From 5012099419eabf732e624aad5fb37ec2a4357694 Mon Sep 17 00:00:00 2001
From: Torsten Grote <t@grobox.de>
Date: Thu, 20 Jun 2024 16:30:06 -0300
Subject: [PATCH] Add UI prototype for selecting file to storage demo app

---
 .../seedvault/restore/RestoreViewModel.kt     |   3 +
 .../storagebackuptester/MainViewModel.kt      |   7 +
 .../restore/DemoFileSelectionFragment.kt      |  36 +++++
 .../restore/DemoSnapshotFragment.kt           |   4 +-
 .../restore/RestoreFragment.kt                |   8 +-
 .../ui/restore/FileSelectionFragment.kt       |  58 ++++++++
 .../backup/storage/ui/restore/FilesAdapter.kt | 126 ++++++++++++++++++
 .../storage/ui/restore/SnapshotFragment.kt    |   6 +-
 .../src/main/res/drawable/ic_audio_file.xml   |  15 +++
 .../main/res/drawable/ic_chevron_right.xml    |  15 +++
 .../lib/src/main/res/drawable/ic_image.xml    |  14 ++
 .../drawable/ic_indeterminate_check_box.xml   |  27 ++++
 .../res/drawable/ic_insert_drive_file.xml     |  15 +++
 .../res/drawable/ic_keyboard_arrow_down.xml   |  15 +++
 .../src/main/res/drawable/ic_video_file.xml   |  14 ++
 .../main/res/layout/fragment_select_files.xml |  58 ++++++++
 storage/lib/src/main/res/layout/item_file.xml |  54 ++++++++
 storage/lib/src/main/res/values/strings.xml   |   4 +
 18 files changed, 471 insertions(+), 8 deletions(-)
 create mode 100644 storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoFileSelectionFragment.kt
 create mode 100644 storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FileSelectionFragment.kt
 create mode 100644 storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FilesAdapter.kt
 create mode 100644 storage/lib/src/main/res/drawable/ic_audio_file.xml
 create mode 100644 storage/lib/src/main/res/drawable/ic_chevron_right.xml
 create mode 100644 storage/lib/src/main/res/drawable/ic_image.xml
 create mode 100644 storage/lib/src/main/res/drawable/ic_indeterminate_check_box.xml
 create mode 100644 storage/lib/src/main/res/drawable/ic_insert_drive_file.xml
 create mode 100644 storage/lib/src/main/res/drawable/ic_keyboard_arrow_down.xml
 create mode 100644 storage/lib/src/main/res/drawable/ic_video_file.xml
 create mode 100644 storage/lib/src/main/res/layout/fragment_select_files.xml
 create mode 100644 storage/lib/src/main/res/layout/item_file.xml

diff --git a/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt b/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt
index 0912fbe2..6a838828 100644
--- a/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt
+++ b/app/src/main/java/com/stevesoltys/seedvault/restore/RestoreViewModel.kt
@@ -46,6 +46,7 @@ import org.calyxos.backup.storage.api.SnapshotItem
 import org.calyxos.backup.storage.api.StorageBackup
 import org.calyxos.backup.storage.restore.RestoreService.Companion.EXTRA_TIMESTAMP_START
 import org.calyxos.backup.storage.restore.RestoreService.Companion.EXTRA_USER_ID
+import org.calyxos.backup.storage.ui.restore.FileSelectionManager
 import org.calyxos.backup.storage.ui.restore.SnapshotViewModel
 import java.util.LinkedList
 
@@ -98,6 +99,8 @@ internal class RestoreViewModel(
         get() = appDataRestoreManager.restoreBackupResult
 
     override val snapshots = storageBackup.getBackupSnapshots().asLiveData(ioDispatcher)
+    override val fileSelectionManager: FileSelectionManager
+        get() = TODO("Not yet implemented")
 
     internal fun loadRestoreSets() = viewModelScope.launch(ioDispatcher) {
         val backups = restoreCoordinator.getAvailableMetadata()?.mapNotNull { (token, metadata) ->
diff --git a/storage/demo/src/main/java/de/grobox/storagebackuptester/MainViewModel.kt b/storage/demo/src/main/java/de/grobox/storagebackuptester/MainViewModel.kt
index 18159b27..a0dd1728 100644
--- a/storage/demo/src/main/java/de/grobox/storagebackuptester/MainViewModel.kt
+++ b/storage/demo/src/main/java/de/grobox/storagebackuptester/MainViewModel.kt
@@ -28,6 +28,7 @@ import org.calyxos.backup.storage.backup.BackupJobService
 import org.calyxos.backup.storage.scanner.DocumentScanner
 import org.calyxos.backup.storage.scanner.MediaScanner
 import org.calyxos.backup.storage.ui.backup.BackupContentViewModel
+import org.calyxos.backup.storage.ui.restore.FileSelectionManager
 import org.calyxos.backup.storage.ui.restore.SnapshotViewModel
 
