Show security patch date under policy management.

To demonstrate the use of the Build.VERSION.SECURITY_PATCH property the
value is retreived, parsed into a date and presented on the policy
management list.

Bug: 29565565
Change-Id: Id38af846a555a4e49041038c02cfb9b1638557ce

Author: AndrewScull

app/src/main/java/com/afwsamples/testdpc/policy/PolicyManagementFragment.java

@@ -107,9 +107,13 @@
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
+import java.text.DateFormat;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
+import java.util.Date;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -204,6 +208,7 @@ public class PolicyManagementFragment extends BaseSearchablePolicyPreferenceFrag
     private static final String CREATE_AND_MANAGE_USER_KEY = "create_and_manage_user";
     private static final String DELEGATED_CERT_INSTALLER_KEY = "manage_cert_installer";
     private static final String DEVICE_OWNER_STATUS_KEY = "device_owner_status";
+    private static final String SECURITY_PATCH_KEY = "security_patch";
     private static final String DISABLE_CAMERA_KEY = "disable_camera";
     private static final String DISABLE_KEYGUARD = "disable_keyguard";
     private static final String DISABLE_SCREEN_CAPTURE_KEY = "disable_screen_capture";
@@ -269,6 +274,7 @@ public class PolicyManagementFragment extends BaseSearchablePolicyPreferenceFrag
     private static final String WIFI_CONFIG_LOCKDOWN_ON = "1";
     private static final String WIFI_CONFIG_LOCKDOWN_OFF = "0";
     private static final String SAFETYNET_ATTEST = "safetynet_attest";
+    private static final String SECURITY_PATCH_FORMAT = "yyyy-MM-dd";
 
     private static final String BATTERY_PLUGGED_ANY = Integer.toString(
             BatteryManager.BATTERY_PLUGGED_AC |
@@ -290,7 +296,7 @@ public class PolicyManagementFragment extends BaseSearchablePolicyPreferenceFrag
             NETWORK_STATS_KEY, DELEGATED_CERT_INSTALLER_KEY, DISABLE_STATUS_BAR,
             REENABLE_STATUS_BAR, DISABLE_KEYGUARD, REENABLE_KEYGUARD, START_KIOSK_MODE,
             SET_PERMISSION_POLICY_KEY, MANAGE_APP_PERMISSIONS_KEY,STAY_ON_WHILE_PLUGGED_IN,
-            WIFI_CONFIG_LOCKDOWN_ENABLE_KEY
+            WIFI_CONFIG_LOCKDOWN_ENABLE_KEY, SECURITY_PATCH_KEY
     };
 
     private static String[] NYC_PLUS_PREFERENCES = {
@@ -442,6 +448,7 @@ public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
         disableIncompatibleManagementOptionsInCurrentProfile();
         disableIncompatibleManagementOptionsByApiLevel();
 
+        loadSecurityPatch();
         reloadCameraDisableUi();
         reloadScreenCaptureDisableUi();
         reloadMuteAudioUi();
@@ -1402,6 +1409,26 @@ public void onClick(DialogInterface dialogInterface, int i) {
                 .show();
     }
 
+    @TargetApi(Build.VERSION_CODES.M)
+    private void loadSecurityPatch() {
+        Preference securityPatchPreference = findPreference(SECURITY_PATCH_KEY);
+        if (!securityPatchPreference.isEnabled()) {
+            return;
+        }
+
+        String buildSecurityPatch = Build.VERSION.SECURITY_PATCH;
+        final Date date;
+        try {
+            date = new SimpleDateFormat(SECURITY_PATCH_FORMAT).parse(buildSecurityPatch);
+        } catch (ParseException e) {
+            securityPatchPreference.setSummary(
+                    getString(R.string.invalid_security_patch, buildSecurityPatch));
+            return;
+        }
+        String display = DateFormat.getDateInstance(DateFormat.MEDIUM).format(date);
+        securityPatchPreference.setSummary(display);
+    }
+
     @TargetApi(Build.VERSION_CODES.LOLLIPOP)
     private void reloadCameraDisableUi() {
         boolean isCameraDisabled = mDevicePolicyManager.getCameraDisabled(mAdminComponentName);

app/src/main/res/values/strings.xml

@@ -119,6 +119,11 @@
     <string name="add">Add</string>
     <string name="clear">Clear</string>
 
+    <!-- Strings for system information -->
+    <string name="invalid_security_patch">Invalid security patch format:
+        <xliff:g id="security_patch">%s</xliff:g></string>
+    <string name="security_patch">Security patch</string>
+
     <!-- Strings for camera and screen capture -->
     <string name="camera_title">Camera, screen capture and audio</string>
     <string name="display_media">Display Media</string>

app/src/main/res/xml/device_policy_header.xml

@@ -20,6 +20,10 @@
     <Preference
             android:key="device_owner_status"
             android:selectable="false"/>
+    <Preference
+        android:key="security_patch"
+        android:title="@string/security_patch"
+        android:selectable="false"/>
 
     <PreferenceCategory
             android:title="@string/accessibility_title">