Create WifiPermissionChecker in SettingsLib

- Get the launched package name from ActivityManager

- Add method to check ACCESS_WIFI_STATE permission

- Add method to check ACCESS_FINE_LOCATION permission

Bug: 187176859
Test: manual test
make RunSettingsLibRoboTests \
    ROBOTEST_FILTER=WifiPermissionCheckerTest

Change-Id: Ia5de60b88fc97ef532941c0c10ebf069d4216134

packages/SettingsLib/src/com/android/settingslib/wifi/WifiPermissionChecker.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settingslib.wifi;
+
+import static android.Manifest.permission.ACCESS_FINE_LOCATION;
+import static android.Manifest.permission.ACCESS_WIFI_STATE;
+import static android.content.pm.PackageManager.PERMISSION_GRANTED;
+
+import android.app.Activity;
+import android.app.ActivityManager;
+import android.app.IActivityManager;
+import android.content.pm.PackageManager;
+import android.os.RemoteException;
+import android.text.TextUtils;
+import android.util.Log;
+
+/**
+ * Helper class to check Wi-Fi permissions.
+ */
+public class WifiPermissionChecker {
+
+    private static final String TAG = "WifiPermChecker";
+
+    private IActivityManager mActivityManager;
+    private PackageManager mPackageManager;
+    private String mLaunchedPackage;
+
+    public WifiPermissionChecker(Activity activity) {
+        this(activity, ActivityManager.getService());
+    }
+
+    public WifiPermissionChecker(Activity activity, IActivityManager activityManager) {
+        mActivityManager = activityManager;
+        mPackageManager = activity.getPackageManager();
+        mLaunchedPackage = getLaunchedFromPackage(activity);
+    }
+
+    /**
+     * Returns the launched package name
+     */
+    public String getLaunchedPackage() {
+        return mLaunchedPackage;
+    }
+
+    /**
+     * Returns whether the launched package can access Wi-Fi information
+     */
+    public boolean canAccessWifiState() {
+        return checkPermission(ACCESS_WIFI_STATE);
+    }
+
+    /**
+     * Returns whether the launched package can access precise location
+     */
+    public boolean canAccessFineLocation() {
+        return checkPermission(ACCESS_FINE_LOCATION);
+    }
+
+    private boolean checkPermission(String permission) {
+        if (mPackageManager == null || TextUtils.isEmpty(mLaunchedPackage)) {
+            Log.e(TAG, "Failed to check package permission!"
+                    + " {PackageManager:" + mPackageManager
+                    + ", LaunchedPackage:" + mLaunchedPackage + "}");
+            return false;
+        }
+
+        if (mPackageManager.checkPermission(permission, mLaunchedPackage) == PERMISSION_GRANTED) {
+            return true;
+        }
+
+        Log.w(TAG, "The launched package does not have the required permission!"
+                + " {LaunchedPackage:" + mLaunchedPackage + ", Permission:" + permission + "}");
+        return false;
+    }
+
+    private String getLaunchedFromPackage(Activity activity) {
+        try {
+            return mActivityManager.getLaunchedFromPackage(activity.getActivityToken());
+        } catch (RemoteException e) {
+            Log.e(TAG, "Can not get the launched package from activity manager!");
+            return null;
+        }
+    }
+}

packages/SettingsLib/tests/robotests/src/com/android/settingslib/wifi/WifiPermissionCheckerTest.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settingslib.wifi;
+
+import static android.Manifest.permission.ACCESS_FINE_LOCATION;
+import static android.Manifest.permission.ACCESS_WIFI_STATE;
+import static android.content.pm.PackageManager.PERMISSION_DENIED;
+import static android.content.pm.PackageManager.PERMISSION_GRANTED;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+import android.app.Activity;
+import android.app.IActivityManager;
+import android.content.pm.PackageManager;
+import android.os.RemoteException;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.junit.MockitoJUnit;
+import org.mockito.junit.MockitoRule;
+import org.robolectric.RobolectricTestRunner;
+
+@RunWith(RobolectricTestRunner.class)
+public class WifiPermissionCheckerTest {
+
+    static final String LAUNCHED_PACKAGE = "TestPackage";
+
+    @Rule
+    public final MockitoRule mMockitoRule = MockitoJUnit.rule();
+    @Mock
+    PackageManager mPackageManager;
+    @Mock
+    IActivityManager mActivityManager;
+    @Mock
+    Activity mActivity;
+
+    WifiPermissionChecker mWifiPermissionChecker;
+
+    @Before
+    public void setUp() {
+        when(mActivity.getPackageManager()).thenReturn(mPackageManager);
+        fakeGetLaunchedFromPackage(LAUNCHED_PACKAGE);
+
+        mWifiPermissionChecker = new WifiPermissionChecker(mActivity, mActivityManager);
+    }
+
+    @Test
+    public void getLaunchedPackage_returnLaunchedFromPackage() {
+        assertThat(mWifiPermissionChecker.getLaunchedPackage()).isEqualTo(LAUNCHED_PACKAGE);
+    }
+
+    @Test
+    public void canAccessWifiState_noPermission_returnFalse() {
+        when(mPackageManager.checkPermission(ACCESS_WIFI_STATE, LAUNCHED_PACKAGE))
+                .thenReturn(PERMISSION_DENIED);
+
+        assertThat(mWifiPermissionChecker.canAccessWifiState()).isFalse();
+    }
+
+    @Test
+    public void canAccessWifiState_hasPermission_returnTrue() {
+        when(mPackageManager.checkPermission(ACCESS_WIFI_STATE, LAUNCHED_PACKAGE))
+                .thenReturn(PERMISSION_GRANTED);
+
+        assertThat(mWifiPermissionChecker.canAccessWifiState()).isTrue();
+    }
+
+    @Test
+    public void canAccessFineLocation_noPermission_returnFalse() {
+        when(mPackageManager.checkPermission(ACCESS_FINE_LOCATION, LAUNCHED_PACKAGE))
+                .thenReturn(PERMISSION_DENIED);
+
+        assertThat(mWifiPermissionChecker.canAccessFineLocation()).isFalse();
+    }
+
+    @Test
+    public void canAccessFineLocation_hasPermission_returnTrue() {
+        when(mPackageManager.checkPermission(ACCESS_FINE_LOCATION, LAUNCHED_PACKAGE))
+                .thenReturn(PERMISSION_GRANTED);
+
+        assertThat(mWifiPermissionChecker.canAccessFineLocation()).isTrue();
+    }
+
+    void fakeGetLaunchedFromPackage(String packageName) {
+        try {
+            when(mActivityManager.getLaunchedFromPackage(any())).thenReturn(packageName);
+        } catch (RemoteException e) {
+            // Do nothing
+        }
+    }
+}