took forever but got it so the main screen actually obeyed the user preference, that was way too much work

.idea/codeStyles/Project.xml

@@ -1,6 +1,5 @@
 <component name="ProjectCodeStyleConfiguration">
   <code_scheme name="Project" version="173">
-    <option name="LINE_SEPARATOR" value="&#10;" />
     <JetCodeStyleSettings>
       <option name="PACKAGES_TO_USE_STAR_IMPORTS">
         <value>
@@ -18,8 +17,20 @@
           <package name="" alias="true" withSubpackages="true" />
         </value>
       </option>
+      <option name="LBRACE_ON_NEXT_LINE" value="true" />
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
     </JetCodeStyleSettings>
+    <codeStyleSettings language="JAVA">
+      <option name="BRACE_STYLE" value="2" />
+      <option name="CLASS_BRACE_STYLE" value="2" />
+      <option name="METHOD_BRACE_STYLE" value="2" />
+      <option name="LAMBDA_BRACE_STYLE" value="2" />
+      <indentOptions>
+        <option name="INDENT_SIZE" value="2" />
+        <option name="CONTINUATION_INDENT_SIZE" value="4" />
+        <option name="TAB_SIZE" value="2" />
+      </indentOptions>
+    </codeStyleSettings>
     <codeStyleSettings language="XML">
       <option name="FORCE_REARRANGE_MODE" value="1" />
       <indentOptions>
@@ -135,6 +146,11 @@
     </codeStyleSettings>
     <codeStyleSettings language="kotlin">
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+      <indentOptions>
+        <option name="INDENT_SIZE" value="2" />
+        <option name="CONTINUATION_INDENT_SIZE" value="4" />
+        <option name="TAB_SIZE" value="2" />
+      </indentOptions>
     </codeStyleSettings>
   </code_scheme>
 </component>

.idea/codeStyles/codeStyleConfig.xml

@@ -1,5 +1,5 @@
 <component name="ProjectCodeStyleConfiguration">
   <state>
-    <option name="PREFERRED_PROJECT_CODE_STYLE" value="Default" />
+    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
   </state>
 </component>

app/src/main/AndroidManifest.xml

@@ -8,7 +8,8 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/Theme.PWM">
+        android:theme="@style/Theme.PWM"
+        android:name=".Entrypoint">
         <activity android:name=".HomeActivity">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

app/src/main/java/com/tarfeef101/pwm/Entrypoint.kt

@@ -0,0 +1,17 @@
+package com.tarfeef101.pwm
+
+import android.app.Application
+import android.content.Context
+
+class Entrypoint : Application()
+{
+  override fun onCreate()
+  {
+    super.onCreate()
+    // load shared preferences file
+    val pref = applicationContext.getSharedPreferences("prefs", android.content.Context.MODE_PRIVATE)
+    // retrieve user dark mode setting
+    val last_dark_setting = pref.getInt("dark", -1)
+    ThemeHelper.apply(last_dark_setting)
+  }
+}

app/src/main/java/com/tarfeef101/pwm/HomeActivity.kt

@@ -1,11 +1,14 @@
 package com.tarfeef101.pwm
 
+import android.content.Context
 import android.content.Intent
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import android.provider.AlarmClock.EXTRA_MESSAGE
 import android.view.View
+import androidx.appcompat.app.AppCompatDelegate
 import kotlinx.android.synthetic.main.activity_home.*
+import kotlinx.android.synthetic.main.activity_theme.*
 
 class HomeActivity : AppCompatActivity()
 {
@@ -19,6 +22,7 @@ class HomeActivity : AppCompatActivity()
             val intent = Intent(this, ThemeActivity::class.java)
             startActivity(intent)
         }
+
         settingsButton.setText("Settings")
         settingsButton.setOnClickListener { _ -> launchThemeSettings()}
     }

app/src/main/java/com/tarfeef101/pwm/ThemeActivity.kt

@@ -15,76 +15,74 @@ import kotlinx.android.synthetic.main.activity_theme.*
 @SuppressLint("SetTextI18n")
 class ThemeActivity : AppCompatActivity()
 {
-    override fun onCreate(savedInstanceState: Bundle?)
-    {
-        super.onCreate(savedInstanceState)
-        setContentView(R.layout.activity_theme)
-
-        // load shared preferences file
-        val pref = this.getPreferences(Context.MODE_PRIVATE)
-        // retrieve user dark mode setting
-        val last_dark_setting = pref.getInt("dark", -1)
-        // set radio button based on this
-        if (last_dark_setting == -1)
-        {
-            // no preference, use default
-            themeRadioGroup.check(radioButtonDefault.id)
-        }
-        else if (last_dark_setting == 0)
-        {
-            // user wants light mode, loser that they are
-            themeRadioGroup.check(radioButtonLight.id)
-        }
-        else
-        {
-            // we have a dark moder!
-            themeRadioGroup.check(radioButtonDark.id)
-        }
+  override fun onCreate(savedInstanceState: Bundle?)
+  {
+    super.onCreate(savedInstanceState)
+    setContentView(R.layout.activity_theme)
 
