From cf4db94885868ef1b35a5f2ad3ef9f7fff428986 Mon Sep 17 00:00:00 2001
From: Jeff Brown <jeffbrown@google.com>
Date: Fri, 3 Sep 2010 10:19:28 -0700
Subject: [PATCH] Add samples for secure views.

Change-Id: Ibe1e63c87f4c6a715009f7bbcdafa552dc2d937c
---
 samples/ApiDemos/AndroidManifest.xml          |   7 +
 samples/ApiDemos/res/layout/secure_view.xml   | 112 ++++++++++++++
 .../res/layout/secure_view_overlay.xml        |  50 ++++++
 samples/ApiDemos/res/values/arrays.xml        |   8 +
 samples/ApiDemos/res/values/strings.xml       |  43 ++++++
 .../example/android/apis/view/SecureView.java | 144 ++++++++++++++++++
 .../android/apis/view/SecureViewOverlay.java  |  74 +++++++++
 7 files changed, 438 insertions(+)
 create mode 100644 samples/ApiDemos/res/layout/secure_view.xml
 create mode 100644 samples/ApiDemos/res/layout/secure_view_overlay.xml
 create mode 100644 samples/ApiDemos/src/com/example/android/apis/view/SecureView.java
 create mode 100644 samples/ApiDemos/src/com/example/android/apis/view/SecureViewOverlay.java

diff --git a/samples/ApiDemos/AndroidManifest.xml b/samples/ApiDemos/AndroidManifest.xml
index f9f423397..aff0373d1 100644
--- a/samples/ApiDemos/AndroidManifest.xml
+++ b/samples/ApiDemos/AndroidManifest.xml
@@ -1450,6 +1450,13 @@
             </intent-filter>
         </activity>
 
+        <activity android:name=".view.SecureView" android:label="Views/Secure View">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.SAMPLE_CODE" />
+            </intent-filter>
+        </activity>
+
         <!-- ************************************* -->
         <!--           GRAPHICS SAMPLES            -->
         <!-- ************************************* -->
diff --git a/samples/ApiDemos/res/layout/secure_view.xml b/samples/ApiDemos/res/layout/secure_view.xml
new file mode 100644
index 000000000..82a1f7938
--- /dev/null
+++ b/samples/ApiDemos/res/layout/secure_view.xml
@@ -0,0 +1,112 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2010 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<!-- Demonstrates secure views. -->
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+    <LinearLayout
+        android:orientation="vertical"
+        android:padding="10dip"
+        android:layout_width="match_parent"
+        android:layout_height="match_parent">
+        <TextView
+            android:id="@+id/secure_view_description"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/secure_view_description"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="10dip"
+            android:textStyle="bold"
+            android:text="@string/secure_view_step1_heading"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/secure_view_step1_detail"/>
+
+        <Button
+            android:id="@+id/secure_view_toast_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:text="@string/secure_view_pop_toast"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="10dip"
+            android:textStyle="bold"
+            android:text="@string/secure_view_step2_heading"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/secure_view_step2_detail"/>
+
+        <Button
+            android:id="@+id/secure_view_unsecure_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:textColor="#833"
+            android:text="@string/secure_view_button"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="10dip"
+            android:textStyle="bold"
+            android:text="@string/secure_view_step3_heading"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/secure_view_step3_detail"/>
+
+        <Button
+            android:id="@+id/secure_view_builtin_secure_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:filterTouchesWhenObscured="true"
+            android:textColor="#833"
+            android:text="@string/secure_view_button"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="10dip"
+            android:textStyle="bold"
+            android:text="@string/secure_view_step4_heading"/>
+
+        <TextView
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="@string/secure_view_step4_detail"/>
+
+        <Button
+            android:id="@+id/secure_view_custom_secure_button"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_gravity="center_horizontal"
+            android:textColor="#833"
+            android:text="@string/secure_view_button"/>
+    </LinearLayout>
+</ScrollView>
