The minimum spacing (in points) to use between items in the same row or column.
- macOS 10.11+
If the delegate does not implement the
collection method, the flow layout object uses the value of this property to set the spacing between items in the same line.
For a vertically scrolling layout, the value represents the minimum spacing between items in the same row. For a horizontally scrolling layout, the value represents the minimum spacing between items in the same column. The layout object uses this spacing only to compute how many items can fit in a single row or column. The actual spacing may be increased after the number of items has been determined, as illustrated in Figure 1.
The default value of this property is