Move date restore view state into ViewModel to survive configuration changes

app/src/main/java/com/stevesoltys/seedvault/restore/InstallProgressFragment.kt

@@ -55,6 +55,9 @@ class InstallProgressFragment : Fragment() {
     }
 
     private fun onInstallResult(installResult: InstallResult) {
+        // skip this screen, if there are no apps to install
+        if (installResult.isEmpty()) viewModel.onNextClicked()
+
         val result = installResult.filterValues { it.status != QUEUED }
         val position = layoutManager.findFirstVisibleItemPosition()
         adapter.update(result.values)

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreProgressAdapter.kt

@@ -9,20 +9,20 @@ import android.view.ViewGroup
 import android.widget.ImageView
 import android.widget.ProgressBar
 import android.widget.TextView
+import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.RecyclerView.Adapter
 import androidx.recyclerview.widget.RecyclerView.ViewHolder
 import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.getAppName
+import com.stevesoltys.seedvault.restore.AppRestoreStatus.IN_PROGRESS
+import com.stevesoltys.seedvault.restore.AppRestoreStatus.SUCCEEDED
 import com.stevesoltys.seedvault.restore.RestoreProgressAdapter.PackageViewHolder
 import java.util.*
 
 internal class RestoreProgressAdapter : Adapter<PackageViewHolder>() {
 
-    private val items = LinkedList<AppRestoreResult>().apply {
+    private val items = LinkedList<AppRestoreResult>()
-        add(AppRestoreResult(MAGIC_PACKAGE_MANAGER, true))
-    }
-    private var isComplete = false
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PackageViewHolder {
         val v = LayoutInflater.from(parent.context).inflate(R.layout.list_item_app_status, parent, false)
@@ -32,28 +32,30 @@ internal class RestoreProgressAdapter : Adapter<PackageViewHolder>() {
     override fun getItemCount() = items.size
 
     override fun onBindViewHolder(holder: PackageViewHolder, position: Int) {
-        holder.bind(items[position], position == 0)
+        holder.bind(items[position])
     }
 
-    fun getLatest(): AppRestoreResult {
+    fun update(newItems: LinkedList<AppRestoreResult>) {
-        return items[0]
+        val diffResult = DiffUtil.calculateDiff(Diff(items, newItems))
+        items.clear()
+        items.addAll(newItems)
+        diffResult.dispatchUpdatesTo(this)
     }
 
-    fun setLatestFailed() {
+    private class Diff(
-        items[0] = AppRestoreResult(items[0].packageName, false)
+            private val oldItems: LinkedList<AppRestoreResult>,
-        notifyItemChanged(0, items[0])
+            private val newItems: LinkedList<AppRestoreResult>) : DiffUtil.Callback() {
-    }
 
-    fun add(item: AppRestoreResult) {
+        override fun getOldListSize() = oldItems.size
-        items.addFirst(item)
+        override fun getNewListSize() = newItems.size
-        notifyItemInserted(0)
-        notifyItemRangeChanged(1, items.size - 1)
-    }
 
-    fun setComplete(): List<String> {
+        override fun areItemsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
-        isComplete = true
+            return oldItems[oldItemPosition].packageName == newItems[newItemPosition].packageName
-        notifyItemChanged(0)
+        }
-        return items.map { it.packageName }
+
+        override fun areContentsTheSame(oldItemPosition: Int, newItemPosition: Int): Boolean {
+            return oldItems[oldItemPosition] == newItems[newItemPosition]
+        }
     }
 
     inner class PackageViewHolder(v: View) : ViewHolder(v) {
@@ -65,7 +67,7 @@ internal class RestoreProgressAdapter : Adapter<PackageViewHolder>() {
         private val appStatus: ImageView = v.findViewById(R.id.appStatus)
         private val progressBar: ProgressBar = v.findViewById(R.id.progressBar)
 
-        fun bind(item: AppRestoreResult, isLatest: Boolean) {
+        fun bind(item: AppRestoreResult) {
             if (item.packageName == MAGIC_PACKAGE_MANAGER) {
                 appIcon.setImageResource(R.drawable.ic_launcher_default)
                 appName.text = context.getString(R.string.restore_magic_package)
@@ -77,11 +79,14 @@ internal class RestoreProgressAdapter : Adapter<PackageViewHolder>() {
                 }
                 appName.text = getAppName(pm, item.packageName)
             }
-            if (isLatest && !isComplete) {
+            if (item.status == IN_PROGRESS) {
                 appStatus.visibility = INVISIBLE
                 progressBar.visibility = VISIBLE
             } else {
-                appStatus.setImageResource(if (item.success) R.drawable.ic_check_green else R.drawable.ic_cancel_red)
+                appStatus.setImageResource(
+                        if (item.status == SUCCEEDED) R.drawable.ic_check_green
+                        else R.drawable.ic_cancel_red
+                )
                 appStatus.visibility = VISIBLE
                 progressBar.visibility = INVISIBLE
             }
@@ -91,4 +96,6 @@ internal class RestoreProgressAdapter : Adapter<PackageViewHolder>() {
 
 }
 
-data class AppRestoreResult(val packageName: String, val success: Boolean)
+internal enum class AppRestoreStatus { IN_PROGRESS, SUCCEEDED, FAILED }
+
+internal data class AppRestoreResult(val packageName: String, val status: AppRestoreStatus)

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreProgressFragment.kt

@@ -51,28 +51,11 @@ class RestoreProgressFragment : Fragment() {
             backupNameView.text = restorableBackup.name
         })
 
