From d841fd0225903791dceb9d06ef7f55344684630f Mon Sep 17 00:00:00 2001
From: Billy Brawner <billy@wbrawner.com>
Date: Fri, 8 Nov 2019 09:30:55 -0600
Subject: [PATCH] Fix various concurrency issues and simplify some logic
 throughout the app

---
 .../simplemarkdown/MarkdownApplication.kt     |   4 -
 .../view/activity/MainActivity.kt             |  19 ++--
 .../view/activity/MarkdownInfoActivity.kt     |  47 ++++++--
 .../view/activity/SplashActivity.kt           |  40 +++----
 .../view/fragment/EditFragment.kt             |  24 ++--
 .../view/fragment/MainMenuFragment.kt         | 107 +++++++-----------
 .../view/fragment/PreviewFragment.kt          |  33 ++----
 .../view/fragment/SettingsFragment.kt         |  55 +++------
 .../view/overrides/SafeListView.kt            |  20 ----
 .../viewmodel/MarkdownViewModel.kt            |  14 +--
 .../res/layout/activity_markdown_info.xml     |   1 -
 app/src/main/res/layout/content_explorer.xml  |  20 ----
 .../layout/preference_list_fragment_safe.xml  |  14 ---
 13 files changed, 143 insertions(+), 255 deletions(-)
 delete mode 100644 app/src/main/java/com/wbrawner/simplemarkdown/view/overrides/SafeListView.kt
 delete mode 100644 app/src/main/res/layout/content_explorer.xml
 delete mode 100644 app/src/main/res/layout/preference_list_fragment_safe.xml

diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/MarkdownApplication.kt b/app/src/main/java/com/wbrawner/simplemarkdown/MarkdownApplication.kt
index 1d033ae..169640c 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/MarkdownApplication.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/MarkdownApplication.kt
@@ -4,12 +4,8 @@ import android.app.Application
 import android.os.StrictMode
 import com.wbrawner.simplemarkdown.utility.CrashlyticsErrorHandler
 import com.wbrawner.simplemarkdown.utility.ErrorHandler
-import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModelFactory
 
 class MarkdownApplication : Application() {
-    val viewModelFactory: MarkdownViewModelFactory by lazy {
-        MarkdownViewModelFactory()
-    }
     val errorHandler: ErrorHandler by lazy {
         CrashlyticsErrorHandler()
     }
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.kt
index f46f972..646754b 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MainActivity.kt
@@ -20,8 +20,8 @@ import androidx.core.content.ContextCompat
 import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProviders
 import androidx.preference.PreferenceManager
-import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
+import com.wbrawner.simplemarkdown.utility.hideKeyboard
 import com.wbrawner.simplemarkdown.view.adapter.EditPagerAdapter
 import com.wbrawner.simplemarkdown.view.fragment.MainMenuFragment
 import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
@@ -49,10 +49,7 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
                             or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                     )
         }
-        viewModel = ViewModelProviders.of(
-                this,
-                (application as MarkdownApplication).viewModelFactory
-        ).get(MarkdownViewModel::class.java)
+        viewModel = ViewModelProviders.of(this).get(MarkdownViewModel::class.java)
         val adapter = EditPagerAdapter(supportFragmentManager, this@MainActivity)
         pager.adapter = adapter
         pager.addOnPageChangeListener(adapter)
@@ -66,6 +63,11 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
         viewModel.fileName.observe(this, Observer<String> {
             title = it
         })
+        intent?.data?.let {
+            launch {
+                viewModel.load(this@MainActivity, it)
+            }
+        }
     }
 
