com.facebook.react.bridge.WritableNativeArray Java Examples

@ReactMethod
public void getCameraImages(ReadableMap data, Callback onSuccess) {
    WritableNativeArray result = new WritableNativeArray();

    for(CameraImage imageData : CameraImagesManager.getCameraImages(this.context,
            data.getInt("first"), data.hasKey("after") ? data.getString("after") : "")) {
        WritableMap imageDataMap = new WritableNativeMap();
        imageDataMap.putString("uri", imageData.getLocalPath());
        imageDataMap.putInt("width", imageData.getWidth());
        imageDataMap.putInt("height", imageData.getHeight());
        imageDataMap.putInt("orientation", imageData.getOrientation());
        imageDataMap.putString("timestamp", Long.toString(imageData.getTimestamp()));

        result.pushMap(imageDataMap);
    }

    onSuccess.invoke(result);
}
 

private WritableMap createRangingResponse(Collection<Beacon> beacons, Region region) {
    WritableMap map = new WritableNativeMap();
    map.putString("identifier", region.getUniqueId());
    map.putString("uuid", region.getId1() != null ? region.getId1().toString() : "");
    WritableArray a = new WritableNativeArray();
    for (Beacon beacon : beacons) {
        WritableMap b = new WritableNativeMap();
        b.putString("uuid", beacon.getId1().toString());
        b.putInt("major", beacon.getId2().toInt());
        b.putInt("minor", beacon.getId3().toInt());
        b.putInt("rssi", beacon.getRssi());
        b.putDouble("distance", beacon.getDistance());
        b.putString("proximity", getProximity(beacon.getDistance()));
        a.pushMap(b);
    }
    map.putArray("beacons", a);
    return map;
}
 

@ReactMethod
public void selectMemberFromGroup(ReadableMap params, Callback callback) {
    String groupId = params.getString("groupId");
    String searchText = params.getString("searchText");
    List<Nick> userList = ConnectionUtil.getInstance().selectMemberFromGroup(groupId, searchText);
    WritableNativeArray array = new WritableNativeArray();

    for (int i = 0; i < userList.size(); i++) {
        Nick nick = userList.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("xmppId", nick.getXmppId());
        map.putString("headerUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("UserList", array);
    re.putBoolean("ok", true);
    callback.invoke(re);
}
 

/**
 * 查询不在星标联系人的好友
 *
 * @param callback
 */
@ReactMethod
public void selectFriendsNotInStarContacts(Callback callback) {
    List<Nick> list = IMDatabaseManager.getInstance().selectFriendsNotInStarContacts();
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < list.size(); i++) {
        Nick nick = list.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("Name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("XmppId", nick.getXmppId());
        map.putString("HeaderUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("contacts", array);
    callback.invoke(re);
}
 

@ReactMethod
public void selectUserNotInStartContacts(String key, Callback callback) {
    List<Nick> list = IMDatabaseManager.getInstance().selectUserNotInStartContacts(key);
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < list.size(); i++) {
        Nick nick = list.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("Name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("XmppId", nick.getXmppId());
        map.putString("HeaderUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("users", array);
    callback.invoke(re);
}
 

@ReactMethod
public void selectStarOrBlackContacts(String pkey, Callback callback) {
    List<Nick> list = IMDatabaseManager.getInstance().selectStarOrBlackContactsAsNick(pkey);
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < list.size(); i++) {
        Nick nick = list.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("Name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("XmppId", nick.getXmppId());
        map.putString("HeaderUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("data", array);
    callback.invoke(re);
}
 

public static WritableArray convertJsonToArray(JSONArray jsonArray) throws JSONException {
    WritableArray array = new WritableNativeArray();

    for (int i = 0; i < jsonArray.length(); i++) {
        Object value = jsonArray.get(i);
        if (value instanceof JSONObject) {
            array.pushMap(convertJsonToMap((JSONObject) value));
        } else if (value instanceof JSONArray) {
            array.pushArray(convertJsonToArray((JSONArray) value));
        } else if (value instanceof Boolean) {
            array.pushBoolean((Boolean) value);
        } else if (value instanceof Integer) {
            array.pushInt((Integer) value);
        } else if (value instanceof Double) {
            array.pushDouble((Double) value);
        } else if (value instanceof String) {
            array.pushString((String) value);
        } else {
            array.pushString(value.toString());
        }
    }
    return array;
}
 

