When System Settings -> Display -> Screen Scaling has been set to 2 or 3, Units::roundToIconSize returns invalid results for SizeSmallMedium. Plasmoids, which call this function, have access to icon sizes which are already multipled by the Screen Scaling factor, but Units::roundToIconSize() does not. So, for example, if Screen Scaling was set to 2, inside a plasmoid's QML code iconSizes.smallMedium == 22 * 2 == 44, but inside roundToIconSize it still equals 22. Therefore, Units::roundToIconSize() returns the following results (assuming Screen Scaling == 2): units.roundToIconSize(32) -> returns 32 // SizeSmall units.roundToIconSize(44) -> returns 32 // SizeSmallMedium - wrong units.roundToIconSize(64) -> returns 64 // SizeMedium units.roundToIconSize(96) -> returns 96 // SizeLarge units.roundToIconSize(128) -> returns 128 // SizeHuge By default, plasmoid.configuration.iconSize == SizeSmallMedium, so all plasmoids using this method will display tiny icons if Screen Scaling >= 2 (e.g. system tray).
Can confirm. Looking at the code (plasma-framework/src/declarativeimports/core/units.cpp), this seems intentional: /*Do *not* use devicePixelIconSize here, we want to use the sizes of the pixmaps of the smallest icons on the disk. And those are unaffected by dpi*/ However I'm not sure if this is correct. We use SVG icons now, and I can confirm the problem of smallMedium icons being rendered at the wrong size.
This is one of the leading causes of icons being too small when using a high dpi scale factor on X11. Raising priority.
*** Bug 428138 has been marked as a duplicate of this bug. ***
*** Bug 424465 has been marked as a duplicate of this bug. ***
*** Bug 420132 has been marked as a duplicate of this bug. ***
*** Bug 391682 has been marked as a duplicate of this bug. ***
A possibly relevant merge request was started @ https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/301
Git commit 4edb830f53aac4833ece024df59441029b01fde6 by Nate Graham. Committed on 28/07/2021 at 15:40. Pushed by ngraham into branch 'master'. Fix Units::roundToIconSize() returning incorrect sizes with non-Qt scaling When not using Qt Scaling (testable by using the Wayland session or setting `PLASMA_USE_QT_SCALING=1` on X11), all pixel sizes are unscaled. E.g. a 22x22 SmallMedium icon must be expressed as 44x44 to Plasma, because it is not aware of Qt's scaling. The `Units::roundToIconSize()` function was failing to do this, thus returning incorrectly small icon sizes. For example you would ask it for the correct icon for a 44px physical area, expecting a SmallMedium icon--but internally the function would would find that 44 is lower than 48 (unscaled Large size), and give you the next smallest size, which is Medium. Unscaled Medium is 32px, which is equivalent to a 16px scaled icon. So you would get a Small icon when you expected a SmallMedium one. Due to quirks of how the icon sizes increase at the larger end, correct results were accidentally returned for larger icon sizes. However small and smallMedium icons were always incorrectly getting the next smallest size instead, most commonly manifesting as ToolButtons and System Tray icons being too small. This commit fixes the problem by scaling all of the icon sizes internally both for the purposes of comparison and returning a final value--but only when not using Qt scaling. Related: bug 381794 FIXED-IN: 5.85 M +41 -27 src/declarativeimports/core/units.cpp M +8 -0 src/declarativeimports/core/units.h https://invent.kde.org/frameworks/plasma-framework/commit/4edb830f53aac4833ece024df59441029b01fde6
*** Bug 355866 has been marked as a duplicate of this bug. ***