Row and column layouts are the most basic type of layout class available in the CAPI, and will be sufficient for many things you want to do. A variety of other layouts are available as well, as described in this section.
Row and column layouts only allow you to position a pane horizontally or vertically (depending on which class you use), but grid layouts let you specify both thus allowing you to create a complete grid of different CAPI panes.
grid-layout supports a title column, as illustrated in
grid-layout (and its subclasses column-layout and row-layout) is a subclass of x-y-adjustable-layout, which allows you to specify adjustments when you position the pane using the initargs
A simple-layout has only one child. Where possible, the child is resized to fit the layout. Simple layouts are sometimes useful when you need to encapsulate a pane.
Pinboard layouts allow you to position a pane anywhere within a window, by specifying the x and y integer coordinates of the pane precisely. They are a means of letting you achieve any effect which you cannot create using the other available layouts, although their use can be correspondingly more complex. They are discussed in more detail in Creating Panes with Your Own Drawing and Input.
CAPI User Guide and Reference Manual (Macintosh version) - 3 Aug 2017