material-components_material-components-android/lib/java/com/google/android/material/internal/ContextUtils.java

/*
 * Copyright (C) 2018 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.internal;

import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP;

import android.app.Activity;
import android.content.Context;
import android.content.ContextWrapper;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;

/**
 * Utils class for {@link Context}.
 *
 * @hide
 */
@RestrictTo(LIBRARY_GROUP)
public class ContextUtils {

  /**
   * Returns the {@link Activity} given a {@link Context} or null if there is no {@link Activity},
   * taking into account the potential hierarchy of {@link ContextWrapper ContextWrappers}.
   */
  @Nullable
  public static Activity getActivity(Context context) {
    while (context instanceof ContextWrapper) {
      if (context instanceof Activity) {
        return (Activity) context;
      }
      context = ((ContextWrapper) context).getBaseContext();
    }
    return null;
  }
}