Merge pull request #4053 from k9mail/settings_export_fragment

Add settings export to settings screen
2019-05-21 21:03:30 +02:00 · 2019-05-21 21:03:30 +02:00 · 1e8b66e29b
commit 1e8b66e29b
parent ec18c9edb7 f3cc89f09d
22 changed files with 888 additions and 2 deletions
--- a/app/core/src/main/java/com/fsck/k9/helper/Timing.kt
+++ b/app/core/src/main/java/com/fsck/k9/helper/Timing.kt
@ -0,0 +1,12 @@
+package com.fsck.k9.helper
+
+import android.os.SystemClock
+
+/**
+ * Executes the given [block] and returns elapsed realtime in milliseconds.
+ */
+inline fun measureRealtimeMillis(block: () -> Unit): Long {
+    val start = SystemClock.elapsedRealtime()
+    block()
+    return SystemClock.elapsedRealtime() - start
+}
--- a/app/ui/build.gradle
+++ b/app/ui/build.gradle
@ -28,6 +28,7 @@ dependencies {
    implementation "androidx.lifecycle:lifecycle-extensions:${versions.androidxLifecycleExtensions}"
    implementation "androidx.navigation:navigation-fragment-ktx:${versions.androidxNavigation}"
    implementation "androidx.navigation:navigation-ui-ktx:${versions.androidxNavigation}"
+    implementation "androidx.constraintlayout:constraintlayout:${versions.androidxConstraintLayout}"
    implementation "de.cketti.library.changelog:ckchangelog:1.2.1"
    implementation "com.github.bumptech.glide:glide:3.6.1"
    implementation "com.splitwise:tokenautocomplete:2.0.7"
@ -38,6 +39,7 @@ dependencies {
    implementation 'com.mikepenz:materialdrawer:6.1.1'
    implementation 'com.mikepenz:fontawesome-typeface:5.3.1.1@aar'
    implementation 'com.github.ByteHamster:SearchPreference:v1.1.4'
+    implementation 'com.mikepenz:fastadapter:3.3.1'

    implementation "commons-io:commons-io:${versions.commonsIo}"
    implementation "androidx.core:core-ktx:${versions.coreKtx}"
--- a/app/ui/src/main/java/com/fsck/k9/ui/helper/CoroutineScopeViewModel.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/helper/CoroutineScopeViewModel.kt
@ -0,0 +1,16 @@
+package com.fsck.k9.ui.helper
+
+import androidx.lifecycle.ViewModel
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+
+abstract class CoroutineScopeViewModel : ViewModel(), CoroutineScope {
+    private val job = Job()
+
+    override val coroutineContext = Dispatchers.Main + job
+
+    override fun onCleared() {
+        job.cancel()
+    }
+}
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/KoinModule.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/KoinModule.kt
@ -4,6 +4,7 @@ import com.fsck.k9.helper.NamedThreadFactory
 import com.fsck.k9.ui.account.AccountsLiveData
 import com.fsck.k9.ui.settings.account.AccountSettingsDataStoreFactory
 import com.fsck.k9.ui.settings.account.AccountSettingsViewModel
+import com.fsck.k9.ui.settings.export.SettingsExportViewModel
 import com.fsck.k9.ui.settings.general.GeneralSettingsDataStore
 import org.koin.android.architecture.ext.viewModel
 import org.koin.dsl.module.applicationContext
@ -20,4 +21,6 @@ val settingsUiModule = applicationContext {

    viewModel { AccountSettingsViewModel(get(), get()) }
    bean { AccountSettingsDataStoreFactory(get(), get(), get("SaveSettingsExecutorService")) }
+
+    viewModel { SettingsExportViewModel(get(), get()) }
 }
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/SettingsListFragment.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/SettingsListFragment.kt
@ -93,6 +93,17 @@ class SettingsListFragment : Fragment() {
        }
        accountSection.setHeader(SettingsDividerItem(getString(R.string.accounts_title)))
        settingsAdapter.add(accountSection)
+
+        val backupSection = Section().apply {
+            val exportSettingsActionItem = SettingsActionItem(
+                    getString(R.string.settings_export_title),
+                    R.id.action_settingsListScreen_to_settingsExportScreen,
+                    R.attr.iconSettingsExport
+            )
+            add(exportSettingsActionItem)
+        }
+        backupSection.setHeader(SettingsDividerItem(getString(R.string.settings_list_backup_category)))
+        settingsAdapter.add(backupSection)
    }

    private fun handleItemClick(item: Item<*>) {
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/export/CheckBoxItem.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/export/CheckBoxItem.kt
@ -0,0 +1,39 @@
+package com.fsck.k9.ui.settings.export
+
+import android.view.View
+import android.widget.CheckBox
+import androidx.recyclerview.widget.RecyclerView
+import com.fsck.k9.ui.R
+import com.mikepenz.fastadapter.FastAdapter
+import com.mikepenz.fastadapter.items.AbstractItem
+import com.mikepenz.fastadapter.listeners.ClickEventHook
+import kotlinx.android.extensions.LayoutContainer
+
+abstract class CheckBoxItem(private val id: Long) : AbstractItem<CheckBoxItem, CheckBoxViewHolder>() {
+    override fun getIdentifier(): Long = id
+
+    override fun getViewHolder(view: View): CheckBoxViewHolder = CheckBoxViewHolder(view)
+
+    override fun bindView(viewHolder: CheckBoxViewHolder, payloads: List<Any>) {
