electron/docs/tutorial/accessibility.md
Felix Rieseberg 69b0a358f3 📝 A11y documentation
2018-02-19 17:36:49 -06:00

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# Accessibility
Making accessible applications is important and we're happy to introduce new
functionality to [Devtron][devtron] and [Spectron][spectron] that gives
developers the opportunity to make their apps better for everyone.
---
Accessibility concerns in Electron applications are similar to those of
websites because they're both ultimately HTML. With Electron apps, however,
you can't use the online resources for accessibility audits because your app
doesn't have a URL to point the auditor to.
These new features bring those auditing tools to your Electron app. You can
choose to add audits to your tests with Spectron or use them within DevTools
with Devtron. Read on for a summary of the tools.
## Spectron
In the testing framework Spectron, you can now audit each window and `<webview>`
tag in your application. For example:
```javascript
app.client.auditAccessibility().then(function (audit) {
if (audit.failed) {
console.error(audit.message)
}
})
```
You can read more about this feature in [Spectron's documentation][spectron-a11y].
## Devtron
In Devtron, there is a new accessibility tab which will allow you to audit a
page in your app, sort and filter the results.
![devtron screenshot][devtron-screenshot]
Both of these tools are using the [Accessibility Developer Tools][a11y-devtools]
library built by Google for Chrome. You can learn more about the accessibility
audit rules this library uses on that [repository's wiki][a11y-devtools-wiki].
If you know of other great accessibility tools for Electron, add them to the
accessibility documentation with a pull request.
## Enabling Accessibility
Electron applications keep accessibility disabled by default for performance
reasons but there are multiple ways to enable it.
### Inside Application
By using [`app.setAccessibilitySupportEnabled(enabled)`][setAccessibilitySupportEnabled],
you can expose accessibility switch to users in the application preferences.
User's system assistive utilities have priority over this setting and will
override it.
### Assistive Technology
Electron application will enable accessibility automatically when it detects
assistive technology (Windows) or VoiceOver (macOS). See Chrome's
[accessibility documentation][a11y-docs] for more details.
On macOS, third-party assistive technology can switch accessibility inside
Electron applications by setting the attribute `AXManualAccessibility`
programmatically:
```objc
CFStringRef kAXManualAccessibility = CFSTR("AXManualAccessibility");
+ (void)enableAccessibility:(BOOL)enable inElectronApplication:(NSRunningApplication *)app
{
AXUIElementRef appRef = AXUIElementCreateApplication(app.processIdentifier);
if (appRef == nil)
return;
CFBooleanRef value = enable ? kCFBooleanTrue : kCFBooleanFalse;
AXUIElementSetAttributeValue(appRef, kAXManualAccessibility, value);
CFRelease(appRef);
}
```
[devtron]: https://electronjs.org/devtron
[devtron-screenshot]: https://cloud.githubusercontent.com/assets/1305617/17156618/9f9bcd72-533f-11e6-880d-389115f40a2a.png
[spectron]: https://electronjs.org/spectron
[spectron-a11y]: https://github.com/electron/spectron#accessibility-testing
[a11y-docs]: https://www.chromium.org/developers/design-documents/accessibility#TOC-How-Chrome-detects-the-presence-of-Assistive-Technology
[a11y-devtools]: https://github.com/GoogleChrome/accessibility-developer-tools
[a11y-devtools-wiki]: https://github.com/GoogleChrome/accessibility-developer-tools/wiki/Audit-Rules
[setAccessibilitySupportEnabled]: ../api/app.md#appsetaccessibilitysupportenabledenabled-macos-windows