WIP: Migrate to ViewModel architecture

Signed-off-by: Billy Brawner <billy@wbrawner.com>

app/build.gradle

@@ -101,7 +101,10 @@ dependencies {
     def coroutines_version = "1.3.0-RC2"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core:$coroutines_version"
     implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:$coroutines_version"
-    implementation 'androidx.lifecycle:lifecycle-extensions:2.0.0'
+
+    def lifecycle_version = "2.0.0"
+    implementation "androidx.lifecycle:lifecycle-extensions:$lifecycle_version"
+    kapt "androidx.lifecycle:lifecycle-compiler:$lifecycle_version"
     implementation 'eu.crydee:syllable-counter:4.0.2'
 }
 

app/src/main/java/com/wbrawner/simplemarkdown/AppComponent.kt

@@ -1,28 +0,0 @@
-package com.wbrawner.simplemarkdown
-
-import android.content.Context
-import com.wbrawner.simplemarkdown.view.activity.MainActivity
-import com.wbrawner.simplemarkdown.view.activity.SplashActivity
-import com.wbrawner.simplemarkdown.view.fragment.EditFragment
-import com.wbrawner.simplemarkdown.view.fragment.PreviewFragment
-import dagger.BindsInstance
-import dagger.Component
-import javax.inject.Singleton
-
-@Singleton
-@Component(modules = [AppModule::class])
-interface AppComponent {
-    fun inject(application: MarkdownApplication)
-    fun inject(activity: MainActivity)
-    fun inject(activity: SplashActivity)
-    fun inject(fragment: EditFragment)
-    fun inject(fragment: PreviewFragment)
-
-    @Component.Builder
-    abstract class Builder {
-        @BindsInstance
-        internal abstract fun context(context: Context): Builder
-
-        internal abstract fun build(): AppComponent
-    }
-}

app/src/main/java/com/wbrawner/simplemarkdown/AppModule.kt

@@ -1,24 +0,0 @@
-package com.wbrawner.simplemarkdown
-
-import com.wbrawner.simplemarkdown.presentation.MarkdownPresenter
-import com.wbrawner.simplemarkdown.presentation.MarkdownPresenterImpl
-import com.wbrawner.simplemarkdown.utility.CrashlyticsErrorHandler
-import com.wbrawner.simplemarkdown.utility.ErrorHandler
-import dagger.Module
-import dagger.Provides
-import javax.inject.Singleton
-
-@Module
-class AppModule {
-    @Provides
-    @Singleton
-    fun provideMarkdownPresenter(errorHandler: ErrorHandler): MarkdownPresenter {
-        return MarkdownPresenterImpl(errorHandler)
-    }
-
-    @Provides
-    @Singleton
-    internal fun provideErrorHandler(): ErrorHandler {
-        return CrashlyticsErrorHandler()
-    }
-}

app/src/main/java/com/wbrawner/simplemarkdown/MarkdownApplication.kt

@@ -1,16 +1,26 @@
 package com.wbrawner.simplemarkdown
 
 import android.app.Application
+import android.os.StrictMode
+import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModelFactory
 
 class MarkdownApplication : Application() {
-
+    val viewModelFactory: MarkdownViewModelFactory by lazy {
-    lateinit var component: AppComponent
+        MarkdownViewModelFactory()
-        private set
+    }
 
     override fun onCreate() {
+        if (BuildConfig.DEBUG) {
+            StrictMode.setThreadPolicy(StrictMode.ThreadPolicy.Builder()
+                    .detectAll()
+                    .penaltyDeath()
+                    .build())
+//        StrictMode.setVmPolicy(StrictMode.VmPolicy.Builder()
+//                .detectAll()
+//                .penaltyLog()
+//                .penaltyDeath()
+//                .build())
+        }
         super.onCreate()
-        component = DaggerAppComponent.builder()
-                .context(this)
-                .build()
     }
 }

app/src/main/java/com/wbrawner/simplemarkdown/model/MarkdownFile.kt

@@ -10,25 +10,4 @@ import java.io.Reader
  */
 class MarkdownFile(var name: String = "Untitled.md", var content: String = "") {
 
-    fun load(name: String, inputStream: InputStream): Boolean {
-        this.name = name
-        return try {
-            this.content = inputStream.reader().use(Reader::readText)
-            true
-        } catch (e: Throwable) {
-            false
-        }
-    }
-
-    fun save(name: String, outputStream: OutputStream): Boolean {
-        this.name = name
-        return try {
-            outputStream.writer().use {
-                it.write(this.content)
-            }
-            true
-        } catch (e: Throwable) {
-            false
-        }
-    }
 }

app/src/main/java/com/wbrawner/simplemarkdown/presentation/MarkdownPresenter.kt

@@ -1,39 +0,0 @@
-package com.wbrawner.simplemarkdown.presentation
-
-import android.content.Context
-import android.net.Uri
-
-import java.io.InputStream
-import java.io.OutputStream
-
-interface MarkdownPresenter {
-    var fileName: String
-    var markdown: String
-    var editView: MarkdownEditView?
-    var previewView: MarkdownPreviewView?
-    suspend fun loadFromUri(context: Context, fileUri: Uri): String?
-    suspend fun loadMarkdown(
-            fileName: String,
-            `in`: InputStream,
-            replaceCurrentFile: Boolean = true
-    ): String?
-    fun newFile(newName: String)
-    suspend fun saveMarkdown(name: String, outputStream: OutputStream): Boolean
-    fun onMarkdownEdited(markdown: String? = null)
-    fun generateHTML(markdown: String = ""): String
-}
-
-interface MarkdownEditView {
-    var markdown: String
-    fun setTitle(title: String)
-
-    fun onFileSaved(success: Boolean)
-
-    fun onFileLoaded(success: Boolean)
-}
-
-interface MarkdownPreviewView {
-    fun updatePreview(html: String)
-}
-
-

app/src/main/java/com/wbrawner/simplemarkdown/presentation/MarkdownPresenterImpl.kt

