I'm writing an anti theft app, and I want when sim card is changed a dialog opens on boot and tell the finder to bring back the phone. This activity must be unleavable, so he can't leave it unless the correct code is entered.
Other situation is when user send a lock SMS to the phone.
I know how a device admin can lock the phone, but lock don't tell the message and the password can't be entered. And lock may not have a password or pattern so the finder can pass it easily.
Maybe a combination of device lock and a full screen activity which disable the keyguard do the job?
In my research, without being installed at the OEM level, you can't make it 100% un-leavable, just really annoying.
In an app I wrote for businesses which use a kiosk, since we weren't at the OEM level, we just kept the menu bar hidden and set the app to be loaded whenever Home was hit. Keeping the menu bar hidden was a pain, but was achieved by making it invisible and then when re-triggered, making it go away after 1 second. It's still able to be exited by hitting the clock in that 1 second, though. :(
Related
iam developing screenlock app for android using a React Native and a little annoyed with the screen pinned dialog that always appears, is there a way to just get rid of it? so what I really want is no dialogue interaction at all with the user
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If you're calling startLockTask() and your device isn't set up as a dedicated device with your app whitelisted, then no you can't prevent it:
Otherwise, the current task will be launched into screen pinning mode. In this case, the system will prompt the user with a dialog requesting permission to use this mode. The user can exit at any time through instructions shown on the request dialog.
The dialog is there to help users understand what's happening, give permission for the app to take over their screen, and know how to get out of it later. It's baked into Android by design, so malicious apps can't cause problems - it's just a limitation you have to deal with, unless you're working with a dedicated device (which can be set up to give apps more control and users less)
Have you thought about immersive mode instead, where you hide the nav bar? The user can get out of that too by swiping to reveal the controls, but it's less intrusive. There's no way to automatically lock the user's screen with no interaction though
I have the following problem.
I'm trying to make an app that locks the screen. The method via DevicePolicyManager works very well. So far so good. But when I lock my phone with DPM the fingerprint unlocking method is disabling and I have to enter my pattern (or PIN or whatever I set) to unlock the phone. If I lock it the normal way (ie with power button) the fingerprint unlocking works.
So my question is
How to lock the screen programmatically and be able to unlock it afterwards via fingerprint?
PS: I have an galaxy s5 mini with marshmallow lineage os
That is the normal flow. It takes the device to restarted state where the device will ask for a pattern or password. Google have not provided any api for this. You can check any app in PlayStore which has locking feature will behave like this.
Edited:
For the below queries you have asked response is shared here
How can a user lock his phone without using the power button (through an app for example) and still be able to unlock it using fingerprint?
There's intentionally no API for apps to call to lock the device.
Is there a security reason/concern around this?
Yes, there's a DOS (denial of service) concern if we allow apps to lock the device. Either intentional or accidental (app bug).
Found it here[https://code.google.com/p/android/issues/detail?id=79735#c115]
I think you need to search for how to lock with app shortcut and not with power button. Atleast I could help to this level.
Notice how the apex launcher or nova launcher got it way around. screen lock through apex launcher or nova launcher doesn't disable fingerprint scanner!
What it actually does is that it sets the screen to complete black i.e. soft lock (which gives user a false impression of screen off) and then after 5-10 seconds the display actually goes off due to time-out.
other app which implemented the same functionality OFF+ (Screen Off / Fingerprint unlock support).（I guess it modifys "lock screen timeout"）
If the phone is rooted then a shell command can be executed to simulate the power key su input keyevent 26 but there might be a fraction of delay.
well, if some root user is looking, there's also a xposed module which solves this issue FingerprintEnabler
I would like to add some points to the JerryGoyal's excellent answer.
Below is the screenshot from Microsoft Launcher which shows the two ways to lock the screen. It clearly states that the method via Device Policy Manager will not work with fingerprint.
A work around is done by showing a black screen until the screen times out.
In the next screen it asks for permission to Modify system settings to alter the screen timeout period.
From https://issuetracker.google.com/issues/37010802#comment148 (posted Aug 9, 2018 08:26AM):
Android 9 finally added a solution for this (or a workaround, it
depends on how you look at it). A new AccessibilityService global
action was added for locking the device [1], [2]. Nova Launcher
already has a screen lock method using this service action in the
latest beta, and it allows for locking the device and keeping
fingerprint unlock and SmartLock working.
What sucks, though, is that users of your app have to enable the
accessibility service for your app. And having any accessibility
service enabled breaks Snackbar animation [3] (it no longer slides on
the screen, it just appears there without any animation).
[1] https://developer.android.com/about/versions/pie/android-9.0#a11y-convenience-actions
[2] https://developer.android.com/reference/android/accessibilityservice/AccessibilityService#GLOBAL_ACTION_LOCK_SCREEN
[3] https://issuetracker.google.com/issues/37092972
I installed an app on my android phone to safe lock certain apps with a password. Since I installed it, sometimes, regardless what i'm doing on the phone/which app i'm using, a full size screen with advertising appears and I have to click an "X" to close it or press back/home button.
(Can be that this screen appears randomly only when I digited a password to unlock an app therefore the safe lock app was active let's say, not sure.)
I was anyway wondering what sort of code is used for this? Anyone?
I'd need it for a less despicable cause: in order to show a transparent view with alertdialog when my timer is up and the app is closed, to imitate the original builtin countdown timer.
I am searching for a way to unlock the device permanently from an app launch. The concept is that I plug in a device via usb to the tablet/phone and the screen unlocks (this is working) and after I exit the app I want the device to return to them home screen. But the thing is that it returns to the lock screen instead of the home screen. Is there a way to do this?
The main idea behind this is to keep the user away from inserting the unlock code multiple times, for no apparent reason.
I'm trying to start an app upon the first boot of the device before the keyguard appears. I need to ensure the first thing the user sees after the boot animation (which I've also changed) is this app. My app is just three screens of text in fullscreen mode with a next button in between them.
I realize that for most cases, this would be a terrible user experience. However, the phones we're shipping have a very specific purpose and because of this I need to meet the following criteria:
my app needs to be the first thing the user sees (after the boot animation of course) when they take the phone out of the box and power it on for the first time.
after the first boot, the phone should function as normal (i.e the keyguard should appear upon bootup instead of my app).
this only needs to work for lollipop since that's the android version we're shipping.
I can modify the Android framework if needed, but a solution where I don't have to is preferred.
My (Failed) Approach
Create an app that starts upon boot. Have the app dismiss the keyguard as the first thing it does.
The problem I found with this approach is the keyguard code is called before the app initialization code so the user sees the keyguard briefly and then sees my app.
A Possible Solution
I think the best way to do this is to add code in the framework to call my app before calling the keyguard. I'm imagining having a boolean that's used to keep track of whether it's the first time the device is powered on. If that boolean is true, open the app. If not, open the keyguard.
The problem is there's a lot of code in the android userspace boot process and I have a quickly-approaching deadline (don't we all?). How can I modify the framework code to show my app before the keyguard?
If there's a better way, please let me know that too!