     override fun onUserLeaveHint() {
@@ -114,11 +116,8 @@ class MainActivity : AppCompatActivity(), ActivityCompat.OnRequestPermissionsRes
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         when (item.itemId) {
             android.R.id.home -> {
-                MainMenuFragment()
-                        .apply {
-                            errorHandler = (application as MarkdownApplication).errorHandler
-                        }
-                        .show(supportFragmentManager, null)
+                MainMenuFragment().show(supportFragmentManager, null)
+                window.decorView.hideKeyboard()
             }
             R.id.action_save -> {
                 launch {
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MarkdownInfoActivity.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MarkdownInfoActivity.kt
index 8d06107..6f7addd 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MarkdownInfoActivity.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/MarkdownInfoActivity.kt
@@ -3,24 +3,32 @@ package com.wbrawner.simplemarkdown.view.activity
 import android.content.res.Configuration
 import android.os.Bundle
 import android.view.MenuItem
+import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.app.AppCompatDelegate
+import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
+import com.wbrawner.simplemarkdown.utility.readAssetToString
+import com.wbrawner.simplemarkdown.utility.toHtml
 import kotlinx.android.synthetic.main.activity_markdown_info.*
+import kotlinx.coroutines.*
+import kotlin.coroutines.CoroutineContext
 
-class MarkdownInfoActivity : AppCompatActivity() {
+class MarkdownInfoActivity : AppCompatActivity(), CoroutineScope {
+    override val coroutineContext: CoroutineContext = Dispatchers.Main
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_markdown_info)
         setSupportActionBar(toolbar)
         supportActionBar?.setDisplayHomeAsUpEnabled(true)
-        val intent = intent
-        if (intent == null || !intent.hasExtra("title") || !intent.hasExtra("html")) {
+        val title = intent?.getStringExtra(EXTRA_TITLE)
+        val fileName = intent?.getStringExtra(EXTRA_FILE)
+        if (title.isNullOrBlank() || fileName.isNullOrBlank()) {
             finish()
             return
         }
-        title = intent.getStringExtra("title")
+
         val isNightMode = AppCompatDelegate.getDefaultNightMode() ==
                 AppCompatDelegate.MODE_NIGHT_YES
                 || resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK == Configuration.UI_MODE_NIGHT_YES
@@ -30,12 +38,29 @@ class MarkdownInfoActivity : AppCompatActivity() {
             R.string.pref_custom_css_default
         }
         val css: String? = getString(defaultCssId)
+        launch {
+            try {
+                val html = assets?.readAssetToString(fileName)
+                        ?.toHtml()
+                        ?: throw RuntimeException("Unable to open stream to $fileName")
+                infoWebview.loadDataWithBaseURL(null,
+                        String.format(FORMAT_CSS, css) + html,
+                        "text/html",
+                        "UTF-8", null
+                )
+            } catch (e: Exception) {
+                (application as MarkdownApplication).errorHandler.reportException(e)
+                Toast.makeText(this@MarkdownInfoActivity, R.string.file_load_error, Toast.LENGTH_SHORT).show()
+                finish()
+            }
+        }
+    }
 
-        infoWebview.loadDataWithBaseURL(null,
-                String.format(FORMAT_CSS, css) + intent.getStringExtra("html"),
-                "text/html",
-                "UTF-8", null
-        )
+    override fun onDestroy() {
+        coroutineContext[Job]?.let {
+            cancel()
+        }
+        super.onDestroy()
     }
 
 
@@ -48,8 +73,10 @@ class MarkdownInfoActivity : AppCompatActivity() {
     }
 
     companion object {
-        var FORMAT_CSS = "<style>" +
+        const val FORMAT_CSS = "<style>" +
                 "%s" +
                 "</style>"
+        const val EXTRA_TITLE = "title"
+        const val EXTRA_FILE = "file"
     }
 }
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/SplashActivity.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/SplashActivity.kt
index 85daafd..f1030ca 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/SplashActivity.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/activity/SplashActivity.kt
@@ -4,13 +4,10 @@ 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 androidx.preference.PreferenceManager
 import com.wbrawner.simplemarkdown.R
-import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
 import kotlinx.coroutines.*
 import kotlin.coroutines.CoroutineContext
 