 private val logEmptyState = """
@@ -47,6 +48,7 @@ class MainViewModel(application: Application) : BackupContentViewModel(applicati
     private val app: App = application as App
     private val settingsManager = app.settingsManager
     override val storageBackup: StorageBackup = app.storageBackup
+    override val fileSelectionManager = FileSelectionManager()
 
     private val _backupLog = MutableLiveData(BackupProgress(0, 0, logEmptyState))
     val backupLog: LiveData<BackupProgress> = _backupLog
@@ -124,6 +126,11 @@ class MainViewModel(application: Application) : BackupContentViewModel(applicati
     }
 
     fun onSnapshotClicked(item: SnapshotItem) {
+        val snapshot = item.snapshot ?: error("${item.storedSnapshot} had null snapshot")
+        fileSelectionManager.onSnapshotChosen(snapshot)
+    }
+
+    fun onFilesSelected(item: SnapshotItem) {
         val snapshot = item.snapshot
         check(snapshot != null)
 
diff --git a/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoFileSelectionFragment.kt b/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoFileSelectionFragment.kt
new file mode 100644
index 00000000..35afa54c
--- /dev/null
+++ b/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoFileSelectionFragment.kt
@@ -0,0 +1,36 @@
+/*
+ * SPDX-FileCopyrightText: 2021 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package de.grobox.storagebackuptester.restore
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.activityViewModels
+import de.grobox.storagebackuptester.MainViewModel
+import org.calyxos.backup.storage.ui.restore.FileSelectionFragment
+
+class DemoFileSelectionFragment : FileSelectionFragment() {
+
+    override val viewModel: MainViewModel by activityViewModels()
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?,
+    ): View {
+        val v = super.onCreateView(inflater, container, savedInstanceState)
+        // val topStub: ViewStub = v.findViewById(R.id.topStub)
+        // topStub.layoutResource = R.layout.footer_snapshot
+        // val header = topStub.inflate()
+        // header.findViewById<Button>(R.id.button).setOnClickListener {
+        //     requireActivity().onBackPressed()
+        // }
+        return v
+    }
+
+
+}
diff --git a/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoSnapshotFragment.kt b/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoSnapshotFragment.kt
index 7117ed33..13fcf328 100644
--- a/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoSnapshotFragment.kt
+++ b/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/DemoSnapshotFragment.kt
@@ -39,8 +39,8 @@ class DemoSnapshotFragment : SnapshotFragment() {
     override fun onSnapshotClicked(item: SnapshotItem) {
         viewModel.onSnapshotClicked(item)
         parentFragmentManager.beginTransaction()
-            .replace(R.id.container, RestoreFragment.newInstance())
-            .addToBackStack("RESTORE")
+            .replace(R.id.container, DemoFileSelectionFragment())
+            .addToBackStack("SELECT")
             .commit()
     }
 
diff --git a/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/RestoreFragment.kt b/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/RestoreFragment.kt
index 3b4f0025..94ce790c 100644
--- a/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/RestoreFragment.kt
+++ b/storage/demo/src/main/java/de/grobox/storagebackuptester/restore/RestoreFragment.kt
@@ -52,17 +52,17 @@ class RestoreFragment : Fragment() {
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        viewModel.restoreLog.observe(viewLifecycleOwner, { progress ->
+        viewModel.restoreLog.observe(viewLifecycleOwner) { progress ->
             progress.text?.let { adapter.addItem(it) }
             horizontalProgressBar.max = progress.total
             horizontalProgressBar.setProgress(progress.current, true)
             list.postDelayed({
                 list.scrollToPosition(adapter.itemCount - 1)
             }, 50)
-        })
-        viewModel.restoreProgressVisible.observe(viewLifecycleOwner, { visible ->
+        }
+        viewModel.restoreProgressVisible.observe(viewLifecycleOwner) { visible ->
             progressBar.visibility = if (visible) VISIBLE else INVISIBLE
-        })
+        }
     }
 
