RecyclerView: 启用预加载

Author: ztc1997

app/src/main/kotlin/com/rayfantasy/icode/extra/PreloadLinearLayoutManager.kt

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2016 Alex Zhang aka. ztc1997
+ *
+ *  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 com.rayfantasy.icode.extra
+
+import android.content.Context
+import android.support.v7.widget.LinearLayoutManager
+import android.support.v7.widget.RecyclerView
+
+class PreloadLinearLayoutManager(context: Context?) : LinearLayoutManager(context) {
+    override fun getExtraLayoutSpace(state: RecyclerView.State?) = 1000
+}

app/src/main/kotlin/com/rayfantasy/icode/ui/activity/BlocksActivity.kt

@@ -2,10 +2,10 @@ package com.rayfantasy.icode.ui.activity
 
 import android.databinding.DataBindingUtil
 import android.os.Bundle
-import android.support.v7.widget.LinearLayoutManager
 import com.h6ah4i.android.widget.advrecyclerview.animator.RefactoredDefaultItemAnimator
 import com.rayfantasy.icode.R
 import com.rayfantasy.icode.databinding.ActivityBlocksBinding
+import com.rayfantasy.icode.extra.PreloadLinearLayoutManager
 import com.rayfantasy.icode.model.ICodeTheme
 import com.rayfantasy.icode.postutil.PostUtil
 import com.rayfantasy.icode.postutil.bean.CodeGood
@@ -29,7 +29,7 @@ class BlocksActivity : ActivityBindingStatus() {
         codeGood = intent.getSerializableExtra("codeGood") as CodeGood
         title = codeGood.title
         with(recyclerView) {
-            layoutManager = LinearLayoutManager(this@BlocksActivity)
+            layoutManager = PreloadLinearLayoutManager(this@BlocksActivity)
             itemAnimator = RefactoredDefaultItemAnimator()
         }
 

app/src/main/kotlin/com/rayfantasy/icode/ui/activity/ReplyActivity.kt

@@ -2,13 +2,13 @@ package com.rayfantasy.icode.ui.activity
 
 import android.databinding.DataBindingUtil
 import android.os.Bundle
-import android.support.v7.widget.LinearLayoutManager
 import android.support.v7.widget.Toolbar
 import com.android.volley.Request
 import com.raizlabs.android.dbflow.sql.language.Select
 import com.rayfantasy.icode.R
 import com.rayfantasy.icode.databinding.ActivityReplyBinding
 import com.rayfantasy.icode.extension.string
+import com.rayfantasy.icode.extra.PreloadLinearLayoutManager
 import com.rayfantasy.icode.model.ICodeTheme
 import com.rayfantasy.icode.postutil.PostUtil
 import com.rayfantasy.icode.postutil.bean.Reply
@@ -71,8 +71,7 @@ class ReplyActivity : ActivityBindingStatus() {
     }
 
     private fun initRecyclerView() {
-        val layoutManager = LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false)
-        reply_recyclerview.layoutManager = layoutManager
+        reply_recyclerview.layoutManager = PreloadLinearLayoutManager(this)
         adapter = ReplyListAdapter(this, SetUniqueList.setUniqueList(getCacheData())) { loadReplys(false) }
         reply_recyclerview.adapter = adapter
 

app/src/main/kotlin/com/rayfantasy/icode/ui/activity/UserActivity.kt

@@ -2,12 +2,12 @@ package com.rayfantasy.icode.ui.activity
 
 import android.databinding.DataBindingUtil
 import android.os.Bundle
-import android.support.v7.widget.LinearLayoutManager
 import android.view.Menu
 import android.view.MenuItem
 import com.android.volley.Request
 import com.rayfantasy.icode.R
 import com.rayfantasy.icode.databinding.ActivityUserBinding
+import com.rayfantasy.icode.extra.PreloadLinearLayoutManager
 import com.rayfantasy.icode.model.ICodeTheme
 import com.rayfantasy.icode.postutil.PostUtil
 import com.rayfantasy.icode.ui.adapter.UserListAdapter
@@ -38,8 +38,7 @@ class UserActivity : ActivityBindingStatus() {
     }
 
