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ReactAccessibilityDelegate.java
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ReactAccessibilityDelegate.java
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/*
* 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.
*/
package com.facebook.react.uimanager;
import android.content.Context;
import android.graphics.Paint;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.text.Layout;
import android.text.Spannable;
import android.text.Spanned;
import android.text.TextUtils;
import android.text.style.AbsoluteSizeSpan;
import android.text.style.ClickableSpan;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.widget.EditText;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.core.view.ViewCompat;
import androidx.core.view.accessibility.AccessibilityNodeInfoCompat;
import androidx.core.view.accessibility.AccessibilityNodeInfoCompat.AccessibilityActionCompat;
import androidx.core.view.accessibility.AccessibilityNodeInfoCompat.RangeInfoCompat;
import androidx.core.view.accessibility.AccessibilityNodeProviderCompat;
import androidx.customview.widget.ExploreByTouchHelper;
import com.facebook.react.R;
import com.facebook.react.bridge.Arguments;
import com.facebook.react.bridge.Dynamic;
import com.facebook.react.bridge.ReactContext;
import com.facebook.react.bridge.ReactNoCrashSoftException;
import com.facebook.react.bridge.ReactSoftExceptionLogger;
import com.facebook.react.bridge.ReadableArray;
import com.facebook.react.bridge.ReadableMap;
import com.facebook.react.bridge.ReadableMapKeySetIterator;
import com.facebook.react.bridge.ReadableType;
import com.facebook.react.bridge.UIManager;
import com.facebook.react.bridge.WritableMap;
import com.facebook.react.uimanager.ReactAccessibilityDelegate.AccessibilityRole;
import com.facebook.react.uimanager.events.Event;
import com.facebook.react.uimanager.events.EventDispatcher;
import com.facebook.react.uimanager.util.ReactFindViewUtil;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
/**
* Utility class that handles the addition of a "role" for accessibility to either a View or
* AccessibilityNodeInfo.
*/
public class ReactAccessibilityDelegate extends ExploreByTouchHelper {
private static final String TAG = "ReactAccessibilityDelegate";
public static final String TOP_ACCESSIBILITY_ACTION_EVENT = "topAccessibilityAction";
private static int sCounter = 0x3f000000;
private static final int TIMEOUT_SEND_ACCESSIBILITY_EVENT = 200;
private static final int SEND_EVENT = 1;
private static final String delimiter = ", ";
private static final int delimiterLength = delimiter.length();
public static final HashMap<String, Integer> sActionIdMap = new HashMap<>();
static {
sActionIdMap.put("activate", AccessibilityActionCompat.ACTION_CLICK.getId());
sActionIdMap.put("longpress", AccessibilityActionCompat.ACTION_LONG_CLICK.getId());
sActionIdMap.put("increment", AccessibilityActionCompat.ACTION_SCROLL_FORWARD.getId());
sActionIdMap.put("decrement", AccessibilityActionCompat.ACTION_SCROLL_BACKWARD.getId());
}
private final View mView;
private final AccessibilityLinks mAccessibilityLinks;
private Handler mHandler;
/**
* Schedule a command for sending an accessibility event. </br> Note: A command is used to ensure
* that accessibility events are sent at most one in a given time frame to save system resources
* while the progress changes quickly.