diff --git a/samples/ApiDemos/res/layout/secure_view_overlay.xml b/samples/ApiDemos/res/layout/secure_view_overlay.xml
new file mode 100644
index 000000000..aaa043af1
--- /dev/null
+++ b/samples/ApiDemos/res/layout/secure_view_overlay.xml
@@ -0,0 +1,50 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2010 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<!-- An overlay that will appear on top of the secure view in an attempt to obscure
+     its true purpose and encourage the user to click on the secure button. -->
+<com.example.android.apis.view.SecureViewOverlay
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+
+    <TextView
+        android:id="@+id/secure_view_overlay_description"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/secure_view_overlay_description"/>
+
+    <Button
+        android:id="@+id/secure_view_overlay_button1"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="#383"
+        android:text="@string/secure_view_overlay_button1"/>
+
+    <Button
+        android:id="@+id/secure_view_overlay_button2"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="#383"
+        android:text="@string/secure_view_overlay_button2"/>
+
+    <Button
+        android:id="@+id/secure_view_overlay_button3"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:textColor="#383"
+        android:text="@string/secure_view_overlay_button3"/>
+</com.example.android.apis.view.SecureViewOverlay>
diff --git a/samples/ApiDemos/res/values/arrays.xml b/samples/ApiDemos/res/values/arrays.xml
index df918cd62..fb309a888 100644
--- a/samples/ApiDemos/res/values/arrays.xml
+++ b/samples/ApiDemos/res/values/arrays.xml
@@ -94,4 +94,12 @@
         <item>Alphanumeric</item>
     </string-array>
 
+    <!-- Used in view/Secure View examples -->
+    <string-array name="secure_view_clicked">
+        <item>*bzzt*\nTransferred $1,000,000 to J. Phisher.  Thank you!</item>
+        <item>*bzzt*\nSending all life savings to the International Cabal of Evil Penguins.</item>
+        <item>*bzzt*\nOpening portal to R\'lyeh.  Long live Cthulhu!</item>
+        <item>*bzzt*\nYou\'re not very good at this, are you?</item>
+        <item>*bzzt*\nGo away...</item>
+    </string-array>
 </resources>
diff --git a/samples/ApiDemos/res/values/strings.xml b/samples/ApiDemos/res/values/strings.xml
index 4713925ea..1649a9232 100644
--- a/samples/ApiDemos/res/values/strings.xml
+++ b/samples/ApiDemos/res/values/strings.xml
@@ -530,6 +530,49 @@
 
     <string name="ratingbar_rating">Rating:</string>
 
+    <string name="secure_view_description">
+        This activity demonstrates a view that detects when it is potentially obscured
+        by other windows.
+    </string>
+    <string name="secure_view_step1_heading">Click me first:</string>
+    <string name="secure_view_step1_detail">
+        Pop up a toast that will overlay and obscure this window in a poor attempt to fool
+        you into clicking the big red buttons.  Don\'t do it!
+    </string>
+    <string name="secure_view_step2_heading">Unfiltered demo:</string>
+    <string name="secure_view_step2_detail">
+        This button does no filtering.  This button will still work as usual while the
+        toast is visible and is spoofing the view.  Careful!
+    </string>
+    <string name="secure_view_step3_heading">Built-in filtering demo:</string>
+    <string name="secure_view_step3_detail">
+        This button uses the built-in secure touch filtering provided by the framework
+        using the android:filterTouchesWhenObscured attribute.  This button will be inoperable
+        while the toast is visible.
+    </string>
+    <string name="secure_view_step4_heading">Custom filtering demo:</string>
+    <string name="secure_view_step4_detail">
+        This button filters touches using a touch listener to examine the MotionEvent flags
+        and warns the user.  This button will display a message if touched while the
+        toast is visible.
+    </string>
+
+    <string name="secure_view_pop_toast">Pop toast</string>
+    <string name="secure_view_button">Don\'t click!  It\'ll cost you!</string>
+    <string name="secure_view_action_dialog_title">Oh no!</string>
+    <string name="secure_view_action_dialog_dismiss">Oops...</string>
+    <string name="secure_view_caught_dialog_title">Saved!</string>
+    <string name="secure_view_caught_dialog_message">
+        Careful!  There appears to be another window partly obscuring this window...
