GridPadDsl.kt

@Composable
public fun GridPad(
    cells: GridPadCells, modifier: Modifier = Modifier, content: GridPadScope.() -> Unit
) {
    val scopeContent: GridPadScopeImpl = GridPadScopeImpl(cells).apply(content)

    Layout(modifier = modifier, content = {
        scopeContent.data.forEach {
            it.item(GridPadItemScopeImpl)
        }
    }) { measurables, constraints ->
        
        // ...

        val cellPlaces = calculateCellPlaces(cells, width = constraints.maxWidth, height = constraints.maxHeight)        
    
        // list of measured children
        val placeables = measurables.mapIndexed { index, measurable ->
            val contentMetaInfo = scopeContent.data[index]
            // calculate the actual maximum cell width in pixels based on the span size
            val maxWidth = (0 until contentMetaInfo.columnSpan).sumOf {
                cellPlaces[contentMetaInfo.row][contentMetaInfo.column + it].width
            }
            // calculate the actual maximum cell height in pixels based on the span size
            val maxHeight = (0 until contentMetaInfo.rowSpan).sumOf {
                cellPlaces[contentMetaInfo.row + it][contentMetaInfo.column].height
            }

            // measurement of children with cell boundary constraints, not the parent
            measurable.measure(
                constraints.copy(
                    minWidth = min(constraints.minWidth, maxWidth),
                    maxWidth = maxWidth,
                    minHeight = min(constraints.minHeight, maxHeight),
                    maxHeight = maxHeight
                )
            )
        }
    
        // ...
    }
}