Angular TreeView - Accessibility

Accessibility Features Overview

NOTE
The overall accessibility level of your application depends on the TreeView features that you use.
Accessibility Requirement Support Level
Right-to-Left Support
Keyboard Navigation Support
Screen Reader Support
Contrast Color Theme
Mobile Device Support
Lighthouse Accessibility Validation
Axe Accessibility Validation
WAVE Accessibility Validation
Section 508 Support
WCAG 2.x Support
  • - All component features meet the requirement
  • - Some component features may not meet the requirement
  • - Accessibility requirement is not supported

Accessibility Standards Compliance

The TreeView component meets a variety of Section 508 and WCAG 2.x compliance standards. Known exceptions:

Section 508 criteria WCAG 2.x criteria Exception description
501 (Web)(Software)
504.2 (Authoring Tool)
602.3 (Support Docs)
1.4.3 Contrast (Minimum) (Level AA)
1.4.11 Non-text Contrast (Level AA 2.1 and 2.2)
TreeView does not support Windows High Contrast themes.

Keyboard Navigation

A user can use the following keys to interact with the TreeView component:

Key Action
Shift + Mouse Wheel Scrolls the content left/right if the scrollDirection property is "horizontal" or "both".
↑ / ↓ Moves focus to the previous/next node.
Home / End Moves focus to the first/last node.
Expands the node.
Collapses the node.
Asterisk Sign (*) Expands all nodes. Available only if expandAllEnabled is set to true.
Minus Sign (-) Collapses all nodes. Available only if expandAllEnabled is set to true.
Enter or Space Selects the node.
Shift + ↑ / Shift + ↓ Extends selection up/down by one node.1
Shift + Home Extends selection up to the first node.1
Shift + End Extends selection down to the last node.1
  1. If showCheckBoxesMode is set to "none", this action has no effect.

Use the registerKeyHandler(key, handler) method to implement a custom handler for a key.

TypeScript
  • import { ..., ViewChild, AfterViewInit } from '@angular/core';
  • import { DxTreeViewModule, DxTreeViewComponent } from 'devextreme-angular';
  • // ...
  • export class AppComponent implements AfterViewInit {
  • @ViewChild(DxTreeViewComponent, { static: false }) treeView: DxTreeViewComponent;
  • // Prior to Angular 8
  • // @ViewChild(DxTreeViewComponent) treeView: DxTreeViewComponent;
  •  
  • ngAfterViewInit () {
  • this.treeView.instance.registerKeyHandler('backspace', function(e) {
  • // The argument "e" contains information on the event
  • });
  • this.treeView.instance.registerKeyHandler('space', function(e) {
  • // ...
  • });
  • }
  • }
  • @NgModule({
  • imports: [
  • // ...
  • DxTreeViewModule
  • ],
  • // ...
  • })

Screen Reader Support

The TreeView component supports screen readers and complies to WAI-ARIA standards.