Settings for the screen magnification feature.

1. Screen magnification on the device has to he explicitly enabled
   by the user before allowing a global gesture related interactions.
   The feature toggle setting is in Settings->Accessibility and it
   is a separate screen with instructions how to use the feature
   and a toggle switch.

2. Added a setting in developer options for toggling the magnification
   auto update feature. If this features is on the screen is zoomed
   out or rotation or activity start. Also if the feature is enabled
   the magnified viewport will scroll to show popped up windows.

bug:5587727

Change-Id: Ic45a21d3a3928e2f5aac034751801f090b261488

1 files changed, 256 insertions, 182 deletions

diff --git a/src/com/android/settings/AccessibilitySettings.java b/src/com/android/settings/AccessibilitySettings.java
index 4047555..592706c 100644
--- a/src/com/android/settings/AccessibilitySettings.java
+++ b/src/com/android/settings/AccessibilitySettings.java
@@ -30,7 +30,6 @@ import android.content.SharedPreferences;
 import android.content.pm.ResolveInfo;
 import android.content.pm.ServiceInfo;
 import android.content.res.Configuration;
-import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
@@ -75,38 +74,42 @@ import java.util.Set;
 public class AccessibilitySettings extends SettingsPreferenceFragment implements DialogCreatable,
         Preference.OnPreferenceChangeListener {
     private static final String DEFAULT_SCREENREADER_MARKET_LINK =
-        "market://search?q=pname:com.google.android.marvin.talkback";
+            "market://search?q=pname:com.google.android.marvin.talkback";
 
     private static final float LARGE_FONT_SCALE = 1.3f;
 
     private static final String SYSTEM_PROPERTY_MARKET_URL = "ro.screenreader.market";
 
     // Timeout before we update the services if packages are added/removed since
-    // the AccessibilityManagerService has to do that processing first to generate
+    // the AccessibilityManagerService has to do that processing first to
+    // generate
     // the AccessibilityServiceInfo we need for proper presentation.
     private static final long DELAY_UPDATE_SERVICES_MILLIS = 1000;
 
     private static final char ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR = ':';
 
     private static final String KEY_INSTALL_ACCESSIBILITY_SERVICE_OFFERED_ONCE =
-        "key_install_accessibility_service_offered_once";
+            "key_install_accessibility_service_offered_once";
 
     // Preference categories
     private static final String SERVICES_CATEGORY = "services_category";
     private static final String SYSTEM_CATEGORY = "system_category";
 
     // Preferences
-    private static final String TOGGLE_LARGE_TEXT_PREFERENCE = "toggle_large_text_preference";
+    private static final String TOGGLE_LARGE_TEXT_PREFERENCE =
+            "toggle_large_text_preference";
     private static final String TOGGLE_POWER_BUTTON_ENDS_CALL_PREFERENCE =
-        "toggle_power_button_ends_call_preference";
+            "toggle_power_button_ends_call_preference";
     private static final String TOGGLE_LOCK_SCREEN_ROTATION_PREFERENCE =
-        "toggle_lock_screen_rotation_preference";
+            "toggle_lock_screen_rotation_preference";
     private static final String TOGGLE_SPEAK_PASSWORD_PREFERENCE =
-        "toggle_speak_password_preference";
+            "toggle_speak_password_preference";
     private static final String SELECT_LONG_PRESS_TIMEOUT_PREFERENCE =
-        "select_long_press_timeout_preference";
+            "select_long_press_timeout_preference";
     private static final String TOGGLE_SCRIPT_INJECTION_PREFERENCE =
-        "toggle_script_injection_preference";
+            "toggle_script_injection_preference";
+    private static final String DISPLAY_MAGNIFICATION_PREFERENCE_SCREEN =
+            "screen_magnification_preference_screen";
 
     // Extras passed to sub-fragments.
     private static final String EXTRA_PREFERENCE_KEY = "preference_key";
@@ -125,12 +128,12 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
 
