android determine if device is in right to left language/layout

Kotlin Code for detect app layout direction :

 val config = resources.configuration
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
        if (config.layoutDirection == View.LAYOUT_DIRECTION_LTR) {
           // showAlertMsg("LTR")
        } else {
           // showAlertMsg( "RTL")
        }
    }
    else {
        //TODO("VERSION.SDK_INT < JELLY_BEAN_MR1")
           }

Gr, a little bit longer googling and I would have found it before posting:

if (ViewCompat.getLayoutDirection(getView()) == ViewCompat.LAYOUT_DIRECTION_LTR) {
    // ...
}
else {
    // ...
}

http://developer.android.com/reference/android/support/v4/view/ViewCompat.html#getLayoutDirection(android.view.View)

I think this is a better way:

val isLeftToRight = TextUtilsCompat.getLayoutDirectionFromLocale(Locale.getDefault()) == ViewCompat.LAYOUT_DIRECTION_LTR

Docs:

https://developer.android.com/reference/android/support/v4/text/TextUtilsCompat.html#getLayoutDirectionFromLocale(java.util.Locale)

Or, if you have minAPI 17 or above, you can just use this:

val isLeftToRight=TextUtils.getLayoutDirectionFromLocale(Locale.getDefault())==View.LAYOUT_DIRECTION_LTR

Docs:

https://developer.android.com/reference/android/text/TextUtils.html#getLayoutDirectionFromLocale(java.util.Locale)

You could create a values-ldrtl folder with a xml file called isrighttoleft.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <bool name="is_right_to_left">true</bool>
</resources>

and in your values folder the same file with:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <bool name="is_right_to_left">false</bool>
</resources>

And finally in Code:

boolean isRightToLeft = getResources().getBoolean(R.bool.is_right_to_left);

The values-ldrtl will only be used on a device where the specific settings (e. g. Language) are right-to-left-read languages.