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. |
Shift + Home | Extends selection up to the first node. |
Shift + End | Extends selection down to the last node. |
Use the registerKeyHandler(key, handler) method to implement a custom handler for a key.
jQuery
JavaScript
function registerKeyHandlers () { const treeView = $("#treeViewContainer").dxTreeView("instance"); treeView.registerKeyHandler("backspace", function(e) { // The argument "e" contains information on the event }); treeView.registerKeyHandler("space", function(e) { // ... }); }
Angular
TypeScript
import { ..., ViewChild, AfterViewInit } from '@angular/core'; import { DxTreeViewModule, DxTreeViewComponent } from 'devextreme-angular'; // ... export class AppComponent implements AfterViewInit { @ViewChild(DxTreeViewComponent, { static: false }) treeView: DxTreeViewComponent; // Prior to Angular 8 // @ViewChild(DxTreeViewComponent) treeView: DxTreeViewComponent; ngAfterViewInit () { this.treeView.instance.registerKeyHandler('backspace', function(e) { // The argument "e" contains information on the event }); this.treeView.instance.registerKeyHandler('space', function(e) { // ... }); } } @NgModule({ imports: [ // ... DxTreeViewModule ], // ... })
Vue
<template> <DxTreeView :ref="myTreeViewRef" /> </template> <script> import 'devextreme/dist/css/dx.light.css'; import DxTreeView from 'devextreme-vue/tree-view'; const myTreeViewRef = 'my-tree-view'; export default { components: { DxTreeView }, data() { return { myTreeViewRef } }, computed: { treeView: function() { return this.$refs[myTreeViewRef].instance; } }, mounted: function() { this.treeView.registerKeyHandler('backspace', function(e) { // The argument "e" contains information on the event }); this.treeView.registerKeyHandler('space', function(e) { // ... }); } } </script>
React
App.js
import React from 'react'; import 'devextreme/dist/css/dx.light.css'; import { TreeView } from 'devextreme-react/tree-view'; class App extends React.Component { constructor(props) { super(props); this.treeViewRef = React.createRef(); } render() { return ( <TreeView ref={this.treeViewRef} /> ); } get treeView() { return this.treeViewRef.current.instance(); } componentDidMount() { this.treeView.registerKeyHandler('backspace', function(e) { // The argument "e" contains information on the event }); this.treeView.registerKeyHandler('space', function(e) { // ... }); } } export default App;
Screen Reader Support
The TreeView component supports screen readers and complies to WAI-ARIA standards.
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