     // Auxiliary members.
     private final static SimpleStringSplitter sStringColonSplitter =
-        new SimpleStringSplitter(ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR);
+            new SimpleStringSplitter(ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR);
 
     private static final Set<ComponentName> sInstalledServices = new HashSet<ComponentName>();
 
     private final Map<String, String> mLongPressTimeoutValuetoTitleMap =
-        new HashMap<String, String>();
+            new HashMap<String, String>();
 
     private final Configuration mCurConfig = new Configuration();
 
@@ -147,11 +150,11 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
 
     private final RotationPolicy.RotationPolicyListener mRotationPolicyListener =
             new RotationPolicy.RotationPolicyListener() {
-        @Override
-        public void onChange() {
-            updateLockScreenRotationCheckbox();
-        }
-    };
+                @Override
+                public void onChange() {
+                    updateLockScreenRotationCheckbox();
+                }
+            };
 
     // Preference controls.
     private PreferenceCategory mServicesCategory;
@@ -164,6 +167,7 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
     private ListPreference mSelectLongPressTimeoutPreference;
     private AccessibilityEnableScriptInjectionPreference mToggleScriptInjectionPreference;
     private Preference mNoServicesMessagePreference;
+    private PreferenceScreen mDisplayMagnificationPreferenceScreen;
 
     private int mLongPressTimeoutDefault;
 
@@ -207,6 +211,12 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         return false;
     }
 
+
+    
+    
+    
+    
+    
     @Override
     public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
         if (mToggleLargeTextPreference == preference) {
@@ -220,6 +230,10 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
             return true;
         } else if (mToggleSpeakPasswordPreference == preference) {
             handleToggleSpeakPasswordPreferenceClick();
+            return true;
+        } else if (mDisplayMagnificationPreferenceScreen == preference) {
+            handleDisplayMagnificationPreferenceScreenClick();
+            return true;
         }
         return super.onPreferenceTreeClick(preferenceScreen, preference);
     }
@@ -252,17 +266,29 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                 mToggleSpeakPasswordPreference.isChecked() ? 1 : 0);
     }
 
+    private void handleDisplayMagnificationPreferenceScreenClick() {
+        Bundle extras = mDisplayMagnificationPreferenceScreen.getExtras();
+        extras.putString(EXTRA_TITLE, getString(
+                R.string.accessibility_screen_magnification_title));
+        extras.putString(EXTRA_SUMMARY, getString(
+                R.string.accessibility_screen_magnification_summary));
+        extras.putBoolean(EXTRA_CHECKED, Settings.Secure.getInt(getContentResolver(),
+                Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED, 0) == 1);
+        super.onPreferenceTreeClick(mDisplayMagnificationPreferenceScreen,
+                mDisplayMagnificationPreferenceScreen);
+    }
+
     private void initializeAllPreferences() {
         mServicesCategory = (PreferenceCategory) findPreference(SERVICES_CATEGORY);
         mSystemsCategory = (PreferenceCategory) findPreference(SYSTEM_CATEGORY);
 
         // Large text.
         mToggleLargeTextPreference =
-            (CheckBoxPreference) findPreference(TOGGLE_LARGE_TEXT_PREFERENCE);
+                (CheckBoxPreference) findPreference(TOGGLE_LARGE_TEXT_PREFERENCE);
 
         // Power button ends calls.
         mTogglePowerButtonEndsCallPreference =
-            (CheckBoxPreference) findPreference(TOGGLE_POWER_BUTTON_ENDS_CALL_PREFERENCE);
+                (CheckBoxPreference) findPreference(TOGGLE_POWER_BUTTON_ENDS_CALL_PREFERENCE);
         if (!KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_POWER)
                 || !Utils.isVoiceCapable(getActivity())) {
             mSystemsCategory.removePreference(mTogglePowerButtonEndsCallPreference);
@@ -270,15 +296,15 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
 
