When user has DISALLOW_USB_FILE_TRANSFER set, disable settings controls.

Under Settings > Storage, remove the "USB computer connection" menu item.
In case someone launches the UsbSettings screen instead, also disable those checkboxes.

Change-Id: I59ec8b16bed4670beeac8d359e5368e4a659061b

src/com/android/settings/deviceinfo/Memory.java

@@ -33,6 +33,7 @@ import android.os.Environment;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.ServiceManager;
+import android.os.UserManager;
 import android.os.storage.IMountService;
 import android.os.storage.StorageEventListener;
 import android.os.storage.StorageManager;
@@ -174,7 +175,10 @@ public class Memory extends SettingsPreferenceFragment {
     @Override
     public void onPrepareOptionsMenu(Menu menu) {
         final MenuItem usb = menu.findItem(R.id.storage_usb);
-        usb.setVisible(!isMassStorageEnabled());
+        UserManager um = (UserManager)getActivity().getSystemService(Context.USER_SERVICE);
+        boolean usbItemVisible = !isMassStorageEnabled()
+                && !um.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER);
+        usb.setVisible(usbItemVisible);
     }
 
     @Override

src/com/android/settings/deviceinfo/UsbSettings.java

@@ -16,20 +16,16 @@
 
 package com.android.settings.deviceinfo;
 
-import android.app.AlertDialog;
-import android.app.Dialog;
 import android.content.BroadcastReceiver;
-import android.content.ContentQueryMap;
-import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.hardware.usb.UsbManager;
 import android.os.Bundle;
+import android.os.UserManager;
 import android.preference.CheckBoxPreference;
 import android.preference.Preference;
 import android.preference.PreferenceScreen;
-import android.provider.Settings;
 import android.util.Log;
 
 import com.android.settings.R;
@@ -73,6 +69,12 @@ public class UsbSettings extends SettingsPreferenceFragment {
         mMtp = (CheckBoxPreference)root.findPreference(KEY_MTP);
         mPtp = (CheckBoxPreference)root.findPreference(KEY_PTP);
 
+        UserManager um = (UserManager) getActivity().getSystemService(Context.USER_SERVICE);
+        if (um.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {
+            mMtp.setEnabled(false);
+            mPtp.setEnabled(false);
+        }
+
         return root;
     }
 
@@ -112,8 +114,12 @@ public class UsbSettings extends SettingsPreferenceFragment {
             mMtp.setChecked(false);
             mPtp.setChecked(false);
         }
-
+        UserManager um = (UserManager) getActivity().getSystemService(Context.USER_SERVICE);
-        if (!mUsbAccessoryMode) {
+        if (um.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {
+            Log.e(TAG, "USB is locked down");
+            mMtp.setEnabled(false);
+            mPtp.setEnabled(false);
+        } else if (!mUsbAccessoryMode) {
             //Enable MTP and PTP switch while USB is not in Accessory Mode, otherwise disable it
             Log.e(TAG, "USB Normal Mode");
             mMtp.setEnabled(true);
@@ -133,6 +139,12 @@ public class UsbSettings extends SettingsPreferenceFragment {
         if (Utils.isMonkeyRunning()) {
             return true;
         }
+        // If this user is disallowed from using USB, don't handle their attempts to change the
+        // setting.
+        UserManager um = (UserManager) getActivity().getSystemService(Context.USER_SERVICE);
+        if (um.hasUserRestriction(UserManager.DISALLOW_USB_FILE_TRANSFER)) {
+            return true;
+        }
 
         String function = "none";
         if (preference == mMtp && mMtp.isChecked()) {