Files
react-native/packages/rn-tester/js/examples/Accessibility/AccessibilityAndroidExample.android.js
T
fabriziobertoglio1987 7b5b114d57 Making links independently focusable by Talkback (#33215)
Summary:
This issue fixes [32004][23]. The Pull Request was previously published by [blavalla][10] with [31757][24].
>This is a follow-up on [D23553222 (https://github.com/facebook/react-native/commit/b352e2da8137452f66717cf1cecb2e72abd727d7)][18], which made links functional by using [Talkback's Links menu][1]. We don't often use this as the sole access point for links due to it being more difficult for users to navigate to and easy for users to miss if they don't listen to the full description, including the hint text that announces that links are available.
The Implementation of the functionality consists of:

Retrieving the accessibility links and triggering the TalkBack Focus over the Text
1. nested Text components with accessibilityRole link are saved as [ReactClickableSpan][17] instances in Android native [TextView][20] ([more info][19])
1. If the TextView contains any [ClickableSpans][15] (which are [nested Text][14] components with role link), set a view tag and reset the accessibility delegate.
3. Obtain each link description, start, end, and position relative to the parent Text (id) from the Span as an [AccessibilityLink][16]
4. Use the [AccessibilityLink][16]  to display TalkBack focus over the link with the `getVirtualViewAt` method (more [info][13])

Implementing ExploreByTouchHelper to detect touches over links and to display TalkBack rectangle around them.
1. ReactAccessibilityDelegate inherits from [ExploreByTouchHelper][12]
2. If the [ReactTextView][21] has an accessibility delegate, trigger ExploreByTouchHelper method [dispatchHoverEvent][22]
3.  Implements the methods `getVirtualViewAt` and `onPopulateBoundsForVirtualView`.
     The two methods implements the following functionalities  (more [info][13]):
    * detecting the TalkBack onPress/focus on nested Text with accessibilityRole="link"
    * displaying TalkBack rectangle around nested Text with accessibilityRole="link"

## Changelog

[Android] [Added] - Make links independently focusable by Talkback

Pull Request resolved: https://github.com/facebook/react-native/pull/33215

Test Plan:
[1]. User Interacts with links through TalkBack default accessibility menu ([link][1])
[2]. The nested link becomes the next focusable element after the parent element that contains it. ([link][2])
[3]. Testing accessibility examples in pr branch ([link][3])
[4]. Testing accessibility android examples in pr branch ([link][4])
[7]. TalkBack focus moves through links in the correct order from top to bottom (PR Branch with [link.id][25]) ([link to video test][7]) ([discussion][26])
[8]. TalkBack focus does not move through links in the correct order from top to bottom (PR Branch without [link.id][25]) ([link to video test][8]) ([discussion][26])

Test on main branch
[5]. Testing accessibility examples in main branch ([link][5])
[6]. Testing accessibility android examples in main branch ([link][6])

[1]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1045593386
[2]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1045593164
[3]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1054900872
[4]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1054918634
[5]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1054888278
[6]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1054891828
[7]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1060073165
[8]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1060098381