         // Lock screen rotation.
         mToggleLockScreenRotationPreference =
-            (CheckBoxPreference) findPreference(TOGGLE_LOCK_SCREEN_ROTATION_PREFERENCE);
+                (CheckBoxPreference) findPreference(TOGGLE_LOCK_SCREEN_ROTATION_PREFERENCE);
 
         // Speak passwords.
         mToggleSpeakPasswordPreference =
-            (CheckBoxPreference) findPreference(TOGGLE_SPEAK_PASSWORD_PREFERENCE);
+                (CheckBoxPreference) findPreference(TOGGLE_SPEAK_PASSWORD_PREFERENCE);
 
         // Long press timeout.
         mSelectLongPressTimeoutPreference =
-            (ListPreference) findPreference(SELECT_LONG_PRESS_TIMEOUT_PREFERENCE);
+                (ListPreference) findPreference(SELECT_LONG_PRESS_TIMEOUT_PREFERENCE);
         mSelectLongPressTimeoutPreference.setOnPreferenceChangeListener(this);
         if (mLongPressTimeoutValuetoTitleMap.size() == 0) {
             String[] timeoutValues = getResources().getStringArray(
@@ -288,13 +314,17 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                     R.array.long_press_timeout_selector_titles);
             final int timeoutValueCount = timeoutValues.length;
             for (int i = 0; i < timeoutValueCount; i++) {
-               mLongPressTimeoutValuetoTitleMap.put(timeoutValues[i], timeoutTitles[i]);
+                mLongPressTimeoutValuetoTitleMap.put(timeoutValues[i], timeoutTitles[i]);
             }
         }
 
         // Script injection.
         mToggleScriptInjectionPreference = (AccessibilityEnableScriptInjectionPreference)
-            findPreference(TOGGLE_SCRIPT_INJECTION_PREFERENCE);
+                findPreference(TOGGLE_SCRIPT_INJECTION_PREFERENCE);
+
+        // Display magnification.
+        mDisplayMagnificationPreferenceScreen = (PreferenceScreen) findPreference(
+                DISPLAY_MAGNIFICATION_PREFERENCE_SCREEN);
     }
 
     private void updateAllPreferences() {
@@ -313,7 +343,7 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         AccessibilityManager accessibilityManager = AccessibilityManager.getInstance(getActivity());
 
         List<AccessibilityServiceInfo> installedServices =
-            accessibilityManager.getInstalledAccessibilityServiceList();
+                accessibilityManager.getInstalledAccessibilityServiceList();
         Set<ComponentName> enabledServices = getEnabledServicesFromSettings(getActivity());
 
         final boolean accessibilityEnabled = Settings.Secure.getInt(getContentResolver(),
@@ -334,11 +364,11 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
 
             preference.setTitle(title);
             final boolean serviceEnabled = accessibilityEnabled
-                && enabledServices.contains(componentName);
+                    && enabledServices.contains(componentName);
             if (serviceEnabled) {
-                preference.setSummary(getString(R.string.accessibility_service_state_on));
+                preference.setSummary(getString(R.string.accessibility_feature_state_on));
             } else {
-                preference.setSummary(getString(R.string.accessibility_service_state_off));
+                preference.setSummary(getString(R.string.accessibility_feature_state_off));
             }
 
             preference.setOrder(i);
@@ -390,7 +420,7 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                         super.onBindView(view);
 
                         LinearLayout containerView =
-                            (LinearLayout) view.findViewById(R.id.message_container);
+                                (LinearLayout) view.findViewById(R.id.message_container);
                         containerView.setGravity(Gravity.CENTER);
 
                         TextView summaryView = (TextView) view.findViewById(R.id.summary);
@@ -423,7 +453,7 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                     Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR,
                     Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_DEFAULT);
             final boolean powerButtonEndsCall =
-                (incallPowerBehavior == Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_HANGUP);
+                    (incallPowerBehavior == Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_HANGUP);
             mTogglePowerButtonEndsCallPreference.setChecked(powerButtonEndsCall);
         }
 