*/
private void scheduleAccessibilityEventSender(View host) {
if (mHandler.hasMessages(SEND_EVENT, host)) {
mHandler.removeMessages(SEND_EVENT, host);
}
Message msg = mHandler.obtainMessage(SEND_EVENT, host);
mHandler.sendMessageDelayed(msg, TIMEOUT_SEND_ACCESSIBILITY_EVENT);
}
/**
* These roles are defined by Google's TalkBack screen reader, and this list should be kept up to
* date with their implementation. Details can be seen in their source code here:
*
* <p>https://github.com/google/talkback/blob/master/utils/src/main/java/Role.java
*/
public enum AccessibilityRole {
NONE,
BUTTON,
TOGGLEBUTTON,
LINK,
SEARCH,
IMAGE,
IMAGEBUTTON,
KEYBOARDKEY,
TEXT,
ADJUSTABLE,
SUMMARY,
HEADER,
ALERT,
CHECKBOX,
COMBOBOX,
MENU,
MENUBAR,
MENUITEM,
PROGRESSBAR,
RADIO,
RADIOGROUP,
SCROLLBAR,
SPINBUTTON,
SWITCH,
TAB,
TABLIST,
TIMER,
LIST,
GRID,
TOOLBAR;
public static String getValue(AccessibilityRole role) {
switch (role) {
case BUTTON:
return "android.widget.Button";
case TOGGLEBUTTON:
return "android.widget.ToggleButton";
case SEARCH:
return "android.widget.EditText";
case IMAGE:
return "android.widget.ImageView";
case IMAGEBUTTON:
return "android.widget.ImageButon";
case KEYBOARDKEY:
return "android.inputmethodservice.Keyboard$Key";
case TEXT:
return "android.widget.TextView";
case ADJUSTABLE:
return "android.widget.SeekBar";
case CHECKBOX:
return "android.widget.CheckBox";
case RADIO:
return "android.widget.RadioButton";
case SPINBUTTON:
return "android.widget.SpinButton";
case SWITCH:
return "android.widget.Switch";
case LIST:
return "android.widget.AbsListView";
case GRID:
return "android.widget.GridView";
case NONE:
case LINK:
case SUMMARY:
case HEADER:
case ALERT:
case COMBOBOX:
case MENU:
case MENUBAR:
case MENUITEM:
case PROGRESSBAR:
case RADIOGROUP:
case SCROLLBAR:
case TAB:
case TABLIST:
case TIMER:
case TOOLBAR:
return "android.view.View";
default:
throw new IllegalArgumentException("Invalid accessibility role value: " + role);
}
}
public static AccessibilityRole fromValue(@Nullable String value) {
for (AccessibilityRole role : AccessibilityRole.values()) {
if (role.name().equalsIgnoreCase(value)) {
return role;
}
}
throw new IllegalArgumentException("Invalid accessibility role value: " + value);
}
public static @Nullable String fromAnyValue(@Nullable String value) {
for (AccessibilityRole role : AccessibilityRole.values()) {
if (getValue(role).equalsIgnoreCase(value)) {
return role.toString();
}
}
return null;
}
}
private final HashMap<Integer, String> mAccessibilityActionsMap;
// State constants for states which have analogs in AccessibilityNodeInfo
private static final String STATE_DISABLED = "disabled";
private static final String STATE_SELECTED = "selected";
private static final String STATE_CHECKED = "checked";
public ReactAccessibilityDelegate(
final View view, boolean originalFocus, int originalImportantForAccessibility) {
super(view);
mView = view;
mAccessibilityActionsMap = new HashMap<Integer, String>();
mHandler =
new Handler() {
@Override
public void handleMessage(Message msg) {
View host = (View) msg.obj;
host.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED);
}
};
// We need to reset these two properties, as ExploreByTouchHelper sets focusable to "true" and
// importantForAccessibility to "Yes" (if it is Auto). If we don't reset these it would force
// every element that has this delegate attached to be focusable, and not allow for
// announcement coalescing.
mView.setFocusable(originalFocus);
ViewCompat.setImportantForAccessibility(mView, originalImportantForAccessibility);
mAccessibilityLinks = (AccessibilityLinks) mView.getTag(R.id.accessibility_links);
}
@Nullable View mAccessibilityLabelledBy;
@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
super.onInitializeAccessibilityNodeInfo(host, info);
final AccessibilityRole accessibilityRole =
(AccessibilityRole) host.getTag(R.id.accessibility_role);
if (accessibilityRole != null) {
setRole(info, accessibilityRole, host.getContext());
}
final Object accessibilityLabelledBy = host.getTag(R.id.labelled_by);
if (accessibilityLabelledBy != null) {
mAccessibilityLabelledBy =
ReactFindViewUtil.findView(host.getRootView(), (String) accessibilityLabelledBy);
if (mAccessibilityLabelledBy != null) {
info.setLabeledBy(mAccessibilityLabelledBy);
}
}
// state is changeable.