[10]: https://github.com/blavalla "blavalla github profile"
[12]: https://github.com/aosp-mirror/platform_frameworks_base/blob/1ac46f932ef88a8f96d652580d8105e361ffc842/core/java/com/android/internal/widget/ExploreByTouchHelper.java#L48 "com/android/internal/widget/ExploreByTouchHelper.java#L48"
[13]: https://github.com/fabriziobertoglio1987/react-native-notes/issues/9#issuecomment-1046384200 "explanation of getVirtualViewAt and onPopulateBoundsForVirtualView"
[14]: https://github.com/aosp-mirror/platform_frameworks_base/blob/1ac46f932ef88a8f96d652580d8105e361ffc842/core/java/android/text/Spannable.java#L3 "core/java/android/text/Spannable.java#L3"
[15]: https://github.com/fabriziobertoglio1987/react-native/blob/561266fc180b96d6337d6c6c5c3323522d66cc44/ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTextViewManager.java#L70-L71 "react/views/text/ReactTextViewManager.java#L70-L71"
[16]: https://github.com/fabriziobertoglio1987/react-native/blob/561266fc180b96d6337d6c6c5c3323522d66cc44/ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactAccessibilityDelegate.java#L680-L685 "react/uimanager/ReactAccessibilityDelegate.java#L680-L685"
[17]: https://github.com/facebook/react-native/blob/561266fc180b96d6337d6c6c5c3323522d66cc44/ReactAndroid/src/main/java/com/facebook/react/views/text/TextLayoutManager.java#L126-L129 "react/views/text/TextLayoutManager.java#L126-L129"
[18]: https://github.com/facebook/react-native/commit/b352e2da8137452f66717cf1cecb2e72abd727d7
[19]: https://github.com/facebook/react-native/issues/30375#issuecomment-781494859 "explanation on how nested Text are converted to Android Spans"
[20]: https://github.com/aosp-mirror/platform_frameworks_base/blob/1ac46f932ef88a8f96d652580d8105e361ffc842/core/java/android/widget/TextView.java#L214-L220 "core/java/android/widget/TextView.java#L214-L220"
[21]: https://github.com/facebook/react-native/blob/485cf6118b0ab0b59e078b96701b69ae64c4dfb7/ReactAndroid/src/main/java/com/facebook/react/views/text/ReactTextView.java#L577 "dispatchHoverEvent in ReactTextView"
[22]: https://github.com/aosp-mirror/platform_frameworks_base/blob/1ac46f932ef88a8f96d652580d8105e361ffc842/core/java/com/android/internal/widget/ExploreByTouchHelper.java#L120-L138 "dispatchHoverEvent in ExploreByTouchHelper"
[23]: https://github.com/facebook/react-native/issues/32004
[24]: https://github.com/facebook/react-native/pull/31757
[25]: https://github.com/fabriziobertoglio1987/react-native/blob/485cf6118b0ab0b59e078b96701b69ae64c4dfb7/ReactAndroid/src/main/java/com/facebook/react/uimanager/ReactAccessibilityDelegate.java#L648 "setting link.id in the AccessibilityLink constructor"
[26]: https://github.com/facebook/react-native/pull/33215/files/485cf6118b0ab0b59e078b96701b69ae64c4dfb7#r820014411 "comment on role of link.id"

Reviewed By: blavalla

Differential Revision: D34687371

Pulled By: philIip

fbshipit-source-id: 8e63c70e9318ad8d27317bd68497705e595dea0f
2022-03-29 13:36:24 -07:00

