CanvasTableModel is a model for a table container used to lay out other canvas items.
It is used in a similar way to how the GtkTable widget is used to lay out GTK+ widgets.
Item models are added to the table using the normal methods, then
set_child_properties is used to specify how each child item is to be positioned within the table (i.e. which row and column it is
in, how much padding it should have and whether it should expand or shrink).
CanvasTableModel is a subclass of CanvasItemModelSimple
and so inherits all of the style properties such as "stroke-color", "fill-color" and "line-width". Setting a style property on a
CanvasTableModel will affect all children of the CanvasTableModel (unless the
children override the property setting).
CanvasTableModel implements the CanvasItemModel
interface, so you can use the CanvasItemModel functions such as
raise and rotate, and
the properties such as "visibility" and "pointer-events".