@@ -1,127 +0,0 @@
-package com.wbrawner.simplemarkdown.presentation
-
-import android.content.Context
-import android.net.Uri
-import android.provider.OpenableColumns
-import com.commonsware.cwac.anddown.AndDown
-import com.wbrawner.simplemarkdown.model.MarkdownFile
-import com.wbrawner.simplemarkdown.utility.ErrorHandler
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.withContext
-import java.io.InputStream
-import java.io.OutputStream
-import javax.inject.Inject
-import javax.inject.Singleton
-
-@Singleton
-class MarkdownPresenterImpl @Inject constructor(private val errorHandler: ErrorHandler) : MarkdownPresenter {
-    @Volatile
-    private var file: MarkdownFile = MarkdownFile()
-    @Volatile
-    override var editView: MarkdownEditView? = null
-        set(value) {
-            field = value
-            onMarkdownEdited(null)
-        }
-    @Volatile
-    override var previewView: MarkdownPreviewView? = null
-
-    override var fileName: String
-        get() = file.name
-        set(name) {
-            file.name = name
-        }
-
-    override var markdown: String
-        get() = file.content
-        set(markdown) {
-            file.content = markdown
-        }
-
-    override suspend fun loadMarkdown(
-            fileName: String,
-            `in`: InputStream,
-            replaceCurrentFile: Boolean
-    ): String? {
-        val tmpFile = MarkdownFile()
-        withContext(Dispatchers.IO) {
-            if (!tmpFile.load(fileName, `in`)) {
-                throw RuntimeException("Failed to load markdown")
-            }
-        }
-        if (replaceCurrentFile) {
-            this.file = tmpFile
-            editView?.let {
-                it.onFileLoaded(true)
-                it.setTitle(fileName)
-                it.markdown = file.content
-                onMarkdownEdited(file.content)
-            }
-        }
-        return generateHTML(tmpFile.content)
-    }
-
-    override fun newFile(newName: String) {
-        editView?.let {
-            file.content = it.markdown
-            it.setTitle(newName)
-            it.markdown = ""
-        }
-        file = MarkdownFile(newName, "")
-    }
-
-    override suspend fun saveMarkdown(name: String, outputStream: OutputStream): Boolean {
-        val result = withContext(Dispatchers.IO) {
-            file.save(name, outputStream)
-        }
-        editView?.let {
-            it.setTitle(file.name)
-            it.onFileSaved(result)
-        }
-        return result
-    }
-
-    override fun onMarkdownEdited(markdown: String?) {
-        this.markdown = markdown ?: file.content
-        previewView?.updatePreview(generateHTML(this.markdown))
-    }
-
-    override fun generateHTML(markdown: String): String {
-        return AndDown().markdownToHtml(markdown, HOEDOWN_FLAGS, 0)
-    }
-
-    override suspend fun loadFromUri(context: Context, fileUri: Uri): String? {
-        return try {
-            var fileName: String? = null
-            if ("content" == fileUri.scheme) {
-                context.contentResolver
-                        .query(
-                                fileUri,
-                                null,
-                                null,
-                                null,
-                                null
-                        )
-                        ?.use {
-                            val nameIndex = it.getColumnIndex(OpenableColumns.DISPLAY_NAME)
-                            it.moveToFirst()
-                            fileName = it.getString(nameIndex)
-                        }
-            } else if ("file" == fileUri.scheme) {
-                fileName = fileUri.lastPathSegment
-            }
-            val inputStream = context.contentResolver.openInputStream(fileUri) ?: return null
-            loadMarkdown(fileName ?: "Untitled.md", inputStream, true)
-        } catch (e: Exception) {
-            errorHandler.reportException(e)
-            editView?.onFileLoaded(false)
-            null
-        }
-    }
-
-    companion object {
-        const val HOEDOWN_FLAGS = AndDown.HOEDOWN_EXT_STRIKETHROUGH or AndDown.HOEDOWN_EXT_TABLES or
-                AndDown.HOEDOWN_EXT_UNDERLINE or AndDown.HOEDOWN_EXT_SUPERSCRIPT or
-                AndDown.HOEDOWN_EXT_FENCED_CODE
-    }
-}

app/src/main/java/com/wbrawner/simplemarkdown/utility/Extensions.kt

@@ -1,8 +1,15 @@
 package com.wbrawner.simplemarkdown.utility
 
 import android.content.Context
+import android.content.res.AssetManager
+import android.net.Uri
+import android.provider.OpenableColumns
 import android.view.View
 import android.view.inputmethod.InputMethodManager
+import com.commonsware.cwac.anddown.AndDown
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.Reader
 
