material-components_material-components-android/tests/javatests/com/google/android/material/datepicker/RecyclerIdlingResource.java

/*
 * Copyright 2019 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.android.material.datepicker;

import androidx.recyclerview.widget.RecyclerView;
import androidx.recyclerview.widget.RecyclerView.OnScrollListener;
import androidx.annotation.NonNull;
import androidx.test.espresso.IdlingResource;

public class RecyclerIdlingResource implements IdlingResource {

  private ResourceCallback resourceCallback;
  private boolean isIdle;

  public RecyclerIdlingResource(RecyclerView recyclerView) {
    isIdle = true;
    recyclerView.addOnScrollListener(
        new OnScrollListener() {
          @Override
          public void onScrollStateChanged(@NonNull RecyclerView recyclerView, int state) {
            isIdle =
                state == RecyclerView.SCROLL_STATE_IDLE
                    || state == RecyclerView.SCROLL_STATE_DRAGGING;
            if (isIdleNow() && resourceCallback != null) {
              resourceCallback.onTransitionToIdle();
            }
          }
        });
  }

  @Override
  public String getName() {
    return "RecyclerView IdlingResource";
  }

  @Override
  public boolean isIdleNow() {
    return isIdle;
  }

  @Override
  public void registerIdleTransitionCallback(ResourceCallback callback) {
    resourceCallback = callback;
  }
}