@@ -443,9 +473,20 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         mSelectLongPressTimeoutPreference.setSummary(mLongPressTimeoutValuetoTitleMap.get(value));
 
         // Script injection.
-        final boolean  scriptInjectionAllowed = (Settings.Secure.getInt(getContentResolver(),
+        final boolean scriptInjectionAllowed = (Settings.Secure.getInt(getContentResolver(),
                 Settings.Secure.ACCESSIBILITY_SCRIPT_INJECTION, 0) == 1);
         mToggleScriptInjectionPreference.setInjectionAllowed(scriptInjectionAllowed);
+
+        // Screen magnification.
+        final boolean magnificationEnabled = Settings.Secure.getInt(getContentResolver(),
+                Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED, 0) == 1;
+        if (magnificationEnabled) {
+            mDisplayMagnificationPreferenceScreen.setSummary(
+                    R.string.accessibility_feature_state_on);            
+        } else {
+            mDisplayMagnificationPreferenceScreen.setSummary(
+                    R.string.accessibility_feature_state_off);
+        }
     }
 
     private void updateLockScreenRotationCheckbox() {
@@ -489,25 +530,28 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         switch (dialogId) {
             case DIALOG_ID_NO_ACCESSIBILITY_SERVICES:
                 return new AlertDialog.Builder(getActivity())
-                    .setTitle(R.string.accessibility_service_no_apps_title)
-                    .setMessage(R.string.accessibility_service_no_apps_message)
-                    .setPositiveButton(android.R.string.ok,
-                        new DialogInterface.OnClickListener() {
-                            public void onClick(DialogInterface dialog, int which) {
-                                // dismiss the dialog before launching the activity otherwise
-                                // the dialog removal occurs after onSaveInstanceState which
-                                // triggers an exception
-                                removeDialog(DIALOG_ID_NO_ACCESSIBILITY_SERVICES);
-                                String screenreaderMarketLink = SystemProperties.get(
-                                        SYSTEM_PROPERTY_MARKET_URL,
-                                        DEFAULT_SCREENREADER_MARKET_LINK);
-                                Uri marketUri = Uri.parse(screenreaderMarketLink);
-                                Intent marketIntent = new Intent(Intent.ACTION_VIEW, marketUri);
-                                startActivity(marketIntent);
-                            }
-                    })
-                    .setNegativeButton(android.R.string.cancel, null)
-                    .create();
+                        .setTitle(R.string.accessibility_service_no_apps_title)
+                        .setMessage(R.string.accessibility_service_no_apps_message)
+                        .setPositiveButton(android.R.string.ok,
+                                new DialogInterface.OnClickListener() {
+                                    public void onClick(DialogInterface dialog, int which) {
+                                        // dismiss the dialog before launching
+                                        // the activity otherwise
+                                        // the dialog removal occurs after
+                                        // onSaveInstanceState which
+                                        // triggers an exception
+                                        removeDialog(DIALOG_ID_NO_ACCESSIBILITY_SERVICES);
+                                        String screenreaderMarketLink = SystemProperties.get(
+                                                SYSTEM_PROPERTY_MARKET_URL,
+                                                DEFAULT_SCREENREADER_MARKET_LINK);
+                                        Uri marketUri = Uri.parse(screenreaderMarketLink);
+                                        Intent marketIntent = new Intent(Intent.ACTION_VIEW,
+                                                marketUri);
+                                        startActivity(marketIntent);
+                                    }
+                                })
+                        .setNegativeButton(android.R.string.cancel, null)
+                        .create();
             default:
                 return null;
         }
@@ -515,8 +559,8 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
 
     private void loadInstalledServices() {
         List<AccessibilityServiceInfo> installedServiceInfos =
-            AccessibilityManager.getInstance(getActivity())
-                .getInstalledAccessibilityServiceList();
+                AccessibilityManager.getInstance(getActivity())
+                        .getInstalledAccessibilityServiceList();
         Set<ComponentName> installedServices = sInstalledServices;
         installedServices.clear();
         final int installedServiceInfoCount = installedServiceInfos.size();
@@ -576,20 +620,6 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         }
     }
 