@@ -18,15 +15,8 @@ class SplashActivity : AppCompatActivity(), CoroutineScope {
 
     override val coroutineContext: CoroutineContext = Dispatchers.Main
 
-    lateinit var viewModel: MarkdownViewModel
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-        viewModel = ViewModelProviders.of(
-                this,
-                (application as MarkdownApplication).viewModelFactory
-        ).get(MarkdownViewModel::class.java)
-
         launch {
             val darkMode = withContext(Dispatchers.IO) {
                 val darkModeValue = PreferenceManager.getDefaultSharedPreferences(this@SplashActivity)
@@ -40,7 +30,7 @@ class SplashActivity : AppCompatActivity(), CoroutineScope {
                     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
+                            AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY
                         } else {
                             AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
                         }
@@ -50,21 +40,21 @@ class SplashActivity : AppCompatActivity(), CoroutineScope {
             }
 
             AppCompatDelegate.setDefaultNightMode(darkMode)
-            withContext(Dispatchers.IO) {
-                var uri = intent?.data
-                if (uri == null) {
-                    uri = PreferenceManager.getDefaultSharedPreferences(this@SplashActivity)
-                            .getString(
-                                    getString(R.string.pref_key_autosave_uri),
-                                    null
-                            )?.let {
-                                Uri.parse(it)
-                            }
-                }
-
-                viewModel.load(this@SplashActivity, uri)
+            val uri = withContext(Dispatchers.IO) {
+                intent?.data
+                        ?: PreferenceManager.getDefaultSharedPreferences(this@SplashActivity)
+                                .getString(
+                                        getString(R.string.pref_key_autosave_uri),
+                                        null
+                                )?.let {
+                                    Uri.parse(it)
+                                }
             }
+
             val startIntent = Intent(this@SplashActivity, MainActivity::class.java)
+                    .apply {
+                        data = uri
+                    }
             startActivity(startIntent)
             finish()
         }
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/EditFragment.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/EditFragment.kt
index 22a4ce3..2c4fd9c 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/EditFragment.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/EditFragment.kt
@@ -3,7 +3,6 @@ package com.wbrawner.simplemarkdown.view.fragment
 import android.annotation.SuppressLint
 import android.graphics.Color
 import android.os.Bundle
-import android.preference.PreferenceManager
 import android.text.Editable
 import android.text.SpannableString
 import android.text.TextWatcher
@@ -19,7 +18,7 @@ import android.widget.TextView
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProviders
-import com.wbrawner.simplemarkdown.MarkdownApplication
+import androidx.preference.PreferenceManager
 import com.wbrawner.simplemarkdown.R
 import com.wbrawner.simplemarkdown.model.Readability
 import com.wbrawner.simplemarkdown.utility.hideKeyboard
@@ -33,7 +32,7 @@ import kotlin.math.abs
 class EditFragment : Fragment(), ViewPagerPage, CoroutineScope {
     private var markdownEditor: EditText? = null
     private var markdownEditorScroller: ScrollView? = null
-    private lateinit var viewModel: MarkdownViewModel
+    lateinit var viewModel: MarkdownViewModel
     override val coroutineContext: CoroutineContext = Dispatchers.Main
     private var readabilityWatcher: TextWatcher? = null
 
@@ -45,6 +44,9 @@ class EditFragment : Fragment(), ViewPagerPage, CoroutineScope {
     @SuppressLint("ClickableViewAccessibility")
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
+        activity?.let {
+            viewModel = ViewModelProviders.of(it).get(MarkdownViewModel::class.java)
+        } ?: return
         markdownEditor = view.findViewById(R.id.markdown_edit)
         markdownEditorScroller = view.findViewById(R.id.markdown_edit_container)
         markdownEditor?.addTextChangedListener(object : TextWatcher {
@@ -95,21 +97,9 @@ class EditFragment : Fragment(), ViewPagerPage, CoroutineScope {
             }
             false
         }
-    }
-
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
-        viewModel = ViewModelProviders.of(
-                this,
-                (requireActivity().application as MarkdownApplication).viewModelFactory
-        ).get(MarkdownViewModel::class.java)
         viewModel.originalMarkdown.observe(this, Observer<String> {
             markdownEditor?.setText(it)
         })
-    }
-
-    override fun onStart() {
-        super.onStart()
         launch {
             val enableReadability = withContext(Dispatchers.IO) {
                 context?.let {
@@ -132,11 +122,11 @@ class EditFragment : Fragment(), ViewPagerPage, CoroutineScope {
         }
     }
 