 fun View.showKeyboard() =
         (context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager)
@@ -11,3 +18,45 @@ fun View.showKeyboard() =
 fun View.hideKeyboard() =
         (context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager)
                 .hideSoftInputFromWindow(windowToken, 0)
+
+suspend fun AssetManager.readAssetToString(asset: String): String? {
+    return withContext(Dispatchers.IO) {
+        open(asset).reader().use(Reader::readText)
+    }
+}
+
+const val HOEDOWN_FLAGS = AndDown.HOEDOWN_EXT_STRIKETHROUGH or AndDown.HOEDOWN_EXT_TABLES or
+        AndDown.HOEDOWN_EXT_UNDERLINE or AndDown.HOEDOWN_EXT_SUPERSCRIPT or
+        AndDown.HOEDOWN_EXT_FENCED_CODE
+
+suspend fun String.toHtml(): String {
+    return withContext(Dispatchers.IO) {
+        AndDown().markdownToHtml(this@toHtml, HOEDOWN_FLAGS, 0)
+    }
+}
+
+suspend fun Uri.getName(context: Context): String {
+    var fileName: String? = null
+    try {
+        if ("content" == scheme) {
+            withContext(Dispatchers.IO) {
+                context.contentResolver.query(
+                        this@getName,
+                        null,
+                        null,
+                        null,
+                        null
+                )?.use {
+                    val nameIndex = it.getColumnIndex(OpenableColumns.DISPLAY_NAME)
+                    it.moveToFirst()
+                    fileName = it.getString(nameIndex)
+                }
+            }
+        } else if ("file" == scheme) {
+            fileName = lastPathSegment
+        }
+    } catch (ignored: Exception) {
+        ignored.printStackTrace()
+    }
+    return fileName ?: "Untitled.md"
+}

app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.kt

@@ -5,10 +5,10 @@ import android.app.Activity
 import android.content.Intent
 import android.content.pm.PackageManager
 import android.content.res.Configuration
+import android.net.Uri
 import android.os.Build
 import android.os.Bundle
 import android.preference.PreferenceManager
-import android.provider.OpenableColumns
 import android.view.Menu
 import android.view.MenuItem
 import android.view.View
@@ -18,11 +18,16 @@ import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.app.ActivityCompat
 import androidx.core.content.ContextCompat
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProviders
 import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
-import com.wbrawner.simplemarkdown.presentation.MarkdownPresenter
 import com.wbrawner.simplemarkdown.utility.ErrorHandler
+import com.wbrawner.simplemarkdown.utility.getName
+import com.wbrawner.simplemarkdown.utility.readAssetToString
+import com.wbrawner.simplemarkdown.utility.toHtml
 import com.wbrawner.simplemarkdown.view.adapter.EditPagerAdapter
+import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
 import kotlinx.android.synthetic.main.activity_main.*
 import kotlinx.coroutines.*
 import java.io.File
@@ -32,12 +37,11 @@ import kotlin.coroutines.CoroutineContext
 
 class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsResultCallback, CoroutineScope {
 
-    @Inject
-    lateinit var presenter: MarkdownPresenter
     @Inject
     lateinit var errorHandler: ErrorHandler
     private var shouldAutoSave = true
     override val coroutineContext: CoroutineContext = Dispatchers.Main
+    private lateinit var viewModel: MarkdownViewModel
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -50,7 +54,10 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
                             or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                     )
         }
-        (application as MarkdownApplication).component.inject(this)
+        viewModel = ViewModelProviders.of(
+                this,
+                (application as MarkdownApplication).viewModelFactory
+        ).get(MarkdownViewModel::class.java)
         val adapter = EditPagerAdapter(supportFragmentManager, this@MainActivity)
         pager.adapter = adapter
         pager.addOnPageChangeListener(adapter)
@@ -60,16 +67,38 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
         if (resources.configuration.orientation == Configuration.ORIENTATION_LANDSCAPE) {
             tabLayout!!.visibility = View.GONE
         }
+        @Suppress("CAST_NEVER_SUCCEEDS")
+        viewModel.fileName.observe(this, Observer<String> {
+            title = it
+        })
     }
 
     override fun onUserLeaveHint() {
         super.onUserLeaveHint()
-        val isAutoSaveEnabled = PreferenceManager.getDefaultSharedPreferences(this)
-                .getBoolean(KEY_AUTOSAVE, true)
-        if (shouldAutoSave && presenter.markdown.isNotEmpty() && isAutoSaveEnabled) {
-
         launch {
-                presenter.saveMarkdown("autosave.md", File(filesDir, "autosave.md").outputStream())
+            withContext(Dispatchers.IO) {
+                val sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this@MainActivity)
+                val isAutoSaveEnabled = sharedPrefs.getBoolean(KEY_AUTOSAVE, true)
+                if (!shouldAutoSave || !isAutoSaveEnabled) {
+                    return@withContext
+                }
+
+                val uri = if (viewModel.save(this@MainActivity)) {
+                    viewModel.uri.value
+                } else {
+                    // The user has left the app, with autosave enabled, and we don't already have a
+                    // Uri for them or for some reason we were unable to save to the original Uri. In
+                    // this case, we need to just save to internal file storage so that we can recover
+                    val fileUri = Uri.fromFile(File(filesDir, viewModel.fileName.value))
+                    if (viewModel.save(this@MainActivity, fileUri)) {
+                        fileUri
+                    } else {
+                        null
+                    }
+                }?: return@withContext
+                sharedPrefs.edit()
+                        .putString(getString(R.string.pref_key_autosave_uri), uri.toString())
+                        .apply()
             }
         }
     }
@@ -89,10 +118,22 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         when (item.itemId) {
-            R.id.action_save -> requestFileOp(REQUEST_SAVE_FILE)
+            R.id.action_save -> {
+                launch {
+                    if (!viewModel.save(this@MainActivity)) {
+                        requestFileOp(REQUEST_SAVE_FILE)
+                    } else {
+                        Toast.makeText(
+                                this@MainActivity,
+                                getString(R.string.file_saved, viewModel.fileName.value),
+                                Toast.LENGTH_SHORT
+                        ).show()
+                    }
+                }
+            }
             R.id.action_share -> {
                 val shareIntent = Intent(Intent.ACTION_SEND)
-                shareIntent.putExtra(Intent.EXTRA_TEXT, presenter.markdown)
+                shareIntent.putExtra(Intent.EXTRA_TEXT, viewModel.markdownUpdates.value)
                 shareIntent.type = "text/plain"
                 startActivity(Intent.createChooser(
                         shareIntent,
@@ -137,9 +178,9 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
         infoIntent.putExtra("title", title)
         launch {
             try {
-                val inputStream = assets?.open(fileName)
+                val html = assets?.readAssetToString(fileName)
+                        ?.toHtml()
                         ?: throw RuntimeException("Unable to open stream to $fileName")
-                val html = presenter.loadMarkdown(fileName, inputStream, false)
                 infoIntent.putExtra("html", html)
                 startActivity(infoIntent)
             } catch (e: Exception) {
@@ -183,17 +224,11 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
                     return
                 }
 
