Add Dracula app theme

app/src/main/java/io/nekohasekai/sagernet/Constants.kt

@@ -14,6 +14,9 @@ object Key {
     const val APP_EXPERT = "isExpert"
     const val APP_THEME = "appTheme"
     const val NIGHT_THEME = "nightTheme"
+    // Remembers the user's night-mode setting before the dark-only Dracula theme
+    // forced it on, so it can be restored when switching to another theme.
+    const val NIGHT_THEME_BEFORE_DRACULA = "nightThemeBeforeDracula"
     const val APP_LANGUAGE = "appLanguage"
     const val SERVICE_MODE = "serviceMode"
     const val MODE_VPN = "vpn"

app/src/main/java/io/nekohasekai/sagernet/database/DataStore.kt

@@ -103,6 +103,9 @@ object DataStore : OnPreferenceDataStoreChangeListener {
     var isExpert by configurationStore.boolean(Key.APP_EXPERT)
     var appTheme by configurationStore.int(Key.APP_THEME)
     var nightTheme by configurationStore.stringToInt(Key.NIGHT_THEME)
+    // -1 = not set (no Dracula override active). Otherwise holds the night-mode
+    // value to restore when leaving the dark-only Dracula theme.
+    var nightThemeBeforeDracula by configurationStore.int(Key.NIGHT_THEME_BEFORE_DRACULA) { -1 }
     var appLanguage by configurationStore.string(Key.APP_LANGUAGE) { "" }
     var serviceMode by configurationStore.string(Key.SERVICE_MODE) { Key.MODE_VPN }
 

app/src/main/java/io/nekohasekai/sagernet/ui/SettingsPreferenceFragment.kt

@@ -65,11 +65,36 @@ class SettingsPreferenceFragment : PreferenceFragmentCompat() {
         addPreferencesFromResource(R.xml.global_preferences)
 
         val appTheme = findPreference<ColorPickerPreference>(Key.APP_THEME)!!
+        val nightTheme = findPreference<SimpleMenuPreference>(Key.NIGHT_THEME)!!
         appTheme.setOnPreferenceChangeListener { _, newTheme ->
             if (DataStore.serviceState.started) {
                 SagerNet.reloadService()
             }
-            val theme = Theme.getTheme(newTheme as Int)
+            val themeId = newTheme as Int
+            val previousTheme = DataStore.appTheme // still the old value at this point
+            // Dracula is a dark-only theme: force night mode on so its #282a36
+            // canvas (values-night) takes effect instead of a washed-out light surface.
+            // Remember the prior night-mode setting so it can be restored on exit.
+            if (themeId == Theme.DRACULA) {
+                if (previousTheme != Theme.DRACULA && DataStore.nightTheme != 1) {
+                    DataStore.nightThemeBeforeDracula = DataStore.nightTheme
+                    DataStore.nightTheme = 1
+                    Theme.currentNightMode = 1
+                    nightTheme.value = "1"
+                    Theme.applyNightTheme()
+                }
+            } else if (previousTheme == Theme.DRACULA) {
+                // Leaving Dracula: restore the night-mode setting we forced on.
+                val restore = DataStore.nightThemeBeforeDracula
+                if (restore != -1) {
+                    DataStore.nightThemeBeforeDracula = -1
+                    DataStore.nightTheme = restore
+                    Theme.currentNightMode = restore
+                    nightTheme.value = restore.toString()
+                    Theme.applyNightTheme()
+                }
+            }
+            val theme = Theme.getTheme(themeId)
             app.setTheme(theme)
             requireActivity().apply {
                 setTheme(theme)
@@ -78,9 +103,11 @@ class SettingsPreferenceFragment : PreferenceFragmentCompat() {
             true
         }
 