+        super.bindView(viewHolder, payloads)
+        viewHolder.checkBox.isChecked = isSelected
+        viewHolder.itemView.isEnabled = isEnabled
+        viewHolder.checkBox.isEnabled = isEnabled
+    }
+}
+
+class CheckBoxViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView), LayoutContainer {
+    val checkBox: CheckBox = itemView.findViewById(R.id.checkBox)
+
+    override val containerView = itemView
+}
+
+class CheckBoxClickEvent(val action: (position: Int, isSelected: Boolean) -> Unit) : ClickEventHook<CheckBoxItem>() {
+    override fun onBind(viewHolder: RecyclerView.ViewHolder): View? {
+        return if (viewHolder is CheckBoxViewHolder) viewHolder.checkBox else null
+    }
+
+    override fun onClick(view: View, position: Int, fastAdapter: FastAdapter<CheckBoxItem>, item: CheckBoxItem) {
+        action(position, !item.isSelected)
+    }
+}
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportFragment.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportFragment.kt
@ -0,0 +1,158 @@
+package com.fsck.k9.ui.settings.export
+
+import android.app.Activity
+import android.content.Intent
+import android.net.Uri
+import android.os.Bundle
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import androidx.fragment.app.Fragment
+import androidx.recyclerview.widget.RecyclerView
+import com.fsck.k9.ui.R
+import com.fsck.k9.ui.observeNotNull
+import com.mikepenz.fastadapter.commons.adapters.FastItemAdapter
+import kotlinx.android.synthetic.main.fragment_settings_export.*
+import org.koin.android.architecture.ext.viewModel
+
+
+class SettingsExportFragment : Fragment() {
+    private val viewModel: SettingsExportViewModel by viewModel()
+
+    private lateinit var settingsExportAdapter: FastItemAdapter<CheckBoxItem>
+
+
+    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
+        return inflater.inflate(R.layout.fragment_settings_export, container, false)
+    }
+
+    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
+        if (savedInstanceState != null) {
+            viewModel.initializeFromSavedState(savedInstanceState)
+        }
+
+        initializeSettingsExportList(view)
+        exportButton.setOnClickListener { viewModel.onExportButtonClicked() }
+        shareButton.setOnClickListener { viewModel.onShareButtonClicked() }
+
+        viewModel.getUiModel().observeNotNull(this) { updateUi(it) }
+        viewModel.getActionEvents().observeNotNull(this) { handleActionEvents(it) }
+    }
+
+    private fun initializeSettingsExportList(view: View) {
+        settingsExportAdapter = FastItemAdapter<CheckBoxItem>().apply {
+            setHasStableIds(true)
+            withOnClickListener { _, _, item: CheckBoxItem, position ->
+                viewModel.onSettingsListItemSelected(position, !item.isSelected)
+                true
+            }
+            withEventHook(CheckBoxClickEvent { position, isSelected ->
+                viewModel.onSettingsListItemSelected(position, isSelected)
+            })
+        }
+
+        val recyclerView = view.findViewById<RecyclerView>(R.id.settingsExportList)
+        recyclerView.adapter = settingsExportAdapter
+    }
+
+    private fun updateUi(model: SettingsExportUiModel) {
+        when (model.exportButton) {
+            ButtonState.DISABLED -> {
+                exportButton.visibility = View.VISIBLE
+                exportButton.isEnabled = false
+            }
+            ButtonState.ENABLED -> {
+                exportButton.visibility = View.VISIBLE
+                exportButton.isEnabled = true
+            }
+            ButtonState.INVISIBLE -> exportButton.visibility = View.INVISIBLE
+            ButtonState.GONE -> exportButton.visibility = View.GONE
+        }
+
+        shareButton.visibility = if (model.isShareButtonVisible) View.VISIBLE else View.GONE
+        progressBar.visibility = if (model.isProgressVisible) View.VISIBLE else View.GONE
+
+        when (model.statusText) {
+            StatusText.HIDDEN -> statusText.visibility = View.GONE
+            StatusText.EXPORT_SUCCESS -> {
+                statusText.visibility = View.VISIBLE
+                statusText.text = getString(R.string.settings_export_success_generic)
+            }
+            StatusText.PROGRESS -> {
+                statusText.visibility = View.VISIBLE
+                statusText.text = getString(R.string.settings_export_progress_text)
+            }
+            StatusText.EXPORT_FAILURE -> {
+                statusText.visibility = View.VISIBLE
+                statusText.text = getString(R.string.settings_export_failure)
+            }
+        }
+
+        setSettingsList(model.settingsList, model.isSettingsListEnabled)
+    }
+
+    //TODO: Update list instead of replacing it completely
+    private fun setSettingsList(items: List<SettingsListItem>, enable: Boolean) {
+        val checkBoxItems = items.map { item ->
+            val checkBoxItem = when (item) {
+                is SettingsListItem.GeneralSettings -> GeneralSettingsItem()
+                is SettingsListItem.Account -> AccountItem(item)