-        viewModel.restoreProgress.observe(this, Observer { currentPackage ->
+        viewModel.restoreProgress.observe(this, Observer { list ->
-            stayScrolledAtTop {
+            stayScrolledAtTop { adapter.update(list) }
-                val latest = adapter.getLatest()
-                if (viewModel.isFailedPackage(latest.packageName)) {
-                    adapter.setLatestFailed()
-                }
-                adapter.add(AppRestoreResult(currentPackage, true))
-            }
         })
 
         viewModel.restoreBackupResult.observe(this, Observer { finished ->
-            val seenPackages = adapter.setComplete()
-            stayScrolledAtTop {
-                // add missing packages as failed
-                val restorableBackup = viewModel.chosenRestorableBackup.value!!
-                val expectedPackages = restorableBackup.packageMetadataMap.keys
-                expectedPackages.removeAll(seenPackages)
-                for (packageName: String in expectedPackages) {
-                    adapter.add(AppRestoreResult(packageName, false))
-                }
-            }
-
             button.isEnabled = true
             if (finished.hasError()) {
                 backupNameView.text = finished.errorMsg

app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt

@@ -15,8 +15,10 @@ import androidx.lifecycle.Transformations.switchMap
 import androidx.lifecycle.asLiveData
 import androidx.lifecycle.viewModelScope
 import com.stevesoltys.seedvault.BackupMonitor
+import com.stevesoltys.seedvault.MAGIC_PACKAGE_MANAGER
 import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.crypto.KeyManager
+import com.stevesoltys.seedvault.restore.AppRestoreStatus.*
 import com.stevesoltys.seedvault.restore.DisplayFragment.RESTORE_APPS
 import com.stevesoltys.seedvault.restore.DisplayFragment.RESTORE_BACKUP
 import com.stevesoltys.seedvault.settings.SettingsManager
@@ -35,6 +37,7 @@ import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.onCompletion
 import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.launch
+import java.util.*
 import kotlin.coroutines.Continuation
 import kotlin.coroutines.resume
 import kotlin.coroutines.suspendCoroutine
@@ -73,8 +76,12 @@ internal class RestoreViewModel(
     private val mNextButtonEnabled = MutableLiveData<Boolean>().apply { value = false }
     internal val nextButtonEnabled: LiveData<Boolean> = mNextButtonEnabled
 
-    private val mRestoreProgress = MutableLiveData<String>()
+    private val mRestoreProgress = MutableLiveData<LinkedList<AppRestoreResult>>().apply {
-    internal val restoreProgress: LiveData<String> get() = mRestoreProgress
+        value = LinkedList<AppRestoreResult>().apply {
+            add(AppRestoreResult(MAGIC_PACKAGE_MANAGER, IN_PROGRESS))
+        }
+    }
+    internal val restoreProgress: LiveData<LinkedList<AppRestoreResult>> get() = mRestoreProgress
 
     private val mRestoreBackupResult = MutableLiveData<RestoreBackupResult>()
     internal val restoreBackupResult: LiveData<RestoreBackupResult> get() = mRestoreBackupResult
@@ -164,7 +171,46 @@ internal class RestoreViewModel(
         }
     }
 
-    fun isFailedPackage(packageName: String) = restoreCoordinator.isFailedPackage(packageName)
+    @WorkerThread
+    // this should be called one package at a time and never concurrently for different packages
+    private fun onRestoreStarted(packageName: String) {
+        // list is never null and always has at least one package
+        val list = mRestoreProgress.value!!
+
+        // check previous package first and change status
+        updateLatestPackage(list)
+        // add current package
+        list.addFirst(AppRestoreResult(packageName, IN_PROGRESS))
+        mRestoreProgress.postValue(list)
+    }
+
+    private fun updateLatestPackage(list: LinkedList<AppRestoreResult>) {
+        val latestResult = list[0]
+        if (restoreCoordinator.isFailedPackage(latestResult.packageName)) {
+            list[0] = latestResult.copy(status = FAILED)
+        } else {
+            list[0] = latestResult.copy(status = SUCCEEDED)
+        }
+    }
+
+    @WorkerThread
+    private fun onRestoreComplete(result: RestoreBackupResult) {
+        // update status of latest package
+        val list = mRestoreProgress.value!!
+        updateLatestPackage(list)
+
+        // add missing packages as failed
+        val seenPackages = list.map { it.packageName }
+        val restorableBackup = chosenRestorableBackup.value!!
+        val expectedPackages = restorableBackup.packageMetadataMap.keys
+        expectedPackages.removeAll(seenPackages)
+        for (packageName: String in expectedPackages) {
+            list.add(AppRestoreResult(packageName, FAILED))
+        }
+        mRestoreProgress.postValue(list)
+
+        mRestoreBackupResult.postValue(result)
+    }
 
     override fun onCleared() {
         super.onCleared()
@@ -189,7 +235,7 @@ internal class RestoreViewModel(
          *   the current device. If no applicable datasets exist, restoreSets will be null.
          */
         override fun restoreSetsAvailable(restoreSets: Array<out RestoreSet>?) {
-            check (continuation != null) { "Getting restore sets without continuation" }
+            check(continuation != null) { "Getting restore sets without continuation" }
 
             val result = if (restoreSets == null || restoreSets.isEmpty()) {
                 RestoreSetResult(app.getString(R.string.restore_set_empty_result))
@@ -241,7 +287,7 @@ internal class RestoreViewModel(
          */
         override fun onUpdate(nowBeingRestored: Int, currentPackage: String) {
             // nowBeingRestored reporting is buggy, so don't use it
-            mRestoreProgress.postValue(currentPackage)
+            onRestoreStarted(currentPackage)
         }
 
         /**
@@ -255,7 +301,7 @@ internal class RestoreViewModel(
                     if (result == 0) null
                     else app.getString(R.string.restore_finished_error)
             )
-            mRestoreBackupResult.postValue(restoreResult)
+            onRestoreComplete(restoreResult)
             closeSession()
         }