Code completion in drawable1.xml for <item >^</item>:
<animation-list /> : Drawable used to render several animated frames.
<bitmap /> : Drawable used to draw bitmaps.
<clip />
<color /> : Drawable used to draw a single color.
<inset />
<layer-list ></layer-list> : Drawable used to render several drawables stacked on top of each  other.
<nine-patch /> : Drawable used to draw 9-patches.
<rotate /> : Drawable used to rotate another drawable.
<scale />
<selector ></selector> : Drawable used to render several states.
<shape ></shape> : Drawable used to render a geometric shape, with a gradient or  a solid color.