Adding SecureTouchListener to drop suspicious touches

package com.android.settingslib;

import android.os.SystemClock;

import android.view.MotionEvent;

import android.view.View;

import android.widget.Toast;

/**

 * A touch listener which consumes touches when another window is partly or wholly obscuring the

 * window containing the view this listener is attached to.

 * Optionally accepts a string to show the user as a toast when consuming an insecure touch

 */

public class SecureTouchListener implements View.OnTouchListener {

    private static final long TAP_DEBOUNCE_TIME = 2000;

    private long mLastToastTime = 0;

    private String mWarningText;

    public SecureTouchListener() {

        this(null);

    }

    public SecureTouchListener(String warningText) {

        mWarningText = warningText;

    }

    @Override

    public boolean onTouch(View v, MotionEvent event) {

        if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) != 0

                || (event.getFlags() & MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED) != 0) {

            if (mWarningText != null) {

                // Show a toast warning the user

                final long currentTime = SystemClock.uptimeMillis();

                if (currentTime - mLastToastTime > TAP_DEBOUNCE_TIME) {

                    mLastToastTime = currentTime;

                    Toast.makeText(v.getContext(), mWarningText, Toast.LENGTH_SHORT).show();

                }

            }

            // Consume the touch event

            return true;

        }

        return false;

    }

}