I did an app Layout purely with (Scrollable)(Column/Rows) inside

window { MaterialTheme { Surface { DesktopTheme { Scaffold(() } } } }

now when I start Mouse selecting Text (e.g. at the top of the rightmost column (see screenshot) Text that is in other columns at the same "height" gets also selected. In the Screenshot I only selected the Text of the rightmost column. But the whole center column and also stuff on the same "height" in the left column gets also selected. (Even if I open the Scaffold Drawer and start Mouse-selecting text in it, text in the bodyContent columns gets also selected) Is this problem "known" or am I doing something wrong ?

You need to wrap each column into DesktopSelectionContainer: https://github.com/JetBrains/compose-jb/blob/master/examples/codeviewer/common/src/desktopMain/kotlin/org/jetbrains/codeviewer/platform/Selection.kt https://github.com/JetBrains/compose-jb/blob/67fc63b73f0aa449553416ba239e25b45db02[…]monMain/kotlin/org/jetbrains/codeviewer/ui/editor/EditorView.kt

ah, ok, thanks is this documented somewhere? (as I tried to extensively research this before bothering you here 🙂 )

No, there is no documentation. Only in Reference We want to disable selection by default and provide a common SelectionContainer instead of DesktopSelectionContainer. So users should explicitly define Composable which should be selectable.