-                val fileName = contentResolver.query(data.data!!, null, null, null, null)
-                        ?.use { cursor ->
-                            val nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)
-                            cursor.moveToFirst()
-                            cursor.getString(nameIndex)
-                        } ?: "Untitled.md"
-
-                contentResolver.openFileDescriptor(data.data!!, "r")?.let {
-                    val fileInput = FileInputStream(it.fileDescriptor)
                 launch {
-                        presenter.loadMarkdown(fileName, fileInput)
+                    val fileLoaded = viewModel.load(this@MainActivity, data.data)
+                    if (!fileLoaded) {
+                        Toast.makeText(this@MainActivity, R.string.file_load_error, Toast.LENGTH_SHORT)
+                                .show()
                     }
                 }
             }
@@ -202,20 +237,8 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
                     return
                 }
 
-                val fileName = contentResolver.query(data.data!!, null, null, null, null)
-                        ?.use { cursor ->
-                            val nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)
-                            cursor.moveToFirst()
-                            cursor.getString(nameIndex)
-                        } ?: "Untitled.md"
-
                 launch {
-                    val outputStream = contentResolver.openOutputStream(data.data!!)
+                    viewModel.save(this@MainActivity, data.data)
-                            ?: throw RuntimeException("Unable to open output stream to save file")
-                    presenter.saveMarkdown(
-                            fileName,
-                            outputStream
-                    )
                 }
             }
             REQUEST_DARK_MODE -> recreate()
@@ -224,11 +247,15 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
     }
 
     private fun promptSaveOrDiscardChanges() {
+        if (viewModel.originalMarkdown.value == viewModel.markdownUpdates.value) {
+            viewModel.reset("Untitled.md")
+            return
+        }
         AlertDialog.Builder(this)
                 .setTitle(R.string.save_changes)
                 .setMessage(R.string.prompt_save_changes)
                 .setNegativeButton(R.string.action_discard) { _, _ ->
-                    presenter.newFile("Untitled.md")
+                    viewModel.reset("Untitled.md")
                 }
                 .setPositiveButton(R.string.action_save) { _, _ ->
                     requestFileOp(REQUEST_SAVE_FILE)
@@ -252,7 +279,7 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
             REQUEST_SAVE_FILE -> {
                 Intent(Intent.ACTION_CREATE_DOCUMENT).apply {
                     type = "text/markdown"
-                    putExtra(Intent.EXTRA_TITLE, presenter.fileName)
+                    putExtra(Intent.EXTRA_TITLE, viewModel.fileName.value)
                 }
             }
             REQUEST_OPEN_FILE -> {
@@ -274,14 +301,11 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
         )
     }
 
-
     override fun onResume() {
         super.onResume()
-        title = presenter.fileName
         shouldAutoSave = true
     }
 
-
     override fun onDestroy() {
         super.onDestroy()
         coroutineContext[Job]?.let {

app/src/main/java/com/wbrawner/simplemarkdown/view/activity/SplashActivity.kt

@@ -1,86 +1,74 @@
 package com.wbrawner.simplemarkdown.view.activity
 
 import android.content.Intent
+import android.net.Uri
 import android.os.Build
 import android.os.Bundle
 import android.preference.PreferenceManager
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.app.AppCompatDelegate
+import androidx.lifecycle.ViewModelProviders
 import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
-import com.wbrawner.simplemarkdown.presentation.MarkdownPresenter
+import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
-import com.wbrawner.simplemarkdown.utility.ErrorHandler
 import kotlinx.coroutines.*
-import java.io.File
-import java.io.FileNotFoundException
-import javax.inject.Inject
 import kotlin.coroutines.CoroutineContext
 
 class SplashActivity : AppCompatActivity(), CoroutineScope {
 
     override val coroutineContext: CoroutineContext = Dispatchers.Main
 
-    @Inject
+    lateinit var viewModel: MarkdownViewModel
-    lateinit var presenter: MarkdownPresenter
-
-    @Inject
-    lateinit var errorHandler: ErrorHandler
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this)
+        viewModel = ViewModelProviders.of(
-        (application as MarkdownApplication).component.inject(this)
+                this,
-        if (sharedPreferences.getBoolean(getString(R.string.error_reports_enabled), true)) {
+                (application as MarkdownApplication).viewModelFactory
-            errorHandler.init(this)
+        ).get(MarkdownViewModel::class.java)
-        }
 
