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.constraintlayout.widget;
  
  import android.content.Context;
  import android.util.AttributeSet;
  
  /**
   * Control the visibility and elevation of the referenced views
   *
   * <b>Added in 1.1</b>
   * <p>
   *     This class controls the visibility of a set of referenced widgets.
   *     Widgets are referenced by being added to a comma separated list of ids, e.g.:
   *     <pre>
   *     {@code
   *          <androidx.constraintlayout.widget.Group
   *              android:id="@+id/group"
   *              android:layout_width="wrap_content"
   *              android:layout_height="wrap_content"
   *              android:visibility="visible"
   *              app:constraint_referenced_ids="button4,button9" />
   *     }
   *     </pre>
   *     <p>
   *         The visibility of the group will be applied to the referenced widgets.
   *         It's a convenient way to easily hide/show a set of widgets
   *         without having to maintain this set
   *         programmatically.
   *     <p>
   *     <h2>Multiple groups</h2>
   *     <p>
   *         Multiple groups can reference the same widgets
   *         -- in that case, the XML declaration order will
   *         define the final visibility state (the group declared last will have the last word).
   * </p>
   */
  public class Group extends ConstraintHelper {
  
      public Group(Context context) {
          super(context);
      }
  
      public Group(Context context, AttributeSet attrs) {
          super(context, attrs);
      }
  
      public Group(Context context, AttributeSet attrs, int defStyleAttr) {
          super(context, attrs, defStyleAttr);
      }
  
      /**
       *
       * @param attrs
       */
      @Override
      protected void init(AttributeSet attrs) {
          super.init(attrs);
          mUseViewMeasure = false;
      }
  
      @Override
      public void onAttachedToWindow() {
          super.onAttachedToWindow();
          applyLayoutFeatures();
      }
  
      @Override
      public void setVisibility(int visibility) {
          super.setVisibility(visibility);
          applyLayoutFeatures();
      }
  
      @Override
      public void setElevation(float elevation) {
          super.setElevation(elevation);
          applyLayoutFeatures();
      }
  
      /**
       *
       * @param container
       */
      @Override
      protected void applyLayoutFeaturesInConstraintSet(ConstraintLayout container) {
          applyLayoutFeatures(container);
      }
  
      /**
       *
       * @param container
       */
      @Override
      public void updatePostLayout(ConstraintLayout container) {
          ConstraintLayout.LayoutParams params = (ConstraintLayout.LayoutParams) getLayoutParams();
          params.mWidget.setWidth(0);
          params.mWidget.setHeight(0);
      }
  }
  