pack
box
are placed when the box is larger that the size of the children. For boxes with horizontal orientation, it is used to indicate the position of children horizontally. For boxes with vertical orientation, it is used to indicate the position of children vertically. The align
attribute is used to specify the position in the opposite direction. You can also specify the value of pack using the style property -moz-box-pack
.
start
center
end
More on box packing in the XUL Tutorial