A Box part has the following properties:
A cell part has two properties to define the alignment of its contained part:
You can change the alignment property of a cell in the following ways:
Cells contained in a Box part have additional spanning properties, which you can use to define cells which span over other cells.
The following figure shows how the parts and properties are presented in
the Composition Editor:
The figure above shows a box which defines as three-by-three grid. There is both a cell which spans vertically and a cell which spans horizontally.
The arrows in an empty cell indicate how it will align its contents.
An arrow is shown at every attachment point. For example, the top left
cell has the alignment set to expand in both dimensions. If there is no
attachment point, the cell centers the part in the corresponding
dimension. In addition to changing the spanning with the spanning
properties, you can change it by direct manipulation with the blue grid
handles. The grid handles are shown in the figure below.
You can drag the grid handles either horizontally or vertically to span a
cell.