content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.weex.ui.component.list;
  
  import android.graphics.Rect;
  import android.support.v7.widget.RecyclerView;
  import android.support.v7.widget.StaggeredGridLayoutManager;
  import android.view.View;
  
  import org.apache.weex.ui.component.WXComponent;
  import org.apache.weex.utils.WXViewUtils;
  
  /**
   * Created by furture on 2018/2/12.
   * recyclerview's height is layout width + column gap,
   * so the the offset should include, leftGap and rightGap is via this
   */
  public class GapItemDecoration extends RecyclerView.ItemDecoration {
  
      private WXListComponent listComponent;
  
      public GapItemDecoration(WXListComponent listComponent) {
          this.listComponent = listComponent;
      }
  
      @Override
      public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
          final Float[] spanOffsets = listComponent.getSpanOffsets();
          if (spanOffsets == null) {
              return;
          }
          int position = parent.getChildAdapterPosition(view);
          if(position < 0) {
              return;
          }
          if(view.getLayoutParams() instanceof StaggeredGridLayoutManager.LayoutParams){
              StaggeredGridLayoutManager.LayoutParams params = (StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams();
              if(params.isFullSpan()){
                  return;
              }
              WXComponent component = listComponent.getChild(position);
              if(component instanceof WXCell){
                  WXCell cell = (WXCell) component;
                  if(cell.isFixed() || cell.isSticky()) {
                      return;
                  }
  
                  if (params.getSpanIndex() >= spanOffsets.length) {
                      return;
                  }
  
                  int index = listComponent.isLayoutRTL() ? spanOffsets.length - params.getSpanIndex() - 1 : params.getSpanIndex();
                  float spanOffset = listComponent.getSpanOffsets()[index];
                  int   spanOffsetPx =  Math.round(WXViewUtils.getRealPxByWidth(spanOffset, listComponent.getViewPortWidth()));
                  if (listComponent.isLayoutRTL()) {
                      outRect.left = -spanOffsetPx;
                      outRect.right = spanOffsetPx;
                  } else {
                      outRect.left = spanOffsetPx;
                      outRect.right = -spanOffsetPx;
                  }
              }
          }
      }
  }
  