+            }
+
+            checkBoxItem
+                    .withSetSelected(item.selected)
+                    .withEnabled(enable)
+        }
+
+        settingsExportAdapter.set(checkBoxItems)
+
+        settingsExportList.isEnabled = enable
+    }
+
+    private fun handleActionEvents(action: Action) {
+        when (action) {
+            is Action.PickDocument -> pickDocument(action.fileNameSuggestion, action.mimeType)
+            is Action.ShareDocument -> shareDocument(action.contentUri, action.mimeType)
+        }
+    }
+
+    private fun pickDocument(fileNameSuggestion: String, mimeType: String) {
+        val createDocumentIntent = Intent(Intent.ACTION_CREATE_DOCUMENT).apply {
+            type = mimeType
+            putExtra(Intent.EXTRA_TITLE, fileNameSuggestion)
+            addCategory(Intent.CATEGORY_OPENABLE)
+        }
+        startActivityForResult(createDocumentIntent, RESULT_PICK_DOCUMENT)
+    }
+
+    private fun shareDocument(contentUri: Uri, mimeType: String) {
+        val shareIntent = Intent(Intent.ACTION_SEND).apply {
+            type = mimeType
+            putExtra(Intent.EXTRA_STREAM, contentUri)
+            addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+        }
+
+        startActivity(Intent.createChooser(shareIntent, null))
+    }
+
+    override fun onSaveInstanceState(outState: Bundle) {
+        super.onSaveInstanceState(outState)
+        viewModel.saveInstanceState(outState)
+    }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+        if (requestCode == RESULT_PICK_DOCUMENT) {
+            val contentUri = data?.data
+            if (resultCode == Activity.RESULT_OK && contentUri != null) {
+                viewModel.onDocumentPicked(contentUri)
+            } else {
+                viewModel.onDocumentPickCanceled()
+            }
+        }
+    }
+
+
+    companion object {
+        private const val RESULT_PICK_DOCUMENT = Activity.RESULT_FIRST_USER
+    }
+}
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportListItems.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportListItems.kt
@ -0,0 +1,32 @@
+package com.fsck.k9.ui.settings.export
+
+import com.fsck.k9.ui.R
+import kotlinx.android.synthetic.main.settings_export_account_list_item.*
+
+
+private const val GENERAL_SETTINGS_ID = 0L
+private const val ACCOUNT_ITEMS_ID_OFFSET = 1L
+
+
+class GeneralSettingsItem : CheckBoxItem(GENERAL_SETTINGS_ID) {
+    override fun getType(): Int = R.id.settings_export_list_general_item
+
+    override fun getLayoutRes(): Int = R.layout.settings_export_general_list_item
+}
+
+
+class AccountItem(account: SettingsListItem.Account) : CheckBoxItem(account.accountNumber + ACCOUNT_ITEMS_ID_OFFSET) {
+    private val displayName = account.displayName
+    private val email = account.email
+
+
+    override fun getType(): Int = R.id.settings_export_list_account_item
+
+    override fun getLayoutRes(): Int = R.layout.settings_export_account_list_item
+
+    override fun bindView(viewHolder: CheckBoxViewHolder, payloads: List<Any>) {
+        super.bindView(viewHolder, payloads)
+        viewHolder.accountDisplayName.text = displayName
+        viewHolder.accountEmail.text = email
+    }
+}
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportUiModel.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportUiModel.kt
@ -0,0 +1,99 @@
+package com.fsck.k9.ui.settings.export
+
+import com.fsck.k9.Account as K9Account
+
+
+class SettingsExportUiModel {
+    var settingsList: List<SettingsListItem> = emptyList()
+    var isSettingsListEnabled = true
+    var exportButton: ButtonState = ButtonState.DISABLED
+    var isShareButtonVisible = false
+    var isProgressVisible = false
+    var statusText = StatusText.HIDDEN
+
+
+    fun enableExportButton() {
+        exportButton = ButtonState.ENABLED
+        isShareButtonVisible = false
+        isProgressVisible = false
+        isSettingsListEnabled = true
+    }
+
+    fun disableExportButton() {
+        exportButton = ButtonState.DISABLED
+        isShareButtonVisible = false
+        isProgressVisible = false
+    }
+
+    fun showProgress() {
+        isProgressVisible = true
+        exportButton = ButtonState.INVISIBLE
+        isShareButtonVisible = false
+        statusText = StatusText.PROGRESS
+        isSettingsListEnabled = false
+    }
+
+    fun showSuccessText() {
+        exportButton = ButtonState.GONE
+        isProgressVisible = false
+        isShareButtonVisible = true
+        isSettingsListEnabled = true
+        statusText = StatusText.EXPORT_SUCCESS
+    }
+
+    fun showFailureText() {
+        exportButton = ButtonState.GONE
+        isShareButtonVisible = false
+        isProgressVisible = false
+        isSettingsListEnabled = true
+        statusText = StatusText.EXPORT_FAILURE
+    }
+
+    fun initializeSettingsList(list: List<SettingsListItem>) {
+        settingsList = list
+        updateExportButtonFromSelection()
+    }
+
+    fun setSettingsListItemSelection(position: Int, select: Boolean) {