final ReadableMap accessibilityState = (ReadableMap) host.getTag(R.id.accessibility_state);
if (accessibilityState != null) {
setState(info, accessibilityState, host.getContext());
}
final ReadableArray accessibilityActions =
(ReadableArray) host.getTag(R.id.accessibility_actions);
if (accessibilityActions != null) {
for (int i = 0; i < accessibilityActions.size(); i++) {
final ReadableMap action = accessibilityActions.getMap(i);
if (!action.hasKey("name")) {
throw new IllegalArgumentException("Unknown accessibility action.");
}
int actionId = sCounter;
String actionLabel = action.hasKey("label") ? action.getString("label") : null;
if (sActionIdMap.containsKey(action.getString("name"))) {
actionId = sActionIdMap.get(action.getString("name"));
} else {
sCounter++;
}
mAccessibilityActionsMap.put(actionId, action.getString("name"));
final AccessibilityActionCompat accessibilityAction =
new AccessibilityActionCompat(actionId, actionLabel);
info.addAction(accessibilityAction);
}
}
// Process accessibilityValue
final ReadableMap accessibilityValue = (ReadableMap) host.getTag(R.id.accessibility_value);
if (accessibilityValue != null
&& accessibilityValue.hasKey("min")
&& accessibilityValue.hasKey("now")
&& accessibilityValue.hasKey("max")) {
final Dynamic minDynamic = accessibilityValue.getDynamic("min");
final Dynamic nowDynamic = accessibilityValue.getDynamic("now");
final Dynamic maxDynamic = accessibilityValue.getDynamic("max");
if (minDynamic != null
&& minDynamic.getType() == ReadableType.Number
&& nowDynamic != null
&& nowDynamic.getType() == ReadableType.Number
&& maxDynamic != null
&& maxDynamic.getType() == ReadableType.Number) {
final int min = minDynamic.asInt();
final int now = nowDynamic.asInt();
final int max = maxDynamic.asInt();
if (max > min && now >= min && max >= now) {
info.setRangeInfo(RangeInfoCompat.obtain(RangeInfoCompat.RANGE_TYPE_INT, min, max, now));
}
}
}
// Expose the testID prop as the resource-id name of the view. Black-box E2E/UI testing
// frameworks, which interact with the UI through the accessibility framework, do not have
// access to view tags. This allows developers/testers to avoid polluting the
// content-description with test identifiers.
final String testId = (String) host.getTag(R.id.react_test_id);
if (testId != null) {
info.setViewIdResourceName(testId);
}
// need to check that string length is not == 0
boolean missingContentDescription = TextUtils.isEmpty(info.getContentDescription());
boolean missingText = TextUtils.isEmpty(info.getText());
boolean missingTextOrDescription = missingContentDescription && missingText;
// add check on placeholder
boolean hasContentToAnnounce =
accessibilityActions != null
|| accessibilityState != null
|| accessibilityLabelledBy != null
|| accessibilityRole != null;
if (missingTextOrDescription && hasContentToAnnounce) {
info.setContentDescription(getTalkbackDescription(host, info));
}
}
@Override
public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(host, event);
// Set item count and current item index on accessibility events for adjustable
// in order to make Talkback announce the value of the adjustable
final ReadableMap accessibilityValue = (ReadableMap) host.getTag(R.id.accessibility_value);
if (accessibilityValue != null
&& accessibilityValue.hasKey("min")
&& accessibilityValue.hasKey("now")
&& accessibilityValue.hasKey("max")) {
final Dynamic minDynamic = accessibilityValue.getDynamic("min");
final Dynamic nowDynamic = accessibilityValue.getDynamic("now");
final Dynamic maxDynamic = accessibilityValue.getDynamic("max");
if (minDynamic != null
&& minDynamic.getType() == ReadableType.Number
&& nowDynamic != null
&& nowDynamic.getType() == ReadableType.Number
&& maxDynamic != null
&& maxDynamic.getType() == ReadableType.Number) {
final int min = minDynamic.asInt();
final int now = nowDynamic.asInt();
final int max = maxDynamic.asInt();
if (max > min && now >= min && max >= now) {
event.setItemCount(max - min);
event.setCurrentItemIndex(now);
}
}
}
}
@Override
public boolean performAccessibilityAction(View host, int action, Bundle args) {
if (mAccessibilityActionsMap.containsKey(action)) {
final WritableMap event = Arguments.createMap();
event.putString("actionName", mAccessibilityActionsMap.get(action));
ReactContext reactContext = (ReactContext) host.getContext();
if (reactContext.hasActiveReactInstance()) {
final int reactTag = host.getId();
final int surfaceId = UIManagerHelper.getSurfaceId(reactContext);
UIManager uiManager = UIManagerHelper.getUIManager(reactContext, reactTag);
if (uiManager != null) {
uiManager
.<EventDispatcher>getEventDispatcher()
.dispatchEvent(
new Event(surfaceId, reactTag) {
@Override
public String getEventName() {
return TOP_ACCESSIBILITY_ACTION_EVENT;
}
@Override
protected WritableMap getEventData() {
return event;
}
});
}
} else {
ReactSoftExceptionLogger.logSoftException(
TAG, new ReactNoCrashSoftException("Cannot get RCTEventEmitter, no CatalystInstance"));
}
// In order to make Talkback announce the change of the adjustable's value,
// schedule to send a TYPE_VIEW_SELECTED event after performing the scroll actions.