-        val nightTheme = findPreference<SimpleMenuPreference>(Key.NIGHT_THEME)!!
         nightTheme.setOnPreferenceChangeListener { _, newTheme ->
             Theme.currentNightMode = (newTheme as String).toInt()
+            // A manual night-mode change takes precedence: drop any pending
+            // Dracula restore so we don't override the user's choice later.
+            DataStore.nightThemeBeforeDracula = -1
             Theme.applyNightTheme()
             true
         }

app/src/main/java/io/nekohasekai/sagernet/utils/Theme.kt

@@ -31,6 +31,7 @@ object Theme {
     const val BLUE_GREY = 20
     const val BLACK = 21
     const val VERDANT_MINT = 22
+    const val DRACULA = 23
 
     private fun defaultTheme() = PINK_SSR
 
@@ -74,6 +75,7 @@ object Theme {
             BLUE_GREY -> R.style.Theme_SagerNet_BlueGrey
             BLACK -> R.style.Theme_SagerNet_Black
             VERDANT_MINT -> R.style.Theme_SagerNet_VerdantMint
+            DRACULA -> R.style.Theme_SagerNet_Dracula
             else -> getTheme(defaultTheme())
         }
     }
@@ -102,6 +104,7 @@ object Theme {
             BLUE_GREY -> R.style.Theme_SagerNet_Dialog_BlueGrey
             BLACK -> R.style.Theme_SagerNet_Dialog_Black
             VERDANT_MINT -> R.style.Theme_SagerNet_Dialog_VerdantMint
+            DRACULA -> R.style.Theme_SagerNet_Dialog_Dracula
             else -> getDialogTheme(defaultTheme())
         }
     }

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

@@ -34,4 +34,9 @@
     <color name="card_elevated_yellow">#2C2A17</color>
     <color name="card_elevated_black">#151515</color>
     <color name="card_elevated_verdant_mint">#10241C</color>
+    <!-- Dracula dark surfaces (official palette). -->
+    <color name="card_elevated_dracula">#343746</color>
+    <color name="dracula_background">#282A36</color>
+    <color name="dracula_surface">#343746</color>
+    <color name="dracula_on_surface">#F8F8F2</color>
 </resources>

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

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <!--
+      Night-only surface overrides.
+
+      Other themes intentionally inherit the Material DayNight defaults, so we do
+      NOT redeclare them here. Only the Dracula theme paints a full custom canvas:
+      the official #282a36 background, #343746 surface, and #f8f8f2 foreground.
+
+      In day mode the Dracula style (values/themes.xml) keeps the standard light
+      surfaces, so accents stay readable even if the user is not in dark mode.
+      Selecting Dracula also forces night mode on (SettingsPreferenceFragment),
+      which is what brings these overrides into effect.
+    -->
+    <style name="Theme.SagerNet.Dracula" parent="Theme.SagerNet">
+        <item name="colorPrimary">@color/color_dracula</item>
+        <item name="colorPrimaryDark">@color/color_dracula_dark</item>
+        <item name="colorAccent">@color/color_dracula_accent</item>
+        <item name="colorMaterial100">@color/color_dracula_100</item>
+        <item name="colorMaterial300">@color/color_dracula_300</item>
+        <item name="cardElevatedSurfaceColor">@color/card_elevated_dracula</item>
+
+        <!-- True Dracula dark canvas. -->
+        <item name="colorSurface">@color/dracula_surface</item>
+        <item name="colorOnSurface">@color/dracula_on_surface</item>
+        <item name="android:colorBackground">@color/dracula_background</item>
+        <item name="colorOnBackground">@color/dracula_on_surface</item>
+        <item name="android:windowBackground">@color/dracula_background</item>
+    </style>
+
+    <style name="Theme.SagerNet.Dialog.Dracula" parent="Theme.SagerNet.Dialog">
+        <item name="colorPrimary">@color/color_dracula</item>
+        <item name="colorPrimaryDark">@color/color_dracula_dark</item>
+        <item name="colorAccent">@color/color_dracula_accent</item>
+        <item name="colorMaterial100">@color/color_dracula_100</item>
+        <item name="colorMaterial300">@color/color_dracula_300</item>
+        <item name="cardElevatedSurfaceColor">@color/card_elevated_dracula</item>
+
+        <item name="colorSurface">@color/dracula_surface</item>
+        <item name="colorOnSurface">@color/dracula_on_surface</item>
+        <item name="android:colorBackground">@color/dracula_background</item>
+        <item name="colorOnBackground">@color/dracula_on_surface</item>
+    </style>
+</resources>

