Restrict Wi-Fi toggle in Internet Settings

- Disable Wi-Fi toggle when user is not allowed to change Wi-Fi state.

- Show restriction message in Wi-Fi toggle summary.

- See the result screenshot in b/203168097#comment24

Bug: 203168097
Test: manual test
atest -c WifiSwitchPreferenceControllerTest

Change-Id: I3cfe2f4f0e855dde91a82babe3a03005c3985d59

src/com/android/settings/network/WifiSwitchPreferenceController.java

@@ -16,19 +16,25 @@
 
 package com.android.settings.network;
 
+import static com.android.settingslib.wifi.WifiEnterpriseRestrictionUtils.isChangeWifiStateAllowed;
+
 import android.content.Context;
+import android.net.wifi.WifiManager;
 
 import androidx.lifecycle.Lifecycle;
 import androidx.lifecycle.LifecycleObserver;
 import androidx.lifecycle.OnLifecycleEvent;
 import androidx.preference.PreferenceScreen;
 
+import com.android.settings.R;
 import com.android.settings.overlay.FeatureFactory;
 import com.android.settings.widget.GenericSwitchController;
 import com.android.settings.wifi.WifiEnabler;
 import com.android.settingslib.RestrictedSwitchPreference;
 import com.android.settingslib.core.AbstractPreferenceController;
 
+import com.google.common.annotations.VisibleForTesting;
+
 /**
  * This controller helps to manage the state of wifi switch preference.
  */
@@ -37,9 +43,12 @@ public class WifiSwitchPreferenceController extends AbstractPreferenceController
 
     public static final String KEY = "main_toggle_wifi";
 
-    private RestrictedSwitchPreference mPreference;
+    @VisibleForTesting
+    boolean mIsChangeWifiStateAllowed;
+    @VisibleForTesting
+    WifiEnabler mWifiEnabler;
 
-    private WifiEnabler mWifiEnabler;
+    private RestrictedSwitchPreference mPreference;
 
     public WifiSwitchPreferenceController(Context context, Lifecycle lifecycle) {
         super(context);
@@ -48,6 +57,7 @@ public class WifiSwitchPreferenceController extends AbstractPreferenceController
         }
 
         lifecycle.addObserver(this);
+        mIsChangeWifiStateAllowed = isChangeWifiStateAllowed(context);
     }
 
     @Override
@@ -64,12 +74,22 @@ public class WifiSwitchPreferenceController extends AbstractPreferenceController
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
         mPreference = screen.findPreference(getPreferenceKey());
+        if (mPreference == null) return;
+
+        mPreference.setChecked(isWifiEnabled());
+        if (!mIsChangeWifiStateAllowed) {
+            mPreference.setEnabled(false);
+            mPreference.setSummary(R.string.not_allowed_by_ent);
+        }
     }
 
     /** Lifecycle.Event.ON_START */
     @OnLifecycleEvent(Lifecycle.Event.ON_START)
     public void onStart() {
-        if (mPreference != null) {
+        // Don't use WifiEnabler when user is not allowed to change Wi-Fi state,
+        // Because the preference needs to be disabled when the user is not allowed to change the
+        // Wi-Fi state, but WifiEnabler will enable the preference when the Wi-Fi state changes.
+        if (mPreference != null && mIsChangeWifiStateAllowed) {
             mWifiEnabler = new WifiEnabler(mContext, new GenericSwitchController(mPreference),
                     FeatureFactory.getFactory(mContext).getMetricsFeatureProvider());
         }
@@ -98,4 +118,10 @@ public class WifiSwitchPreferenceController extends AbstractPreferenceController
             mWifiEnabler.pause();
         }
     }
+
+    private boolean isWifiEnabled() {
+        WifiManager wifiManager = mContext.getSystemService(WifiManager.class);
+        if (wifiManager == null) return false;
+        return wifiManager.isWifiEnabled();
+    }
 }