Components: [mat-tree] Keyboard Interaction recommended by WAI-ARIA

[johanekhager]

Bug, feature request, or proposal:

Feature request

What is the expected behavior?

Read expected behavior under "Keyboard interactions" at w3.org/TR/wai-aria-practices/#TreeView. Should use TAB to focus [mat-tree] and use arrows to navigate. Similar to radio button behaviour.

What is the current behavior?

TAB and SHIFT + TAB to navigate. SPACE or ENTER to open/close a node.

What are the steps to reproduce?

Look at the example here: w3.org/TR/wai-aria-practices/examples/treeview/treeview-1/treeview-1a.html

What is the use-case or motivation for changing an existing behavior?

To make [mat-tree] more usable and accessible. Especially important when having lots of items in a tree.

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

@angular: 6.1.4
@angular/material: 6.4.6
OS: Windows 10
Chrome: 69.0.3497.81
Typescript: 2.7.2

Is there anything else we should know?

No

[crisbeto]

That should be what https://github.com/angular/material2/pull/10691 is doing.

[BobbyJoStefflTR]

This issue no longer has an active pull request associated, will this be revisited?