-    override fun onDestroy() {
+    override fun onDestroyView() {
         coroutineContext[Job]?.let {
             cancel()
         }
-        super.onDestroy()
+        super.onDestroyView()
     }
 
     override fun onSelected() {
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/MainMenuFragment.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/MainMenuFragment.kt
index 77030e6..70f66dd 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/MainMenuFragment.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/MainMenuFragment.kt
@@ -1,31 +1,21 @@
 package com.wbrawner.simplemarkdown.view.fragment
 
-import android.content.Context
 import android.content.Intent
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import android.widget.Toast
 import com.google.android.material.bottomsheet.BottomSheetDialogFragment
 import com.wbrawner.simplemarkdown.R
-import com.wbrawner.simplemarkdown.utility.ErrorHandler
-import com.wbrawner.simplemarkdown.utility.readAssetToString
-import com.wbrawner.simplemarkdown.utility.toHtml
 import com.wbrawner.simplemarkdown.view.activity.MainActivity
 import com.wbrawner.simplemarkdown.view.activity.MarkdownInfoActivity
+import com.wbrawner.simplemarkdown.view.activity.MarkdownInfoActivity.Companion.EXTRA_FILE
+import com.wbrawner.simplemarkdown.view.activity.MarkdownInfoActivity.Companion.EXTRA_TITLE
 import com.wbrawner.simplemarkdown.view.activity.SettingsActivity
 import com.wbrawner.simplemarkdown.view.activity.SupportActivity
 import kotlinx.android.synthetic.main.fragment_menu_main.*
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.launch
-import kotlin.coroutines.CoroutineContext
-
-class MainMenuFragment : BottomSheetDialogFragment(), CoroutineScope {
-    override val coroutineContext: CoroutineContext = Dispatchers.Main
-    lateinit var errorHandler: ErrorHandler
 
