content: /*
   * Copyright (C) 2013 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 android.view;
  
  import android.annotation.NonNull;
  import android.content.Context;
  import android.graphics.drawable.Drawable;
  
  /**
   * A group overlay is an extra layer that sits on top of a ViewGroup
   * (the "host view") which is drawn after all other content in that view
   * (including the view group's children). Interaction with the overlay
   * layer is done by adding and removing views and drawables.
   *
   * <p>ViewGroupOverlay is a subclass of {@link ViewOverlay}, adding the ability to
   * manage views for overlays on ViewGroups, in addition to the drawable
   * support in ViewOverlay.</p>
   *
   * @see ViewGroup#getOverlay()
   */
  public class ViewGroupOverlay extends ViewOverlay {
  
      ViewGroupOverlay(Context context, View hostView) {
          super(context, hostView);
      }
  
      /**
       * Adds a {@code View} to the overlay. The bounds of the added view should be
       * relative to the host view. Any view added to the overlay should be
       * removed when it is no longer needed or no longer visible.
       *
       * <p>Views in the overlay are visual-only; they do not receive input
       * events and do not participate in focus traversal. Overlay views
       * are intended to be transient, such as might be needed by a temporary
       * animation effect.</p>
       *
       * <p>If the view has a parent, the view will be removed from that parent
       * before being added to the overlay. Also, if that parent is attached
       * in the current view hierarchy, the view will be repositioned
       * such that it is in the same relative location inside the activity. For
       * example, if the view's current parent lies 100 pixels to the right
       * and 200 pixels down from the origin of the overlay's
       * host view, then the view will be offset by (100, 200).</p>
       *
       * <p>{@code View}s added with this API will be drawn in the order they were
       * added. Drawing of the overlay views will happen before drawing of any of the
       * {@code Drawable}s added with {@link #add(Drawable)} API even if a call to
       * this API happened after the call to {@link #add(Drawable)}.</p>
       *
       * <p>Passing <code>null</code> parameter will result in an
       * {@link IllegalArgumentException} being thrown.</p>
       *
       * @param view The {@code View} to be added to the overlay. The added view will be
       * drawn when the overlay is drawn.
       * @see #remove(View)
       * @see ViewOverlay#add(Drawable)
       */
      public void add(@NonNull View view) {
          mOverlayViewGroup.add(view);
      }
  
      /**
       * Removes the specified {@code View} from the overlay. Passing <code>null</code> parameter
       * will result in an {@link IllegalArgumentException} being thrown.
       *
       * @param view The {@code View} to be removed from the overlay.
       * @see #add(View)
       * @see ViewOverlay#remove(Drawable)
       */
      public void remove(@NonNull View view) {
          mOverlayViewGroup.remove(view);
      }
  }
  