     override fun onStart() {
diff --git a/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FileSelectionFragment.kt b/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FileSelectionFragment.kt
new file mode 100644
index 00000000..0d58385c
--- /dev/null
+++ b/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FileSelectionFragment.kt
@@ -0,0 +1,58 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.calyxos.backup.storage.ui.restore
+
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.annotation.CallSuper
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.Lifecycle.State.STARTED
+import androidx.lifecycle.flowWithLifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.recyclerview.widget.RecyclerView
+import kotlinx.coroutines.launch
+import org.calyxos.backup.storage.R
+
+public abstract class FileSelectionFragment : Fragment() {
+
+    protected abstract val viewModel: SnapshotViewModel
+    private lateinit var list: RecyclerView
+    private lateinit var adapter: FilesAdapter
+
+    override fun onCreateView(
+        inflater: LayoutInflater,
+        container: ViewGroup?,
+        savedInstanceState: Bundle?,
+    ): View {
+        requireActivity().setTitle(R.string.select_files_title)
+
+        val v = inflater.inflate(R.layout.fragment_select_files, container, false)
+        list = v.findViewById(R.id.list)
+
+        return v
+    }
+
+    @CallSuper
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        adapter = FilesAdapter(
+            viewModel.fileSelectionManager::onExpandClicked,
+            viewModel.fileSelectionManager::onCheckedChanged,
+        )
+        list.adapter = adapter
+        lifecycleScope.launch {
+            viewModel.fileSelectionManager.files.flowWithLifecycle(lifecycle, STARTED).collect {
+                onFileItemsChanged(it)
+            }
+        }
+    }
+
+    @CallSuper
+    public open fun onFileItemsChanged(filesItems: List<FilesItem>) {
+        adapter.submitList(filesItems)
+    }
+}
diff --git a/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FilesAdapter.kt b/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FilesAdapter.kt
new file mode 100644
index 00000000..ba63fbcd
--- /dev/null
+++ b/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/FilesAdapter.kt
@@ -0,0 +1,126 @@
+/*
+ * SPDX-FileCopyrightText: 2024 The Calyx Institute
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package org.calyxos.backup.storage.ui.restore
+
+import android.content.res.Resources
+import android.text.format.DateUtils.FORMAT_ABBREV_ALL
+import android.text.format.DateUtils.getRelativeTimeSpanString
+import android.text.format.Formatter
+import android.view.LayoutInflater
+import android.view.View
+import android.view.View.VISIBLE
+import android.view.ViewGroup
+import android.widget.CheckBox
+import android.widget.ImageView
+import android.widget.TextView
+import androidx.core.content.ContextCompat.getDrawable
+import androidx.core.view.updatePadding
+import androidx.recyclerview.widget.DiffUtil
+import androidx.recyclerview.widget.ListAdapter
+import androidx.recyclerview.widget.RecyclerView.ViewHolder
+import org.calyxos.backup.storage.R
+import org.calyxos.backup.storage.backup.BackupMediaFile.MediaType.AUDIO
+import org.calyxos.backup.storage.backup.BackupMediaFile.MediaType.IMAGES
+import org.calyxos.backup.storage.backup.BackupMediaFile.MediaType.VIDEO
+import org.calyxos.backup.storage.ui.restore.FilesAdapter.FilesViewHolder
+
+private class FilesItemCallback : DiffUtil.ItemCallback<FilesItem>() {
+    override fun areItemsTheSame(oldItem: FilesItem, newItem: FilesItem): Boolean {
+        if (oldItem is FileItem && newItem is FileItem) return newItem.file == oldItem.file
+        if (oldItem is FolderItem && newItem is FolderItem) return newItem.name == oldItem.name
+        return false
+    }
+
+    override fun areContentsTheSame(oldItem: FilesItem, newItem: FilesItem): Boolean {
+        if (oldItem is FileItem && newItem is FileItem) return newItem.selected == oldItem.selected
+        if (oldItem is FolderItem && newItem is FolderItem) {