-    private static ToggleSwitch createAndAddActionBarToggleSwitch(Activity activity) {
-        ToggleSwitch toggleSwitch = new ToggleSwitch(activity);
-        final int padding = activity.getResources().getDimensionPixelSize(
-                R.dimen.action_bar_switch_padding);
-        toggleSwitch.setPadding(0, 0, padding, 0);
-        activity.getActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM,
-                ActionBar.DISPLAY_SHOW_CUSTOM);
-        activity.getActionBar().setCustomView(toggleSwitch,
-                new ActionBar.LayoutParams(ActionBar.LayoutParams.WRAP_CONTENT,
-                        ActionBar.LayoutParams.WRAP_CONTENT,
-                        Gravity.CENTER_VERTICAL | Gravity.END));
-        return toggleSwitch;
-    }
-
     public static class ToggleSwitch extends Switch {
 
         private OnBeforeCheckedChangeListener mOnBeforeListener;
@@ -621,87 +651,21 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
     }
 
     public static class ToggleAccessibilityServicePreferenceFragment
-            extends SettingsPreferenceFragment implements DialogInterface.OnClickListener {
+            extends ToggleFeaturePreferenceFragment implements DialogInterface.OnClickListener {
 
         private static final int DIALOG_ID_ENABLE_WARNING = 1;
         private static final int DIALOG_ID_DISABLE_WARNING = 2;
 
-        private String mPreferenceKey;
-
-        private ToggleSwitch mToggleSwitch;
-
         private CharSequence mEnableWarningTitle;
         private CharSequence mEnableWarningMessage;
         private CharSequence mDisableWarningTitle;
         private CharSequence mDisableWarningMessage;
 
-        private Preference mSummaryPreference;
-
-        private CharSequence mSettingsTitle;
-        private Intent mSettingsIntent;
-
         private int mShownDialogId;
 
-        // TODO: Showing sub-sub fragment does not handle the activity title
-        //       so we do it but this is wrong. Do a real fix when there is time.
-        private CharSequence mOldActivityTitle;
-
-        @Override
-        public void onCreate(Bundle savedInstanceState) {
-            super.onCreate(savedInstanceState);
-            PreferenceScreen preferenceScreen = getPreferenceManager().createPreferenceScreen(
-                    getActivity());
-            setPreferenceScreen(preferenceScreen);
-            mSummaryPreference = new Preference(getActivity()) {
-                @Override
-                protected void onBindView(View view) {
-                    super.onBindView(view);
-                    TextView summaryView = (TextView) view.findViewById(R.id.summary);
-                    summaryView.setText(getSummary());
-                    sendAccessibilityEvent(summaryView);
-                }
-
-                private void sendAccessibilityEvent(View view) {
-                    // Since the view is still not attached we create, populate,
-                    // and send the event directly since we do not know when it
-                    // will be attached and posting commands is not as clean.
-                    AccessibilityManager accessibilityManager =
-                        AccessibilityManager.getInstance(getActivity());
-                    if (accessibilityManager.isEnabled()) {
-                        AccessibilityEvent event = AccessibilityEvent.obtain();
-                        event.setEventType(AccessibilityEvent.TYPE_VIEW_FOCUSED);
-                        view.onInitializeAccessibilityEvent(event);
-                        view.dispatchPopulateAccessibilityEvent(event);
-                        accessibilityManager.sendAccessibilityEvent(event);
-                    }
-                }
-            };
-            mSummaryPreference.setPersistent(false);
-            mSummaryPreference.setLayoutResource(R.layout.text_description_preference);
-            preferenceScreen.addPreference(mSummaryPreference);
-        }
-
-        @Override
-        public void onViewCreated(View view, Bundle savedInstanceState) {
-            super.onViewCreated(view, savedInstanceState);
-            installActionBarToggleSwitch();
-            processArguments();
-            getListView().setDivider(null);
-            getListView().setEnabled(false);
-        }
-
         @Override
-        public void onDestroyView() {
-            getActivity().getActionBar().setCustomView(null);
-            if (mOldActivityTitle != null) {
-                getActivity().getActionBar().setTitle(mOldActivityTitle);
-            }
-            mToggleSwitch.setOnBeforeCheckedChangeListener(null);
-            super.onDestroyView();
-        }
-
         public void onPreferenceToggled(String preferenceKey, boolean enabled) {
-             // Parse the enabled services.
+            // Parse the enabled services.
             Set<ComponentName> enabledServices = getEnabledServicesFromSettings(getActivity());
 
