feat(app): add app theme selector

app/src/main/java/com/github/ashutoshgngwr/noice/MainActivity.kt

@@ -8,10 +8,12 @@ import android.os.Bundle
 import android.util.Log
 import android.view.MenuItem
 import androidx.appcompat.app.ActionBarDrawerToggle
+import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.app.AppCompatDelegate
 import androidx.core.view.GravityCompat
 import androidx.fragment.app.Fragment
+import androidx.preference.PreferenceManager
 import com.github.ashutoshgngwr.noice.fragment.AboutFragment
 import com.github.ashutoshgngwr.noice.fragment.PresetFragment
 import com.github.ashutoshgngwr.noice.fragment.SleepTimerFragment
@@ -23,14 +25,17 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
 
   companion object {
     private const val TAG = "MainActivity"
+    private const val PREF_APP_THEME = "app_theme"
+    private const val APP_THEME_LIGHT = 0
+    private const val APP_THEME_DARK = 1
+    private const val APP_THEME_SYSTEM_DEFAULT = 2
   }
 
   private lateinit var actionBarDrawerToggle: ActionBarDrawerToggle
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
-    // force night mode and use custom theme with correct color values
-    AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES)
+    AppCompatDelegate.setDefaultNightMode(getNightModeFromPrefs())
 
     setContentView(R.layout.activity_main)
 
@@ -97,6 +102,15 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
       R.id.sleep_timer -> {
         setFragment(SleepTimerFragment::class.java)
       }
+      R.id.app_theme -> {
+        AlertDialog.Builder(this)
+          .setSingleChoiceItems(R.array.app_themes, getAppTheme()) { dialog, which ->
+            dialog.dismiss()
+            setAppTheme(which)
+          }
+          .setTitle(R.string.app_theme)
+          .show()
+      }
       R.id.about -> {
         setFragment(AboutFragment::class.java)
       }
@@ -143,6 +157,42 @@ class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelecte
     }
   }
 
+  /**
+   * Gets user setting for app theme and converts it into its corresponding value from
+   * array ([AppCompatDelegate.MODE_NIGHT_NO], [AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM],
+   * [AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM]).
+   */
+  private fun getNightModeFromPrefs(): Int {
+    return when (getAppTheme()) {
+      APP_THEME_LIGHT -> AppCompatDelegate.MODE_NIGHT_NO
+      APP_THEME_DARK -> AppCompatDelegate.MODE_NIGHT_YES
+      APP_THEME_SYSTEM_DEFAULT -> AppCompatDelegate.MODE_NIGHT_FOLLOW_SYSTEM
+      else -> AppCompatDelegate.MODE_NIGHT_UNSPECIFIED
+    }
+  }
+
+  /**
+   * Gets user setting for current app theme.
+   * Returns one of [APP_THEME_LIGHT], [APP_THEME_DARK] or [APP_THEME_SYSTEM_DEFAULT]
+   */
+  private fun getAppTheme(): Int {
+    return PreferenceManager.getDefaultSharedPreferences(this)
+      .getInt(PREF_APP_THEME, APP_THEME_SYSTEM_DEFAULT)
+  }
+
+  /**
+   * Sets user setting for current app theme.
+   * @param newTheme should be one of [APP_THEME_LIGHT], [APP_THEME_DARK] or [APP_THEME_SYSTEM_DEFAULT]
+   */
+  private fun setAppTheme(newTheme: Int) {
+    PreferenceManager.getDefaultSharedPreferences(this)
+      .edit()
+      .putInt(PREF_APP_THEME, newTheme)
+      .apply()
+
+    recreate()
+  }
+
   private fun <T : Fragment> setFragment(fragmentClass: Class<T>) {
     val tag = fragmentClass.simpleName
 

app/src/main/res/drawable-anydpi/ic_action_theme.xml

@@ -0,0 +1,11 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="#FFFFFF"
+    android:alpha="0.8">
+    <path
+        android:fillColor="#FF000000"
+        android:pathData="M20,15.31L23.31,12 20,8.69V4h-4.69L12,0.69 8.69,4H4v4.69L0.69,12 4,15.31V20h4.69L12,23.31 15.31,20H20v-4.69zM12,18V6c3.31,0 6,2.69 6,6s-2.69,6 -6,6z"/>
+</vector>

app/src/main/res/drawable/app_banner.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<bitmap xmlns:android="http://schemas.android.com/apk/res/android"
+  android:src="@drawable/app_banner_base"
+  android:tint="@color/about_description_text_color" />

app/src/main/res/menu/main.xml

@@ -19,6 +19,12 @@
     android:title="@string/sleep_timer"
     android:checkable="true" />
 
+  <item
+    android:id="@+id/app_theme"
+    android:icon="@drawable/ic_action_theme"
+    android:title="@string/app_theme"
+    android:checkable="false" />
+
   <item
     android:id="@+id/about"
     android:icon="@drawable/ic_action_info"

app/src/main/res/values-night/colors.xml

@@ -1,4 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
+  <color name="colorBackground">#373740</color>
+  <color name="colorCardBackground">#33333d</color>
   <color name="about_background_color">#373740</color>
+  <color name="colorHint">#828297</color>
 </resources>

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

@@ -3,8 +3,8 @@
   <color name="colorPrimary">#27272f</color>
   <color name="colorPrimaryDark">#000000</color>
   <color name="colorAccent">#1eb980</color>
-  <color name="colorBackground">#373740</color>
-  <color name="colorCardBackground">#33333d</color>
-  <color name="about_background_color">#373740</color>
-  <color name="colorHint">#828297</color>
+  <color name="colorBackground">#f8fAf9</color>
+  <color name="colorCardBackground">#f1f5f4</color>
+  <color name="about_background_color">#f8fAf9</color>
+  <color name="colorHint">#7d7d68</color>
 </resources>

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

@@ -117,4 +117,10 @@
   <string name="auto_sleep_schedule_error">Auto sleep timer can not be set to 00:00!</string>
   <string name="auto_sleep_schedule_success">Scheduled auto sleep timer!</string>
   <string name="auto_sleep_schedule_cancelled">Auto sleep timer cancelled!</string>
+  <string name="app_theme">Theme</string>
+  <string-array name="app_themes">
+    <item>Light</item>
+    <item>Dark</item>
+    <item>System default</item>
+  </string-array>
 </resources>

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

@@ -1,6 +1,6 @@
 <resources>
 
-  <style name="AppTheme" parent="Theme.AppCompat">
+  <style name="AppTheme" parent="Theme.AppCompat.DayNight.DarkActionBar">
     <item name="colorPrimary">@color/colorPrimary</item>
     <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
     <item name="colorAccent">@color/colorAccent</item>