+        Something unutterably HORRIBLE might have happened.
+    </string>
+    <string name="secure_view_caught_dialog_dismiss">Phew!</string>
+
+    <string name="secure_view_overlay_description">A toast!  A toast!</string>
+    <string name="secure_view_overlay_button1">Totally safe, trust me...</string>
+    <string name="secure_view_overlay_button2">Clicky?</string>
+    <string name="secure_view_overlay_button3">Think of the penguins!</string>
+
     <!-- ============================== -->
     <!--  GoogleLogin examples strings  -->
     <!-- ============================== -->
diff --git a/samples/ApiDemos/src/com/example/android/apis/view/SecureView.java b/samples/ApiDemos/src/com/example/android/apis/view/SecureView.java
new file mode 100644
index 000000000..b9aaeabcd
--- /dev/null
+++ b/samples/ApiDemos/src/com/example/android/apis/view/SecureView.java
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.apis.view;
+
+import com.example.android.apis.R;
+
+import android.app.Activity;
+import android.app.AlertDialog;
+import android.os.Bundle;
+import android.view.Gravity;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.view.View.OnTouchListener;
+import android.widget.Button;
+import android.widget.Toast;
+
+
+/**
+ * This activity demonstrates two different ways in which views can be made more secure to
+ * touch spoofing attacks by leveraging framework features.
+ *
+ * The activity presents 3 buttons that obtensibly perform a risky security critical
+ * function.  Under ordinary circumstances, the user would never click on these buttons
+ * or would at least think long and hard about it.  However, a carefully crafted toast can
+ * overlay the contents of the activity in such a way as to make the user believe the buttons
+ * are innocuous.  Since the toast cannot receive input, the touches are passed down to the
+ * activity potentially yielding an effect other than what the user intended.
+ *
+ * To simulate the spoofing risk, this activity pops up a specially crafted overlay as
+ * a toast layed out so as to cover the buttons and part of the descriptive text.
+ * For the purposes of this demonstration, pretend that the overlay was actually popped
+ * up by a malicious application published by the International Cabal of Evil Penguins.
+ *
+ * The 3 buttons are set up as follows:
+ *
+ * 1. The "unsecured button" does not apply any touch filtering of any kind.
+ *    When the toast appears, this button remains clickable as usual which creates an
+ *    opportunity for spoofing to occur.
+ *
+ * 2. The "built-in secured button" leverages the android:filterTouchesWhenObscured view
+ *    attribute to ask the framework to filter out touches when the window is obscured.
+ *    When the toast appears, the button does not receive the touch and appears to be inoperable.
+ *
+ * 3. The "custom secured button" adds a touch listener to the button which intercepts the
+ *    touch event and checks whether the window is obscured.  If so, it warns the user and
+ *    drops the touch event.  This example is intended to demonstrate how a view can
+ *    perform its own filtering and provide additional feedback by examining the {@MotionEvent}
+ *    flags to determine whether the window is obscured.  Here we use a touch listener but
+ *    a custom view subclass could perform the filtering by overriding
+ *    {@link View#onFilterTouchEventForSecurity(MotionEvent)}.
+ *
+ * Refer to the comments on {@View} for more information about view security.
+ */
+public class SecureView extends Activity {
+    private int mClickCount;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setContentView(R.layout.secure_view);
+
+        Button toastButton = (Button) findViewById(R.id.secure_view_toast_button);
+        toastButton.setOnClickListener(new OnClickListener() {
+            public void onClick(View v) {
+                showOverlay();
+            }
+        });
+
+        Button unsecureButton = (Button) findViewById(R.id.secure_view_unsecure_button);
+        setClickedAction(unsecureButton);
+
+        Button builtinSecureButton = (Button) findViewById(R.id.secure_view_builtin_secure_button);
+        setClickedAction(builtinSecureButton);
+
+        Button customSecureButton = (Button) findViewById(R.id.secure_view_custom_secure_button);
+        setClickedAction(customSecureButton);
+        setTouchFilter(customSecureButton);
+    }
+
+    private void showOverlay() {
+        // Generate a toast view with a special layout that will position itself right
+        // on top of this view's interesting widgets.  Sneaky huh?