+        settingsList[position].selected = select
+        statusText = StatusText.HIDDEN
+        isShareButtonVisible = false
+        updateExportButtonFromSelection()
+    }
+
+    private fun updateExportButtonFromSelection() {
+        if (isProgressVisible || isShareButtonVisible) return
+
+        val atLeastOnceSelected = settingsList.any { it.selected }
+        if (atLeastOnceSelected) {
+            enableExportButton()
+        } else {
+            disableExportButton()
+        }
+    }
+}
+
+sealed class SettingsListItem {
+    var selected: Boolean = true
+
+    object GeneralSettings : SettingsListItem()
+    data class Account(
+            val accountNumber: Int,
+            val displayName: String,
+            val email: String
+    ) : SettingsListItem()
+}
+
+enum class ButtonState {
+    DISABLED,
+    ENABLED,
+    INVISIBLE,
+    GONE
+}
+
+enum class StatusText {
+    HIDDEN,
+    PROGRESS,
+    EXPORT_SUCCESS,
+    EXPORT_FAILURE
+}
--- a/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportViewModel.kt
+++ b/app/ui/src/main/java/com/fsck/k9/ui/settings/export/SettingsExportViewModel.kt
@ -0,0 +1,213 @@
+package com.fsck.k9.ui.settings.export
+
+import android.content.Context
+import android.net.Uri
+import android.os.Bundle
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import com.fsck.k9.Preferences
+import com.fsck.k9.helper.SingleLiveEvent
+import com.fsck.k9.helper.measureRealtimeMillis
+import com.fsck.k9.preferences.SettingsExporter
+import com.fsck.k9.ui.helper.CoroutineScopeViewModel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+
+private typealias AccountUuid = String
+private typealias AccountNumber = Int
+
+class SettingsExportViewModel(val context: Context, val preferences: Preferences) : CoroutineScopeViewModel() {
+    private val uiModelLiveData = MutableLiveData<SettingsExportUiModel>()
+    private val actionLiveData = SingleLiveEvent<Action>()
+
+    private val uiModel = SettingsExportUiModel()
+    private var accountsMap: Map<AccountNumber, AccountUuid> = emptyMap()
+    private var savedSelection: SavedListItemSelection? = null
+    private var contentUri: Uri? = null
+
+    private val includeGeneralSettings: Boolean
+        get() {
+            return savedSelection?.includeGeneralSettings
+                    ?: uiModel.settingsList.first { it is SettingsListItem.GeneralSettings }.selected
+        }
+
+    private val selectedAccounts: Set<AccountUuid>
+        get() {
+            return savedSelection?.selectedAccountUuids
+                    ?: uiModel.settingsList.asSequence()
+                            .filterIsInstance<SettingsListItem.Account>()
+                            .filter { it.selected }
+                            .map {
+                                accountsMap[it.accountNumber] ?: error("Unknown account number: ${it.accountNumber}")
+                            }
+                            .toSet()
+        }
+
+
+    fun getActionEvents(): LiveData<Action> = actionLiveData
+
+    fun getUiModel(): LiveData<SettingsExportUiModel> {
+        if (uiModelLiveData.value == null) {
+            uiModelLiveData.value = uiModel
+
+            launch {
+                val accounts = withContext(Dispatchers.IO) { preferences.accounts }
+
+                accountsMap = accounts.map { it.accountNumber to it.uuid }.toMap()
+
+                val listItems = savedSelection.let { savedState ->
+                    val generalSettings = SettingsListItem.GeneralSettings.apply {
+                        selected = savedState == null || savedState.includeGeneralSettings
+                    }
+
+                    val accountListItems = accounts.map { account ->
+                        SettingsListItem.Account(account.accountNumber, account.displayName, account.email).apply {
+                            selected = savedState == null || account.uuid in savedState.selectedAccountUuids
+                        }
+                    }
+
+                    listOf(generalSettings) + accountListItems
+                }
+
+                updateUiModel {
+                    initializeSettingsList(listItems)
+                }
+            }
+        }
+
+        return uiModelLiveData
+    }
+
+
+    fun initializeFromSavedState(savedInstanceState: Bundle) {
+        savedSelection = SavedListItemSelection(
+                includeGeneralSettings = savedInstanceState.getBoolean(STATE_INCLUDE_GENERAL_SETTINGS),
+                selectedAccountUuids = savedInstanceState.getStringArray(STATE_SELECTED_ACCOUNTS)?.toSet() ?: emptySet()
+        )
+
+        uiModel.apply {
+            isSettingsListEnabled = savedInstanceState.getBoolean(STATE_SETTINGS_LIST_ENABLED)
+            exportButton = ButtonState.valueOf(
+                    savedInstanceState.getString(STATE_EXPORT_BUTTON, ButtonState.DISABLED.name)
+            )
+            isShareButtonVisible = savedInstanceState.getBoolean(STATE_SHARE_BUTTON_VISIBLE)