+class MainMenuFragment : BottomSheetDialogFragment() {
     override fun onCreateView(
             inflater: LayoutInflater,
             container: ViewGroup?,
@@ -34,20 +24,47 @@ class MainMenuFragment : BottomSheetDialogFragment(), CoroutineScope {
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
-        mainMenuNavigationView.setNavigationItemSelectedListener {
-            when (it.itemId) {
-                R.id.action_help -> showInfoActivity(context, R.id.action_help)
-                R.id.action_settings -> {
-                    val settingsIntent = Intent(context, SettingsActivity::class.java)
-                    startActivityForResult(settingsIntent, MainActivity.REQUEST_DARK_MODE)
-                }
-                R.id.action_libraries -> showInfoActivity(context, R.id.action_libraries)
-                R.id.action_privacy -> showInfoActivity(context, R.id.action_privacy)
-                R.id.action_support -> Intent(context, SupportActivity::class.java)
-                        .apply {
-                            startActivity(this)
-                            dialog?.dismiss()
-                        }
+        mainMenuNavigationView.setNavigationItemSelectedListener { menuItem ->
+            val (intentClass, fileName, title) = when (menuItem.itemId) {
+                R.id.action_help -> Triple(
+                        MarkdownInfoActivity::class.java,
+                        "Cheatsheet.md",
+                        R.string.action_help
+                )
+                R.id.action_settings -> Triple(
+                        SettingsActivity::class.java,
+                        null,
+                        null
+                )
+                R.id.action_libraries -> Triple(
+                        MarkdownInfoActivity::class.java,
+                        "Libraries.md",
+                        R.id.action_libraries
+                )
+                R.id.action_privacy -> Triple(
+                        MarkdownInfoActivity::class.java,
+                        "Privacy Policy.md",
+                        R.id.action_libraries
+                )
+                R.id.action_support -> Triple(
+                        SupportActivity::class.java,
+                        null,
+                        null
+                )
+                else -> throw IllegalStateException("This shouldn't happen")
+            }
+            val intent = Intent(context, intentClass)
+            fileName?.let {
+                intent.putExtra(EXTRA_FILE, it)
+            }
+            title?.let {
+                intent.putExtra(EXTRA_TITLE, getString(it))
+            }
+            if (intentClass == SettingsActivity::class.java) {
+                startActivityForResult(intent, MainActivity.REQUEST_DARK_MODE)
+            } else {
+                startActivity(intent)
+                dialog?.dismiss()
             }
             true
         }
@@ -61,40 +78,4 @@ class MainMenuFragment : BottomSheetDialogFragment(), CoroutineScope {
         }
         super.onActivityResult(requestCode, resultCode, data)
     }
-
-    private fun showInfoActivity(context: Context?, action: Int) {
-        val infoIntent = Intent(context, MarkdownInfoActivity::class.java)
-        var fileName = ""
-        var title = ""
-        when (action) {
-            R.id.action_help -> {
-                fileName = "Cheatsheet.md"
-                title = getString(R.string.action_help)
-            }
-            R.id.action_libraries -> {
-                fileName = "Libraries.md"
-                title = getString(R.string.action_libraries)
-            }
-            R.id.action_privacy -> {
-                fileName = "Privacy Policy.md"
-                title = getString(R.string.action_privacy)
-            }
-        }
-        infoIntent.putExtra("title", title)
-        launch {
-            // TODO: Refactor this to have the info activity load the markdown instead of doing
-            //  it here
-            try {
-                val html = context?.assets?.readAssetToString(fileName)
-                        ?.toHtml()
-                        ?: throw RuntimeException("Unable to open stream to $fileName")
-                infoIntent.putExtra("html", html)
-                startActivity(infoIntent, null)
-            } catch (e: Exception) {
-                errorHandler.reportException(e)
-                Toast.makeText(context, R.string.file_load_error, Toast.LENGTH_SHORT).show()
-            }
-            dialog?.dismiss()
-        }
-    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/PreviewFragment.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/PreviewFragment.kt
index 3d6726f..e5f963b 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/PreviewFragment.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/PreviewFragment.kt
@@ -3,7 +3,6 @@ package com.wbrawner.simplemarkdown.view.fragment
 import android.content.res.Configuration.UI_MODE_NIGHT_MASK
 import android.content.res.Configuration.UI_MODE_NIGHT_YES
 import android.os.Bundle
-import android.preference.PreferenceManager
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -12,8 +11,8 @@ import androidx.appcompat.app.AppCompatDelegate
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Observer
 import androidx.lifecycle.ViewModelProviders
+import androidx.preference.PreferenceManager
 import com.wbrawner.simplemarkdown.BuildConfig
-import com.wbrawner.simplemarkdown.MarkdownApplication
 import com.wbrawner.simplemarkdown.R
 import com.wbrawner.simplemarkdown.utility.toHtml
 import com.wbrawner.simplemarkdown.viewmodel.MarkdownViewModel
@@ -35,14 +34,9 @@ class PreviewFragment : Fragment(), CoroutineScope {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         markdownPreview = view.findViewById(R.id.markdown_view)
         WebView.setWebContentsDebuggingEnabled(BuildConfig.DEBUG)
-    }
-
-    override fun onActivityCreated(savedInstanceState: Bundle?) {
-        super.onActivityCreated(savedInstanceState)
-        viewModel = ViewModelProviders.of(
-                this,
-                (requireActivity().application as MarkdownApplication).viewModelFactory
-        ).get(MarkdownViewModel::class.java)
+        activity?.let {
+            viewModel = ViewModelProviders.of(it).get(MarkdownViewModel::class.java)
+        } ?: return
         launch {
             val isNightMode = AppCompatDelegate.getDefaultNightMode() ==
                     AppCompatDelegate.MODE_NIGHT_YES
@@ -53,18 +47,19 @@ class PreviewFragment : Fragment(), CoroutineScope {
                 R.string.pref_custom_css_default
             }
             val css = withContext(Dispatchers.IO) {
+                val context = context ?: return@withContext null
                 @Suppress("ConstantConditionIf")
                 if (!BuildConfig.ENABLE_CUSTOM_CSS) {
-                    requireActivity().getString(defaultCssId)
+                    context.getString(defaultCssId)
                 } else {
-                    PreferenceManager.getDefaultSharedPreferences(requireActivity())
+                    PreferenceManager.getDefaultSharedPreferences(context)
                             .getString(
                                     getString(R.string.pref_custom_css),
                                     getString(defaultCssId)
-                            ) ?: ""
+                            )
                 }
             }
-            style = String.format(FORMAT_CSS, css)
+            style = String.format(FORMAT_CSS, css ?: "")
             updateWebContent(viewModel.markdownUpdates.value ?: "")
             viewModel.markdownUpdates.observe(this@PreviewFragment, Observer<String> {
                 updateWebContent(it)
@@ -85,6 +80,9 @@ class PreviewFragment : Fragment(), CoroutineScope {
     }
 