final AccessibilityRole accessibilityRole =
(AccessibilityRole) host.getTag(R.id.accessibility_role);
final ReadableMap accessibilityValue = (ReadableMap) host.getTag(R.id.accessibility_value);
if (accessibilityRole == AccessibilityRole.ADJUSTABLE
&& (action == AccessibilityActionCompat.ACTION_SCROLL_FORWARD.getId()
|| action == AccessibilityActionCompat.ACTION_SCROLL_BACKWARD.getId())) {
if (accessibilityValue != null && !accessibilityValue.hasKey("text")) {
scheduleAccessibilityEventSender(host);
}
return super.performAccessibilityAction(host, action, args);
}
return true;
}
return super.performAccessibilityAction(host, action, args);
}
private static void setState(
AccessibilityNodeInfoCompat info, ReadableMap accessibilityState, Context context) {
final ReadableMapKeySetIterator i = accessibilityState.keySetIterator();
while (i.hasNextKey()) {
final String state = i.nextKey();
final Dynamic value = accessibilityState.getDynamic(state);
if (state.equals(STATE_SELECTED) && value.getType() == ReadableType.Boolean) {
info.setSelected(value.asBoolean());
} else if (state.equals(STATE_DISABLED) && value.getType() == ReadableType.Boolean) {
info.setEnabled(!value.asBoolean());
} else if (state.equals(STATE_CHECKED) && value.getType() == ReadableType.Boolean) {
final boolean boolValue = value.asBoolean();
info.setCheckable(true);
info.setChecked(boolValue);
if (info.getClassName().equals(AccessibilityRole.getValue(AccessibilityRole.SWITCH))) {
info.setText(
context.getString(
boolValue ? R.string.state_on_description : R.string.state_off_description));
}
}
}
}
/** Strings for setting the Role Description in english */
// TODO: Eventually support for other languages on talkback
public static void setRole(
AccessibilityNodeInfoCompat nodeInfo, AccessibilityRole role, final Context context) {
if (role == null) {
role = AccessibilityRole.NONE;
}
nodeInfo.setClassName(AccessibilityRole.getValue(role));
if (role.equals(AccessibilityRole.LINK)) {
nodeInfo.setRoleDescription(context.getString(R.string.link_description));
} else if (role.equals(AccessibilityRole.IMAGE)) {
nodeInfo.setRoleDescription(context.getString(R.string.image_description));
} else if (role.equals(AccessibilityRole.IMAGEBUTTON)) {
nodeInfo.setRoleDescription(context.getString(R.string.imagebutton_description));
nodeInfo.setClickable(true);
} else if (role.equals(AccessibilityRole.BUTTON)) {
nodeInfo.setClickable(true);
} else if (role.equals(AccessibilityRole.TOGGLEBUTTON)) {
nodeInfo.setClickable(true);
nodeInfo.setCheckable(true);
} else if (role.equals(AccessibilityRole.SUMMARY)) {
nodeInfo.setRoleDescription(context.getString(R.string.summary_description));
} else if (role.equals(AccessibilityRole.HEADER)) {
final AccessibilityNodeInfoCompat.CollectionItemInfoCompat itemInfo =
AccessibilityNodeInfoCompat.CollectionItemInfoCompat.obtain(0, 1, 0, 1, true);
nodeInfo.setCollectionItemInfo(itemInfo);
} else if (role.equals(AccessibilityRole.ALERT)) {
nodeInfo.setRoleDescription(context.getString(R.string.alert_description));
} else if (role.equals(AccessibilityRole.COMBOBOX)) {
nodeInfo.setRoleDescription(context.getString(R.string.combobox_description));
} else if (role.equals(AccessibilityRole.MENU)) {
nodeInfo.setRoleDescription(context.getString(R.string.menu_description));
} else if (role.equals(AccessibilityRole.MENUBAR)) {
nodeInfo.setRoleDescription(context.getString(R.string.menubar_description));
} else if (role.equals(AccessibilityRole.MENUITEM)) {
nodeInfo.setRoleDescription(context.getString(R.string.menuitem_description));
} else if (role.equals(AccessibilityRole.PROGRESSBAR)) {
nodeInfo.setRoleDescription(context.getString(R.string.progressbar_description));
} else if (role.equals(AccessibilityRole.RADIOGROUP)) {
nodeInfo.setRoleDescription(context.getString(R.string.radiogroup_description));
} else if (role.equals(AccessibilityRole.SCROLLBAR)) {
nodeInfo.setRoleDescription(context.getString(R.string.scrollbar_description));
} else if (role.equals(AccessibilityRole.SPINBUTTON)) {
nodeInfo.setRoleDescription(context.getString(R.string.spinbutton_description));
} else if (role.equals(AccessibilityRole.TAB)) {
nodeInfo.setRoleDescription(context.getString(R.string.rn_tab_description));
} else if (role.equals(AccessibilityRole.TABLIST)) {
nodeInfo.setRoleDescription(context.getString(R.string.tablist_description));
} else if (role.equals(AccessibilityRole.TIMER)) {
nodeInfo.setRoleDescription(context.getString(R.string.timer_description));
} else if (role.equals(AccessibilityRole.TOOLBAR)) {
nodeInfo.setRoleDescription(context.getString(R.string.toolbar_description));
}
}
public static void setDelegate(
final View view, boolean originalFocus, int originalImportantForAccessibility) {
// if a view already has an accessibility delegate, replacing it could cause
// problems,
// so leave it alone.