+            isProgressVisible = savedInstanceState.getBoolean(STATE_PROGRESS_VISIBLE)
+            statusText = StatusText.valueOf(savedInstanceState.getString(STATE_STATUS_TEXT, StatusText.HIDDEN.name))
+        }
+
+        contentUri = savedInstanceState.getParcelable(STATE_CONTENT_URI)
+    }
+
+    fun onExportButtonClicked() {
+        updateUiModel {
+            disableExportButton()
+        }
+
+        startExportSettings()
+    }
+
+    fun onShareButtonClicked() {
+        sendActionEvent(Action.ShareDocument(contentUri!!, SETTINGS_MIME_TYPE))
+    }
+
+    private fun startExportSettings() {
+        val exportFileName = SettingsExporter.generateDatedExportFileName()
+        sendActionEvent(Action.PickDocument(exportFileName, SETTINGS_MIME_TYPE))
+    }
+
+    fun onDocumentPicked(contentUri: Uri) {
+        this.contentUri = contentUri
+
+        updateUiModel {
+            showProgress()
+        }
+
+        val includeGeneralSettings = this.includeGeneralSettings
+        val selectedAccounts = this.selectedAccounts
+
+        launch {
+            try {
+                val elapsed = measureRealtimeMillis {
+                    withContext(Dispatchers.IO) {
+                        SettingsExporter.exportToUri(context, includeGeneralSettings, selectedAccounts, contentUri)
+                    }
+                }
+
+                if (elapsed < MIN_PROGRESS_DURATION) {
+                    delay(MIN_PROGRESS_DURATION - elapsed)
+                }
+
+                updateUiModel {
+                    showSuccessText()
+                }
+            } catch (e: Exception) {
+                updateUiModel {
+                    showFailureText()
+                }
+            }
+        }
+    }
+
+    fun onDocumentPickCanceled() {
+        updateUiModel {
+            enableExportButton()
+        }
+    }
+
+    fun saveInstanceState(outState: Bundle) {
+        outState.putBoolean(STATE_SETTINGS_LIST_ENABLED, uiModel.isSettingsListEnabled)
+        outState.putString(STATE_EXPORT_BUTTON, uiModel.exportButton.name)
+        outState.putBoolean(STATE_SHARE_BUTTON_VISIBLE, uiModel.isShareButtonVisible)
+        outState.putBoolean(STATE_PROGRESS_VISIBLE, uiModel.isProgressVisible)
+        outState.putString(STATE_STATUS_TEXT, uiModel.statusText.name)
+
+        outState.putBoolean(STATE_INCLUDE_GENERAL_SETTINGS, includeGeneralSettings)
+        outState.putStringArray(STATE_SELECTED_ACCOUNTS, selectedAccounts.toTypedArray())
+
+        outState.putParcelable(STATE_CONTENT_URI, contentUri)
+    }
+
+    fun onSettingsListItemSelected(position: Int, isSelected: Boolean) {
+        savedSelection = null
+
+        updateUiModel {
+            setSettingsListItemSelection(position, isSelected)
+        }
+    }
+
+    private fun updateUiModel(block: SettingsExportUiModel.() -> Unit) {
+        uiModel.block()
+        uiModelLiveData.value = uiModel
+    }
+
+    private fun sendActionEvent(action: Action) {
+        actionLiveData.value = action
+    }
+
+
+    companion object {
+        private const val MIN_PROGRESS_DURATION = 1000L
+        private const val SETTINGS_MIME_TYPE = "application/octet-stream"
+
+        private const val STATE_SETTINGS_LIST_ENABLED = "settingsListEnabled"
+        private const val STATE_EXPORT_BUTTON = "exportButton"
+        private const val STATE_SHARE_BUTTON_VISIBLE = "shareButtonVisible"
+        private const val STATE_PROGRESS_VISIBLE = "progressVisible"
+        private const val STATE_STATUS_TEXT = "statusText"
+        private const val STATE_INCLUDE_GENERAL_SETTINGS = "includeGeneralSettings"
+        private const val STATE_SELECTED_ACCOUNTS = "selectedAccounts"
+        private const val STATE_CONTENT_URI = "contentUri"
+    }
+}
+
+sealed class Action {
+    class PickDocument(val fileNameSuggestion: String, val mimeType: String) : Action()
+    class ShareDocument(val contentUri: Uri, val mimeType: String) : Action()
+}
+
+private data class SavedListItemSelection(
+        val includeGeneralSettings: Boolean,
+        val selectedAccountUuids: Set<AccountUuid>
+)
--- a/app/ui/src/main/res/drawable-anydpi/ic_export_dark.xml
+++ b/app/ui/src/main/res/drawable-anydpi/ic_export_dark.xml
@ -0,0 +1,9 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="#FFFFFF"
+      android:pathData="m8,7h3V16h2V7h3L12,3ZM4,19v2h16v-2z"/>
+</vector>
--- a/app/ui/src/main/res/drawable-anydpi/ic_export_light.xml
+++ b/app/ui/src/main/res/drawable-anydpi/ic_export_light.xml
@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:alpha="0.54"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+  <path
+      android:fillColor="#FF000000"
+      android:pathData="m8,7h3V16h2V7h3L12,3ZM4,19v2h16v-2z"/>
+</vector>
--- a/app/ui/src/main/res/layout/fragment_settings_export.xml
+++ b/app/ui/src/main/res/layout/fragment_settings_export.xml
@ -0,0 +1,94 @@
+<?xml version="1.0" encoding="utf-8"?>
+<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:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/settingsExportList"