+            return newItem.selected == oldItem.selected && newItem.expanded == oldItem.expanded &&
+                newItem.partiallySelected == oldItem.partiallySelected
+        }
+        return false
+    }
+}
+
+internal class FilesAdapter(
+    private val onExpandClicked: (FolderItem) -> Unit,
+    private val onCheckedChanged: (FilesItem) -> Unit,
+) : ListAdapter<FilesItem, FilesViewHolder>(FilesItemCallback()) {
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): FilesViewHolder {
+        val v = LayoutInflater.from(parent.context).inflate(R.layout.item_file, parent, false)
+        return FilesViewHolder(v)
+    }
+
+    override fun onBindViewHolder(holder: FilesViewHolder, position: Int) {
+        holder.bind(getItem(position))
+    }
+
+    inner class FilesViewHolder(itemView: View) : ViewHolder(itemView) {
+
+        private val context = itemView.context
+        private val expandView: ImageView = itemView.findViewById(R.id.expandView)
+        private val nameView: TextView = itemView.findViewById(R.id.nameView)
+        private val infoView: TextView = itemView.findViewById(R.id.infoView)
+        private val checkBox: CheckBox = itemView.findViewById(R.id.checkBox)
+
+        private val indentPadding = (8 * Resources.getSystem().displayMetrics.density).toInt()
+        private val checkBoxDrawable = checkBox.buttonDrawable
+        private val indeterminateDrawable =
+            getDrawable(context, R.drawable.ic_indeterminate_check_box)
+
+        fun bind(item: FilesItem) {
+            if (item is FolderItem) {
+                expandView.visibility = VISIBLE
+                val res = if (item.expanded) {
+                    R.drawable.ic_keyboard_arrow_down
+                } else {
+                    R.drawable.ic_chevron_right
+                }
+                expandView.setImageResource(res)
+                itemView.setOnClickListener {
+                    onExpandClicked(item)
+                }
+            } else if (item is FileItem) {
+                expandView.setImageResource(getDrawableResource(item))
+                itemView.setOnClickListener(null)
+            }
+            itemView.updatePadding(left = indentPadding * item.level)
+            nameView.text = item.name
+
+            val now = System.currentTimeMillis()
+            var text = Formatter.formatShortFileSize(context, item.size)
+            item.lastModified?.let {
+                text += " - " + getRelativeTimeSpanString(it, now, 0L, FORMAT_ABBREV_ALL)
+            }
+            if (item is FolderItem) {
+                val numStr = context.getString(R.string.select_files_number_of_files, item.numFiles)
+                text += " - $numStr"
+            }
+            infoView.text = text
+            // unset and re-reset onCheckedChangeListener while updating checked state
+            checkBox.setOnCheckedChangeListener(null)
+            checkBox.isChecked = item.selected
+            checkBox.setOnCheckedChangeListener { _, _ ->
+                onCheckedChanged(item)
+            }
+            if (item is FolderItem && item.partiallySelected) {
+                checkBox.buttonDrawable = indeterminateDrawable
+            } else {
+                checkBox.buttonDrawable = checkBoxDrawable
+            }
+        }
+    }
+
+    private fun getDrawableResource(item: FileItem): Int = item.file.mediaFile?.type?.let { type ->
+        when (type) {
+            IMAGES -> R.drawable.ic_image
+            VIDEO -> R.drawable.ic_video_file
+            AUDIO -> R.drawable.ic_audio_file
+            else -> R.drawable.ic_insert_drive_file
+        }
+    } ?: R.drawable.ic_insert_drive_file
+
+}
diff --git a/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/SnapshotFragment.kt b/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/SnapshotFragment.kt
index 6982e94d..27be7100 100644
--- a/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/SnapshotFragment.kt
+++ b/storage/lib/src/main/java/org/calyxos/backup/storage/ui/restore/SnapshotFragment.kt
@@ -22,6 +22,7 @@ import org.calyxos.backup.storage.api.SnapshotResult
 