+        SecureViewOverlay overlay = (SecureViewOverlay)
+                getLayoutInflater().inflate(R.layout.secure_view_overlay, null);
+        overlay.setActivityToSpoof(this);
+
+        Toast toast = new Toast(getApplicationContext());
+        toast.setGravity(Gravity.FILL, 0, 0);
+        toast.setView(overlay);
+        toast.show();
+    }
+
+    private void setClickedAction(Button button) {
+        button.setOnClickListener(new OnClickListener() {
+            public void onClick(View v) {
+                String[] messages = getResources().getStringArray(R.array.secure_view_clicked);
+                String message = messages[mClickCount++ % messages.length];
+
+                new AlertDialog.Builder(SecureView.this)
+                    .setTitle(R.string.secure_view_action_dialog_title)
+                    .setMessage(message)
+                    .setNeutralButton(getResources().getString(
+                            R.string.secure_view_action_dialog_dismiss), null)
+                    .show();
+            }
+        });
+    }
+
+    private void setTouchFilter(Button button) {
+        button.setOnTouchListener(new OnTouchListener() {
+            public boolean onTouch(View v, MotionEvent event) {
+                if ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) != 0) {
+                    if (event.getAction() == MotionEvent.ACTION_UP) {
+                        new AlertDialog.Builder(SecureView.this)
+                            .setTitle(R.string.secure_view_caught_dialog_title)
+                            .setMessage(R.string.secure_view_caught_dialog_message)
+                            .setNeutralButton(getResources().getString(
+                                    R.string.secure_view_caught_dialog_dismiss), null)
+                            .show();
+                    }
+                    // Return true to prevent the button from processing the touch.
+                    return true;
+                }
+                return false;
+            }
+        });
+    }
+}
diff --git a/samples/ApiDemos/src/com/example/android/apis/view/SecureViewOverlay.java b/samples/ApiDemos/src/com/example/android/apis/view/SecureViewOverlay.java
new file mode 100644
index 000000000..2095fee3f
--- /dev/null
+++ b/samples/ApiDemos/src/com/example/android/apis/view/SecureViewOverlay.java
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.android.apis.view;
+
+import com.example.android.apis.R;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+
+/**
+ * This view is part of the {@link SecureView} demonstration activity.
+ *
+ * This view is constructed in such a way as to obscure the buttons and descriptive
+ * text of the activity in a poor attempt to fool the user into clicking on the buttons
+ * despite the activity telling the user that they may be harmful.
+ */
+public class SecureViewOverlay extends ViewGroup {
+    private SecureView mActivity;
+
+    public SecureViewOverlay(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public void setActivityToSpoof(SecureView activity) {
+        this.mActivity = activity;
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        measureChildren(widthMeasureSpec, heightMeasureSpec);
+
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        spoofLayout(findViewById(R.id.secure_view_overlay_description),
+                mActivity.findViewById(R.id.secure_view_description));
+        spoofLayout(findViewById(R.id.secure_view_overlay_button1),
+                mActivity.findViewById(R.id.secure_view_unsecure_button));
+        spoofLayout(findViewById(R.id.secure_view_overlay_button2),
+                mActivity.findViewById(R.id.secure_view_builtin_secure_button));
+        spoofLayout(findViewById(R.id.secure_view_overlay_button3),
+                mActivity.findViewById(R.id.secure_view_custom_secure_button));
+    }
+
+    private void spoofLayout(View spoof, View original) {
+        final int[] globalPos = new int[2];
+        getLocationOnScreen(globalPos);
+        int x = globalPos[0];
+        int y = globalPos[1];
+
+        original.getLocationOnScreen(globalPos);
+        x = globalPos[0] - x;
+        y = globalPos[1] - y;
+        spoof.layout(x, y, x + original.getWidth(), y + original.getHeight());
+    }
+}