     override fun onDestroyView() {
+        coroutineContext[Job]?.let {
+            cancel()
+        }
         markdownPreview?.let {
             (it.parent as ViewGroup).removeView(it)
             it.destroy()
@@ -93,13 +91,6 @@ class PreviewFragment : Fragment(), CoroutineScope {
         super.onDestroyView()
     }
 
-    override fun onDestroy() {
-        coroutineContext[Job]?.let {
-            cancel()
-        }
-        super.onDestroy()
-    }
-
     companion object {
         var FORMAT_CSS = "<style>" +
                 "%s" +
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/SettingsFragment.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/SettingsFragment.kt
index 7962e55..cb7574e 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/SettingsFragment.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/view/fragment/SettingsFragment.kt
@@ -3,61 +3,42 @@ 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
-import android.preference.PreferenceManager
-import android.view.LayoutInflater
-import android.view.View
-import android.view.ViewGroup
 import androidx.appcompat.app.AppCompatDelegate
+import androidx.preference.ListPreference
+import androidx.preference.PreferenceFragmentCompat
+import androidx.preference.PreferenceManager
 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(),
+    : PreferenceFragmentCompat(),
         SharedPreferences.OnSharedPreferenceChangeListener,
         CoroutineScope {
+    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
+        addPreferencesFromResource(R.xml.pref_general)
+    }
+
     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@SettingsFragment)
-                (findPreference(getString(R.string.pref_key_dark_mode)) as? ListPreference)?.let {
-                    setListPreferenceSummary(sharedPreferences, it)
-                }
-                @Suppress("ConstantConditionIf")
-                if (!BuildConfig.ENABLE_CUSTOM_CSS) {
-                    preferenceScreen.removePreference(findPreference(getString(R.string.pref_custom_css)))
-                }
+        launch(context = Dispatchers.IO) {
+            val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(activity)
+            sharedPreferences.registerOnSharedPreferenceChangeListener(this@SettingsFragment)
+            (findPreference(getString(R.string.pref_key_dark_mode)) as? ListPreference)?.let {
+                setListPreferenceSummary(sharedPreferences, it)
+            }
+            @Suppress("ConstantConditionIf")
+            if (!BuildConfig.ENABLE_CUSTOM_CSS) {
+                preferenceScreen.removePreference(findPreference(getString(R.string.pref_custom_css)))
             }
         }
     }
 