+        android:layout_width="match_parent"
+        android:layout_height="0dp"
+        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+        app:layout_constraintBottom_toTopOf="@+id/bottomBar"
+        app:layout_constraintTop_toTopOf="parent"
+        tools:listitem="@layout/settings_export_account_list_item" />
+
+    <androidx.constraintlayout.widget.ConstraintLayout
+        android:id="@+id/bottomBar"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:background="?attr/bottomBarBackground"
+        android:elevation="8dp"
+        android:minHeight="56dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        tools:ignore="UnusedAttribute">
+
+        <Button
+            android:id="@+id/exportButton"
+            style="@style/Widget.AppCompat.Button.Colored"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="4dp"
+            android:layout_marginEnd="8dp"
+            android:layout_marginBottom="4dp"
+            android:enabled="false"
+            android:text="@string/settings_export_button"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintTop_toTopOf="parent" />
+
+        <Button
+            android:id="@+id/shareButton"
+            style="@style/Widget.AppCompat.Button.Colored"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="4dp"
+            android:layout_marginEnd="8dp"
+            android:layout_marginBottom="4dp"
+            android:text="@string/settings_export_share_button"
+            android:visibility="gone"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintTop_toTopOf="parent" />
+
+        <androidx.constraintlayout.widget.Barrier
+            android:id="@+id/buttonBarrier"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            app:barrierDirection="left"
+            app:constraint_referenced_ids="exportButton,shareButton" />
+
+        <ProgressBar
+            android:id="@+id/progressBar"
+            style="?android:attr/progressBarStyle"
+            android:layout_width="32dp"
+            android:layout_height="32dp"
+            android:indeterminate="true"
+            android:visibility="gone"
+            app:layout_constraintBottom_toBottomOf="@+id/exportButton"
+            app:layout_constraintEnd_toEndOf="@+id/exportButton"
+            app:layout_constraintStart_toStartOf="@+id/exportButton"
+            app:layout_constraintTop_toTopOf="@+id/exportButton" />
+
+        <TextView
+            android:id="@+id/statusText"
+            android:layout_width="0dp"
+            android:layout_height="wrap_content"
+            android:layout_marginStart="16dp"
+            android:layout_marginTop="8dp"
+            android:layout_marginEnd="16dp"
+            android:layout_marginBottom="8dp"
+            android:visibility="gone"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="@+id/buttonBarrier"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toTopOf="parent"
+            tools:text="Exporting…"
+            tools:visibility="visible" />
+
+    </androidx.constraintlayout.widget.ConstraintLayout>
+
+</androidx.constraintlayout.widget.ConstraintLayout>
+
--- a/app/ui/src/main/res/layout/settings_export_account_list_item.xml
+++ b/app/ui/src/main/res/layout/settings_export_account_list_item.xml
@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="utf-8"?>
+<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:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="?attr/selectableItemBackground"
+    android:clickable="true"
+    android:focusable="true">
+
+    <CheckBox
+        android:id="@+id/checkBox"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:focusable="false"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toStartOf="@id/guideline"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/accountDisplayName"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginEnd="16dp"
+        android:layout_marginTop="8dp"
+        android:duplicateParentState="true"
+        android:textAppearance="?android:attr/textAppearanceListItem"
+        app:layout_constraintBottom_toTopOf="@+id/accountEmail"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/guideline"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_chainStyle="packed"
+        tools:text="Account name" />
+
+    <TextView
+        android:id="@+id/accountEmail"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:layout_marginEnd="16dp"
+        android:duplicateParentState="true"
+        android:textAppearance="?android:attr/textAppearanceSmall"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/guideline"
+        app:layout_constraintTop_toBottomOf="@+id/accountDisplayName"
+        tools:text="user@domain.example" />
+
+    <androidx.constraintlayout.widget.Guideline
+        android:id="@+id/guideline"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        app:layout_constraintGuide_begin="72dp" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
--- a/app/ui/src/main/res/layout/settings_export_general_list_item.xml
