Show "uninstall for all users" when >1 users installed it.

Bug: 32167081
Test: make SettingsTests

Change-Id: I407549838d40c160a84a36f2d9ebaa8dc73d6008

src/com/android/settings/applications/InstalledAppDetails.java

@@ -53,6 +53,7 @@ import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
 import android.service.notification.NotificationListenerService.Ranking;
+import android.support.annotation.VisibleForTesting;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.Preference.OnPreferenceClickListener;
 import android.support.v7.preference.PreferenceCategory;
@@ -461,6 +462,8 @@ public class InstalledAppDetails extends AppInfoBase
             showIt = false;
         } else if (mUserManager.getUsers().size() < 2) {
             showIt = false;
+        } else if (PackageUtil.countPackageInUsers(mPm, mUserManager, mPackageName) < 2) {
+            showIt = false;
         }
         menu.findItem(UNINSTALL_ALL_USERS_MENU).setVisible(showIt);
         mUpdatedSysApp = (mAppEntry.info.flags & ApplicationInfo.FLAG_UPDATED_SYSTEM_APP) != 0;
@@ -1164,6 +1167,37 @@ public class InstalledAppDetails extends AppInfoBase
         }
     }
 
+    /**
+     * Elicit this class for testing. Test cannot be done in robolectric because it
+     * invokes the new API.
+     */
+    @VisibleForTesting
+    public static class PackageUtil {
+        /**
+         * Count how many users in device have installed package {@paramref packageName}
+         */
+        public static int countPackageInUsers(PackageManager packageManager, UserManager
+                userManager, String packageName) {
+            final List<UserInfo> userInfos = userManager.getUsers(true);
+            int count = 0;
+
+            for (final UserInfo userInfo : userInfos) {
+                try {
+                    // Use this API to check whether user has this package
+                    final ApplicationInfo info = packageManager.getApplicationInfoAsUser(
+                            packageName, PackageManager.GET_META_DATA, userInfo.id);
+                    if ((info.flags & ApplicationInfo.FLAG_INSTALLED) != 0) {
+                        count++;
+                    }
+                } catch(NameNotFoundException e) {
+                    Log.e(TAG, "Package: " + packageName + " not found for user: " + userInfo.id);
+                }
+            }
+
+            return count;
+        }
+    }
+
     private static class DisableChanger extends AsyncTask<Object, Object, Object> {
         final PackageManager mPm;
         final WeakReference<InstalledAppDetails> mActivity;

tests/app/src/com/android/settings/applications/PackageUtilTest.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (C) 2016 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.settings.applications;
+
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.UserInfo;
+import android.os.UserManager;
+import android.support.test.filters.SmallTest;
+import android.support.test.runner.AndroidJUnit4;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static junit.framework.Assert.assertEquals;
+import static org.mockito.Mockito.when;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class PackageUtilTest {
+    private static final String ALL_USERS_APP_NAME = "com.google.allusers.app";
+    private static final String ONE_USER_APP_NAME = "com.google.oneuser.app";
+    private static final int USER1_ID = 1;
+    private static final int USER2_ID = 11;
+
+    @Mock
+    private PackageManager mMockPackageManager;
+    @Mock
+    private UserManager mMockUserManager;
+
+    private InstalledAppDetails.PackageUtil mPackageUtil;
+    private List<UserInfo> mUserInfos;
+
+    @Before
+    public void setUp() throws PackageManager.NameNotFoundException {
+        MockitoAnnotations.initMocks(this);
+
+        mUserInfos = new ArrayList<>();
+        mUserInfos.add(new UserInfo(USER1_ID, "lei", 0));
+        mUserInfos.add(new UserInfo(USER2_ID, "yue", 0));
+        when(mMockUserManager.getUsers(true)).thenReturn(mUserInfos);
+
+        ApplicationInfo usersApp = new ApplicationInfo();
+        usersApp.flags = ApplicationInfo.FLAG_INSTALLED;
+
+        when(mMockPackageManager.getApplicationInfoAsUser(
+                ALL_USERS_APP_NAME, PackageManager.GET_META_DATA, USER1_ID))
+                .thenReturn(usersApp);
+        when(mMockPackageManager.getApplicationInfoAsUser(
+                ALL_USERS_APP_NAME, PackageManager.GET_META_DATA, USER2_ID))
+                .thenReturn(usersApp);
+
+        when(mMockPackageManager.getApplicationInfoAsUser(
+                ONE_USER_APP_NAME, PackageManager.GET_META_DATA, USER1_ID))
+                .thenReturn(usersApp);
+
+        when(mMockPackageManager.getApplicationInfoAsUser(
+                ONE_USER_APP_NAME, PackageManager.GET_META_DATA, USER2_ID))
+                .thenThrow(new PackageManager.NameNotFoundException());
+
+        mPackageUtil = new InstalledAppDetails.PackageUtil();
+    }
+
+    @Test
+    public void testCountPackageInUsers_twoUsersInstalled_returnTwo() {
+        assertEquals(2, mPackageUtil.countPackageInUsers(
+                mMockPackageManager, mMockUserManager, ALL_USERS_APP_NAME));
+    }
+
+    @Test
+    public void testCountPackageInUsers_oneUsersInstalled_returnOne() {
+        assertEquals(1, mPackageUtil.countPackageInUsers(
+                mMockPackageManager, mMockUserManager, ONE_USER_APP_NAME));
+    }
+}