@ReactMethod
public void selectGroupMemberForKick(ReadableMap params, Callback callback) {
    String groupId = params.getString("groupId");
    List<Nick> userList = ConnectionUtil.getInstance().selectGroupMemberForKick(groupId);
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < userList.size(); i++) {
        Nick nick = userList.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("xmppId", nick.getXmppId());
        map.putString("headerUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("UserList", array);
    re.putBoolean("ok", true);
    callback.invoke(re);
}
 

/**
 * 根据好友
 *
 * @param params
 * @param callback
 */
@ReactMethod
public void selectFriendsForGroupAdd(ReadableMap params, Callback callback) {
    String groupId = params.getString("groupId");
    List<Nick> userList = ConnectionUtil.getInstance().selectFriendsForGroupAdd(groupId);
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < userList.size(); i++) {
        Nick nick = userList.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("xmppId", nick.getXmppId());
        map.putString("headerUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        map.putString("desc",nick.getDescInfo());
        map.putBoolean("friend", true);
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("UserList", array);
    re.putBoolean("ok", true);
    callback.invoke(re);

}
 

/**
 * 根据文字搜索联系人
 *
 * @param params
 * @param callback
 */
@ReactMethod
public void selectUserListByText(ReadableMap params, Callback callback) {
    String groupId = params.getString("groupId");
    String searchText = params.getString("searchText");
    List<Nick> userList = ConnectionUtil.getInstance().SelectUserListBySearchText(groupId, searchText);
    WritableNativeArray array = new WritableNativeArray();

    for (int i = 0; i < userList.size(); i++) {
        Nick nick = userList.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("name", TextUtils.isEmpty(nick.getName()) ? nick.getXmppId() : nick.getName());
        map.putString("xmppId", nick.getXmppId());
        map.putString("headerUri", TextUtils.isEmpty(nick.getHeaderSrc()) ? defaultUserImage : nick.getHeaderSrc());
        map.putBoolean("hasInGroup", nick.isInGroup());
        map.putString("desc",nick.getDescInfo());
        array.pushMap(map);

    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("UserList", array);
    re.putBoolean("ok", true);
    callback.invoke(re);
}
 

/**
 * 根据搜索字段获取群组
 *
 * @param searchText
 * @param callback
 */
@ReactMethod
public void searchGroupListWithKey(String searchText, Callback callback) {
    List<Nick> nickList = ConnectionUtil.getInstance().SelectGroupListBySearchText(searchText, 100);
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < nickList.size(); i++) {
        Nick n = nickList.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("title", n.getName());
        map.putString("GroupId", n.getGroupId());
        String url = n.getHeaderSrc();
        if (TextUtils.isEmpty(url)) {
            url = defaultMucImage;
        }
        map.putString("HeaderUri", url);
        map.putString("Name", n.getName());
        array.pushMap(map);
    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("groupList", array);
    callback.invoke(re);
}
 

/**
 * 获取群列表
 *
 * @param callback
 */
@ReactMethod
public void getGroupList(Callback callback) {
    List<Nick> nickList = ConnectionUtil.getInstance().SelectAllGroup();
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < nickList.size(); i++) {
        Nick n = nickList.get(i);
        WritableNativeMap map = new WritableNativeMap();
        map.putString("title", n.getName());
        map.putString("GroupId", n.getGroupId());
        String url = n.getHeaderSrc();
        if (TextUtils.isEmpty(url)) {
            url = defaultMucImage;
        }
        map.putString("HeaderUri", url);
        map.putString("Name", n.getName());
        array.pushMap(map);
    }
    WritableNativeMap re = new WritableNativeMap();
    re.putArray("groupList", array);
    callback.invoke(re);
}
 

public void onTimedMetaDataAvailable(MediaPlayer mp, TimedMetaData data) {
    WritableMap event = Arguments.createMap();

    try {
        String rawMeta  = new String(data.getMetaData(), "UTF-8");
        WritableMap id3 = Arguments.createMap();

        id3.putString(EVENT_PROP_METADATA_VALUE, rawMeta.substring(rawMeta.lastIndexOf("\u0003") + 1));
        id3.putString(EVENT_PROP_METADATA_IDENTIFIER, "id3/TDEN");

