feat: 优化代码

app/src/main/java/io/legado/app/ui/book/changecover/ChangeCoverDialog.kt

@@ -5,17 +5,17 @@ import android.util.DisplayMetrics
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import androidx.fragment.app.DialogFragment
 import androidx.fragment.app.FragmentManager
 import androidx.lifecycle.Observer
+import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.GridLayoutManager
 import io.legado.app.R
+import io.legado.app.base.BaseDialogFragment
 import io.legado.app.utils.getViewModel
 import kotlinx.android.synthetic.main.dialog_change_source.*
 
 
-class ChangeCoverDialog : DialogFragment(),
-    ChangeCoverViewModel.CallBack,
+class ChangeCoverDialog : BaseDialogFragment(),
     CoverAdapter.CallBack {
 
     companion object {
@@ -35,7 +35,7 @@ class ChangeCoverDialog : DialogFragment(),
 
     private var callBack: CallBack? = null
     private lateinit var viewModel: ChangeCoverViewModel
-    override lateinit var adapter: CoverAdapter
+    lateinit var adapter: CoverAdapter
 
     override fun onStart() {
         super.onStart()
@@ -51,11 +51,10 @@ class ChangeCoverDialog : DialogFragment(),
     ): View? {
         callBack = activity as? CallBack
         viewModel = getViewModel(ChangeCoverViewModel::class.java)
-        viewModel.callBack = this
         return inflater.inflate(R.layout.dialog_change_cover, container)
     }
 
-    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+    override fun onFragmentCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         viewModel.searchStateData.observe(viewLifecycleOwner, Observer {
             refresh_progress_bar.isAutoLoading = it
@@ -70,6 +69,15 @@ class ChangeCoverDialog : DialogFragment(),
         viewModel.loadDbSearchBook()
     }
 
+    override fun observeLiveBus() {
+        super.observeLiveBus()
+        viewModel.searchBooksLiveData.observe(viewLifecycleOwner, Observer {
+            val diffResult = DiffUtil.calculateDiff(DiffCallBack(adapter.getItems(), it))
+            adapter.setItems(it)
+            diffResult.dispatchUpdatesTo(adapter)
+        })
+    }
+
     override fun changeTo(coverUrl: String) {
         callBack?.coverChangeTo(coverUrl)
         dismiss()

app/src/main/java/io/legado/app/ui/book/changecover/ChangeCoverViewModel.kt

@@ -6,22 +6,23 @@ import androidx.lifecycle.MutableLiveData
 import io.legado.app.App
 import io.legado.app.base.BaseViewModel
 import io.legado.app.constant.AppPattern
+import io.legado.app.data.entities.SearchBook
 import io.legado.app.help.AppConfig
 import io.legado.app.help.coroutine.Coroutine
 import io.legado.app.model.WebBook
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.asCoroutineDispatcher
-import kotlinx.coroutines.withContext
 import java.util.concurrent.Executors
 
 class ChangeCoverViewModel(application: Application) : BaseViewModel(application) {
     private var searchPool =
         Executors.newFixedThreadPool(AppConfig.threadCount).asCoroutineDispatcher()
-    var callBack: CallBack? = null
     var name: String = ""
     var author: String = ""
     private var task: Coroutine<*>? = null
     val searchStateData = MutableLiveData<Boolean>()
+    val searchBooksLiveData = MutableLiveData<List<SearchBook>>()
+    private val searchBooks = ArrayList<SearchBook>()
 
     fun initData(bundle: Bundle) {
         bundle.getString("name")?.let {
@@ -34,13 +35,15 @@ class ChangeCoverViewModel(application: Application) : BaseViewModel(application
 
     fun loadDbSearchBook() {
         execute {
-            App.db.searchBookDao().getEnableHasCover(name, author)
-        }.onSuccess {
-            it?.let {
-                callBack?.adapter?.setItems(it)
+            App.db.searchBookDao().getEnableHasCover(name, author).let {
+                searchBooks.addAll(it)
+                if (it.size <= 1) {
+                    searchBooksLiveData.postValue(searchBooks)
+                    search()
+                } else {
+                    searchBooksLiveData.postValue(searchBooks)
+                }
             }
-        }.onFinally {
-            search()
         }
     }
 
@@ -59,12 +62,9 @@ class ChangeCoverViewModel(application: Application) : BaseViewModel(application
                                 && !searchBook.coverUrl.isNullOrEmpty()
                             ) {
                                 App.db.searchBookDao().insert(searchBook)
-                                callBack?.adapter?.let { adapter ->
-                                    if (!adapter.getItems().contains(searchBook)) {
-                                        withContext(Dispatchers.Main) {
-                                            adapter.addItem(searchBook)
-                                        }
-                                    }
+                                if (!searchBooks.contains(searchBook)) {
+                                    searchBooks.add(searchBook)
+                                    searchBooksLiveData.postValue(searchBooks)
                                 }
                             }
                         }
@@ -82,7 +82,4 @@ class ChangeCoverViewModel(application: Application) : BaseViewModel(application
         searchPool.close()
     }
 
-    interface CallBack {
-        var adapter: CoverAdapter
-    }
 }

app/src/main/java/io/legado/app/ui/book/changecover/DiffCallBack.kt

@@ -0,0 +1,52 @@
+package io.legado.app.ui.book.changecover
+
+import android.os.Bundle
+import androidx.recyclerview.widget.DiffUtil
+import io.legado.app.data.entities.SearchBook
+
+class DiffCallBack(private val oldItems: List<SearchBook>, private val newItems: List<SearchBook>) :
+    DiffUtil.Callback() {
+
+    override fun getOldListSize(): Int {
+        return oldItems.size
+    }
+
+    override fun getNewListSize(): Int {
+        return newItems.size
+    }
+
+    override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
+        val oldItem = oldItems[oldItemPosition]
+        val newItem = newItems[newItemPosition]
+        return oldItem.bookUrl == newItem.bookUrl
+    }
+
+    override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
+        val oldItem = oldItems[oldItemPosition]
+        val newItem = newItems[newItemPosition]
+        if (oldItem.originName != newItem.originName) {
+            return false
+        }
+        if (oldItem.coverUrl != newItem.coverUrl) {
+            return false
+        }
+        return true
+    }
+
+    override fun getChangePayload(oldItemPosition: Int, newItemPosition: Int): Any? {
+        val oldItem = oldItems[oldItemPosition]
+        val newItem = newItems[newItemPosition]
+        val payload = Bundle()
+        if (oldItem.originName != newItem.originName) {
+            payload.putString("name", newItem.originName)
+        }
+        if (oldItem.coverUrl != newItem.coverUrl) {
+            payload.putString("coverUrl", newItem.coverUrl)
+        }
+        if (payload.isEmpty) {
+            return null
+        }
+        return payload
+    }
+
+}

app/src/main/java/io/legado/app/ui/book/changesource/ChangeSourceViewModel.kt

@@ -45,7 +45,8 @@ class ChangeSourceViewModel(application: Application) : BaseViewModel(applicatio
         execute {
             App.db.searchBookDao().getByNameAuthorEnable(name, author).let {
                 searchBooks.addAll(it)
-                if (it.isEmpty()) {
+                if (it.size <= 1) {
+                    upAdapter()
                     search()
                 } else {
                     upAdapter()