-    override fun onCreateView(
-            inflater: LayoutInflater,
-            container: ViewGroup?,
-            savedInstanceState: Bundle?
-    ): View? {
-        return inflater.inflate(R.layout.preference_list_fragment_safe, container, false)
-    }
-
     override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
         if (!isAdded) return
         val preference = findPreference(key) as? ListPreference ?: return
@@ -66,7 +47,7 @@ class SettingsFragment
             return
         }
         var darkMode: Int = if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.P) {
-            AppCompatDelegate.MODE_NIGHT_AUTO
+            AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY
         } else {
             AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
         }
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/view/overrides/SafeListView.kt b/app/src/main/java/com/wbrawner/simplemarkdown/view/overrides/SafeListView.kt
deleted file mode 100644
index d645a7c..0000000
--- a/app/src/main/java/com/wbrawner/simplemarkdown/view/overrides/SafeListView.kt
+++ /dev/null
@@ -1,20 +0,0 @@
-package com.wbrawner.simplemarkdown.view.overrides
-
-import android.content.Context
-import android.util.AttributeSet
-import android.widget.ListView
-
-class SafeListView : ListView {
-    constructor(context: Context) : super(context)
-
-    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
-
-    constructor(context: Context, attrs: AttributeSet, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
-
-    override fun onDetachedFromWindow() {
-        try {
-            super.onDetachedFromWindow()
-        } catch (ignored: Exception) {
-        }
-    }
-}
diff --git a/app/src/main/java/com/wbrawner/simplemarkdown/viewmodel/MarkdownViewModel.kt b/app/src/main/java/com/wbrawner/simplemarkdown/viewmodel/MarkdownViewModel.kt
index e9f3896..ceb4ccc 100644
--- a/app/src/main/java/com/wbrawner/simplemarkdown/viewmodel/MarkdownViewModel.kt
+++ b/app/src/main/java/com/wbrawner/simplemarkdown/viewmodel/MarkdownViewModel.kt
@@ -4,7 +4,6 @@ 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
@@ -78,7 +77,7 @@ class MarkdownViewModel : ViewModel() {
         return try {
             withContext(coroutineContext) {
                 outputStream.writer().use {
-                    it.write(markdownUpdates.value)
+                    it.write(markdownUpdates.value ?: "")
                 }
             }
             true
@@ -93,14 +92,3 @@ class MarkdownViewModel : ViewModel() {
         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
-    }
-}
diff --git a/app/src/main/res/layout/activity_markdown_info.xml b/app/src/main/res/layout/activity_markdown_info.xml
index cadf264..37750c9 100644
--- a/app/src/main/res/layout/activity_markdown_info.xml
+++ b/app/src/main/res/layout/activity_markdown_info.xml
@@ -38,5 +38,4 @@
             android:background="@color/colorBackground" />
     </com.google.android.material.card.MaterialCardView>
 
-
 </androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/app/src/main/res/layout/content_explorer.xml b/app/src/main/res/layout/content_explorer.xml
deleted file mode 100644
index 6af3651..0000000
--- a/app/src/main/res/layout/content_explorer.xml
+++ /dev/null
@@ -1,20 +0,0 @@
-<?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"
-    app:layout_behavior="@string/appbar_scrolling_view_behavior"
-    tools:context="com.wbrawner.simplemarkdown.view.activity.ExplorerActivity"
-    tools:showIn="@layout/activity_explorer">
-
-    <com.wbrawner.simplemarkdown.view.overrides.SafeListView
-        android:id="@+id/file_list"
-        android:layout_width="0dp"
-        android:layout_height="0dp"
-        app:layout_constraintBottom_toBottomOf="parent"
-        app:layout_constraintEnd_toEndOf="parent"
-        app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
-
-</androidx.constraintlayout.widget.ConstraintLayout>
diff --git a/app/src/main/res/layout/preference_list_fragment_safe.xml b/app/src/main/res/layout/preference_list_fragment_safe.xml
deleted file mode 100644
index 12e4008..0000000
--- a/app/src/main/res/layout/preference_list_fragment_safe.xml
+++ /dev/null
@@ -1,14 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-
-<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent"
-    android:background="@android:color/transparent"
-    android:orientation="vertical">
-
-    <com.wbrawner.simplemarkdown.view.overrides.SafeListView
-        android:id="@android:id/list"
-        android:layout_width="match_parent"
-        android:layout_height="match_parent" />
-
-</LinearLayout>
\ No newline at end of file