        WritableArray metadata = new WritableNativeArray();

        metadata.pushMap(id3);

        event.putArray(EVENT_PROP_METADATA, metadata);
        event.putDouble(EVENT_PROP_TARGET, getId());
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }

    mEventEmitter.receiveEvent(getId(), Events.EVENT_TIMED_METADATA.toString(), event);
}
 

private WritableArray convertArrayListToWritableArray(List arrayList) {
    WritableArray writableArray = new WritableNativeArray();

    for(int i = 0; i < arrayList.size(); i++) {
        Object object = arrayList.get(i);

        if(object instanceof String) {
            writableArray.pushString((String) object);
        }
        else {
            JSONObject jsonObject = objectToJSONObject(object);
            writableArray.pushMap((WritableMap) jsonObject);
        }
    }

    return writableArray;

}
 

@ReactMethod
public void searchFilesByXmppId(String xmppid, Callback callback) {
    WritableNativeArray writableNativeArray = new WritableNativeArray();
    JSONArray jsonArray = ConnectionUtil.getInstance().searchFilesMsgByXmppid(xmppid);
    for (int i = 0; i < jsonArray.length(); i++) {
        try {
            JSONObject jsonObject = jsonArray.getJSONObject(i);
            WritableNativeMap writableNativeMap = new WritableNativeMap();
            writableNativeMap.putString("from", jsonObject.optString("from"));
            writableNativeMap.putString("content", jsonObject.optString("content"));
            writableNativeMap.putString("time", jsonObject.optString("time"));
            writableNativeMap.putString("name", jsonObject.optString("name"));
            writableNativeMap.putString("headerSrc", jsonObject.optString("headerSrc"));
            writableNativeArray.pushMap(writableNativeMap);
        } catch (JSONException e) {
            e.printStackTrace();
        }

    }
    if (callback != null) {
        WritableNativeMap map = new WritableNativeMap();
        map.putArray("files", writableNativeArray);
        callback.invoke(map);
    }
}
 

@ReactMethod
public void getAllItems(ReadableMap options, Promise pm) {

    String name = sharedPreferences(options);

    Map<String, ?> allEntries = prefs(name).getAll();
    WritableArray resultData = new WritableNativeArray();

    for (Map.Entry<String, ?> entry : allEntries.entrySet()) {
        WritableMap entryMap = new WritableNativeMap();

        entryMap.putString("key", entry.getKey());
        entryMap.putString("value", entry.getValue().toString());
        entryMap.putString("service", name);
        resultData.pushMap(entryMap);
    }

    WritableArray resultWrapper = new WritableNativeArray();
    resultWrapper.pushArray(resultData);
    pm.resolve(resultWrapper);
}
 

public static WritableArray convertArrayToWritableArray(Object[] input) {
    WritableArray output = new WritableNativeArray();

    for (int i = 0; i < input.length; i++) {
        Object value = input[i];
        if (value instanceof Map) {
            output.pushMap(convertMapToWritableMap((Map<String, Object>) value));
        } else if (value instanceof  JSONArray) {
            output.pushArray(convertArrayToWritableArray((Object[]) value));
        } else if (value instanceof  Boolean) {
            output.pushBoolean((Boolean) value);
        } else if (value instanceof  Integer) {
            output.pushInt((Integer) value);
        } else if (value instanceof  Double) {
            output.pushDouble((Double) value);
        } else if (value instanceof String)  {
            output.pushString((String) value);
        } else {
            output.pushString(value.toString());
        }
    }
    return output;
}
 