if (!ViewCompat.hasAccessibilityDelegate(view)
&& (view.getTag(R.id.accessibility_role) != null
|| view.getTag(R.id.accessibility_state) != null
|| view.getTag(R.id.accessibility_actions) != null
|| view.getTag(R.id.react_test_id) != null
|| view.getTag(R.id.accessibility_links) != null)) {
ViewCompat.setAccessibilityDelegate(
view,
new ReactAccessibilityDelegate(view, originalFocus, originalImportantForAccessibility));
}
}
// Explicitly re-set the delegate, even if one has already been set.
public static void resetDelegate(
final View view, boolean originalFocus, int originalImportantForAccessibility) {
ViewCompat.setAccessibilityDelegate(
view,
new ReactAccessibilityDelegate(view, originalFocus, originalImportantForAccessibility));
}
@Override
protected int getVirtualViewAt(float x, float y) {
if (mAccessibilityLinks == null
|| mAccessibilityLinks.size() == 0
|| !(mView instanceof TextView)) {
return INVALID_ID;
}
TextView textView = (TextView) mView;
if (!(textView.getText() instanceof Spanned)) {
return INVALID_ID;
}
Layout layout = textView.getLayout();
if (layout == null) {
return INVALID_ID;
}
x -= textView.getTotalPaddingLeft();
y -= textView.getTotalPaddingTop();
x += textView.getScrollX();
y += textView.getScrollY();
int line = layout.getLineForVertical((int) y);
int charOffset = layout.getOffsetForHorizontal(line, x);
ClickableSpan clickableSpan = getFirstSpan(charOffset, charOffset, ClickableSpan.class);
if (clickableSpan == null) {
return INVALID_ID;
}
Spanned spanned = (Spanned) textView.getText();
int start = spanned.getSpanStart(clickableSpan);
int end = spanned.getSpanEnd(clickableSpan);
final AccessibilityLinks.AccessibleLink link = mAccessibilityLinks.getLinkBySpanPos(start, end);
return link != null ? link.id : INVALID_ID;
}
@Override
protected void getVisibleVirtualViews(List<Integer> virtualViewIds) {
if (mAccessibilityLinks == null) {
return;
}
for (int i = 0; i < mAccessibilityLinks.size(); i++) {
virtualViewIds.add(i);
}
}
@Override
protected void onPopulateNodeForVirtualView(
int virtualViewId, @NonNull AccessibilityNodeInfoCompat node) {
// If we get an invalid virtualViewId for some reason (which is known to happen in API 19 and
// below), return an "empty" node to prevent from crashing. This will never be presented to
// the user, as Talkback filters out nodes with no content to announce.
if (mAccessibilityLinks == null) {
node.setContentDescription("");
node.setBoundsInParent(new Rect(0, 0, 1, 1));
return;
}
final AccessibilityLinks.AccessibleLink accessibleTextSpan =
mAccessibilityLinks.getLinkById(virtualViewId);
if (accessibleTextSpan == null) {
node.setContentDescription("");
node.setBoundsInParent(new Rect(0, 0, 1, 1));
return;
}
node.setContentDescription(accessibleTextSpan.description);
node.addAction(AccessibilityNodeInfoCompat.ACTION_CLICK);
node.setBoundsInParent(getBoundsInParent(accessibleTextSpan));
node.setRoleDescription(mView.getResources().getString(R.string.link_description));
node.setClassName(AccessibilityRole.getValue(AccessibilityRole.BUTTON));
}
private Rect getBoundsInParent(AccessibilityLinks.AccessibleLink accessibleLink) {
// This view is not a text view, so return the entire views bounds.
