Replacing accessibility service permissions with capability attributes.

Accessibility services can perform special operations such as retrieve
the screen content, enable explore by touch, etc. To ensure the user
is aware that the service will perform special operations we were using
permissions. However, the special operations cannot be performed unless
the service is really enabled by the user and it is at this point that
we want to notify the user about the service capabilities.

This change adds the list of the service capabilities to the enable
warining dialog such that the user can asses whether to he/she is fine
with this service performing certain special operations.

Main change:https://googleplex-android-review.googlesource.com/#/c/298110/

bug:8633951

Change-Id: I1617fa82126b9a674cb74a15d7004a7cc007c7d3

res/layout/enable_accessibility_service_dialog_content.xml

@@ -0,0 +1,45 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2013 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.
+-->
+
+<ScrollView
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:scrollbarStyle="outsideOverlay"
+    android:gravity="top">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        android:paddingStart="16dip"
+        android:paddingEnd="16dip" >
+
+        <TextView android:id="@+id/capabilities_header"
+            android:layout_width="fill_parent"
+            android:layout_height="wrap_content"
+            android:padding="10dip"
+            android:textAppearance="?android:attr/textAppearanceMedium" />
+
+        <LinearLayout android:id="@+id/capabilities"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:orientation="vertical"
+            android:padding="10dip" />
+
+    </LinearLayout>
+
+</ScrollView>

res/values/strings.xml

@@ -3177,30 +3177,24 @@
     <!-- Summary for the disabled state of an accessiblity feature. [CHAR LIMIT=10] -->
     <string name="accessibility_feature_state_off">Off</string>
 
-     <!-- Title for a warning message about security implications of enabling an accessibility service,
+    <!-- Title for a warning about security implications of enabling an accessibility
-         displayed as a dialog message when the user selects to enable an accessibility service (tablet). [CHAR LIMIT=NONE] -->
+         service. [CHAR LIMIT=NONE] -->
-    <string name="accessibility_service_security_warning_title">Use
+    <string name="enable_service_title">Use
          <xliff:g id="service" example="TalkBack">%1$s</xliff:g>?</string>
-    <!-- Summary for a warning message about security implications of enabling an accessibility service,
+    <!-- Title for the list of capabilities of an accessibility service. -->
-         displayed as a dialog message when the user selects to enable an accessibility service (tablet). [CHAR LIMIT=NONE] -->
+    <string name="capabilities_list_title"><xliff:g id="service" example="TalkBack">%1$s</xliff:g>
-    <string name="accessibility_service_security_warning_summary" product="tablet">
+        needs to:</string>
-            <xliff:g id="accessibility_service_name">%1$s</xliff:g> can
-            collect all of the text you type, except passwords. This includes personal data such as credit card
-            numbers. It can also collect data about your interactions with the tablet.</string>
-    <!-- Summary for a warning message about security implications of enabling an accessibility service,
-         displayed as a dialog message when the user selects to enable an accessibility service (phone). [CHAR LIMIT=NONE] -->
-    <string name="accessibility_service_security_warning_summary" product="default">
-            <xliff:g id="accessibility_service_name">%1$s</xliff:g> can
-            collect all of the text you type, except passwords. This includes personal data such as credit card
-            numbers. It can also collect data about your interactions with the phone.</string>
 
-    <!-- Title for a warning about disabling an accessibility service displayed as a dialog message when the user
+    <!-- Title for the capability of an accessibility service to receive events and keys. -->
-         selects to disable that service. This avoids accidental disabling. [CHAR LIMIT=NONE] -->
+    <string name="capability_title_receiveAccessibilityEvents">Observe your actions</string>
-    <string name="accessibility_service_disable_warning_title">Stop
+    <!-- Description for the capability of an accessibility service to receive events and keys. -->
-         <xliff:g id="service" example="TalkBack">%1$s</xliff:g>?</string>
+    <string name="capability_desc_receiveAccessibilityEvents">Receive notifications when you\'re
-    <!-- Summary for a warning about disabling accessibility service displayed as a dialog message when the user
+        interacting with an app.</string>
-         selects to disable that service. This avoids accidental disabling. [CHAR LIMIT=NONE] -->
+
-    <string name="accessibility_service_disable_warning_summary">Touching OK will
+    <!-- Title for a warning about disabling an accessibility service. [CHAR LIMIT=NONE] -->
+    <string name="disable_service_title">Stop<xliff:g id="service" example="TalkBack">%1$s</xliff:g>?</string>
+    <!-- Message for a warning about disabling accessibility service. [CHAR LIMIT=NONE] -->
+    <string name="disable_service_message">Touching OK will
         stop <xliff:g id="service" example="TalkBack">%1$s</xliff:g>.</string>
 
