TreeIterables

extends Object

java.lang.Object
↳	androidx.test.espresso.util.TreeIterables

Class Overview

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 Classes
class	TreeIterables.ViewAndDistance	Represents the distance a given view is from the root view.

Public Methods
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.
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.
static Iterable<TreeIterables.ViewAndDistance>	depthFirstViewTraversalWithDistance(View root) Creates an iterable that traverses the tree formed by the given root.

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Inherited Methods

From class java.lang.Object

Public Methods

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
`root`	`View`: the non-null, root view.

Returns
`Iterable<View>`

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
`root`	`View`: the non-null, root view.

Returns
`Iterable<View>`

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
`root`	`View`: 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.