Request location permission for WiFi network listing

Request the ACCESS_FINE_LOCATION permission prior to calling
WifiManager.getConfiguredNetworks.

TestDPC can no longer grant itself this permission.

Also, fix a crash in DevicePolicyManagerGatewayImpl when TestDPC is not
a DPC.

Bug: 185463607
Bug: 182894941
Test: Manual, create a work profile and start "Modify Wi-Fi configuration" fragment.
Change-Id: Iaf40e344e55a667c75b4d52ffc19e8664df7b572

Author: eranmes

app/src/main/java/com/afwsamples/testdpc/DevicePolicyManagerGatewayImpl.java

@@ -31,6 +31,7 @@
 import android.os.UserManager;
 import android.util.Log;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import com.afwsamples.testdpc.common.ReflectionUtil;
 import com.afwsamples.testdpc.common.ReflectionUtil.ReflectionIsTemporaryException;
@@ -92,11 +93,18 @@ public DevicePolicyManager getDevicePolicyManager() {
 
     @Override
     public boolean isProfileOwnerApp() {
+        if (mAdminComponentName == null) {
+            return false;
+        }
         return mDevicePolicyManager.isProfileOwnerApp(mAdminComponentName.getPackageName());
     }
 
     @Override
     public boolean isDeviceOwnerApp() {
+        if (mAdminComponentName == null) {
+            return false;
+        }
+
         return mDevicePolicyManager.isDeviceOwnerApp(mAdminComponentName.getPackageName());
     }
 

app/src/main/java/com/afwsamples/testdpc/policy/wifimanagement/WifiModificationFragment.java

@@ -16,13 +16,14 @@
 
 package com.afwsamples.testdpc.policy.wifimanagement;
 
-import static android.net.wifi.WifiEnterpriseConfig.Eap;
-
+import android.Manifest;
 import android.Manifest.permission;
+import android.app.Activity;
 import android.app.AlertDialog;
 import android.app.DialogFragment;
 import android.app.Fragment;
 import android.content.Context;
+import android.content.pm.PackageManager;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiManager;
 import android.os.Build.VERSION_CODES;
@@ -35,14 +36,20 @@
 import android.widget.CheckedTextView;
 import android.widget.ListView;
 import android.widget.TextView;
+import android.widget.Toast;
+
+import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
-import com.afwsamples.testdpc.DeviceAdminReceiver;
+import androidx.core.content.ContextCompat;
+
 import com.afwsamples.testdpc.R;
-import com.afwsamples.testdpc.common.PermissionsHelper;
 import com.afwsamples.testdpc.common.Util;
+
 import java.util.ArrayList;
 import java.util.List;
 
+import static android.net.wifi.WifiEnterpriseConfig.Eap;
+
 /**
  * Fragment for WiFi configuration editing.
  */
@@ -115,6 +122,17 @@ public void onResume() {
         updateConfigsList();
     }
 
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
+                                           @NonNull int[] grantResults) {
+        if (grantResults[0] != PackageManager.PERMISSION_GRANTED) {
+            showToast("Location permission denied, network list unavailable.");
+        } else {
+            updateConfigsList();
+        }
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+    }
+
     @RequiresApi(api = VERSION_CODES.M)
     @Override
     public View onCreateView(LayoutInflater inflater, final ViewGroup container,
@@ -132,14 +150,13 @@ public View onCreateView(LayoutInflater inflater, final ViewGroup container,
         mConfigsList.setAdapter(mConfigsAdapter);
         mConfigsList.setChoiceMode(ListView.CHOICE_MODE_SINGLE);
 
-        if (Util.SDK_INT >= VERSION_CODES.M) {
-            PermissionsHelper
-                .ensureRequiredPermissions(new String[]{permission.ACCESS_FINE_LOCATION},
-                    DeviceAdminReceiver.getComponentName(this.getActivity()), this.getContext());
+        if (shouldRequestLocationPermission(getContext())) {
+            requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
+                    /* requestCode= */ 0);
+        } else {
+            updateConfigsList();
         }
 
-        updateConfigsList();
-
         Button updateConfigButton = (Button) view.findViewById(R.id.updateSelectedConfig);
         if (updateConfigButton != null) {
             updateConfigButton.setOnClickListener(new View.OnClickListener() {
@@ -200,10 +217,26 @@ public void onDismiss() {
     public void onCancel() {
     }
 
+    public static boolean shouldRequestLocationPermission(Context context) {
+        if (Util.SDK_INT < VERSION_CODES.M) {
+            return false;
+        }
+
+        return ContextCompat.checkSelfPermission(context, permission.ACCESS_FINE_LOCATION)
+                != PackageManager.PERMISSION_GRANTED;
+    }
+
     private void showError(final String message) {
         new AlertDialog.Builder(getActivity()).setTitle(R.string.wifi_modification_error_title)
                 .setIconAttribute(android.R.attr.alertDialogIcon)
                 .setMessage(message).setPositiveButton(android.R.string.ok, null).show();
     }
 
+    private void showToast(String msg) {
+        Activity activity = getActivity();
+        if (activity == null || activity.isFinishing()) {
+            return;
+        }
+        Toast.makeText(activity, msg, Toast.LENGTH_SHORT).show();
+    }
 }