+++ b/app/ui/src/main/res/layout/settings_export_general_list_item.xml
@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<androidx.constraintlayout.widget.ConstraintLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:layout_width="match_parent"
+    android:layout_height="wrap_content"
+    android:background="?attr/selectableItemBackground"
+    android:clickable="true"
+    android:focusable="true"
+    android:minHeight="?android:attr/listPreferredItemHeightSmall">
+
+    <CheckBox
+        android:id="@+id/checkBox"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:focusable="false"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toStartOf="@id/guideline"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <TextView
+        android:id="@+id/title"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_marginBottom="8dp"
+        android:layout_marginEnd="16dp"
+        android:layout_marginTop="8dp"
+        android:duplicateParentState="true"
+        android:text="@string/general_settings_title"
+        android:textAppearance="?android:attr/textAppearanceListItem"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="@+id/guideline"
+        app:layout_constraintTop_toTopOf="parent" />
+
+    <androidx.constraintlayout.widget.Guideline
+        android:id="@+id/guideline"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        app:layout_constraintGuide_begin="72dp" />
+
+</androidx.constraintlayout.widget.ConstraintLayout>
--- a/app/ui/src/main/res/navigation/navigation_settings.xml
+++ b/app/ui/src/main/res/navigation/navigation_settings.xml
@ -22,6 +22,9 @@
        <action
            android:id="@+id/action_settingsListScreen_to_addAccountScreen"
            app:destination="@id/addAccountScreen" />
+        <action
+            android:id="@+id/action_settingsListScreen_to_settingsExportScreen"
+            app:destination="@id/settingsExportScreen" />
    </fragment>

    <activity
@ -41,4 +44,10 @@
        android:label="@string/account_setup_basics_title"
        tools:layout="@layout/account_setup_basics"/>

+    <fragment
+        android:id="@+id/settingsExportScreen"
+        android:name="com.fsck.k9.ui.settings.export.SettingsExportFragment"
+        android:label="@string/settings_export_title"
+        tools:layout="@layout/fragment_settings_export"/>
+
 </navigation>
--- a/app/ui/src/main/res/values/attrs.xml
+++ b/app/ui/src/main/res/values/attrs.xml
@ -2,6 +2,7 @@
 <resources>

    <declare-styleable name="K9Styles">
+        <attr name="bottomBarBackground" format="reference|color" />
        <attr name="iconUnifiedInbox" format="reference" />
        <attr name="iconFolder" format="reference" />
        <attr name="iconFolderInbox" format="reference" />
@ -63,6 +64,7 @@
        <attr name="iconSettingsGeneral" format="reference" />
        <attr name="iconSettingsAccount" format="reference" />
        <attr name="iconSettingsAccountAdd" format="reference" />
+        <attr name="iconSettingsExport" format="reference" />
        <attr name="textColorPrimaryRecipientDropdown" format="reference" />
        <attr name="textColorSecondaryRecipientDropdown" format="reference" />
        <attr name="backgroundColorChooseAccountHeader" format="color" />
--- a/app/ui/src/main/res/values/ids.xml
+++ b/app/ui/src/main/res/values/ids.xml
@ -8,4 +8,7 @@
    <item type="id" name="dialog_attachment_progress"/>
    <item type="id" name="dialog_account_setup_error"/>

+    <item type="id" name="settings_export_list_general_item"/>
+    <item type="id" name="settings_export_list_account_item"/>
+
 </resources>
--- a/app/ui/src/main/res/values/strings.xml
+++ b/app/ui/src/main/res/values/strings.xml
@ -991,6 +991,15 @@ Please submit bug reports, contribute new features and ask questions at
    <string name="messagelist_sent_to_me_sigil">»</string>
    <string name="messagelist_sent_cc_me_sigil">›</string>

+    <string name="settings_list_backup_category">Backup</string>
+
+    <string name="settings_export_title">Export settings</string>
+    <string name="settings_export_button">Export</string>
+    <string name="settings_export_share_button">Share</string>
+    <string name="settings_export_progress_text">Exporting settings…</string>
+    <string name="settings_export_success_generic">Settings successfully exported</string>
+    <string name="settings_export_failure">Failed to export settings</string>
+
    <string name="import_export_action">Settings Import &amp; Export</string>
    <string name="settings_export_account">Export account settings</string>
    <string name="settings_export_all">Export settings and accounts</string>
@ -1002,7 +1011,6 @@ Please submit bug reports, contribute new features and ask questions at
    <string name="settings_exporting">Exporting settings…</string>
    <string name="settings_importing">Importing settings…</string>
    <string name="settings_import_scanning_file">Scanning file…</string>
-    <string name="settings_export_success_generic">Settings successfully exported</string>