     <!-- Title for the prompt shown as a placeholder if no accessibility serivices are installed. [CHAR LIMIT=50] -->

src/com/android/settings/AccessibilitySettings.java

@@ -50,12 +50,14 @@ import android.text.TextUtils.SimpleStringSplitter;
 import android.view.Gravity;
 import android.view.KeyCharacterMap;
 import android.view.KeyEvent;
+import android.view.LayoutInflater;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
 import android.view.accessibility.AccessibilityEvent;
 import android.view.accessibility.AccessibilityManager;
+import android.widget.ImageView;
 import android.widget.LinearLayout;
 import android.widget.Switch;
 import android.widget.TextView;
@@ -118,13 +120,9 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
     private static final String EXTRA_CHECKED = "checked";
     private static final String EXTRA_TITLE = "title";
     private static final String EXTRA_SUMMARY = "summary";
-    private static final String EXTRA_ENABLE_WARNING_TITLE = "enable_warning_title";
-    private static final String EXTRA_ENABLE_WARNING_MESSAGE = "enable_warning_message";
-    private static final String EXTRA_DISABLE_WARNING_TITLE = "disable_warning_title";
-    private static final String EXTRA_DISABLE_WARNING_MESSAGE = "disable_warning_message";
     private static final String EXTRA_SETTINGS_TITLE = "settings_title";
     private static final String EXTRA_SETTINGS_COMPONENT_NAME = "settings_component_name";
-    private static final String EXTRA_SERVICE_COMPONENT_NAME = "service_component_name";
+    private static final String EXTRA_ACCESSIBILITY_SERVICE_INFO = "accessibility_service_info";
 
     // Dialog IDs.
     private static final int DIALOG_ID_NO_ACCESSIBILITY_SERVICES = 1;
@@ -409,20 +407,6 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
             }
             extras.putString(EXTRA_SUMMARY, description);
 
-            CharSequence applicationLabel = info.getResolveInfo().loadLabel(getPackageManager());
-
-            extras.putString(EXTRA_ENABLE_WARNING_TITLE, getString(
-                    R.string.accessibility_service_security_warning_title, applicationLabel));
-            extras.putString(EXTRA_ENABLE_WARNING_MESSAGE, getString(
-                    R.string.accessibility_service_security_warning_summary, applicationLabel));
-
-            extras.putString(EXTRA_DISABLE_WARNING_TITLE, getString(
-                    R.string.accessibility_service_disable_warning_title,
-                    applicationLabel));
-            extras.putString(EXTRA_DISABLE_WARNING_MESSAGE, getString(
-                    R.string.accessibility_service_disable_warning_summary,
-                    applicationLabel));
-
             String settingsClassName = info.getSettingsActivityName();
             if (!TextUtils.isEmpty(settingsClassName)) {
                 extras.putString(EXTRA_SETTINGS_TITLE,
@@ -432,7 +416,7 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                                 settingsClassName).flattenToString());
             }
 
-            extras.putString(EXTRA_SERVICE_COMPONENT_NAME, componentName.flattenToString());
+            extras.putParcelable(EXTRA_ACCESSIBILITY_SERVICE_INFO, info);
 
             mServicesCategory.addPreference(preference);
         }
@@ -698,10 +682,7 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
             }
         };
 
-        private CharSequence mEnableWarningTitle;
+        private AccessibilityServiceInfo mAccessibilityServiceInfo;
-        private CharSequence mEnableWarningMessage;
-        private CharSequence mDisableWarningTitle;
-        private CharSequence mDisableWarningMessage;
 
         private String mComponentName;
 
@@ -767,32 +748,113 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                     Settings.Secure.ACCESSIBILITY_ENABLED, accessibilityEnabled ? 1 : 0);
         }
 