             // Determine enabled services and accessibility state.
@@ -722,16 +686,17 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                 }
                 // Disabling the last service disables accessibility.
                 accessibilityEnabled = enabledAndInstalledServiceCount > 1
-                    || (enabledAndInstalledServiceCount == 1
-                            && !installedServices.contains(toggledService));
+                        || (enabledAndInstalledServiceCount == 1
+                        && !installedServices.contains(toggledService));
                 enabledServices.remove(toggledService);
             }
 
             // Update the enabled services setting.
             StringBuilder enabledServicesBuilder = new StringBuilder();
-            // Keep the enabled services even if they are not installed since we have
-            // no way to know whether the application restore process has completed.
-            // In general the system should be responsible for the clean up not settings.
+            // Keep the enabled services even if they are not installed since we
+            // have no way to know whether the application restore process has
+            // completed. In general the system should be responsible for the
+            // clean up not settings.
             for (ComponentName enabledService : enabledServices) {
                 enabledServicesBuilder.append(enabledService.flattenToString());
                 enabledServicesBuilder.append(ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR);
@@ -750,14 +715,6 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
         }
 
         @Override
-        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
-            super.onCreateOptionsMenu(menu, inflater);
-            MenuItem menuItem = menu.add(mSettingsTitle);
-            menuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
-            menuItem.setIntent(mSettingsIntent);
-        }
-
-        @Override
         public Dialog onCreateDialog(int dialogId) {
             CharSequence title = null;
             CharSequence message = null;
@@ -776,13 +733,13 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                     throw new IllegalArgumentException();
             }
             return new AlertDialog.Builder(getActivity())
-                .setTitle(title)
-                .setIconAttribute(android.R.attr.alertDialogIcon)
-                .setMessage(message)
-                .setCancelable(true)
-                .setPositiveButton(android.R.string.ok, this)
-                .setNegativeButton(android.R.string.cancel, this)
-                .create();
+                    .setTitle(title)
+                    .setIconAttribute(android.R.attr.alertDialogIcon)
+                    .setMessage(message)
+                    .setCancelable(true)
+                    .setPositiveButton(android.R.string.ok, this)
+                    .setNegativeButton(android.R.string.cancel, this)
+                    .create();
         }
 
         @Override
@@ -806,8 +763,9 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
             }
         }
 
-        private void installActionBarToggleSwitch() {
-            mToggleSwitch = createAndAddActionBarToggleSwitch(getActivity());
+        @Override
+        protected void onInstallActionBarToggleSwitch() {
+            super.onInstallActionBarToggleSwitch();
             mToggleSwitch.setOnBeforeCheckedChangeListener(new OnBeforeCheckedChangeListener() {
                 @Override
                 public boolean onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked) {
@@ -833,28 +791,9 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
             });
         }
 
