Qfyilyi

I am trying to make a view in Android which cannot be closed. I mean that all UI system buttons (Home, back, status bar, etc.) are disabled.
Destination way to close app or to open not blocked view is NFC card.

I have been trying to do this for last week and i have no more idea.
Maybe someone of you will know how to do that.
Thanks for any help.

I am able to hide navigation and status bar, but if I swipe from edge of the screen then it appears again.

Most of working things I have found on the developer.android.com and in (GitHub repo).

But still I am able to close app.

Playground code: https://github.com/BoguskiAdam/AndroidNoUiButtons

_________________________

EDIT:

I have seen few applications like that. I want to make it to be
something like in the 'kiosk' mode. User shouldn't be allowed to
minimalize application. He may only use it but he can't go to the
first view. Only I can open first view using NFC card. NFC is
configured to open first view (which is not available for user) which
contains configuration etc and allows me to close app.

_________________________

Manifest

<?xml version="1.0" encoding="utf-8"?>

<manifest

        xmlns:android="http://schemas.android.com/apk/res/android"

        xmlns:tools="http://schemas.android.com/tools"

        package="com.example.adam.nohome">



    <uses-permission android:name="android.permission.REORDER_TASKS"/>



    <application

            android:allowBackup="true"

            android:icon="@mipmap/ic_launcher"

            android:label="@string/app_name"

            android:roundIcon="@mipmap/ic_launcher_round"

            android:supportsRtl="true"

            android:theme="@style/AppTheme"

            tools:ignore="GoogleAppIndexingWarning">

        <activity

                android:name=".MainActivity"

                android:configChanges="orientation|keyboardHidden|screenSize"

                android:label="Test label"

                android:theme="@style/AppTheme.NoActionBar">

            <intent-filter>

                <action android:name="android.intent.action.MAIN"/>

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

            </intent-filter>

        </activity>

        <activity

                android:name=".NoUiActivity"

                android:configChanges="orientation|keyboardHidden|screenSize"

                android:label="Test tittle"

                android:theme="@style/AppTheme.NoActionBar">

            <intent-filter>

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

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

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

            </intent-filter>

        </activity>

    </application>



</manifest>

View XML:

<?xml version="1.0" encoding="utf-8"?>

<android.support.constraint.ConstraintLayout

        xmlns:android="http://schemas.android.com/apk/res/android"

        xmlns:tools="http://schemas.android.com/tools"

        xmlns:app="http://schemas.android.com/apk/res-auto"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:background="#000"

        tools:context=".NoUiActivity">

</android.support.constraint.ConstraintLayout>

View code:

package com.example.adam.nohome



import android.app.ActivityManager

import android.content.Context

import android.content.Intent

import android.graphics.Color

import android.support.v7.app.AppCompatActivity

import android.os.Bundle

import android.os.PersistableBundle

import android.util.Log

import android.view.*



class NoUiActivity : AppCompatActivity() {



    override fun onCreate(savedInstanceState: Bundle?, persistentState: PersistableBundle?) {

        supportActionBar?.setDisplayHomeAsUpEnabled(false)



        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_no_ui)



        hideUi()

    }



    override fun onPause() {

        val activityManager = applicationContext

            .getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager



        activityManager.moveTaskToFront(taskId, 0)

        super.onPause()

    }



    private fun hideUi() {

        window.statusBarColor = Color.TRANSPARENT



        setGestureDetector()

        hideSystemUI()

        setUiListener()

    }



    private fun setGestureDetector() {

        val contentView = window.decorView

        contentView.isClickable = true

        val clickDetector = GestureDetector(this,

            object : GestureDetector.SimpleOnGestureListener() {

                override fun onSingleTapUp(e: MotionEvent): Boolean {

                    hideSystemUI()

                    return true

                }

            }

        )

        contentView.setOnTouchListener { _, motionEvent -> clickDetector.onTouchEvent(motionEvent) }

    }



        private fun hideSystemUI() {

        window.decorView.systemUiVisibility = (

                View.SYSTEM_UI_FLAG_LAYOUT_STABLE

                        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION

                        or View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN

                        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION

                        or View.SYSTEM_UI_FLAG_FULLSCREEN

                        //or View.SYSTEM_UI_FLAG_LOW_PROFILE

                        or View.SYSTEM_UI_FLAG_IMMERSIVE

                )

    }





//    private fun hideSystemUI() {

//        window.decorView.systemUiVisibility = (

//                View.SYSTEM_UI_FLAG_LAYOUT_STABLE

//                        or View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION

//                        or View.SYSTEM_UI_FLAG_HIDE_NAVIGATION

//                        or View.SYSTEM_UI_FLAG_IMMERSIVE

//                )

//    }



    private fun setUiListener() {

        window.decorView.setOnSystemUiVisibilityChangeListener { flags ->

            run {

                supportActionBar?.hide()

                hideSystemUI()

            }

        }

    }



    override fun onOptionsItemSelected(item: MenuItem): Boolean {

        //handle the click on the back arrow click



        val result = when (item.itemId) {

            android.R.id.home -> {

                onBackPressed()

                true

            }



            else -> super.onOptionsItemSelected(item)

        }

        return result

    }





    override fun onWindowFocusChanged(hasFocus: Boolean) {

        super.onWindowFocusChanged(hasFocus)

        hideSystemUI()

    }



    // It recognize here only 'Back' button

    override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {

        if (keyCode == KeyEvent.KEYCODE_BACK || keyCode == KeyEvent.KEYCODE_HOME || keyCode == KeyEvent.KEYCODE_MOVE_HOME) {

            return true;

        }

        return super.onKeyDown(keyCode, event)

    }

}

First view that opens view that cannot be closed:

Second view that shouldn't allow to easily go close app:

Second view after swipe from edge of the screen:

SOLVED: Used Spinned screen / kiosk / Cosu mode. I had additional
problem with allowing NFC but found workaround.
How can I send a string through NFC while Screen-Pinning?

You might want to take a look at

https://developer.android.com/work/cosu

This allows you to lock a single application to the screen, and hide the Home and Recents buttons to prevent users from escaping the app.

Beware that this is only possible if you own the device, you can NOT do this with the phone from your target audience.

These type of things are mainly used used for a single purpose, such as digital signage, ticket printing, point of sale, or inventory management.