/**
 * 获取日历功能城市列表
 *
 * @param callback
 */
@ReactMethod
public void getTripCity(Callback callback) {

    List<CityLocal.DataBean> list = IMDatabaseManager.getInstance().getCityList();
    WritableNativeMap map = new WritableNativeMap();
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < list.size(); i++) {
        WritableNativeMap item = new WritableNativeMap();
        item.putString("CityName", list.get(i).getCityName());
        item.putInt("CityId", list.get(i).getId());
        array.pushMap(item);
    }
    map.putBoolean("ok", true);
    map.putArray("cityList", array);
    callback.invoke(map);

}
 

/**
 * 获取日历功能区域列表
 *
 * @param callback
 */
@ReactMethod
public void getTripArea(Callback callback) {
    List<AreaLocal.DataBean.ListBean> list = IMDatabaseManager.getInstance().getAreaList();
    WritableNativeMap map = new WritableNativeMap();
    WritableNativeArray array = new WritableNativeArray();
    for (int i = 0; i < list.size(); i++) {
        WritableNativeMap item = new WritableNativeMap();
        item.putString("AddressName", list.get(i).getAreaName());
        item.putInt("AddressNumber", list.get(i).getAreaID());
        item.putString("rStartTime", list.get(i).getMorningStarts());
        item.putString("rEndTime", list.get(i).getEveningEnds());
        array.pushMap(item);
    }
    map.putBoolean("ok", true);
    map.putArray("areaList", array);
    callback.invoke(map);


}
 

public void testStringWithMultibyteUTF8Characters() {
  TestJavaToJSArgumentsModule jsModule = mInstance.getJSModule(TestJavaToJSArgumentsModule.class);

  WritableNativeMap map = new WritableNativeMap();
  map.putString("two-bytes", "\u00A2");
  map.putString("three-bytes", "\u20AC");
  map.putString("four-bytes", "\uD83D\uDE1C");
  map.putString(
      "mixed",
      "\u017C\u00F3\u0142\u0107 g\u0119\u015Bl\u0105 \u6211 \uD83D\uDE0E ja\u017A\u0107");

  jsModule.receiveMapWithMultibyteUTF8CharacterString(map);
  waitForBridgeAndUIIdle();
  mAssertModule.verifyAssertsAndReset();

  WritableArray array = new WritableNativeArray();
  array.pushString("\u00A2");
  array.pushString("\u20AC");
  array.pushString("\uD83D\uDE1C");
  array.pushString(
      "\u017C\u00F3\u0142\u0107 g\u0119\u015Bl\u0105 \u6211 \uD83D\uDE0E ja\u017A\u0107");

  jsModule.receiveArrayWithMultibyteUTF8CharacterString(array);
  waitForBridgeAndUIIdle();
  mAssertModule.verifyAssertsAndReset();
}
 

@ReactMethod
public void getInstalledApps(Promise promise) {
    WritableNativeArray params = new WritableNativeArray();
    PackageManager pm = reactContext.getPackageManager();
    List<ApplicationInfo> apps = pm.getInstalledApplications(0);
    for(ApplicationInfo app : apps) {
        if ((pm.getLaunchIntentForPackage(app.packageName) != null) &&
                !thisApp.equals(app.packageName)) {
            WritableNativeMap param = new WritableNativeMap();
            String appName = app.loadLabel(pm).toString();
            String appPackage = app.packageName;
            String appIcon = saveIcon(appPackage, app.loadIcon(pm));
            //Log.d(TAG, "name: "+appName);
            //Log.d(TAG, "app: "+appPackage);
            //Log.d(TAG, "icon: "+appIcon);
            param.putString("name", appName);
            param.putString("app", appPackage);
            param.putString("icon", appIcon);
            //sendEvent("installedApps", param);
            params.pushMap(param);
        }
    }
    promise.resolve(params);
}
 

public void testMapWithNullStringValue() {
  WritableNativeMap map = new WritableNativeMap();
  map.putString("string", null);
  map.putArray("array", null);
  map.putMap("map", null);