-        private void processArguments() {
-            Bundle arguments = getArguments();
-
-            // Key.
-            mPreferenceKey = arguments.getString(EXTRA_PREFERENCE_KEY);
-
-            // Enabled.
-            final boolean enabled = arguments.getBoolean(EXTRA_CHECKED);
-            mToggleSwitch.setCheckedInternal(enabled);
-
-            // Title.
-            PreferenceActivity activity = (PreferenceActivity) getActivity();
-            if (!activity.onIsMultiPane() || activity.onIsHidingHeaders()) {
-                mOldActivityTitle = getActivity().getTitle();
-                String title = arguments.getString(EXTRA_TITLE);
-                getActivity().getActionBar().setTitle(title);
-            }
-
-            // Summary.
-            String summary = arguments.getString(EXTRA_SUMMARY);
-            mSummaryPreference.setSummary(summary);
-
+        @Override
+        protected void onProcessArguments(Bundle arguments) {
+            super.onProcessArguments(arguments);
             // Settings title and intent.
             String settingsTitle = arguments.getString(EXTRA_SETTINGS_TITLE);
             String settingsComponentName = arguments.getString(EXTRA_SETTINGS_COMPONENT_NAME);
@@ -867,22 +806,157 @@ public class AccessibilitySettings extends SettingsPreferenceFragment implements
                     setHasOptionsMenu(true);
                 }
             }
-
             // Enable warning title.
             mEnableWarningTitle = arguments.getCharSequence(
                     AccessibilitySettings.EXTRA_ENABLE_WARNING_TITLE);
-
             // Enable warning message.
             mEnableWarningMessage = arguments.getCharSequence(
                     AccessibilitySettings.EXTRA_ENABLE_WARNING_MESSAGE);
-
             // Disable warning title.
             mDisableWarningTitle = arguments.getString(
                     AccessibilitySettings.EXTRA_DISABLE_WARNING_TITLE);
-
             // Disable warning message.
             mDisableWarningMessage = arguments.getString(
                     AccessibilitySettings.EXTRA_DISABLE_WARNING_MESSAGE);
         }
     }
+
+    public static class ToggleScreenMagnificationPreferenceFragment
+            extends ToggleFeaturePreferenceFragment {
+        @Override
+        protected void onPreferenceToggled(String preferenceKey, boolean enabled) {
+            Settings.Secure.putInt(getContentResolver(),
+                    Settings.Secure.ACCESSIBILITY_DISPLAY_MAGNIFICATION_ENABLED, enabled? 1 : 0);
+        }
+
+        @Override
+        protected void onInstallActionBarToggleSwitch() {
+            super.onInstallActionBarToggleSwitch();
+            mToggleSwitch.setOnBeforeCheckedChangeListener(new OnBeforeCheckedChangeListener() {
+                @Override
+                public boolean onBeforeCheckedChanged(ToggleSwitch toggleSwitch, boolean checked) {
+                    toggleSwitch.setCheckedInternal(checked);
+                    getArguments().putBoolean(EXTRA_CHECKED, checked);
+                    onPreferenceToggled(mPreferenceKey, checked);
+                    return false;
+                }
+            });
+        }
+    }
+
+    public static abstract class ToggleFeaturePreferenceFragment
+            extends SettingsPreferenceFragment {
+
+        protected ToggleSwitch mToggleSwitch;
+
+        protected String mPreferenceKey;
+        protected Preference mSummaryPreference;
+
+        protected CharSequence mSettingsTitle;
+        protected Intent mSettingsIntent;
+
+        // TODO: Showing sub-sub fragment does not handle the activity title
+        // so we do it but this is wrong. Do a real fix when there is time.
+        private CharSequence mOldActivityTitle;
+
+        @Override
+        public void onCreate(Bundle savedInstanceState) {
+            super.onCreate(savedInstanceState);
+            PreferenceScreen preferenceScreen = getPreferenceManager().createPreferenceScreen(
+                    getActivity());
+            setPreferenceScreen(preferenceScreen);
+            mSummaryPreference = new Preference(getActivity()) {
+                @Override
+                protected void onBindView(View view) {
+                    super.onBindView(view);
+                    TextView summaryView = (TextView) view.findViewById(R.id.summary);
