, however what I see when using this is that if my cursor is on top of a multi instance program, the scrolling will switch between the instances of the program under the cursor, but if the cursor is on top of a single instance program, scrolling will instead go the focus go to the next or previous (depending on whether you're scrolling down or up) task in the task manager, this change isn't relative to where our cursor is but where the focus is.

so if we have 5 task open and task 3 is focused, if every task is single instance then no matter where the cursor is, scrolling will take us to either task 2 or 4.

If possible I'd like to have the option to have the multi-instance behavior applied to single instance programs, so instead for moving ahead or backwards in the task list, it will instead focus the task under the cursor at the time of scrolling.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74.0
Qt Version: 5.15.1

Comment 1 Nate Graham 2021-04-07 09:24:46 UTC

*** Bug 429525 has been marked as a duplicate of this bug. ***

Comment 2 irchaika 2021-04-07 20:39:35 UTC

Where is the relevant code for this? I downloaded plasma-desktop's code, and checked icontasks, also checked tasksmanager but couldn't find something directly related.

Comment 3 Nate Graham 2021-04-08 20:05:36 UTC

Probably applets/taskmanager/package/contents/ui/code/tools.js in the plasma-desktop repo, but I'm not 100% sure.

Comment 4 irchaika 2021-04-09 04:19:00 UTC

Created attachment 137444 [details]
patch to change the behavior

(In reply to Nate Graham from comment #3)
> Probably applets/taskmanager/package/contents/ui/code/tools.js in the
> plasma-desktop repo, but I'm not 100% sure.

It indeed was, I had a lot of trouble navigating the code, here's a pretty bad hack that works for what I wanted. This should be taken into account:

-If you scroll on empty space that belongs to the applet, or on a pinned but unopened program, it will still scroll to the next-previous program (I'd rather it did nothing in those scenarios, but can't really be bothered).
-I think said scrolling might have been reverted compared to how it would normally work.

If someone else wants to do something t hat isn't a complete hack, take into account that: 
-"anchor" represents the program we're scrolling over.
-tasksModel.requestActivate(target) is what actually sets the focus.
-and target is an element of the array taskIndexList.

I couldn't find a better way to find the position of anchor in TaskIndexList so I used "pushCounter".

Comment 5 Nate Graham 2021-04-09 19:48:47 UTC

Now that you've got a preliminary patch, I would recommend submitting it! It's okay if it's not perfect, but it's much easier to do code review on GitLab than here in the bug report. :) Here's the documentation: https://community.kde.org/Infrastructure/GitLab

Make sure to add 

BUG 427122

to the commit message on its own line.