From 55a4dfdbca50f266b2c1bf5fa4af1d2d31beeb6d Mon Sep 17 00:00:00 2001
From: xz-dev <xiangzhedev@gmail.com>
Date: Tue, 22 Sep 2020 17:59:38 +0800
Subject: [PATCH] =?UTF-8?q?perf:=20=E4=BC=98=E5=8C=96=E5=88=97=E8=A1=A8?=
 =?UTF-8?q?=E6=93=8D=E4=BD=9C=E9=A2=84=E6=B5=8B=E7=AE=97=E6=B3=95?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../net/xzos/upgradeall/utils/ListUtils.kt    | 28 +++++++++++++++----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/app/src/main/java/net/xzos/upgradeall/utils/ListUtils.kt b/app/src/main/java/net/xzos/upgradeall/utils/ListUtils.kt
index f480df69..b9bf2053 100644
--- a/app/src/main/java/net/xzos/upgradeall/utils/ListUtils.kt
+++ b/app/src/main/java/net/xzos/upgradeall/utils/ListUtils.kt
@@ -25,28 +25,46 @@ fun <E> list1ToList2(list1: List<E>, list2: List<E>): List<ListOperationStepBase
     }
     val tmpList = list1.toMutableList()
     val operationSteps = mutableListOf<ListOperationStepBase>()
+    // 删除多余项
     for (item in delList) {
         val index = tmpList.indexOf(item)
         operationSteps.add(ListDelOperationStep(index))
         tmpList.removeAt(index)
     }
+    // 添加缺失项
+    val addItemMap = hashMapOf<E, Int>()
     for (item in addList) {
         val index = list2.indexOf(item)
         if (index < tmpList.size) {
             tmpList.add(index, item)
-            operationSteps.add(ListAddOperationStep(index, item))
+            addItemMap[item] = index
         } else {
             tmpList.add(item)
-            operationSteps.add(ListAddOperationStep(tmpList.size - 1, item))
+            addItemMap[item] = tmpList.size - 1
         }
     }
+    // 还原位置
+    val swapItemMap = mutableMapOf<E, Pair<Int, Int>>()
     for (i in tmpList.indices) {
         val item = tmpList[i]
         val newIndex = list2.indexOf(item)
-        if (i != newIndex && newIndex < tmpList.size) {
+        if (i != newIndex) {
             tmpList[i] = tmpList[newIndex].also { tmpList[newIndex] = tmpList[i] }
-            operationSteps.add((ListSwapOperationStep(i, newIndex)))
+            if (item in addItemMap) {
+                addItemMap[item] = newIndex
+            } else {
+                swapItemMap[item]?.let {
+                    swapItemMap[item] = Pair(it.first, newIndex)
+                } ?: run { swapItemMap[item] = Pair(i, newIndex) }
+            }
         }
     }
+    val sorted = addItemMap.toList().sortedBy { (_, value) -> value }.toMap()
+    for ((item, index) in sorted.entries) {
+        operationSteps.add(ListAddOperationStep(index, item))
+    }
+    for ((_, index) in swapItemMap) {
+        operationSteps.add((ListSwapOperationStep(index.first, index.second)))
+    }
     return operationSteps
-}
\ No newline at end of file
+}