Add MainSwitch for Fast Pair settings

Bug: 203579197
Test: Built and verified by logs
Change-Id: I68ef55f2601cce0f51a746d108187c94e496fb71

res/values/strings.xml

@@ -5825,7 +5825,8 @@
 
     <!-- Fast Pair setting summary in settings screen [CHAR LIMIT=50] -->
     <string name="fast_pair_settings_summary">Nearby detection of Fast Pair bluetooth devices.</string>
-
+    <!-- Title for Fast Pair main switch preferences. [CHAR LIMIT=50] -->
+    <string name="fast_pair_main_switch_title">Scan for nearby devices</string>
     <!-- Printing settings -->
     <skip />
 

res/xml/fast_pair_settings.xml

@@ -21,4 +21,8 @@
     android:title="@string/fast_pair_settings"
     settings:keywords="@string/keywords_fast_pair">
 
-</PreferenceScreen>
+    <com.android.settingslib.widget.MainSwitchPreference
+        android:key="fast_pair_scan_switch"
+        android:title="@string/fast_pair_main_switch_title" />
+
+</PreferenceScreen>

src/com/android/settings/nearby/FastPairSettingsFragment.java

@@ -17,11 +17,16 @@
 package com.android.settings.nearby;
 
 import android.app.settings.SettingsEnums;
+import android.os.Bundle;
+import android.provider.Settings;
 
 import com.android.settings.R;
 import com.android.settings.SettingsPreferenceFragment;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settingslib.search.SearchIndexable;
+import com.android.settingslib.widget.MainSwitchPreference;
+
+import java.util.Objects;
 
 /**
  * Fragment with the top level fast pair settings.
@@ -29,6 +34,21 @@ import com.android.settingslib.search.SearchIndexable;
 @SearchIndexable(forTarget = SearchIndexable.ALL & ~SearchIndexable.ARC)
 public class FastPairSettingsFragment extends SettingsPreferenceFragment {
 
+    private static final String SCAN_SWITCH_KEY = "fast_pair_scan_switch";
+
+    @Override
+    public void onCreate(Bundle icicle) {
+        super.onCreate(icicle);
+
+        MainSwitchPreference mainSwitchPreference = Objects.requireNonNull(
+                findPreference(SCAN_SWITCH_KEY));
+        mainSwitchPreference.addOnSwitchChangeListener(
+                (switchView, isChecked) ->
+                        Settings.Secure.putInt(getContentResolver(),
+                                Settings.Secure.FAST_PAIR_SCAN_ENABLED, isChecked ? 1 : 0));
+        mainSwitchPreference.setChecked(isFastPairScanAvailable());
+    }
+
     @Override
     public int getMetricsCategory() {
         return SettingsEnums.CONNECTION_DEVICE_ADVANCED_FAST_PAIR;
@@ -47,4 +67,8 @@ public class FastPairSettingsFragment extends SettingsPreferenceFragment {
     public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
             new BaseSearchIndexProvider(R.xml.fast_pair_settings);
 
+    private boolean isFastPairScanAvailable() {
+        return Settings.Secure.getInt(getContentResolver(),
+                Settings.Secure.FAST_PAIR_SCAN_ENABLED, 1) != 0;
+    }
 }