TooltipArea currently attempts to detect the pointer exiting "into the tooltip" (to avoid hiding the tooltip in this case) by checking whether the location of the pointer is inside the TooltipArea. This is wrong, however, because:

1. There could be a real exit event (not into the tooltip) while the pointer is still inside the bounds of the tooltip area. For example, when exiting through the left edge, the exit event could be at x=0.
2. The pointer could exit into another, overlapping, element. Here too, the tooltip should be hidden even though the pointer is inside the bounds of the tooltip area.

Fixes https://youtrack.jetbrains.com/issue/CMP-8739

Testing

Tested manually and added several unit tests.

@OptIn(ExperimentalComposeUiApi::class)
fun main() = singleWindowApplication {
    Box(Modifier.size(200.dp)) {
        BoxWithTooltip(text = "Red", color = Color.Red, Modifier.size(150.dp))
        BoxWithTooltip(text = "Blue", color = Color.Blue, Modifier.align(Alignment.BottomEnd).size(150.dp))
    }
}

@OptIn(ExperimentalFoundationApi::class)
@Composable
fun BoxWithTooltip(
    text: String,
    color: Color,
    modifier: Modifier = Modifier,
    content: @Composable BoxScope.() -> Unit = {}
) {
    TooltipArea(
        tooltip = { Text(text, Modifier.background(Color.White).border(1.dp, Color.Black).padding(8.dp)) },
        modifier = modifier
    ) {
        Box(modifier = Modifier.fillMaxSize().background(color)) {
            content()
        }
    }
}

Release Notes

Fixes - Desktop

• Fix the condition for hiding the tooltip in a TooltipArea on a pointer-exit event while the pointer is still inside the area.