-        val darkModeValue = sharedPreferences.getString(
+        launch {
+            val darkMode = withContext(Dispatchers.IO) {
+                val darkModeValue = PreferenceManager.getDefaultSharedPreferences(this@SplashActivity)
+                        .getString(
                                 getString(R.string.pref_key_dark_mode),
                                 getString(R.string.pref_value_auto)
                         )
 
-        var darkMode = if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
+                return@withContext when {
+                    darkModeValue.equals(getString(R.string.pref_value_light), ignoreCase = true) -> AppCompatDelegate.MODE_NIGHT_NO
+                    darkModeValue.equals(getString(R.string.pref_value_dark), ignoreCase = true) -> AppCompatDelegate.MODE_NIGHT_YES
+                    else -> {
+                        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
                             AppCompatDelegate.MODE_NIGHT_AUTO
                         } else {
                             AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
                         }
+                    }
+                }
 
-        if (darkModeValue != null && !darkModeValue.isEmpty()) {
-            if (darkModeValue.equals(getString(R.string.pref_value_light), ignoreCase = true)) {
-                darkMode = AppCompatDelegate.MODE_NIGHT_NO
-            } else if (darkModeValue.equals(getString(R.string.pref_value_dark), ignoreCase = true)) {
-                darkMode = AppCompatDelegate.MODE_NIGHT_YES
-            }
             }
+
             AppCompatDelegate.setDefaultNightMode(darkMode)
-
+            withContext(Dispatchers.IO) {
-        if (intent?.data != null) {
+                var uri = intent?.data
-            launch {
+                if (uri == null) {
-                presenter.loadFromUri(applicationContext, intent.data!!)
+                    uri = PreferenceManager.getDefaultSharedPreferences(this@SplashActivity)
-            }
+                            .getString(
-        } else {
+                                    getString(R.string.pref_key_autosave_uri),
-            presenter.fileName = "Untitled.md"
+                                    null
-            val autosave = File(filesDir, "autosave.md")
+                            )?.let {
-            if (autosave.exists()) {
+                                Uri.parse(it)
-                try {
-                    launch {
-                        presenter.loadMarkdown(
-                                "Untitled.md",
-                                autosave.inputStream(),
-                                true
-                        )
-                        autosave.delete()
-                    }
-                } catch (ignored: FileNotFoundException) {
-                    return
-                }
                             }
                 }
 
-        val startIntent = Intent(this, MainActivity::class.java)
+                viewModel.load(this@SplashActivity, uri)
+            }
+            val startIntent = Intent(this@SplashActivity, MainActivity::class.java)
             startActivity(startIntent)
             finish()
         }
+    }
 
     override fun onDestroy() {
         super.onDestroy()

app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/EditFragment.kt

@@ -16,31 +16,24 @@ import android.view.ViewGroup
 import android.widget.EditText
 import android.widget.ScrollView
 import android.widget.TextView
-import android.widget.Toast
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProviders
 import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
 import com.wbrawner.simplemarkdown.model.Readability
-import com.wbrawner.simplemarkdown.presentation.MarkdownEditView
-import com.wbrawner.simplemarkdown.presentation.MarkdownPresenter
 import com.wbrawner.simplemarkdown.utility.hideKeyboard
 import com.wbrawner.simplemarkdown.utility.showKeyboard
 import com.wbrawner.simplemarkdown.view.ViewPagerPage
+import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
 import kotlinx.coroutines.*
-import javax.inject.Inject
 import kotlin.coroutines.CoroutineContext
 import kotlin.math.abs
 
-class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope {
+class EditFragment : Fragment(), ViewPagerPage, CoroutineScope {
-    @Inject
-    lateinit var presenter: MarkdownPresenter
     private var markdownEditor: EditText? = null
     private var markdownEditorScroller: ScrollView? = null
-    override var markdown: String
+    private lateinit var viewModel: MarkdownViewModel
-        get() = markdownEditor?.text?.toString() ?: ""
-        set(value) {
-            markdownEditor?.setText(value)
-        }
     override val coroutineContext: CoroutineContext = Dispatchers.Main
 
     @SuppressLint("ClickableViewAccessibility")
@@ -67,7 +60,7 @@ class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope
                     delay(50)
                     if (searchText != searchFor)
                         return@launch
-                    presenter.onMarkdownEdited(searchText)
+                    viewModel.updateMarkdown(searchText)
                 }
             }
 
@@ -78,8 +71,15 @@ class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope
             }
 
