Editing, moving and customizing widgets in Plasma Desktop improved a lot in 5.17, and then in 5.18 it will get a brand new edit mode, to be really efficient editing your desktop layout (and have less visual noise by default).

This week another new feature landed in the edit mode for 5.18: it’s possible to set some plasmoids without background and a nice drop shadow, for an extra clean and modern look for your desktop.

In addition, a plasmoid can specify this backgroundless shadowed mode as its new default, like the digital clock now does (when is on the deskop)

Applet developers will have to opt in this feature: doesn’t always make sense everywhere and some may still be buggy. Some default plasmoids, especially in kdeplasma-addons have been set to support it.

If you are writing a plasmoid and want to support this background removal, in the main QML item of your plasmoid you can do:

Item {
    id: root   
    Plasmoid.backgroundHints: PlasmaCore.Types.DefaultBackground
                             | PlasmaCore.Types.ConfigurableBackground
    ...
}

Or, if you want to default toi the new background-less, automatic shadow:

Item {
    id: root   
    Plasmoid.backgroundHints: PlasmaCore.Types.ShadowBackground
                             | PlasmaCore.Types.ConfigurableBackground
    ...
}

Of course the NoBackground option is still there if a shadow isn’t what the graphic style of the plasmoid needs.

A notice that needs to be kept in mind, is that for color inversion to work automatically, one should never do:

    color: theme.textColor

But rather

    color: PlasmaCore.ColorScope.textColor

Which is a good way to get ready for Qt6 anyways, as context properties are going to be removed in the next Qt major release.