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

@@ -26,6 +26,7 @@
         <item>@color/material_blue_grey_500</item>
         <item>@color/material_light_black</item>
         <item>@color/color_verdant_mint</item>
+        <item>@color/color_dracula</item>
     </integer-array>
 
     <color name="material_amber_100">#FFECB3</color>
@@ -291,6 +292,15 @@
     <color name="color_verdant_mint_100">#B4D7C6</color>
     <color name="color_verdant_mint_300">#509177</color>
 
+    <!-- Dracula theme accents (https://draculatheme.com). Purple primary,
+         pink accent. Surfaces are overridden in values-night for the true
+         #282a36 canvas; see Theme.SagerNet.Dracula. -->
+    <color name="color_dracula">#BD93F9</color>
+    <color name="color_dracula_dark">#6272A4</color>
+    <color name="color_dracula_accent">#FF79C6</color>
+    <color name="color_dracula_100">#E9DDFB</color>
+    <color name="color_dracula_300">#9A7BD0</color>
+
     <color name="color_ng_black_accent">#9E9E9E</color>
     <color name="color_ng_black_primary">#2B2B2B</color>
 
@@ -329,5 +339,6 @@
     <color name="card_elevated_yellow">#FFFDEF</color>
     <color name="card_elevated_black">#EEEEEE</color>
     <color name="card_elevated_verdant_mint">#EBF9F3</color>
+    <color name="card_elevated_dracula">#F1EAFB</color>
 
 </resources>

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

@@ -595,6 +595,19 @@
         <item name="cardElevatedSurfaceColor">@color/card_elevated_verdant_mint</item>
     </style>
 
+    <!-- Dracula: purple primary, pink accent. Accent colors apply in any mode;
+         the true #282a36 dark canvas (colorSurface/colorBackground/colorOnSurface)
+         is layered on in values-night/themes.xml. Selecting this theme forces
+         night mode on (see SettingsPreferenceFragment). -->
+    <style name="Theme.SagerNet.Dracula" parent="Theme.SagerNet">
+        <item name="colorPrimary">@color/color_dracula</item>
+        <item name="colorPrimaryDark">@color/color_dracula_dark</item>
+        <item name="colorAccent">@color/color_dracula_accent</item>
+        <item name="colorMaterial100">@color/color_dracula_100</item>
+        <item name="colorMaterial300">@color/color_dracula_300</item>
+        <item name="cardElevatedSurfaceColor">@color/card_elevated_dracula</item>
+    </style>
+
     <style name="Theme.SagerNet.Dialog.Black" parent="Theme.SagerNet.Dialog">
         <item name="colorPrimary">@color/color_ng_black_primary</item>
         <item name="colorPrimaryDark">@color/color_ng_black_primary</item>
@@ -622,6 +635,15 @@
         <item name="cardElevatedSurfaceColor">@color/card_elevated_verdant_mint</item>
     </style>
 
+    <style name="Theme.SagerNet.Dialog.Dracula" parent="Theme.SagerNet.Dialog">
+        <item name="colorPrimary">@color/color_dracula</item>
+        <item name="colorPrimaryDark">@color/color_dracula_dark</item>
+        <item name="colorAccent">@color/color_dracula_accent</item>
+        <item name="colorMaterial100">@color/color_dracula_100</item>
+        <item name="colorMaterial300">@color/color_dracula_300</item>
+        <item name="cardElevatedSurfaceColor">@color/card_elevated_dracula</item>
+    </style>
+
     <style name="Theme.Start" parent="Theme.MaterialComponents.DayNight">
         <item name="android:navigationBarColor">@android:color/transparent</item>
         <item name="colorPrimary">@android:color/transparent</item>