Bug 489375

Created attachment 171131 [details]
Excessive width by default (panel height 46px)

SUMMARY
The default width of tasks in non-icons-only mode is way too wide when not using Inline Grouping.

STEPS TO REPRODUCE
1. Use the non-icons-only task manager in a horizontal panel. The panel 
2. Turn off Grouping in Behavior settings. Or turn on grouping and turn on "Combine into single button".
3. Open, say, Konsole and close other windows
4. Notice the one task can be double the size of its label
5. Turn on grouping and turn off "combine into single button" (Inline Grouping mode)
6. Notice the width is a lot more sensible now

OBSERVED RESULT
Excessive width for text labels when not using inline grouping.

EXPECTED RESULT
A more sensible width for text labels at all times.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux (6.6.35-2-lts)
KDE Plasma Version: 6.1.0
KDE Frameworks Version: 6.3.0 
Qt Version: 6.7.2

ADDITIONAL INFORMATION

The Inline Grouping mode was added in https://phabricator.kde.org/D1881 and https://phabricator.kde.org/D1882.

This behavior is caused by (a) task items (plasma-desktop/applets/taskmanager/[...]/ui/Task.qml) using the max width for items, and (b) the max width being 1.6x the min width when not using inline grouping. In ui/code/layoutmetrics.js, commented for context:

    function preferredMaxWidth() {
        if (tasks.iconsOnly) {/* ... */}
    
        // Not icons only & using inline grouping
        if (tasks.plasmoid.configuration.groupingStrategy != 0 && !tasks.plasmoid.configuration.groupPopups && !tasks.iconsOnly) {
            return preferredMinWidth();
        }
    
        // default case, which is why too wide
        return Math.floor(preferredMinWidth() * 1.6);
    }