content: /*
   * Copyright (C) 2021 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 androidx.test.platform.view.inspector;
  
  import android.os.Build.VERSION;
  import android.os.Build.VERSION_CODES;
  import android.view.View;
  import android.view.inspector.WindowInspector;
  import androidx.annotation.RestrictTo;
  import androidx.test.internal.platform.reflect.ReflectionException;
  import androidx.test.internal.platform.reflect.ReflectiveField;
  import androidx.test.internal.platform.reflect.ReflectiveMethod;
  import androidx.test.internal.util.Checks;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Compat class that supports {@link android.viee.inspector.WindowInspector} functionality on older
   * Android SDKs.
   *
   * @hide
   */
  @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) // currently used by core, consider making public
  public class WindowInspectorCompat {
  
    // type WindowManagerGlobal
    private static final ReflectiveMethod<Object> getWindowManagerGlobalReflectiveCall =
        new ReflectiveMethod<>("android.view.WindowManagerGlobal", "getInstance");
  
    private static final ReflectiveField<List<View>> windowViewsReflectiveField =
        new ReflectiveField<>("android.view.WindowManagerGlobal", "mViews");
  
    /**
     * Thrown when there is a failure retrieving window views.
     *
     * <p>This should only occur if the device does not support the view retrieval mechanism used on
     * used on APIs < 29, before WindowInspector existed.
     *
     * @hide
     */
    @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
    public static class ViewRetrievalException extends Exception {
  
      ViewRetrievalException(Throwable cause) {
        super("failed to retrieve window views", cause);
      }
    }
  
    private WindowInspectorCompat() {}
  
    /**
     * Retrieves the list of window views attached to the current process.
     *
     * <p>On APIs 29 and above, this will call through to {@link
     * WindowInspector#getGlobalWindowViews()}. On older APIs, this will make a best effort attempt to
     * retrieve the window views.
     *
     * <p>Must be called from UI thread.
     *
     * @return the list of window Views
     * @throws IllegalStateException if called from a non-UI thread. ViewRetrievalException if views
     *     could not be retrieved.
     */
    public static List<View> getGlobalWindowViews() throws ViewRetrievalException {
      Checks.checkMainThread();
  
      if (VERSION.SDK_INT >= VERSION_CODES.Q) {
        return WindowInspector.getGlobalWindowViews();
      } else {
        try {
          return getViews(getWindowManager());
        } catch (ReflectionException e) {
          throw new ViewRetrievalException(e.getCause());
        }
      }
    }
  
    private static Object getWindowManager() throws ReflectionException {
      return getWindowManagerGlobalReflectiveCall.invokeStatic();
    }
  
    private static List<View> getViews(Object windowManagerGlobal) throws ReflectionException {
      return new ArrayList<>(windowViewsReflectiveField.get(windowManagerGlobal));
    }
  }
  