isAnyScreenLayerSecure() Android secure screen detection

isScreenSecure.Java

import org.apache.commons.io.IOUtils;
import se.vidstige.jadb.JadbDevice;
import se.vidstige.jadb.JadbException;

import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.nio.charset.Charset;

private static final int FLAG_SECURE_BITMASK = 0x2000;
private static final int BASE_HEX = 16;

/**
 * Checks whether any layer on screen is secure.
 *
 * @param device An Android Device
 * @return If any layer on screen is secure
 * @throws IOException   If the stream processing fails
 * @throws JadbException If working with the device fails
 * @see <a href="https://stackoverflow.com/a/45952980/2291928">
 * How to query FLAG_SECURE from current APK screen via command line?</a>
 * <p>
 * You can find out if some specific window has the FLAG_SECURE set
 * by checking mAttr line in the {@code dumpsys window <window id>}
 * <p><pre>
 * {@code
 * $ dumpsys window com.android.settings | grep 'mAttrs='
 * > mAttrs=WM.LayoutParams{(0,0)(fillxfill) sim=#20 ty=1 fl=#85810100 pfl=0x20000 wanim=0x103046a vsysui=0x700 needsMenuKey=2}
 * }
 * </pre>
 * <p>
 * The fl= value is the WindowManager.LayoutParams().flags of that window in hex.
 * FLAG_SECURE is a bitmask with the value of 0x2000. This is how you can check it right in the adb shell:
 * {@code for f in $(dumpsys window com.android.settings | grep 'mAttrs=' | grep -o ' fl=#[^ ]*'); do [[ $((16#${f#*#}&8192)) -ne 0 ]] && echo 'FLAG_SECURE is set' || echo 'FLAG_SECURE is not set'; done}
 */
public static boolean isAnyScreenLayerSecure(JadbDevice device) throws IOException, JadbException
{
    InputStream inputStream = device.executeShell("dumpsys window | grep 'mAttrs=' | grep -o ' fl=#[^ ]*'");
    for (String flag : IOUtils.readLines(inputStream, Charset.defaultCharset()))
    {
        flag = flag.split("#")[1];
        BigInteger maskedFlag = new BigInteger(flag, BASE_HEX).and(BigInteger.valueOf(FLAG_SECURE_BITMASK));
        if (!maskedFlag.equals(BigInteger.ZERO))
        {
            return true;
        }
    }
    return false;
}