-        // define objects, set text values for em
-        radioButtonDefault.setText("System Default")
-        radioButtonDark.setText("Dark")
-        radioButtonLight.setText("Light")
+    // load shared preferences file
+    val pref = this.getSharedPreferences("prefs", Context.MODE_PRIVATE)
+    // retrieve user dark mode setting
+    val last_dark_setting = pref.getInt("dark", -1)
+    // set radio button based on this
+    if (last_dark_setting == -1)
+    {
+      // no preference, use default
+      themeRadioGroup.check(radioButtonDefault.id)
+    } else if (last_dark_setting == 0)
+    {
+      // user wants light mode, loser that they are
+      themeRadioGroup.check(radioButtonLight.id)
+    } else
+    {
+      // we have a dark moder!
+      themeRadioGroup.check(radioButtonDark.id)
+    }
 
-        // set system theme based on active user choice
-        fun setTheme()
-        {
-            val active = findViewById<RadioButton>(themeRadioGroup.checkedRadioButtonId)
-            when (active)
-            {
-                radioButtonDefault ->
-                {
-                    with (pref.edit())
-                    {
-                        putInt("dark", -1)
-                        apply()
-                    }
-                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM)
-                }
-                radioButtonDark ->
-                {
-                    with (pref.edit())
-                    {
-                        putInt("dark", 1)
-                        apply()
-                    }
-                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
-                }
-                radioButtonLight ->
-                {
-                    with (pref.edit())
-                    {
-                        putInt("dark", 0)
-                        apply()
-                    }
-                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
-                }
-            }
-            themeStatus.setText(active.getText())
-        }
+    // define objects, set text values for em
+    radioButtonDefault.setText("System Default")
+    radioButtonDark.setText("Dark")
+    radioButtonLight.setText("Light")
 
-        // set the listener for changes to the radio button group
-        setTheme()
-        themeRadioGroup.setOnCheckedChangeListener { _, _ -> setTheme()}
+    // set system theme based on active user choice
+    fun setTheme()
+    {
+      val active = findViewById<RadioButton>(themeRadioGroup.checkedRadioButtonId)
+      when (active)
+      {
+          radioButtonDefault ->
+          {
+              with(pref.edit())
+              {
+                  putInt("dark", -1)
+                  apply()
+              }
+              ThemeHelper.apply(-1)
+          }
+          radioButtonDark ->
+          {
+              with(pref.edit())
+              {
+                  putInt("dark", 1)
+                  apply()
+              }
+              ThemeHelper.apply(1)
+          }
+          radioButtonLight ->
+          {
+              with(pref.edit())
+              {
+                  putInt("dark", 0)
+                  apply()
+              }
+              ThemeHelper.apply(0)
+          }
+      }
+      themeStatus.setText(active.getText())
     }
+
+    // set the listener for changes to the radio button group
+    setTheme()
+    themeRadioGroup.setOnCheckedChangeListener { _, _ -> setTheme() }
+  }
 }

app/src/main/java/com/tarfeef101/pwm/ThemeHelper.kt

@@ -0,0 +1,44 @@
+package com.tarfeef101.pwm
+
+import androidx.appcompat.app.AppCompatDelegate
+
+object ThemeHelper
+{
+    fun apply(pref: Int)
+    {
+        when (pref)
+        {
+            -1 ->
+            {
+                if (AppCompatDelegate.getDefaultNightMode() != AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM)
+                {
+                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM)
+                }
+            }
+
+            0 ->
+            {
+                if (AppCompatDelegate.getDefaultNightMode() != AppCompatDelegate.MODE_NIGHT_NO)
+                {
+                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_NO)
+                }
+            }
+
+            1 ->
+            {
+                if (AppCompatDelegate.getDefaultNightMode() != AppCompatDelegate.MODE_NIGHT_YES)
+                {
+                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
+                }
+            }
+
+            else ->
+            {
+                if (AppCompatDelegate.getDefaultNightMode() != AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY)
+                {
+                    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_AUTO_BATTERY)
+                }
+            }
+        }
+    }
+}