public final class TreeIterables

Utility methods for iterating over tree structured items.

Since the view hierarchy is a tree - having a method of iterating over its contents is useful.

This is generalized for any object which can display tree like qualities - but this generalization was done for testability concerns (since creating View hierarchies is a pain).

Only public methods of this utility class are considered public API of the test framework.

Summary

Nested types

Represents the distance a given view is from the root view.

Public methods
static Iterable<View>

Returns an iterable which iterates thru the provided view and its children in a breadth-first, row-level-order traversal.
static Iterable<View>

Returns an iterable which iterates thru the provided view and its children in a depth-first, in-order traversal.
static Iterable<TreeIterables.ViewAndDistance>

Creates an iterable that traverses the tree formed by the given root.

Public methods

breadthFirstViewTraversal

public static Iterable<View> breadthFirstViewTraversal(View root)

Returns an iterable which iterates thru the provided view and its children in a breadth-first, row-level-order traversal. That is to say that for a view such as: Root / | \ A R U /| |\ B D G N Will be iterated: Root, A, R, U, B, D, G, N

Parameters
View root

the non-null, root view.

depthFirstViewTraversal

public static Iterable<View> depthFirstViewTraversal(View root)

Returns an iterable which iterates thru the provided view and its children in a depth-first, in-order traversal. That is to say that for a view such as: Root / | \ A R U /| |\ B D G N Will be iterated: Root, A, B, D, R, G, N, U.

Parameters
View root

the non-null, root view.

depthFirstViewTraversalWithDistance

public static Iterable<TreeIterables.ViewAndDistance> depthFirstViewTraversalWithDistance(View root)

Creates an iterable that traverses the tree formed by the given root.

Along with iteration order, the distance from the root element is also tracked.

Parameters
View root

the root view to track from.
Returns
Iterable<TreeIterables.ViewAndDistance>

An iterable of ViewAndDistance containing the view tree in a depth first order with the distance of a given node from the root.