Bug 40087: Implement a switch for english locale spoofing

app/src/main/java/org/mozilla/fenix/components/Core.kt

@@ -93,7 +93,8 @@ class Core(private val context: Context, private val crashReporter: CrashReporti
             suspendMediaWhenInactive = false,
             forceUserScalableContent = context.settings().forceEnableZoom,
             loginAutofillEnabled = context.settings().shouldAutofillLogins,
-            torSecurityLevel = context.settings().torSecurityLevel().intRepresentation
+            torSecurityLevel = context.settings().torSecurityLevel().intRepresentation,
+            spoofEnglish = context.settings().spoofEnglish
         )
 
         GeckoEngine(

app/src/main/java/org/mozilla/fenix/settings/advanced/DefaultLocaleSettingsController.kt

@@ -7,6 +7,7 @@ package org.mozilla.fenix.settings.advanced
 import android.app.Activity
 import android.content.Context
 import mozilla.components.support.locale.LocaleManager
+import org.mozilla.fenix.ext.components
 import java.util.Locale
 
 interface LocaleSettingsController {
@@ -55,5 +56,9 @@ class DefaultLocaleSettingsController(
         config.setLocale(locale)
         config.setLayoutDirection(locale)
         resources.updateConfiguration(config, resources.displayMetrics)
+        // A slightly hacky way of triggering a `runtime.settings.locales` update,
+        // so that the locales are updated in GeckoView.
+        val spoofEnglish = context.components.core.engine.settings.spoofEnglish
+        context.components.core.engine.settings.spoofEnglish = spoofEnglish
     }
 }

app/src/main/java/org/mozilla/fenix/settings/advanced/LocaleSettingsFragment.kt

@@ -20,6 +20,8 @@ import mozilla.components.support.ktx.android.view.hideKeyboard
 import mozilla.components.support.locale.LocaleManager
 import org.mozilla.fenix.R
 import org.mozilla.fenix.components.StoreProvider
+import org.mozilla.fenix.ext.requireComponents
+import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.ext.showToolbar
 
 class LocaleSettingsFragment : Fragment() {
@@ -38,7 +40,9 @@ class LocaleSettingsFragment : Fragment() {
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View? {
-        val view = inflater.inflate(R.layout.fragment_locale_settings, container, false)
+        val view = inflater.inflate(R.layout.fragment_locale_settings, container, false).also {
+            bindEnableSwitch(it)
+        }
 
         store = getStore()
         interactor = LocaleSettingsInteractor(
@@ -51,6 +55,16 @@ class LocaleSettingsFragment : Fragment() {
         return view
     }
 
+    @SuppressWarnings("LongMethod")
+    private fun bindEnableSwitch(view: View) {
+        val switch = view.enable_switch
+        switch.isChecked = requireComponents.core.engine.settings.spoofEnglish
+        switch.setOnCheckedChangeListener { _, isChecked ->
+            context?.settings()?.spoofEnglish = isChecked
+            requireComponents.core.engine.settings.spoofEnglish = isChecked
+        }
+    }
+
     override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
         inflater.inflate(R.menu.languages_list, menu)
         val searchItem = menu.findItem(R.id.search)

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

@@ -204,6 +204,11 @@ class Settings(private val appContext: Context) : PreferencesHolder {
         else -> SecurityLevel.STANDARD
     }
 
+    var spoofEnglish by booleanPreference(
+        appContext.getPreferenceKey(R.string.pref_key_spoof_english),
+        default = false
+    )
+
     // If any of the prefs have been modified, quit displaying the fenix moved tip
     fun shouldDisplayFenixMovingTip(): Boolean =
         preferences.getBoolean(

app/src/main/res/layout/fragment_locale_settings.xml

@@ -7,13 +7,30 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent">
 
+    <com.google.android.material.switchmaterial.SwitchMaterial
+        android:id="@+id/enable_switch"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_vertical|end"
+        android:background="?android:attr/selectableItemBackground"
+        android:checked="true"
+        android:clickable="true"
+        android:focusable="true"
+        android:layout_marginStart="54dp"
+        android:padding="16dp"
+        android:text="@string/tor_spoof_english"
+        android:textColor="?primaryText"
+        android:textSize="16sp"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"  />
     <FrameLayout
         android:id="@+id/locale_container"
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="0dp"
         app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toBottomOf="@id/enable_switch" />
 
 </androidx.constraintlayout.widget.ConstraintLayout>

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

@@ -253,4 +253,6 @@
     <string name="pref_key_tor_network_settings_tor_ready">pref_key_tor_network_settings_tor_ready</string>
     <string name="pref_key_tor_network_settings_state">pref_key_tor_network_settings_state</string>
     <string name="pref_key_tor_network_settings_bridges_enabled">pref_key_tor_network_settings_bridges_enabled</string>
+
+    <string name="pref_key_spoof_english" translatable="false">pref_key_spoof_english</string>
 </resources>

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

@@ -70,4 +70,6 @@
     <string name="tor_security_level_safest_option">Safest</string>
     <string name="tor_security_level_safest_description">Only allow website features required for static sites and basic services. These changes affect images, media, and scripts.</string>
 
+    <!-- Spoof locale to English -->
+    <string name="tor_spoof_english">Request English versions of web pages for enhanced privacy</string>
 </resources>