+//        extras.putString(EXTRA_ENABLE_WARNING_TITLE, getString(
+//                R.string.accessibility_service_security_warning_title, applicationLabel));
+//        extras.putString(EXTRA_ENABLE_WARNING_MESSAGE, getString(
+//                R.string.accessibility_service_security_warning_summary, applicationLabel));
+//
+//        extras.putString(EXTRA_DISABLE_WARNING_TITLE, getString(
+//                R.string.accessibility_service_disable_warning_title,
+//                applicationLabel));
+//        extras.putString(EXTRA_DISABLE_WARNING_MESSAGE, getString(
+//                R.string.accessibility_service_disable_warning_summary,
+//                applicationLabel));
+
         @Override
         public Dialog onCreateDialog(int dialogId) {
-            CharSequence title = null;
-            CharSequence message = null;
             switch (dialogId) {
                 case DIALOG_ID_ENABLE_WARNING:
                     mShownDialogId = DIALOG_ID_ENABLE_WARNING;
-                    title = mEnableWarningTitle;
+                    return new AlertDialog.Builder(getActivity())
-                    message = mEnableWarningMessage;
+                        .setTitle(getString(R.string.enable_service_title,
-                    break;
+                                mAccessibilityServiceInfo.getResolveInfo()
+                                .loadLabel(getPackageManager())))
+                        .setIconAttribute(android.R.attr.alertDialogIcon)
+                        .setView(createEnableDialogContentView())
+                        .setCancelable(true)
+                        .setPositiveButton(android.R.string.ok, this)
+                        .setNegativeButton(android.R.string.cancel, this)
+                        .create();
                 case DIALOG_ID_DISABLE_WARNING:
                     mShownDialogId = DIALOG_ID_DISABLE_WARNING;
-                    title = mDisableWarningTitle;
+                    return new AlertDialog.Builder(getActivity())
-                    message = mDisableWarningMessage;
+                        .setTitle(getString(R.string.disable_service_title,
-                    break;
+                                mAccessibilityServiceInfo.getResolveInfo()
+                                .loadLabel(getPackageManager())))
+                        .setIconAttribute(android.R.attr.alertDialogIcon)
+                        .setMessage(getString(R.string.disable_service_message,
+                                mAccessibilityServiceInfo.getResolveInfo()
+                                .loadLabel(getPackageManager())))
+                        .setCancelable(true)
+                        .setPositiveButton(android.R.string.ok, this)
+                        .setNegativeButton(android.R.string.cancel, this)
+                        .create();
                 default:
                     throw new IllegalArgumentException();
             }
-            return new AlertDialog.Builder(getActivity())
+        }
-                    .setTitle(title)
+
-                    .setIconAttribute(android.R.attr.alertDialogIcon)
+        private View createEnableDialogContentView() {
-                    .setMessage(message)
+            LayoutInflater inflater = (LayoutInflater) getSystemService(
-                    .setCancelable(true)
+                    Context.LAYOUT_INFLATER_SERVICE);
-                    .setPositiveButton(android.R.string.ok, this)
+
-                    .setNegativeButton(android.R.string.cancel, this)
+            View content = inflater.inflate(R.layout.enable_accessibility_service_dialog_content,
-                    .create();
+                    null);
+
+            TextView capabilitiesHeaderView = (TextView) content.findViewById(
+                    R.id.capabilities_header);
+            capabilitiesHeaderView.setText(getString(R.string.capabilities_list_title,
+                    mAccessibilityServiceInfo.getResolveInfo().loadLabel(getPackageManager())));
+
+            LinearLayout capabilitiesView = (LinearLayout) content.findViewById(R.id.capabilities);
+
+            // This capability is implicit for all services.
+            View capabilityView = inflater.inflate(
+                    com.android.internal.R.layout.app_permission_item_old, null);
+
+            ImageView imageView = (ImageView) capabilityView.findViewById(
+                    com.android.internal.R.id.perm_icon);
+            imageView.setImageDrawable(getResources().getDrawable(
+                    com.android.internal.R.drawable.ic_text_dot));
+
+            TextView labelView = (TextView) capabilityView.findViewById(
+                    com.android.internal.R.id.permission_group);
+            labelView.setText(getString(R.string.capability_title_receiveAccessibilityEvents));
+
+            TextView descriptionView = (TextView) capabilityView.findViewById(
+                    com.android.internal.R.id.permission_list);
+            descriptionView.setText(getString(R.string.capability_desc_receiveAccessibilityEvents));
+
+            List<AccessibilityServiceInfo.CapabilityInfo> capabilities =
+                    mAccessibilityServiceInfo.getCapabilityInfos();
+
+            capabilitiesView.addView(capabilityView);
+
+            // Service specific capabilities.
+            final int capabilityCount = capabilities.size();
+            for (int i = 0; i < capabilityCount; i++) {
+                AccessibilityServiceInfo.CapabilityInfo capability = capabilities.get(i);
+
+                capabilityView = inflater.inflate(
+                        com.android.internal.R.layout.app_permission_item_old, null);
+
+                imageView = (ImageView) capabilityView.findViewById(
+                        com.android.internal.R.id.perm_icon);
+                imageView.setImageDrawable(getResources().getDrawable(
+                        com.android.internal.R.drawable.ic_text_dot));
+
+                labelView = (TextView) capabilityView.findViewById(
+                        com.android.internal.R.id.permission_group);
+                labelView.setText(getString(capability.titleResId));
+
+                descriptionView = (TextView) capabilityView.findViewById(
+                        com.android.internal.R.id.permission_list);
+                descriptionView.setText(getString(capability.descResId));
+
+                capabilitiesView.addView(capabilityView);
+            }
+
+            return content;
         }
 