 public interface SnapshotViewModel {
     public val snapshots: LiveData<SnapshotResult>
+    public val fileSelectionManager: FileSelectionManager
 }
 
 internal interface SnapshotClickListener {
@@ -46,7 +47,7 @@ public abstract class SnapshotFragment : Fragment(), SnapshotClickListener {
 
         val adapter = SnapshotAdapter(this)
         list.adapter = adapter
-        viewModel.snapshots.observe(viewLifecycleOwner, {
+        viewModel.snapshots.observe(viewLifecycleOwner) {
             progressBar.visibility = INVISIBLE
             when (it) {
                 is SnapshotResult.Success -> {
@@ -54,6 +55,7 @@ public abstract class SnapshotFragment : Fragment(), SnapshotClickListener {
                         emptyStateView.visibility = VISIBLE
                     } else adapter.submitList(it.snapshots)
                 }
+
                 is SnapshotResult.Error -> {
                     val color = resources.getColor(R.color.design_default_color_error, null)
                     emptyStateView.setTextColor(color)
@@ -61,7 +63,7 @@ public abstract class SnapshotFragment : Fragment(), SnapshotClickListener {
                     emptyStateView.visibility = VISIBLE
                 }
             }
-        })
+        }
         return v
     }
 
diff --git a/storage/lib/src/main/res/drawable/ic_audio_file.xml b/storage/lib/src/main/res/drawable/ic_audio_file.xml
new file mode 100644
index 00000000..0b0611a5
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_audio_file.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?android:attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M14,2H6C4.9,2 4.01,2.9 4.01,4L4,20c0,1.1 0.89,2 1.99,2H18c1.1,0 2,-0.9 2,-2V8L14,2zM16,13h-3v3.75c0,1.24 -1.01,2.25 -2.25,2.25S8.5,17.99 8.5,16.75c0,-1.24 1.01,-2.25 2.25,-2.25c0.46,0 0.89,0.14 1.25,0.38V11h4V13zM13,9V3.5L18.5,9H13z" />
+
+</vector>
diff --git a/storage/lib/src/main/res/drawable/ic_chevron_right.xml b/storage/lib/src/main/res/drawable/ic_chevron_right.xml
new file mode 100644
index 00000000..949eb789
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_chevron_right.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?android:attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M10,6L8.59,7.41 13.17,12l-4.58,4.59L10,18l6,-6z" />
+
+</vector>
diff --git a/storage/lib/src/main/res/drawable/ic_image.xml b/storage/lib/src/main/res/drawable/ic_image.xml
new file mode 100644
index 00000000..1b588184
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_image.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?android:attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M21,19V5c0,-1.1 -0.9,-2 -2,-2H5c-1.1,0 -2,0.9 -2,2v14c0,1.1 0.9,2 2,2h14c1.1,0 2,-0.9 2,-2zM8.5,13.5l2.5,3.01L14.5,12l4.5,6H5l3.5,-4.5z" />
+</vector>
diff --git a/storage/lib/src/main/res/drawable/ic_indeterminate_check_box.xml b/storage/lib/src/main/res/drawable/ic_indeterminate_check_box.xml
new file mode 100644
index 00000000..e7c6f933
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_indeterminate_check_box.xml
@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="32dp"
+    android:height="32dp"
+    android:tint="?colorAccent"
+    android:viewportWidth="48"
+    android:viewportHeight="48">
+    <group
+        android:name="icon_null"
+        android:scaleX="0.2"
+        android:scaleY="0.2"
+        android:translateX="6"
+        android:translateY="6">
+        <group
+            android:name="check"
+            android:scaleX="7.5"
+            android:scaleY="7.5">
+            <path
+                android:name="check_path_merged"
+                android:fillColor="#FF000000"
+                android:pathData="M19,3H5C3.9,3 3,3.9 3,5v14c0,1.1 0.9,2 2,2h14c1.1,0 2,-0.9 2,-2V5C21,3.9 20.1,3 19,3zM17,13H7v-2h10V13z" />
+        </group>
+    </group>
+</vector>
diff --git a/storage/lib/src/main/res/drawable/ic_insert_drive_file.xml b/storage/lib/src/main/res/drawable/ic_insert_drive_file.xml
new file mode 100644
index 00000000..75218ff2
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_insert_drive_file.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?android:attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M6,2c-1.1,0 -1.99,0.9 -1.99,2L4,20c0,1.1 0.89,2 1.99,2L18,22c1.1,0 2,-0.9 2,-2L20,8l-6,-6L6,2zM13,9L13,3.5L18.5,9L13,9z" />
+
+</vector>
diff --git a/storage/lib/src/main/res/drawable/ic_keyboard_arrow_down.xml b/storage/lib/src/main/res/drawable/ic_keyboard_arrow_down.xml
new file mode 100644
index 00000000..e2e867bf
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_keyboard_arrow_down.xml
@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?android:attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M7.41,8.59L12,13.17l4.59,-4.58L18,10l-6,6 -6,-6 1.41,-1.41z" />
+
+</vector>
diff --git a/storage/lib/src/main/res/drawable/ic_video_file.xml b/storage/lib/src/main/res/drawable/ic_video_file.xml
new file mode 100644
index 00000000..13f26331
--- /dev/null
+++ b/storage/lib/src/main/res/drawable/ic_video_file.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: Material Design Authors / Google LLC