  WritableNativeArray array = new WritableNativeArray();
  array.pushString(null);
  array.pushArray(null);
  array.pushMap(null);

  mInstance.getJSModule(TestJavaToJSArgumentsModule.class)
      .receiveMapAndArrayWithNullValues(map, array);
  waitForBridgeAndUIIdle();
  mAssertModule.verifyAssertsAndReset();
}
 

public void testMapWithArrays() {
  WritableNativeMap map = new WritableNativeMap();
  WritableNativeArray a1 = new WritableNativeArray();
  WritableNativeArray a2 = new WritableNativeArray();
  a1.pushDouble(3);
  a1.pushDouble(1);
  a1.pushDouble(4);
  a2.pushDouble(1);
  a2.pushDouble(9);
  map.putArray("array1", a1);
  map.putArray("array2", a2);

  mInstance.getJSModule(TestJavaToJSArgumentsModule.class).receiveMapWithArrays(map);
  waitForBridgeAndUIIdle();
  mAssertModule.verifyAssertsAndReset();
}
 

public WritableMap toJSObject(CheckoutResult result) {
    // We use this "Ignore if null" principle for all returned dictionary
    WritableMap mapToReturn = new WritableNativeMap();
    if (result.getTransactionId() != null) {
        mapToReturn.putString("transactionId", result.getTransactionId());
    }
    mapToReturn.putString("transactionClientId", result.getTransactionClientId());
    mapToReturn.putString("locationId", result.getLocationId());
    mapToReturn.putString("createdAt", DateFormatUtils.formatISO8601UTC(result.getCreatedAt()));
    Money totalMoney = result.getTotalMoney();
    mapToReturn.putMap("totalMoney", moneyConverter.toJSObject(totalMoney));
    Money totalTipMoney = result.getTotalTipMoney();
    mapToReturn.putMap("totalTipMoney", moneyConverter.toJSObject(totalTipMoney));

    WritableArray jsTenders = new WritableNativeArray();
    for (Tender tender : result.getTenders()) {
        jsTenders.pushMap(tenderConverter.toJSObject(tender));
    }
    mapToReturn.putArray("tenders", jsTenders);

    return mapToReturn;
}
 

public static WritableNativeArray convertDataSet(DataSet dataSet) {
    WritableNativeArray jsonDataSet = new WritableNativeArray();
    for (DataPoint dp : dataSet.getDataPoints()) {
        WritableNativeMap jsonDataPoint = new WritableNativeMap();

        jsonDataPoint.putString("type", dp.getDataType().getName());
        jsonDataPoint.putString("source", dp.getOriginalDataSource().getAppPackageName());
        jsonDataPoint.putString("start", dateFormat.format(dp.getStartTime(TimeUnit.MILLISECONDS)));
        jsonDataPoint.putString("end", dateFormat.format(dp.getEndTime(TimeUnit.MILLISECONDS)));

        WritableNativeArray jsonFieldValuePairs = new WritableNativeArray();
        for (Field field : dp.getDataType().getFields()) {
            WritableNativeMap jsonFieldValuePair = new WritableNativeMap();
            jsonFieldValuePair.putString("field", field.getName());
            jsonFieldValuePair.putString("value", dp.getValue(field).toString());
            jsonFieldValuePairs.pushMap(jsonFieldValuePair);
        }
        jsonDataPoint.putArray("fields", jsonFieldValuePairs);

        jsonDataSet.pushMap(jsonDataPoint);
    }
    return jsonDataSet;
}
 

public static WritableArray convertJsonToArray(JSONArray jsonArray) throws JSONException {
    WritableArray array = new WritableNativeArray();

    for (int i = 0; i < jsonArray.length(); i++) {
        Object value = jsonArray.get(i);
        if (value instanceof JSONObject) {
            array.pushMap(convertJsonToMap((JSONObject) value));
        } else if (value instanceof  JSONArray) {
            array.pushArray(convertJsonToArray((JSONArray) value));
        } else if (value instanceof  Boolean) {
            array.pushBoolean((Boolean) value);
        } else if (value instanceof  Integer) {
            array.pushInt((Integer) value);
        } else if (value instanceof  Double) {
            array.pushDouble((Double) value);
        } else if (value instanceof String)  {
            array.pushString((String) value);
        } else {
            array.pushString(value.toString());
        }
    }
    return array;
}
 