         })
-        val sharedPrefs = PreferenceManager.getDefaultSharedPreferences(requireContext())
+        var enableReadability = false
-        val enableReadability = sharedPrefs.getBoolean(getString(R.string.readability_enabled), false)
+        launch {
+             enableReadability = withContext(Dispatchers.IO) {
+                 context?.let {
+                     PreferenceManager.getDefaultSharedPreferences(it)
+                             .getBoolean(getString(R.string.readability_enabled), false)
+                 }?: false
+             }
+        }
         if (enableReadability) {
             markdownEditor?.addTextChangedListener(object : TextWatcher {
                 private var previousValue = ""
@@ -97,10 +97,10 @@ class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope
                         if (searchText != searchFor)
                             return@launch
                         val start = System.currentTimeMillis()
-                        if (markdown.isEmpty()) return@launch
+                        if (searchFor.isEmpty()) return@launch
-                        if (previousValue == markdown) return@launch
+                        if (previousValue == searchFor) return@launch
-                        val readability = Readability(markdown)
+                        val readability = Readability(searchFor)
-                        val span = SpannableString(markdown)
+                        val span = SpannableString(searchFor)
                         for (sentence in readability.sentences()) {
                             var color = Color.TRANSPARENT
                             if (sentence.syllableCount() > 25) color = Color.argb(100, 229, 232, 42)
@@ -108,7 +108,7 @@ class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope
                             span.setSpan(BackgroundColorSpan(color), sentence.start(), sentence.end(), 0)
                         }
                         markdownEditor?.setTextKeepState(span, TextView.BufferType.SPANNABLE)
-                        previousValue = markdown
+                        previousValue = searchFor
                         val timeTakenMs = System.currentTimeMillis() - start
                         Log.d("SimpleMarkdown", "Handled markdown in " + timeTakenMs + "ms")
                     }
@@ -148,21 +148,13 @@ class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope
 
     override fun onActivityCreated(savedInstanceState: Bundle?) {
         super.onActivityCreated(savedInstanceState)
-        @Suppress("CAST_NEVER_SUCCEEDS")
+        viewModel = ViewModelProviders.of(
-        (activity?.application as? MarkdownApplication)?.component?.inject(this)
+                this,
-        presenter.editView = this@EditFragment
+                (requireActivity().application as MarkdownApplication).viewModelFactory
-    }
+        ).get(MarkdownViewModel::class.java)
-
+        viewModel.originalMarkdown.observe(this, Observer<String> {
-    override fun onResume() {
+            markdownEditor?.setText(it)
-        super.onResume()
+        })
-        presenter.editView = this
-        markdown = presenter.markdown
-    }
-
-    override fun onPause() {
-        super.onPause()
-        presenter.editView = null
-        markdownEditor?.hideKeyboard()
     }
 
     override fun onDestroy() {
@@ -179,26 +171,4 @@ class EditFragment : Fragment(), MarkdownEditView, ViewPagerPage, CoroutineScope
     override fun onDeselected() {
         markdownEditor?.hideKeyboard()
     }
-
+}
-    override fun setTitle(title: String) {
-        val activity = activity
-        if (activity != null) {
-            activity.title = title
-        }
-    }
-
-    override fun onFileSaved(success: Boolean) {
-        val message: String = if (success) {
-            getString(R.string.file_saved, presenter.fileName)
-        } else {
-            getString(R.string.file_save_error)
-        }
-        Toast.makeText(activity, message, Toast.LENGTH_SHORT).show()
-    }
-
-    override fun onFileLoaded(success: Boolean) {
-        // TODO: Investigate why this fires off so often
-        //        int message = success ? R.string.file_loaded : R.string.file_load_error;
-        //        Toast.makeText(getActivity(), message, Toast.LENGTH_SHORT).show();
-    }
-}// Required empty public constructor

app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/PreviewFragment.kt

@@ -1,6 +1,5 @@
 package com.wbrawner.simplemarkdown.view.fragment
 
-import android.content.SharedPreferences
 import android.content.res.Configuration.UI_MODE_NIGHT_MASK
 import android.content.res.Configuration.UI_MODE_NIGHT_YES
 import android.os.Bundle
@@ -11,19 +10,20 @@ import android.view.ViewGroup
 import android.webkit.WebView
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.Observer
+import androidx.lifecycle.ViewModelProviders
 import com.wbrawner.simplemarkdown.BuildConfig
 import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
-import com.wbrawner.simplemarkdown.presentation.MarkdownPresenter
+import com.wbrawner.simplemarkdown.utility.toHtml
-import com.wbrawner.simplemarkdown.presentation.MarkdownPreviewView
+import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
-import javax.inject.Inject
+import kotlinx.coroutines.*
+import kotlin.coroutines.CoroutineContext
 
-
+class PreviewFragment : Fragment(), CoroutineScope {
-class PreviewFragment : Fragment(), MarkdownPreviewView {
+    override val coroutineContext: CoroutineContext = Dispatchers.Main
-    @Inject
+    lateinit var viewModel: MarkdownViewModel
-    lateinit var presenter: MarkdownPresenter
     private var markdownPreview: WebView? = null
-    private var sharedPreferences: SharedPreferences? = null
 
     override fun onCreateView(
             inflater: LayoutInflater,
@@ -32,13 +32,17 @@ class PreviewFragment : Fragment(), MarkdownPreviewView {
     ): View? = inflater.inflate(R.layout.fragment_preview, container, false)
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
-        sharedPreferences = PreferenceManager.getDefaultSharedPreferences(view.context)
         markdownPreview = view.findViewById(R.id.markdown_view)
-        (activity?.application as? MarkdownApplication)?.component?.inject(this)
         WebView.setWebContentsDebuggingEnabled(BuildConfig.DEBUG)
     }
 