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:tint="?android:attr/colorControlNormal"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M14,2H6.01c-1.1,0 -2,0.89 -2,2L4,20c0,1.1 0.9,2 2,2h12c1.1,0 2,-0.9 2,-2V8L14,2zM13,9V3.5L18.5,9H13zM14,14l2,-1.06v4.12L14,16v1c0,0.55 -0.45,1 -1,1H9c-0.55,0 -1,-0.45 -1,-1v-4c0,-0.55 0.45,-1 1,-1h4c0.55,0 1,0.45 1,1V14z" />
+</vector>
diff --git a/storage/lib/src/main/res/layout/fragment_select_files.xml b/storage/lib/src/main/res/layout/fragment_select_files.xml
new file mode 100644
index 00000000..6896ca9b
--- /dev/null
+++ b/storage/lib/src/main/res/layout/fragment_select_files.xml
@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <com.google.android.material.appbar.AppBarLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content">
+
+        <com.google.android.material.appbar.CollapsingToolbarLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            app:layout_scrollFlags="scroll|enterAlwaysCollapsed">
+
+            <ViewStub
+                android:id="@+id/topStub"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:inflatedId="@+id/topStub"
+                app:layout_constraintEnd_toEndOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toTopOf="parent"
+                tools:layout="@layout/item_custom"
+                tools:visibility="visible" />
+
+        </com.google.android.material.appbar.CollapsingToolbarLayout>
+
+    </com.google.android.material.appbar.AppBarLayout>
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/list"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent"
+        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+        app:layout_constraintBottom_toTopOf="@+id/bottomStub"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/topStub"
+        tools:listitem="@layout/item_file" />
+
+    <com.google.android.material.floatingactionbutton.ExtendedFloatingActionButton
+        android:id="@+id/fab"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="bottom|end"
+        android:layout_margin="16dp"
+        android:text="@string/select_files_button_restore"
+        android:textColor="#ffffff"
+        app:backgroundTint="?colorAccent"
+        app:icon="@drawable/ic_cloud_restore"
+        app:iconTint="#ffffff"
+        app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent" />
+
+</androidx.coordinatorlayout.widget.CoordinatorLayout>
diff --git a/storage/lib/src/main/res/layout/item_file.xml b/storage/lib/src/main/res/layout/item_file.xml
new file mode 100644
index 00000000..b9262f72
--- /dev/null
+++ b/storage/lib/src/main/res/layout/item_file.xml
@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="utf-8"?><!--
+  SPDX-FileCopyrightText: 2021 The Calyx Institute
+  SPDX-License-Identifier: Apache-2.0
+  -->
+<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:id="@+id/layout"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="?selectableItemBackground"
+    android:paddingVertical="8dp">
+
+    <ImageView
+        android:id="@+id/expandView"
+        android:layout_width="48dp"
+        android:layout_height="48dp"
+        android:scaleType="center"
+        android:src="@drawable/ic_folder"
+        app:layout_constraintEnd_toStartOf="@+id/nameView"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/nameView"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:textAppearance="?android:attr/textAppearanceListItem"
+        app:layout_constraintEnd_toStartOf="@+id/checkBox"
+        app:layout_constraintStart_toEndOf="@+id/expandView"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:text="File/folder name which might be quite long, who knows...?" />
+
+    <TextView
+        android:id="@+id/infoView"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginTop="8dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="@+id/nameView"
+        app:layout_constraintHorizontal_chainStyle="spread_inside"
+        app:layout_constraintStart_toStartOf="@+id/nameView"
+        app:layout_constraintTop_toBottomOf="@+id/nameView"
+        tools:text="24h ago - 23 MB" />
+
+    <androidx.appcompat.widget.AppCompatCheckBox
+        android:id="@+id/checkBox"
+        android:layout_width="48dp"
+        android:layout_height="48dp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toEndOf="@+id/nameView"
+        app:layout_constraintTop_toTopOf="parent" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/storage/lib/src/main/res/values/strings.xml b/storage/lib/src/main/res/values/strings.xml
index d9413da1..99e32902 100644
--- a/storage/lib/src/main/res/values/strings.xml
+++ b/storage/lib/src/main/res/values/strings.xml
@@ -22,4 +22,8 @@
     <string name="snapshots_title">Available storage backups</string>
     <string name="snapshots_empty">No storage backups found\n\nSorry, but there is nothing that can be restored.</string>
     <string name="snapshots_error">Error loading snapshots</string>
+
+    <string name="select_files_title">Files to be restored</string>
+    <string name="select_files_number_of_files">%1$d file(s)</string>
+    <string name="select_files_button_restore">Restore checked files</string>
 </resources>