1 /*
2  * Copyright (C) 2024 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.wallpaper.picker.common.ui.view
17 
18 import android.graphics.Rect
19 import android.view.View
20 import androidx.core.view.ViewCompat
21 import androidx.recyclerview.widget.RecyclerView
22 
23 /** Item spacing used by the RecyclerView. */
24 class ItemSpacing(
25     private val itemSpacingDp: Int,
26 ) : RecyclerView.ItemDecoration() {
27 
getItemOffsetsnull28     override fun getItemOffsets(
29         outRect: Rect,
30         view: View,
31         parent: RecyclerView,
32         state: RecyclerView.State,
33     ) {
34         val itemPosition = parent.getChildAdapterPosition(view)
35         val addSpacingToStart = itemPosition > 0
36         val addSpacingToEnd = itemPosition < (parent.adapter?.itemCount ?: 0) - 1
37         val isRtl = parent.layoutManager?.layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL
38         val density = parent.context.resources.displayMetrics.density
39         val halfItemSpacingPx = itemSpacingDp.toPx(density) / 2
40         if (!isRtl) {
41             outRect.left = if (addSpacingToStart) halfItemSpacingPx else 0
42             outRect.right = if (addSpacingToEnd) halfItemSpacingPx else 0
43         } else {
44             outRect.left = if (addSpacingToEnd) halfItemSpacingPx else 0
45             outRect.right = if (addSpacingToStart) halfItemSpacingPx else 0
46         }
47     }
48 
toPxnull49     private fun Int.toPx(density: Float): Int {
50         return (this * density).toInt()
51     }
52 
53     companion object {
54         const val TAB_ITEM_SPACING_DP = 12
55         const val ITEM_SPACING_DP = 8
56     }
57 }
58