1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.android.customization.picker.common.ui.view
17 
18 import android.graphics.Rect
19 import android.view.View
20 import androidx.recyclerview.widget.RecyclerView
21 
22 /** Item spacing used by the horizontal RecyclerView with 2 rows. */
23 class DoubleRowListItemSpacing(
24     private val edgeItemSpacePx: Int,
25     private val itemHorizontalSpacePx: Int,
26     private val itemVerticalSpacePx: Int,
27 ) : RecyclerView.ItemDecoration() {
getItemOffsetsnull28     override fun getItemOffsets(
29         outRect: Rect,
30         view: View,
31         parent: RecyclerView,
32         state: RecyclerView.State,
33     ) {
34         val itemIndex = parent.getChildAdapterPosition(view)
35         val columnIndex = itemIndex / 2
36         val isRtl = parent.layoutManager?.layoutDirection == View.LAYOUT_DIRECTION_RTL
37 
38         val itemCount = parent.adapter?.itemCount ?: 0
39         val columnCount = (itemCount + 1) / 2
40         when {
41             columnCount == 1 -> {
42                 outRect.left = edgeItemSpacePx
43                 outRect.right = edgeItemSpacePx
44             }
45             columnIndex > 0 && columnIndex < columnCount - 1 -> {
46                 outRect.left = itemHorizontalSpacePx
47                 outRect.right = itemHorizontalSpacePx
48             }
49             columnIndex == 0 -> {
50                 outRect.left = if (!isRtl) edgeItemSpacePx else itemHorizontalSpacePx
51                 outRect.right = if (isRtl) edgeItemSpacePx else itemHorizontalSpacePx
52             }
53             columnIndex == columnCount - 1 -> {
54                 outRect.right = if (!isRtl) edgeItemSpacePx else itemHorizontalSpacePx
55                 outRect.left = if (isRtl) edgeItemSpacePx else itemHorizontalSpacePx
56             }
57         }
58 
59         if (itemIndex % 2 == 0) {
60             outRect.bottom = itemVerticalSpacePx
61         }
62     }
63 }
64