34,333
edits
Changes
→Introducing the Android GridLayout and Space Classes
== Introducing the Android GridLayout and Space Classes ==
The purpose of the GridLayout is to allow child views to be positioned in a grid arrangement. The GridLayout essentially consists of a number of invisible horizontal and vertical grid lines that serve to divide the layout view into a series of rows and columns, with each intersecting row and column forming a cell which can, in turn, contain one or more views. The grid lines are referred to as indices, which are numbered starting at 0 for the line at the leading edge of the layout. Row and column numbering also starts at 0 beginning in the top left hand corner of the grid (though, as will be discovered later in the this chapter, the Graphical Layout tool considers this to be position 1).
The positioning of a view within a cell can be defined through the use of gravity settings on that child view. The gravity of a child view can, for example, be configured such that the view appears centered, fills the entire cell or is positioned in a specific corner of the cell within which it resides.
Another useful class that can be used in conjunction with the GridLayout is the Space class. This is a very simple class, the sole purpose of which is to create gaps within layouts. In the case of the GridLayout class, a Space view can be placed in any cell much like any other view object.
In addition to using the Space class to create gaps, the spacing around views in cells can be controlled via the various margin layout properties (top, bottom, left and right) of each child.
== The GridLayout Example ==