-    override fun updatePreview(html: String) {
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        viewModel = ViewModelProviders.of(
+                this,
+                (requireActivity().application as MarkdownApplication).viewModelFactory
+        ).get(MarkdownViewModel::class.java)
+        viewModel.markdownUpdates.observe(this, Observer<String> {
             markdownPreview?.post {
                 val isNightMode = AppCompatDelegate.getDefaultNightMode() ==
                         AppCompatDelegate.MODE_NIGHT_YES
@@ -48,30 +52,28 @@ class PreviewFragment : Fragment(), MarkdownPreviewView {
                 } else {
                     R.string.pref_custom_css_default
                 }
+                launch {
+                    val css = withContext(Dispatchers.IO) {
                         @Suppress("ConstantConditionIf")
-            val css: String? = if (!BuildConfig.ENABLE_CUSTOM_CSS) {
+                        if (!BuildConfig.ENABLE_CUSTOM_CSS) {
-                context?.getString(defaultCssId)
+                            requireActivity().getString(defaultCssId)
                         } else {
-                sharedPreferences!!.getString(
+                            PreferenceManager.getDefaultSharedPreferences(requireActivity())
+                                    .getString(
                                             getString(R.string.pref_custom_css),
                                             getString(defaultCssId)
-                )
+                                    )?: ""
+                        }
                     }
-
                     val style = String.format(FORMAT_CSS, css)
-
                     markdownPreview?.loadDataWithBaseURL(null,
-                    style + html,
+                            style + it.toHtml(),
                             "text/html",
                             "UTF-8", null
                     )
                 }
             }
-
+        })
-    override fun onResume() {
-        super.onResume()
-        presenter.previewView = this
-        presenter.onMarkdownEdited()
     }
 
     override fun onDestroyView() {
@@ -84,8 +86,10 @@ class PreviewFragment : Fragment(), MarkdownPreviewView {
     }
 
     override fun onDestroy() {
+        coroutineContext[Job]?.let {
+            cancel()
+        }
         super.onDestroy()
-        presenter.previewView = null
     }
 
     companion object {

app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/SettingsFragment.kt

@@ -3,6 +3,7 @@ package com.wbrawner.simplemarkdown.view.fragment
 import android.content.SharedPreferences
 import android.os.Build
 import android.os.Bundle
+import android.os.StrictMode
 import android.preference.ListPreference
 import android.preference.Preference
 import android.preference.PreferenceFragment
@@ -13,21 +14,41 @@ import android.view.ViewGroup
 import androidx.appcompat.app.AppCompatDelegate
 import com.wbrawner.simplemarkdown.BuildConfig
 import com.wbrawner.simplemarkdown.R
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import java.lang.Exception
+import kotlin.coroutines.CoroutineContext
 
-class SettingsFragment : PreferenceFragment(), SharedPreferences.OnSharedPreferenceChangeListener {
+class SettingsFragment
-    override fun onCreate(savedInstanceState: Bundle?) {
+    : PreferenceFragment(),
-        super.onCreate(savedInstanceState)
+        SharedPreferences.OnSharedPreferenceChangeListener,
+        CoroutineScope {
+    override val coroutineContext: CoroutineContext = Dispatchers.Main
+
+    override fun onActivityCreated(savedInstanceState: Bundle?) {
+        super.onActivityCreated(savedInstanceState)
+        launch {
+            withContext(Dispatchers.IO) {
+                try {
+                    // This can be thrown when recreating the activity for theme changes
                     addPreferencesFromResource(R.xml.pref_general)
+                } catch (ignored: Exception) {
+                    return@withContext
+                }
                 val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(activity)
-        sharedPreferences.registerOnSharedPreferenceChangeListener(this)
+                sharedPreferences.registerOnSharedPreferenceChangeListener(this@SettingsFragment)
-        setListPreferenceSummary(
+                (findPreference(getString(R.string.pref_key_dark_mode)) as? ListPreference)?.let {
-                sharedPreferences,
+                    setListPreferenceSummary(sharedPreferences, it)
-                findPreference(getString(R.string.pref_key_dark_mode))
+                }
-        )
+                @Suppress("ConstantConditionIf")
                 if (!BuildConfig.ENABLE_CUSTOM_CSS) {
                     preferenceScreen.removePreference(findPreference(getString(R.string.pref_custom_css)))
                 }
             }
+        }
+    }
 
     override fun onCreateView(
             inflater: LayoutInflater,
@@ -39,18 +60,18 @@ class SettingsFragment : PreferenceFragment(), SharedPreferences.OnSharedPrefere
 
     override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
         if (!isAdded) return
-        val preference = findPreference(key)
+        val preference = findPreference(key) as? ListPreference ?: return
-        if (preference is ListPreference) {
         setListPreferenceSummary(sharedPreferences, preference)
+        if (preference.key != getString(R.string.pref_key_dark_mode)) {
+            return
         }
-        if (preference.key == getString(R.string.pref_key_dark_mode)) {
         var darkMode: Int = if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
             AppCompatDelegate.MODE_NIGHT_AUTO
         } else {
             AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
         }
         val darkModeValue = sharedPreferences.getString(preference.key, null)
-            if (darkModeValue != null && !darkModeValue.isEmpty()) {
+        if (darkModeValue != null && darkModeValue.isNotEmpty()) {
             if (darkModeValue.equals(getString(R.string.pref_value_light), ignoreCase = true)) {
                 darkMode = AppCompatDelegate.MODE_NIGHT_NO
             } else if (darkModeValue.equals(getString(R.string.pref_value_dark), ignoreCase = true)) {
@@ -60,13 +81,14 @@ class SettingsFragment : PreferenceFragment(), SharedPreferences.OnSharedPrefere
         AppCompatDelegate.setDefaultNightMode(darkMode)
         activity?.recreate()
     }
-    }
 
