How to restrict tablet screen orientation

Question

I want to restrict my tablet to launch at specific screen orientation like landscape? I'm taking here about the whole tablet not a specific app, and for sure I'm not taking about locking off the Auto Rotate in the tablet after it launches, I'm taking about restricting the tablet to launch at landscape/protrait.

Answer 1

found the answer, an app that will run just one time.

create an app and add a permission to it's manifest to write_settings & listen-to-boot :

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

then make a receiver class which extends BroadcastReceivertype, with the fowlloing permissions:

    <receiver android:enabled="true" android:exported="true" 
        android:name="com.example.BootCompletedReceiver"
        android:permission="android.permission.RECEIVE_BOOT_COMPLETED">
        <intent-filter>
                <action android:name="android.intent.action.BOOT_COMPLETED" />
                <action android:name="android.intent.action.QUICKBOOT_POWERON" />
                <category android:name="android.intent.category.DEFAULT" />
        </intent-filter>
    </receiver>

then in the onReceive() method of the receiver class:

ContentResolver contentResolver = context.getContentResolver();
        //To handle device rotation 
        Settings.System.putInt(contentResolver, Settings.System.ACCELEROMETER_ROTATION, 0);
        Settings.System.putInt(contentResolver, Settings.System.USER_ROTATION, Surface.ROTATION_90); // 0 for default, then 90, 180, 270

Then run this app just one time to write that permissions to the system, and then you don't need it again.