Kiosk mode in Android

Question

You can autostart applications on boot by listening to the android.intent.action.BOOT_COMPLETED intent in a BroadcastReceiver and start your Activity from there. In the Activity you can register yourself as the new default homescreen[1] and handle the keys.

I think there are some instances that you can't handle without modifying the framework (like longpress on Home to show currently active Applications) - I could also be mistaken though.

But for a prototype that could be sufficient.

Have fun tinkering!

[1]:

<intent-filter>
 <action android:name="android.intent.action.MAIN" />
 <category android:name="android.intent.category.HOME" />
 <category android:name="android.intent.category.DEFAULT" />
</intent-filter>

You could customise this (disable access to menu, limit application addition etc) to enable kiosk. http://code.google.com/p/android-launcher-plus/

In the new Android L Preview, Google has announced Task Locking, which does exactly that. It does seem to need root however.

The L Developer Preview introduces a new task locking API that lets you temporarily restrict users from leaving your app or being interrupted by notifications. This could be used, for example, if you are developing an education app to support high stakes assessment requirements on Android. Once your app activates this mode, users will not be able to see notifications, access other apps, or return to the Home screen, until your app exits the mode.

To prevent unauthorized usage, only authorized apps can activate task locking. Furthermore, task locking authorization must be granted by a specially-configured device owner app, through the android.app.admin.DevicePolicyManager.setLockTaskComponents() method.

To set up a device owner, follow these steps:

• Attach a device running an Android userdebug build to your development machine.
• Install your device owner app.
• Create a device_owner.xml file and save it to the /data/system directory on the device.

$ adb root
$ adb shell stop
$ rm /tmp/device_owner.xml
$ echo "<?xml version='1.0' encoding='utf-8' standalone='yes' ?>" >> /tmp/device_owner.xml
$ echo "&device-owner package=\"<your_device_owner_package>\" name=\"*<your_organization_name>\" />" >> /tmp/device_owner.xml
$ adb push /tmp/device_owner.xml /data/system/device_owner.xml
$ adb reboot

Before using the task locking API in your app, verify that your activity is authorized by calling DevicePolicyManager.isLockTaskPermitted().

To activate task locking, call android.app.Activity.startLockTask() from your authorized activity.

When task locking is active, the following behavior takes effect:

• The status bar is blank, and user notifications and status information is hidden.
• The Home and Recent Apps buttons are hidden.
• Other apps may not launch new activities.
• The current app may start new activities, as long as doing so does not create new tasks.
• The user remains locked on your app until an authorized activity calls Activity.stopLockTask().

After searching for this for a while I've come up with a good solution. This only works on rooted devices though, but I guess if it's just for this one app then rooting it shouldn't be a problem.

• Make your application the launcher by adding

  <category android:name="android.intent.category.HOME" /> 
  

  to your intent-filter

• Make sure your app collapses the toolbar so you cannot reach the notification bar see How to disable status bar / notification bar on android programmatically? or http://blog.vogella.com/2011/02/28/android-hidding-the-status-and-title-bar/

• Then to stop any other programs from opening by mistake use an Accessibility Service to check for Window State Changed, compare the package to a white or black list and use ActivityManager.killBackgroundProcesses to kill if it shouldn't run.

Also check out http://thebitplague.wordpress.com/2013/04/05/kiosk-mode-on-the-nexus-7/ for another way

Starting your app on boot

the BEST way to accomplish this is setting your app as the launcher

<activity ...
  android:launchMode="singleInstance"
  android:windowActionBar="false">
    <intent-filter>
      <action android:name="android.intent.action.MAIN" />
      <category android:name="android.intent.category.HOME" />
      <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>
</activity>

Locking your app

the most reliable way is to use a device with Lollipop or greater and make use of

startLockTask

first you must set your app as the device owner. NB your device must be unprovisioned: if you registered it you should do a factory reset and skip the account registration.

to be able to register your app you must first setup a DeviceAdminReceiver component:

package com.example.myapp;

public class MyDeviceAdminReceiver extends android.app.admin.DeviceAdminReceiver {
    @Override
    public void onEnabled(Context context, Intent intent) {
        Toast.makeText(context, "Device admin permission received", Toast.LENGTH_SHORT).show();
    }

    @Override
    public CharSequence onDisableRequested(Context context, Intent intent) {
        return "are you sure?";
    }

    @Override
    public void onDisabled(Context context, Intent intent) {
        Toast.makeText(context, "Device admin permission revoked", Toast.LENGTH_SHORT).show();
    }


    @Override
    public void onLockTaskModeExiting(Context context, Intent intent) {
        // here you must re-lock your app. make your activity know of this event and make it call startLockTask again!
    }
}

once you have an unprovisioned device you can launch the following command from adb (no root required)

adb shell dpm set-device-owner com.example.myapp/.MyDeviceAdminReceiver

to avoid android asking the user permissions to pin your app you must call setLockTaskPackages

finally!

@Override
public void onResume(){
    super.onResume();
    DevicePolicyManager mDevicePolicyManager = (DevicePolicyManager) getSystemService(
            Context.DEVICE_POLICY_SERVICE);
    ComponentName mAdminComponentName = new ComponentName(getApplicationContext(), MyDeviceAdminReceiver.class);
    mDevicePolicyManager.setLockTaskPackages(mAdminComponentName, new String[]{getPackageName()});
    startLockTask();
}
@Override
public void finish(){
    stopLockTask();
    super.finish();
}