if (!(mView instanceof TextView)) {
return new Rect(0, 0, mView.getWidth(), mView.getHeight());
}
TextView textView = (TextView) mView;
Layout textViewLayout = textView.getLayout();
if (textViewLayout == null) {
return new Rect(0, 0, textView.getWidth(), textView.getHeight());
}
Rect rootRect = new Rect();
double startOffset = accessibleLink.start;
double endOffset = accessibleLink.end;
double startXCoordinates = textViewLayout.getPrimaryHorizontal((int) startOffset);
final Paint paint = new Paint();
AbsoluteSizeSpan sizeSpan =
getFirstSpan(accessibleLink.start, accessibleLink.end, AbsoluteSizeSpan.class);
float textSize = sizeSpan != null ? sizeSpan.getSize() : textView.getTextSize();
paint.setTextSize(textSize);
int textWidth = (int) Math.ceil(paint.measureText(accessibleLink.description));
int startOffsetLineNumber = textViewLayout.getLineForOffset((int) startOffset);
int endOffsetLineNumber = textViewLayout.getLineForOffset((int) endOffset);
boolean isMultiline = startOffsetLineNumber != endOffsetLineNumber;
textViewLayout.getLineBounds(startOffsetLineNumber, rootRect);
int verticalOffset = textView.getScrollY() + textView.getTotalPaddingTop();
rootRect.top += verticalOffset;
rootRect.bottom += verticalOffset;
rootRect.left += startXCoordinates + textView.getTotalPaddingLeft() - textView.getScrollX();
// The bounds for multi-line strings should *only* include the first line. This is because for
// API 25 and below, Talkback's click is triggered at the center point of these bounds, and if
// that center point is outside the spannable, it will click on something else. There is no
// harm in not outlining the wrapped part of the string, as the text for the whole string will
// be read regardless of the bounding box.
if (isMultiline) {
return new Rect(rootRect.left, rootRect.top, rootRect.right, rootRect.bottom);
}
return new Rect(rootRect.left, rootRect.top, rootRect.left + textWidth, rootRect.bottom);
}
@Override
protected boolean onPerformActionForVirtualView(
int virtualViewId, int action, @Nullable Bundle arguments) {
return false;
}
protected @Nullable <T> T getFirstSpan(int start, int end, Class<T> classType) {
if (!(mView instanceof TextView) || !(((TextView) mView).getText() instanceof Spanned)) {
return null;
}
Spanned spanned = (Spanned) ((TextView) mView).getText();
T[] spans = spanned.getSpans(start, end, classType);
return spans.length > 0 ? spans[0] : null;
}
public static class AccessibilityLinks {
private final List<AccessibleLink> mLinks;
public AccessibilityLinks(ClickableSpan[] spans, Spannable text) {
ArrayList<AccessibleLink> links = new ArrayList<>();
for (int i = 0; i < spans.length; i++) {
ClickableSpan span = spans[i];
int start = text.getSpanStart(span);
int end = text.getSpanEnd(span);
// zero length spans, and out of range spans should not be included.
if (start == end || start < 0 || end < 0 || start > text.length() || end > text.length()) {
continue;
}
final AccessibleLink link = new AccessibleLink();
link.description = text.subSequence(start, end).toString();
link.start = start;
link.end = end;
// ID is the reverse of what is expected, since the ClickableSpans are returned in reverse
// order due to being added in reverse order. If we don't do this, focus will move to the
// last link first and move backwards.
//
// If this approach becomes unreliable, we should instead look at their start position and
// order them manually.
link.id = spans.length - 1 - i;
links.add(link);
}
mLinks = links;
}
@Nullable
public AccessibleLink getLinkById(int id) {
for (AccessibleLink link : mLinks) {
if (link.id == id) {
return link;
}
}
return null;
}
@Nullable
public AccessibleLink getLinkBySpanPos(int start, int end) {
for (AccessibleLink link : mLinks) {
if (link.start == start && link.end == end) {
return link;
}
}
return null;
}
public int size() {
return mLinks.size();
}
private static class AccessibleLink {
public String description;
public int start;
public int end;
public int id;
}
}
@Override
public @Nullable AccessibilityNodeProviderCompat getAccessibilityNodeProvider(View host) {
// Only set a NodeProvider if we have virtual views, otherwise just return null here so that
// we fall back to the View class's default behavior. If we don't do this, then Views with
// no virtual children will fall back to using ExploreByTouchHelper's onPopulateNodeForHost
// method to populate their AccessibilityNodeInfo, which defaults to doing nothing, so no
// AccessibilityNodeInfo will be created. Alternatively, we could override
// onPopulateNodeForHost instead, and have it create an AccessibilityNodeInfo for the host
// but this is what the default View class does by itself, so we may as well defer to it.
if (mAccessibilityLinks != null) {
return super.getAccessibilityNodeProvider(host);
}
return null;
}
/**
* Determines if the supplied {@link View} and {@link AccessibilityNodeInfoCompat} has any
* children which are not independently accessibility focusable and also have a spoken
* description.