         @Override
@@ -823,23 +885,15 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                 @Override
                 public boolean onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked) {
                     if (checked) {
-                        if (!TextUtils.isEmpty(mEnableWarningMessage)) {
+                        toggleSwitch.setCheckedInternal(false);
-                            toggleSwitch.setCheckedInternal(false);
+                        getArguments().putBoolean(EXTRA_CHECKED, false);
-                            getArguments().putBoolean(EXTRA_CHECKED, false);
+                        showDialog(DIALOG_ID_ENABLE_WARNING);
-                            showDialog(DIALOG_ID_ENABLE_WARNING);
-                            return true;
-                        }
-                        onPreferenceToggled(mPreferenceKey, true);
                     } else {
-                        if (!TextUtils.isEmpty(mDisableWarningMessage)) {
+                        toggleSwitch.setCheckedInternal(true);
-                            toggleSwitch.setCheckedInternal(true);
+                        getArguments().putBoolean(EXTRA_CHECKED, true);
-                            getArguments().putBoolean(EXTRA_CHECKED, true);
+                        showDialog(DIALOG_ID_DISABLE_WARNING);
-                            showDialog(DIALOG_ID_DISABLE_WARNING);
-                            return true;
-                        }
-                        onPreferenceToggled(mPreferenceKey, false);
                     }
-                    return false;
+                    return true;
                 }
             });
         }
@@ -859,20 +913,12 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                     setHasOptionsMenu(true);
                 }
             }
-            // Enable warning title.
+
-            mEnableWarningTitle = arguments.getCharSequence(
+            mAccessibilityServiceInfo = arguments.getParcelable(EXTRA_ACCESSIBILITY_SERVICE_INFO);
-                    AccessibilitySettings.EXTRA_ENABLE_WARNING_TITLE);
+
-            // Enable warning message.
+            ServiceInfo serviceInfo = mAccessibilityServiceInfo.getResolveInfo().serviceInfo;
-            mEnableWarningMessage = arguments.getCharSequence(
+            mComponentName = new ComponentName(serviceInfo.packageName,
-                    AccessibilitySettings.EXTRA_ENABLE_WARNING_MESSAGE);
+                    serviceInfo.name).flattenToString();
-            // Disable warning title.
-            mDisableWarningTitle = arguments.getString(
-                    AccessibilitySettings.EXTRA_DISABLE_WARNING_TITLE);
-            // Disable warning message.
-            mDisableWarningMessage = arguments.getString(
-                    AccessibilitySettings.EXTRA_DISABLE_WARNING_MESSAGE);
-            // Component name.
-            mComponentName = arguments.getString(EXTRA_SERVICE_COMPONENT_NAME);
         }
     }