     private fun initRecyclerView() {
-        val layoutManager = LinearLayoutManager(this)
-        user_recyclerview.layoutManager = layoutManager
+        user_recyclerview.layoutManager = PreloadLinearLayoutManager(this)
         adapter = UserListAdapter(this, username, ArrayList()) {}
         user_recyclerview.adapter = adapter
         refresh()

app/src/main/kotlin/com/rayfantasy/icode/ui/activity/WriteCodeActivity.kt

@@ -3,13 +3,13 @@ package com.rayfantasy.icode.ui.activity
 import android.databinding.DataBindingUtil
 import android.os.Bundle
 import android.support.design.widget.Snackbar
-import android.support.v7.widget.LinearLayoutManager
 import com.android.volley.Request
 import com.h6ah4i.android.widget.advrecyclerview.animator.RefactoredDefaultItemAnimator
 import com.h6ah4i.android.widget.advrecyclerview.draggable.RecyclerViewDragDropManager
 import com.rayfantasy.icode.R
 import com.rayfantasy.icode.databinding.ActivityWriteCodeBinding
 import com.rayfantasy.icode.extension.snackBar
+import com.rayfantasy.icode.extra.PreloadLinearLayoutManager
 import com.rayfantasy.icode.model.ICodeTheme
 import com.rayfantasy.icode.postutil.PostUtil
 import com.rayfantasy.icode.postutil.bean.CodeGood
@@ -33,7 +33,7 @@ class WriteCodeActivity : ActivityBindingStatus() {
         recyclerViewDragDropManager.setInitiateOnLongPress(true)
         recyclerViewDragDropManager.setInitiateOnMove(false)
         with(recyclerView) {
-            layoutManager = LinearLayoutManager(this@WriteCodeActivity)
+            layoutManager = PreloadLinearLayoutManager(this@WriteCodeActivity)
             adapter = recyclerViewDragDropManager.createWrappedAdapter(blockAdapter)
             itemAnimator = RefactoredDefaultItemAnimator()
             recyclerViewDragDropManager.attachRecyclerView(this)

app/src/main/kotlin/com/rayfantasy/icode/ui/fragment/MainFragment.kt

@@ -1,13 +1,13 @@
 package com.rayfantasy.icode.ui.fragment
 
 import android.os.Bundle
-import android.support.v7.widget.LinearLayoutManager
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
 import com.android.volley.Request
 import com.raizlabs.android.dbflow.sql.language.Select
 import com.rayfantasy.icode.databinding.FragmentMainBinding
+import com.rayfantasy.icode.extra.PreloadLinearLayoutManager
 import com.rayfantasy.icode.model.ICodeTheme
 import com.rayfantasy.icode.postutil.PostUtil
 import com.rayfantasy.icode.postutil.bean.CodeGood
@@ -54,7 +54,7 @@ class MainFragment : FragmentBase() {
     }
 
     private fun initRecyclerView() {
-        val layoutManager = LinearLayoutManager(activity, LinearLayoutManager.VERTICAL, false)
+        val layoutManager = PreloadLinearLayoutManager(activity)
         view.recyclerView.layoutManager = layoutManager
         adapter = CodeListAdapter(activity, SetUniqueList.setUniqueList(getCacheData())) { loadCodeGoods(false) }
         view.recyclerView.adapter = adapter
@@ -77,13 +77,13 @@ class MainFragment : FragmentBase() {
                 //如果结果为空，则表示没有更多内容了
                 adapter.footerState = LoadMoreAdapter.FOOTER_STATE_NO_MORE
             } else {
-
                 if (refresh) {
                     adapter.codeGoods.clear()
                 }
                 //否则将结果加入codeGoods，并刷新adapter
                 adapter.codeGoods.addAll(it)
-                adapter.notifyDataSetChanged()
+                if (refresh) adapter.notifyDataSetChanged()
+                else adapter.notifyItemRangeInserted(adapter.itemCount - 1 - it.size, it.size)
                 cacheData(adapter.codeGoods)
             }
             /*}*/