-    private fun setListPreferenceSummary(sharedPreferences: SharedPreferences, preference: Preference) {
+    private fun setListPreferenceSummary(sharedPreferences: SharedPreferences, preference: ListPreference) {
-        val listPreference = preference as ListPreference
+        val storedValue = sharedPreferences.getString(
-        val storedValue = sharedPreferences.getString(preference.getKey(), null) ?: return
+                preference.key,
-        val index = listPreference.findIndexOfValue(storedValue)
+                null
+        ) ?: return
+        val index = preference.findIndexOfValue(storedValue)
         if (index < 0) return
-        preference.setSummary(listPreference.entries[index].toString())
+        preference.summary = preference.entries[index].toString()
     }
 }

app/src/main/java/com/wbrawner/simplemarkdown/viewmodel/MarkdownViewModel.kt

@@ -0,0 +1,106 @@
+package com.wbrawner.simplemarkdown.viewmodel
+
+import android.content.Context
+import android.net.Uri
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import com.wbrawner.simplemarkdown.utility.getName
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.FileInputStream
+import java.io.InputStream
+import java.io.OutputStream
+import java.io.Reader
+import kotlin.coroutines.CoroutineContext
+
+class MarkdownViewModel : ViewModel() {
+    private val coroutineContext: CoroutineContext = Dispatchers.IO
+    val fileName = MutableLiveData<String>().apply {
+        postValue("Untitled.md")
+    }
+    val markdownUpdates = MutableLiveData<String>()
+    val originalMarkdown = MutableLiveData<String>()
+    val uri = MutableLiveData<Uri>()
+
+    fun updateMarkdown(markdown: String?) {
+        this.markdownUpdates.postValue(markdown ?: "")
+    }
+
+    suspend fun load(context: Context, uri: Uri?): Boolean {
+        if (uri == null) return false
+        return withContext(Dispatchers.IO) {
+            context.contentResolver.openFileDescriptor(uri, "r")?.use {
+                val fileInput = FileInputStream(it.fileDescriptor)
+                val fileName = uri.getName(context)
+                return@withContext if (load(fileInput)) {
+                    this@MarkdownViewModel.fileName.postValue(fileName)
+                    this@MarkdownViewModel.uri.postValue(uri)
+                    true
+                } else {
+                    false
+                }
+            } ?: false
+        }
+    }
+
+    suspend fun load(inputStream: InputStream): Boolean {
+        return try {
+            withContext(coroutineContext) {
+                val content = inputStream.reader().use(Reader::readText)
+                originalMarkdown.postValue(content)
+                markdownUpdates.postValue(content)
+            }
+            true
+        } catch (e: Throwable) {
+            e.printStackTrace()
+            false
+        }
+    }
+
+    suspend fun save(context: Context, givenUri: Uri? = this.uri.value): Boolean {
+        val uri = givenUri ?: this.uri.value ?: return false
+        return withContext(Dispatchers.IO) {
+            val fileName = uri.getName(context)
+            val outputStream = context.contentResolver.openOutputStream(uri)
+                    ?: return@withContext false
+            if (save(outputStream)) {
+                this@MarkdownViewModel.fileName.postValue(fileName)
+                this@MarkdownViewModel.uri.postValue(uri)
+                true
+            } else {
+                false
+            }
+        }
+    }
+
+    suspend fun save(outputStream: OutputStream): Boolean {
+        return try {
+            withContext(coroutineContext) {
+                outputStream.writer().use {
+                    it.write(markdownUpdates.value)
+                }
+            }
+            true
+        } catch (e: Throwable) {
+            false
+        }
+    }
+
+    fun reset(untitledFileName: String) {
+        fileName.postValue(untitledFileName)
+        originalMarkdown.postValue("")
+        markdownUpdates.postValue("")
+    }
+}
+
+class MarkdownViewModelFactory : ViewModelProvider.Factory {
+    private val markdownViewModel: MarkdownViewModel by lazy {
+        MarkdownViewModel()
+    }
+
+    override fun <T : ViewModel?> create(modelClass: Class<T>): T {
+        @Suppress("UNCHECKED_CAST")
+        return markdownViewModel as T
+    }
+}

app/src/main/res/values/strings.xml

@@ -60,6 +60,7 @@
     <string name="pref_key_dark_mode_light" translatable="false">light</string>
     <string name="pref_key_dark_mode_dark" translatable="false">dark</string>
     <string name="pref_key_dark_mode_auto" translatable="false">auto</string>
+    <string name="pref_key_autosave_uri" translatable="false">autosave.uri</string>
     <string name="save_changes">Save Changes</string>
     <string name="prompt_save_changes">Would you like to save your changes?</string>
     <string name="action_discard">Discard</string>

app/src/main/res/xml/pref_general.xml

@@ -14,7 +14,7 @@
     <ListPreference
         android:entries="@array/pref_entries_dark_mode"
         android:entryValues="@array/pref_values_dark_mode"
-        android:defaultValue="@string/pref_value_auto"
+        android:defaultValue="@string/pref_key_dark_mode_auto"
         android:key="@string/pref_key_dark_mode"
         android:title="@string/title_dark_mode" />
     <SwitchPreference