1 /*
2  * Copyright (C) 2016 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package com.android.packageinstaller.permission.ui;
18 
19 import android.content.Context;
20 import android.util.AttributeSet;
21 import android.view.MotionEvent;
22 import android.widget.Button;
23 
24 /**
25  * Extension of Button that uses the hidden MotionEvent flag for partially obscured windows to
26  * prevent tapjacking attacks.
27  */
28 public class SecureButtonView extends Button {
29 
SecureButtonView(Context context)30     public SecureButtonView(Context context) {
31         this(context, null);
32     }
33 
SecureButtonView(Context context, AttributeSet attrs)34     public SecureButtonView(Context context, AttributeSet attrs) {
35         this(context, attrs, 0);
36     }
37 
SecureButtonView(Context context, AttributeSet attrs, int defStyleAttr)38     public SecureButtonView(Context context, AttributeSet attrs, int defStyleAttr) {
39         this(context, attrs, defStyleAttr, 0);
40     }
41 
SecureButtonView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)42     public SecureButtonView(Context context, AttributeSet attrs, int defStyleAttr,
43             int defStyleRes) {
44         super(context, attrs, defStyleAttr, defStyleRes);
45     }
46 
47     @Override
onFilterTouchEventForSecurity(MotionEvent event)48     public boolean onFilterTouchEventForSecurity(MotionEvent event) {
49         if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) != 0
50                 || (event.getFlags() & MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED) != 0) {
51             // Window is obscured, drop this touch.
52             return false;
53         }
54         return true;
55     }
56 }
57