*
* <p>NOTE: Accessibility services will include these children's descriptions in the closest
* focusable ancestor.
*
* @param view The {@link View} to evaluate
* @param node The {@link AccessibilityNodeInfoCompat} to evaluate
* @return {@code true} if it has any non-actionable speaking descendants within its subtree
*/
public static boolean hasNonActionableSpeakingDescendants(
@Nullable AccessibilityNodeInfoCompat node, @Nullable View view) {
if (node == null || view == null || !(view instanceof ViewGroup)) {
return false;
}
final ViewGroup viewGroup = (ViewGroup) view;
for (int i = 0, count = viewGroup.getChildCount(); i < count; i++) {
final View childView = viewGroup.getChildAt(i);
if (childView == null) {
continue;
}
final AccessibilityNodeInfoCompat childNode = AccessibilityNodeInfoCompat.obtain();
try {
ViewCompat.onInitializeAccessibilityNodeInfo(childView, childNode);
if (!childNode.isVisibleToUser()) {
continue;
}
if (isAccessibilityFocusable(childNode, childView)) {
continue;
}
if (isSpeakingNode(childNode, childView)) {
return true;
}
} finally {
if (childNode != null) {
childNode.recycle();
}
}
}
return false;
}
/**
* Returns whether the node has valid RangeInfo.
*
* @param node The node to check.
* @return Whether the node has valid RangeInfo.
*/
public static boolean hasValidRangeInfo(@Nullable AccessibilityNodeInfoCompat node) {
if (node == null) {
return false;
}
@Nullable final RangeInfoCompat rangeInfo = node.getRangeInfo();
if (rangeInfo == null) {
return false;
}
final float maxProgress = rangeInfo.getMax();
final float minProgress = rangeInfo.getMin();
final float currentProgress = rangeInfo.getCurrent();
final float diffProgress = maxProgress - minProgress;
return (diffProgress > 0.0f)
&& (currentProgress >= minProgress)
&& (currentProgress <= maxProgress);
}
/**
* Returns whether the specified node has state description.
*
* @param node The node to check.
* @return {@code true} if the node has state description.
*/
private static boolean hasStateDescription(@Nullable AccessibilityNodeInfoCompat node) {
return node != null
&& (!TextUtils.isEmpty(node.getStateDescription())
|| node.isCheckable()
|| hasValidRangeInfo(node));
}
/**
* Returns whether the supplied {@link View} and {@link AccessibilityNodeInfoCompat} would produce
* spoken feedback if it were accessibility focused. NOTE: not all speaking nodes are focusable.
*
* @param view The {@link View} to evaluate
* @param node The {@link AccessibilityNodeInfoCompat} to evaluate
* @return {@code true} if it meets the criterion for producing spoken feedback
*/
public static boolean isSpeakingNode(
@Nullable AccessibilityNodeInfoCompat node, @Nullable View view) {
if (node == null || view == null) {
return false;
}
final int important = ViewCompat.getImportantForAccessibility(view);
if (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS
|| (important == ViewCompat.IMPORTANT_FOR_ACCESSIBILITY_NO && node.getChildCount() <= 0)) {
return false;
}
return hasText(node)
|| hasStateDescription(node)
|| node.isCheckable()
|| hasNonActionableSpeakingDescendants(node, view);
}
public static boolean hasText(@Nullable AccessibilityNodeInfoCompat node) {
return node != null
&& node.getCollectionInfo() == null
&& (!TextUtils.isEmpty(node.getText())
|| !TextUtils.isEmpty(node.getContentDescription())
|| !TextUtils.isEmpty(node.getHintText()));
}
/**
* Determines if the provided {@link View} and {@link AccessibilityNodeInfoCompat} meet the
* criteria for gaining accessibility focus.
