- 封闭类:
- PathFinder
public static class PathFinder.PathElement
extends java.lang.Object
a path element E matches a view V if each non "prefix" or "index"
attribute of E is equal to (or characteristic of) V.
So
E.viewClassName == 'com.temp.Awesome' =) V instanceof com.tempAwesome
E.id == 123 =) V.getId() == 123
The index attribute, counting from root to leaf, and first child to last child, selects a particular
matching view amongst all possible matches. Indexing starts at zero, like an array
index. So E.index == 2 means "Select the third possible match for this element"
The prefix attribute refers to the position of the matched views in the hierarchy,
relative to the current position of the path being searched. The "current position" of
a path element is determined by the path that preceeded that element:
- The current position of the empty path is the root view
- The current position of a non-empty path is the children of any element that matched the last
element of that path.
Prefix values can be:
ZERO_LENGTH_PREFIX- the next match must occur at the current position (so at the root
view if this is the first element of a path, or at the matching children of the views
already matched by the preceeding portion of the path.) If a path element with ZERO_LENGTH_PREFIX
has no index, then *all* matching elements of the path will be matched, otherwise indeces
will count from first child to last child.
SHORTEST_PREFIX- the next match must occur at some descendant of the current position.
SHORTEST_PREFIX elements are indexed depth-first, first child to last child. For performance
reasons, at most one element will ever be matched to a SHORTEST_PREFIX element, so
elements with no index will be treated as having index == 0