Type ID

IDFromBits is the inverse of Bits.

Item returns the identity of item n in the anonymous scope: for examples, previews and tests that need a few identities and no tree of their own. Item(0) is the zero ID, "no target", so a number kept in a plain field can say so. An application with more than a screenful of controls names them in a Tree.

Bits packs the identity into 64 bits, for carrying it between processes (the development reload worker and its window). The number means something only to the Tree that made it; the process that receives it may compare it and send it back, and nothing else.

In returns the item number of an identity that is item i of the list scope, and false for any other identity: the way a handler reads which row was clicked.

if row, ok := id.In(rows); ok { open(row) }

IsZero reports whether the ID is "no target".

Name returns the ID's name within its scope: for an item of a list, its number.

Scope returns the place the ID is in.