@ReactMethod
public void getAccountsByType (String accountType, Promise promise) {
		manager = AccountManager.get(_reactContext);
		Account[] account_list = manager.getAccountsByType(accountType);
		WritableNativeArray result = new WritableNativeArray();

		for(Account account: account_list)
		{
			Integer index = indexForAccount(account);

			WritableNativeMap account_object = new WritableNativeMap();
			account_object.putInt("_index", (int)index);
			account_object.putString("name", account.name);
			account_object.putString("type", account.type);
			result.pushMap(account_object);
		}

		promise.resolve(result);
}
 

@ReactMethod
public void getAllKeys(String service, Promise promise) {
    try {
        service = getDefaultServiceIfNull(service);
        final PrefsStorage prefsStorage = new PrefsStorage(getReactApplicationContext(), service);
        String[] allKeys = prefsStorage.getAllKeys();
        WritableArray keyArray = new WritableNativeArray();
        for (String key : allKeys) {
            keyArray.pushString(key);
        }
        promise.resolve(keyArray);
        return;
    } catch (Exception e) {
        Log.e(SECURE_STORAGE_MODULE, e.getMessage());
        promise.reject(E_KEYSTORE_ACCESS_ERROR, e);
    }
}
 

@ReactMethod
void callJavaScript() {
    Activity activity = getCurrentActivity();
    if (activity != null) {
        MainApplication application = (MainApplication) activity.getApplication();
        ReactNativeHost reactNativeHost = application.getReactNativeHost();
        ReactInstanceManager reactInstanceManager = reactNativeHost.getReactInstanceManager();
        ReactContext reactContext = reactInstanceManager.getCurrentReactContext();

        if (reactContext != null) {
            CatalystInstance catalystInstance = reactContext.getCatalystInstance();
            WritableNativeArray params = new WritableNativeArray();
            params.pushString("Hello, JavaScript!");

            // AFAIK, this approach to communicate from Java to JavaScript is officially undocumented.
            // Use at own risk; prefer events.
            // Note: Here we call 'alert', which shows UI. If this is done from an activity that
            // doesn't forward lifecycle events to React Native, it wouldn't work.
            catalystInstance.callFunction("JavaScriptVisibleToJava", "alert", params);
        }
    }
}
 

/**
 * Destroys `touches` by removing touch objects at indices `indices`. This is
 * to maintain compatibility with W3C touch "end" events, where the active
 * touches don't include the set that has just been "ended".
 *
 * This method was originally in ReactNativeRenderer.js
 *
 * TODO: this method is a copy from ReactNativeRenderer.removeTouchesAtIndices and it needs
 * to be rewritten in a more efficient way,
 *
 * @param touches {@link WritableArray} Deserialized touch objects.
 * @param indices {WritableArray} Indices to remove from `touches`.
 * @return {Array<Touch>} Subsequence of removed touch objects.
 */
private Pair<WritableArray, WritableArray> removeTouchesAtIndices(WritableArray touches, WritableArray indices) {
  WritableArray rippedOut = new WritableNativeArray();
  // use an unsafe downcast to alias to nullable elements,
  // so we can delete and then compact.
  WritableArray tempTouches = new WritableNativeArray();
  Set<Integer> rippedOutIndices = new HashSet<>();
  for (int i = 0; i < indices.size(); i++) {
    int index = indices.getInt(i);
    rippedOut.pushMap(getWritableMap(touches.getMap(index)));
    rippedOutIndices.add(index);
  }
  for (int j = 0 ; j < touches.size() ; j++) {
    if (!rippedOutIndices.contains(j)) {
      tempTouches.pushMap(getWritableMap(touches.getMap(j)));
    }
  }

  return new Pair<>(rippedOut, tempTouches);
}