com.facebook.react.uimanager.AccessibilityRoleUtil.java Source code

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Here is the source code for com.facebook.react.uimanager.AccessibilityRoleUtil.java

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// Copyright (c) 2004-present, Facebook, Inc.

// 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.annotation.TargetApi;
import android.content.Context;
import android.os.Build;
import android.support.v4.view.AccessibilityDelegateCompat;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
import android.view.View;
import android.view.accessibility.AccessibilityNodeInfo;
import com.facebook.react.R;
import com.facebook.react.bridge.ReadableArray;
import java.util.Locale;
import javax.annotation.Nullable;

/**
 * Utility class that handles the addition of a "role" for accessibility to either a View or
 * AccessibilityNodeInfo.
 */

public class AccessibilityRoleUtil {

    /**
     * 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(null), BUTTON("android.widget.Button"), LINK("android.widget.ViewGroup"), SEARCH(
                "android.widget.EditText"), IMAGE("android.widget.ImageView"), IMAGEBUTTON(
                        "android.widget.ImageView"), KEYBOARDKEY("android.inputmethodservice.Keyboard$Key"), TEXT(
                                "android.widget.ViewGroup"), ADJUSTABLE("android.widget.SeekBar");

        @Nullable
        private final String mValue;

        AccessibilityRole(String type) {
            mValue = type;
        }

        @Nullable
        public String getValue() {
            return mValue;
        }

        public static AccessibilityRole fromValue(String value) {
            for (AccessibilityRole role : AccessibilityRole.values()) {
                if (role.getValue() != null && role.getValue().equals(value)) {
                    return role;
                }
            }
            return AccessibilityRole.NONE;
        }
    }

    private AccessibilityRoleUtil() {
        // No instances
    }

    public static void setRole(final View view, final AccessibilityRole role) {
        // if a view already has an accessibility delegate, replacing it could cause problems,
        // so leave it alone.
        if (!ViewCompat.hasAccessibilityDelegate(view)) {
            ViewCompat.setAccessibilityDelegate(view, new AccessibilityDelegateCompat() {
                @Override
                public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
                    super.onInitializeAccessibilityNodeInfo(host, info);
                    setRole(info, role, view.getContext());
                }
            });
        }
    }

    /**
     * Strings for setting the Role Description in english
     */

    //TODO: Eventually support fot other languages on talkback

    public static void setRole(AccessibilityNodeInfoCompat nodeInfo, final AccessibilityRole role,
            final Context context) {
        nodeInfo.setClassName(role.getValue());
        if (Locale.getDefault().getLanguage().equals(new Locale("en").getLanguage())) {
            if (role.equals(AccessibilityRole.LINK)) {
                nodeInfo.setRoleDescription(context.getString(R.string.link_description));
            }
            if (role.equals(AccessibilityRole.SEARCH)) {
                nodeInfo.setRoleDescription(context.getString(R.string.search_description));
            }
            if (role.equals(AccessibilityRole.IMAGE)) {
                nodeInfo.setRoleDescription(context.getString(R.string.image_description));
            }
            if (role.equals(AccessibilityRole.IMAGEBUTTON)) {
                nodeInfo.setRoleDescription(context.getString(R.string.image_button_description));
            }
            if (role.equals(AccessibilityRole.ADJUSTABLE)) {
                nodeInfo.setRoleDescription(context.getString(R.string.adjustable_description));
            }
        }
        if (role.equals(AccessibilityRole.IMAGEBUTTON)) {
            nodeInfo.setClickable(true);
        }
    }

    /**
     * Method for setting accessibilityRole on view properties.
     */
    public static void updateAccessibilityRole(View view, String role) {
        if (role == null) {
            view.setAccessibilityDelegate(null);
        }
        try {
            setRole(view, AccessibilityRole.valueOf(role.toUpperCase()));
        } catch (NullPointerException e) {
            view.setAccessibilityDelegate(null);
        } catch (IllegalArgumentException e) {
            view.setAccessibilityDelegate(null);
        }
    }
}