+                    summaryView.setText(getSummary());
+                    sendAccessibilityEvent(summaryView);
+                }
+
+                private void sendAccessibilityEvent(View view) {
+                    // Since the view is still not attached we create, populate,
+                    // and send the event directly since we do not know when it
+                    // will be attached and posting commands is not as clean.
+                    AccessibilityManager accessibilityManager =
+                            AccessibilityManager.getInstance(getActivity());
+                    if (accessibilityManager.isEnabled()) {
+                        AccessibilityEvent event = AccessibilityEvent.obtain();
+                        event.setEventType(AccessibilityEvent.TYPE_VIEW_FOCUSED);
+                        view.onInitializeAccessibilityEvent(event);
+                        view.dispatchPopulateAccessibilityEvent(event);
+                        accessibilityManager.sendAccessibilityEvent(event);
+                    }
+                }
+            };
+            mSummaryPreference.setPersistent(false);
+            mSummaryPreference.setLayoutResource(R.layout.text_description_preference);
+            preferenceScreen.addPreference(mSummaryPreference);
+        }
+
+        @Override
+        public void onViewCreated(View view, Bundle savedInstanceState) {
+            super.onViewCreated(view, savedInstanceState);
+            onInstallActionBarToggleSwitch();
+            onProcessArguments(getArguments());
+            getListView().setDivider(null);
+            getListView().setEnabled(false);
+        }
+
+        @Override
+        public void onDestroyView() {
+            getActivity().getActionBar().setCustomView(null);
+            if (mOldActivityTitle != null) {
+                getActivity().getActionBar().setTitle(mOldActivityTitle);
+            }
+            mToggleSwitch.setOnBeforeCheckedChangeListener(null);
+            super.onDestroyView();
+        }
+
+        protected abstract void onPreferenceToggled(String preferenceKey, boolean enabled);
+
+        @Override
+        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+            super.onCreateOptionsMenu(menu, inflater);
+            MenuItem menuItem = menu.add(mSettingsTitle);
+            menuItem.setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
+            menuItem.setIntent(mSettingsIntent);
+        }
+
+        protected void onInstallActionBarToggleSwitch() {
+            mToggleSwitch = createAndAddActionBarToggleSwitch(getActivity());
+        }
+
+        private ToggleSwitch createAndAddActionBarToggleSwitch(Activity activity) {
+            ToggleSwitch toggleSwitch = new ToggleSwitch(activity);
+            final int padding = activity.getResources().getDimensionPixelSize(
+                    R.dimen.action_bar_switch_padding);
+            toggleSwitch.setPadding(0, 0, padding, 0);
+            activity.getActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM,
+                    ActionBar.DISPLAY_SHOW_CUSTOM);
+            activity.getActionBar().setCustomView(toggleSwitch,
+                    new ActionBar.LayoutParams(ActionBar.LayoutParams.WRAP_CONTENT,
+                            ActionBar.LayoutParams.WRAP_CONTENT,
+                            Gravity.CENTER_VERTICAL | Gravity.END));
+            return toggleSwitch;
+        }
+
+        protected void onProcessArguments(Bundle arguments) {
+            // Key.
+            mPreferenceKey = arguments.getString(EXTRA_PREFERENCE_KEY);
+            // Enabled.
+            final boolean enabled = arguments.getBoolean(EXTRA_CHECKED);
+            mToggleSwitch.setCheckedInternal(enabled);
+            // Title.
+            PreferenceActivity activity = (PreferenceActivity) getActivity();
+            if (!activity.onIsMultiPane() || activity.onIsHidingHeaders()) {
+                mOldActivityTitle = getActivity().getTitle();
+                String title = arguments.getString(EXTRA_TITLE);
+                getActivity().getActionBar().setTitle(title);
+            }
+            // Summary.
+            String summary = arguments.getString(EXTRA_SUMMARY);
+            mSummaryPreference.setSummary(summary);
+        }
+    }
 }