    <string name="settings_import_global_settings_success">Imported global settings</string>
    <string name="settings_import_success">Imported <xliff:g id="accounts">%s</xliff:g></string>
    <string name="settings_import_account_imported_as">Imported <xliff:g id="original_account_name">%s</xliff:g> as <xliff:g id="account_name_after_import">%s</xliff:g></string>
@ -1010,7 +1018,6 @@ Please submit bug reports, contribute new features and ask questions at
        <item quantity="one">1 account</item>
        <item quantity="other"><xliff:g id="numAccounts">%s</xliff:g> accounts</item>
    </plurals>
-    <string name="settings_export_failure">Failed to export settings</string>
    <string name="settings_import_failure">Failed to import any settings</string>
    <string name="settings_export_success_header">Export succeeded</string>
    <string name="settings_export_failed_header">Export failed</string>
--- a/app/ui/src/main/res/values/themes.xml
+++ b/app/ui/src/main/res/values/themes.xml
@ -14,6 +14,7 @@
        <item name="android:windowLightStatusBar" tools:targetApi="23">true</item>
        <item name="colorPrimary">@color/md_grey_100</item>
        <item name="colorPrimaryDark">@color/md_grey_100</item>
+        <item name="bottomBarBackground">@color/md_grey_50</item>

        <item name="material_drawer_background">@color/material_drawer_background</item>
        <item name="material_drawer_primary_text">@color/material_drawer_primary_text</item>
@ -89,6 +90,7 @@
        <item name="iconSettingsGeneral">@drawable/ic_cog_light</item>
        <item name="iconSettingsAccount">@drawable/ic_account_light</item>
        <item name="iconSettingsAccountAdd">@drawable/ic_account_plus_light</item>
+        <item name="iconSettingsExport">@drawable/ic_export_light</item>
        <item name="textColorPrimaryRecipientDropdown">@android:color/primary_text_light</item>
        <item name="textColorSecondaryRecipientDropdown">@android:color/secondary_text_light</item>
        <item name="messageListSelectedBackgroundColor">#8038B8E2</item>
@ -130,6 +132,7 @@
        <item name="android:windowLightStatusBar" tools:targetApi="23">false</item>
        <item name="colorPrimary">@color/md_grey_900</item>
        <item name="colorPrimaryDark">@color/md_grey_900</item>
+        <item name="bottomBarBackground">@color/md_grey_900</item>

        <item name="material_drawer_background">@color/material_drawer_dark_background</item>
        <item name="material_drawer_primary_text">@color/material_drawer_dark_primary_text</item>
@ -205,6 +208,7 @@
        <item name="iconSettingsGeneral">@drawable/ic_cog_dark</item>
        <item name="iconSettingsAccount">@drawable/ic_account_dark</item>
        <item name="iconSettingsAccountAdd">@drawable/ic_account_plus_dark</item>
+        <item name="iconSettingsExport">@drawable/ic_export_dark</item>
        <item name="textColorPrimaryRecipientDropdown">@android:color/primary_text_dark</item>
        <item name="textColorSecondaryRecipientDropdown">@android:color/secondary_text_dark</item>
        <item name="messageListSelectedBackgroundColor">#8038B8E2</item>
--- a/build.gradle
+++ b/build.gradle
@ -13,6 +13,7 @@ buildscript {
                'androidxLifecycleExtensions': '2.0.0',
                'androidxAnnotation': '1.0.1',
                'androidxNavigation': '2.0.0',
+                'androidxConstraintLayout': '1.1.3',
                'coreKtx': '1.0.1',
                'preferencesFix': '1.0.0',
                'okio': '1.14.0',
--- a/images/drawable-src/ic_export.svg
+++ b/images/drawable-src/ic_export.svg
@ -0,0 +1,60 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   width="24"
+   height="24"
+   viewBox="0 0 24 24"
+   version="1.1"
+   id="svg6"
+   sodipodi:docname="ic_export.svg"
+   inkscape:version="0.92.3 (2405546, 2018-03-11)">
+  <metadata
+     id="metadata12">
+    <rdf:RDF>
+      <cc:Work
+         rdf:about="">
+        <dc:format>image/svg+xml</dc:format>
+        <dc:type
+           rdf:resource="http://purl.org/dc/dcmitype/StillImage" />
+        <dc:title />
+      </cc:Work>
+    </rdf:RDF>
+  </metadata>
+  <defs
+     id="defs10" />
+  <sodipodi:namedview
+     pagecolor="#ffffff"
+     bordercolor="#666666"
+     borderopacity="1"
+     objecttolerance="10"
+     gridtolerance="10"
+     guidetolerance="10"
+     inkscape:pageopacity="0"
+     inkscape:pageshadow="2"
+     inkscape:window-width="1859"
+     inkscape:window-height="1145"
+     id="namedview8"
+     showgrid="false"
+     inkscape:zoom="27.812866"
+     inkscape:cx="18.87956"
+     inkscape:cy="10.262807"
+     inkscape:window-x="61"
+     inkscape:window-y="27"
+     inkscape:window-maximized="1"
+     inkscape:current-layer="svg6" />
+  <path
+     d="M0 0h24v24H0z"
+     fill="none"
+     id="path4" />
+  <path
+     id="path822"
+     d="m 8,6.9999999 h 3 V 16 h 2 V 6.9999999 h 3 L 12,3.0000001 Z M 4,19 v 2 h 16 v -2 z"
+     inkscape:connector-curvature="0"
+     sodipodi:nodetypes="ccccccccccccc" />
+</svg>