270 lines
8.0 KiB
JavaScript

/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*
* @format
* @flow strict-local
*/
'use strict';
const React = require('react');
import RNTesterBlock from '../../components/RNTesterBlock';
import RNTesterPage from '../../components/RNTesterPage';
import {
Alert,
StyleSheet,
Text,
View,
TouchableWithoutFeedback,
} from 'react-native';
const importantForAccessibilityValues = [
'auto',
'yes',
'no',
'no-hide-descendants',
];
type AccessibilityAndroidExampleState = {
count: number,
backgroundImportantForAcc: number,
forgroundImportantForAcc: number,
};
class AccessibilityAndroidExample extends React.Component<
{},
AccessibilityAndroidExampleState,
> {
state: AccessibilityAndroidExampleState = {
count: 0,
backgroundImportantForAcc: 0,
forgroundImportantForAcc: 0,
};
_addOne = () => {
this.setState({
count: ++this.state.count,
});
};
_changeBackgroundImportantForAcc = () => {
this.setState({
backgroundImportantForAcc: (this.state.backgroundImportantForAcc + 1) % 4,
});
};
_changeForgroundImportantForAcc = () => {
this.setState({
forgroundImportantForAcc: (this.state.forgroundImportantForAcc + 1) % 4,
});
};
render(): React.Node {
return (
<RNTesterPage title={'Accessibility Android APIs'}>
<RNTesterBlock title="LiveRegion">
<TouchableWithoutFeedback onPress={this._addOne}>
<View style={styles.embedded}>
<Text>Click me</Text>
</View>
</TouchableWithoutFeedback>
<View accessibilityLiveRegion="polite">
<Text>Clicked {this.state.count} times</Text>
</View>
</RNTesterBlock>
<RNTesterBlock title="Overlapping views and importantForAccessibility property">
<View style={styles.container}>
<TouchableWithoutFeedback
accessible={true}
accessibilityLabel="First layout"
importantForAccessibility={
importantForAccessibilityValues[
this.state.backgroundImportantForAcc
]
}>
<View accessible={true} style={styles.touchableContainer}>
<Text style={{fontSize: 25}}>Hello</Text>
</View>
</TouchableWithoutFeedback>
<View
style={{
position: 'absolute',
left: 10,
top: 25,
right: 10,
height: 110,
backgroundColor: 'yellow',
opacity: 0.5,
}}
accessible={true}
accessibilityLabel="Second layout"
importantForAccessibility={
importantForAccessibilityValues[
this.state.forgroundImportantForAcc
]
}>
<View accessible={true}>
<Text style={{fontSize: 20}}>world</Text>
</View>
</View>
</View>
<TouchableWithoutFeedback
onPress={this._changeBackgroundImportantForAcc}>
<View style={styles.embedded}>
<Text>
Change importantForAccessibility for background layout.
</Text>
</View>
</TouchableWithoutFeedback>
<View accessible={true}>
<Text>Background layout importantForAccessibility</Text>
<Text>
{
importantForAccessibilityValues[
this.state.backgroundImportantForAcc
]
}
</Text>
</View>
<TouchableWithoutFeedback
onPress={this._changeForgroundImportantForAcc}>
<View style={styles.embedded}>
<Text>
Change importantForAccessibility for forground layout.
</Text>
</View>
</TouchableWithoutFeedback>
<View accessible={true}>
<Text>Forground layout importantForAccessibility</Text>
<Text>
{
importantForAccessibilityValues[
this.state.forgroundImportantForAcc
]
}
</Text>
</View>
</RNTesterBlock>
<RNTesterBlock title="Links">
<Text style={styles.paragraph}>
In the following example, the words "test", "inline links", "another
link", and "link that spans multiple lines because the text is so
long", should each be independantly focusable elements, announced as
their content followed by ", Link".
</Text>
<Text style={styles.paragraph}>
They should be focused in order from top to bottom *after* the
contents of the entire paragraph.
</Text>
<Text style={styles.paragraph}>
Focusing on the paragraph itself should also announce that there are
"links avaialable", and opening Talkback's links menu should show
these same links.
</Text>
<Text style={styles.paragraph}>
Clicking on each link, or selecting the link From Talkback's links
menu should trigger an alert.
</Text>
<Text style={styles.paragraph}>
The links that wraps to multiple lines will intentionally only draw
a focus outline around the first line, but using the "explore by
touch" tap-and-drag gesture should move focus to this link even if
the second line is touched.
</Text>
<Text style={styles.paragraph}>
Using the "Explore by touch" gesture and touching an area that is
*not* a link should move focus to the entire paragraph.
</Text>
<Text style={styles.exampleTitle}>Example</Text>
<Text style={styles.paragraph} accessible={true}>
This is a{' '}
<Text
style={styles.link}
accessibilityRole="link"
onPress={() => {
Alert.alert('pressed test');
}}>
test
</Text>{' '}
of{' '}
<Text
style={styles.link}
accessibilityRole="link"
onPress={() => {
Alert.alert('pressed Inline Links');
}}>
inline links
</Text>{' '}
in React Native. Here's{' '}
<Text
style={styles.link}
accessibilityRole="link"
onPress={() => {
Alert.alert('pressed another link');
}}>
another link
</Text>
. Here is a{' '}
<Text
style={styles.link}
accessibilityRole="link"
onPress={() => {
Alert.alert('pressed long link');
}}>
link that spans multiple lines because the text is so long.
</Text>
This sentence has no links in it.
</Text>
</RNTesterBlock>
</RNTesterPage>
);
}
}
const styles = StyleSheet.create({
touchableContainer: {
position: 'absolute',
left: 10,
top: 10,
right: 10,
height: 100,
backgroundColor: 'green',
},
embedded: {
backgroundColor: 'yellow',
padding: 10,
},
container: {
flex: 1,
backgroundColor: 'white',
padding: 10,
height: 150,
},
paragraph: {
paddingBottom: 10,
},
link: {
color: 'blue',
fontWeight: 'bold',
},
exampleTitle: {
fontWeight: 'bold',
fontSize: 20,
},
});
exports.title = 'AccessibilityAndroid';
exports.description = 'Android specific Accessibility APIs.';
exports.examples = [
{
title: 'Accessibility elements',
render(): React.Element<typeof AccessibilityAndroidExample> {
return <AccessibilityAndroidExample />;
},
},
];