*
* <p>Note: this is evaluating general focusability by accessibility services, and does not mean
* this view will be guaranteed to be focused by specific services such as Talkback. For Talkback
* focusability, see {@link #isTalkbackFocusable(View)}
*
* @param view The {@link View} to evaluate
* @param node The {@link AccessibilityNodeInfoCompat} to evaluate
* @return {@code true} if it is possible to gain accessibility focus
*/
public static boolean isAccessibilityFocusable(
@Nullable AccessibilityNodeInfoCompat node, @Nullable View view) {
if (node == null || view == null) {
return false;
}
// Never focus invisible nodes.
if (!node.isVisibleToUser()) {
return false;
}
// Always focus "actionable" nodes.
return node.isScreenReaderFocusable() || isActionableForAccessibility(node);
}
/**
* Returns whether a node is actionable. That is, the node supports one of {@link
* AccessibilityNodeInfoCompat#isClickable()}, {@link AccessibilityNodeInfoCompat#isFocusable()},
* or {@link AccessibilityNodeInfoCompat#isLongClickable()}.
*
* @param node The {@link AccessibilityNodeInfoCompat} to evaluate
* @return {@code true} if node is actionable.
*/
public static boolean isActionableForAccessibility(@Nullable AccessibilityNodeInfoCompat node) {
if (node == null) {
return false;
}
if (node.isClickable() || node.isLongClickable() || node.isFocusable()) {
return true;
}
final List actionList = node.getActionList();
return actionList.contains(AccessibilityNodeInfoCompat.ACTION_CLICK)
|| actionList.contains(AccessibilityNodeInfoCompat.ACTION_LONG_CLICK)
|| actionList.contains(AccessibilityNodeInfoCompat.ACTION_FOCUS);
}
/**
* Returns a cached instance if such is available otherwise a new one.
*
* @param view The {@link View} to derive the AccessibilityNodeInfo properties from.
* @return {@link FlipperObject} containing the properties.
*/
@Nullable
public static AccessibilityNodeInfoCompat createNodeInfoFromView(View view) {
if (view == null) {
return null;
}
final AccessibilityNodeInfoCompat nodeInfo = AccessibilityNodeInfoCompat.obtain();
// For some unknown reason, Android seems to occasionally throw a NPE from
// onInitializeAccessibilityNodeInfo.
try {
ViewCompat.onInitializeAccessibilityNodeInfo(view, nodeInfo);
} catch (NullPointerException e) {
if (nodeInfo != null) {
nodeInfo.recycle();
}
return null;
}
return nodeInfo;
}
private static boolean supportsAction(AccessibilityNodeInfoCompat node, int action) {
if (node != null) {
final int supportedActions = node.getActions();
if ((supportedActions & action) == action) {
return true;
}
}
return false;
}
/**
* Adds the state segments of Talkback's response to a given list. This should be kept up to date
* as much as necessary. Details can be seen in the source code here :
*
* <p>https://github.com/google/talkback/compositor/src/main/res/raw/compositor.json - search for
* "description_for_tree_status", "get_switch_state"
*
* <p>https://github.com/google/talkback/compositor/src/main/res/values/strings.xml
*/
private static void addStateSegments(
StringBuilder talkbackSegments, AccessibilityNodeInfoCompat node) {
// selected status is always prepended
if (node.isSelected()) {
talkbackSegments.append("selected" + delimiter);
}
// documented in reactnative accessibilityState
// https://reactnative.dev/docs/accessibility#accessibilitystate
// next check collapse/expand/checked status
if (supportsAction(node, AccessibilityNodeInfoCompat.ACTION_EXPAND)) {
talkbackSegments.append("collapsed" + delimiter);
}
if (supportsAction(node, AccessibilityNodeInfoCompat.ACTION_COLLAPSE)) {
talkbackSegments.append("expanded" + delimiter);
}
}
public static @Nullable String getRoleDescription(AccessibilityNodeInfoCompat node) {
CharSequence role = node.getRoleDescription();
String roleDescription;
if (role == null || role == "") {
roleDescription =
ReactAccessibilityDelegate.AccessibilityRole.fromAnyValue((String) node.getClassName());
} else {
roleDescription = role.toString();
}
return roleDescription;
}
/**
* Creates the text that Google's TalkBack screen reader will read aloud for a given {@link View}.
* This may be any combination of the {@link View}'s {@code text}, {@code contentDescription}, and
* the {@code text} and {@code contentDescription} of any ancestor {@link View}.
*
* <p>This description is generally ported over from Google's TalkBack screen reader, and this
* should be kept up to date with their implementation (as much as necessary). Details can be seen
* in their source code here:
*