A new ui flow for screen pinning feature

The purpose of this change is to resolve a number of security issue
around screen pinning.
See more detail go/screen-pinning-allows

There're a few change for Settings app.

- Rename the screen pinning to app pinning.
- Change the string description for app pinning.
- Pop up a warning dialog while user is enabling this feature.

Test: Rebuilt rom and see new ui flow.
Bug: 151332926
Change-Id: Ife07d7b95ab5dccb2aed7f2bc8fa32f97763bd63

res/values/strings.xml

@@ -9219,9 +9219,34 @@
     <string name="switch_off_text">Off</string>
 
     <!-- [CHAR LIMIT=28] Screen pinning title -->
-    <string name="screen_pinning_title">Screen pinning</string>
+    <string name="screen_pinning_title">App pinning</string>
-    <!-- [CHAR LIMIT=300] Screen pinning description -->
+    <!-- [CHAR LIMIT=none] Screen pinning description -->
-    <string name="screen_pinning_description">When this setting is turned on, you can use screen pinning to keep the current screen in view until you unpin.\n\nTo use screen pinning:\n\n1. Make sure screen pinning is turned on\n\n2. Open Overview\n\n3. Tap the app icon at the top of the screen, then tap Pin</string>
+    <string name="screen_pinning_description">
+        App pinning allows you to keep the current app in view until you unpin it. This feature can be used, for example, to let a trusted friend play a specific game.
+        \n\nWhen an app is pinned, the pinned app may open other apps and personal data may be accessible.
+        \n\nTo use app pinning:
+        \t\n1.\tTurn on app pinning
+        \t\n2.\tOpen Overview
+        \t\n3.\tTap the app icon at the top of the screen, then tap Pin
+    </string>
+    <!-- [CHAR LIMIT=none] Screen pinning description -->
+    <string name="screen_pinning_guest_mode_description">
+        App pinning allows you to keep the current app in view until you unpin it. This feature can be used, for example, to let a trusted friend play a specific game.
+        \n\nWhen an app is pinned, the pinned app may open other apps and personal data may be accessible.
+        \n\nIf you want to securely share your device with someone, try using a guest profile instead.
+        \n\nTo use app pinning:
+        \t\n1.\tTurn on app pinning
+        \t\n2.\tOpen Overview
+        \t\n3.\tTap the app icon at the top of the screen, then tap Pin
+    </string>
+    <!-- [CHAR LIMIT=300] Screen pinning title -->
+    <string name="screen_pinning_dialog_message">
+        When app is pinned:
+        \n\n\u2022\t\tPersonal data may be accessible
+        \n\t\t(such as contacts and email content)
+        \n\u2022\t\tPinned app may open other apps
+        \n\nOnly use app pinning with people you trust.
+    </string>
     <!-- [CHAR LIMIT=60] Unlock setting for screen pinning -->
     <string name="screen_pinning_unlock_pattern">Ask for unlock pattern before unpinning</string>
     <!-- [CHAR LIMIT=60] Unlock setting for screen pinning -->

src/com/android/settings/security/ScreenPinningSettings.java

@@ -18,6 +18,7 @@ package com.android.settings.security;
 import android.app.admin.DevicePolicyManager;
 import android.app.settings.SettingsEnums;
 import android.content.Context;
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 import android.os.UserHandle;
@@ -25,6 +26,7 @@ import android.provider.SearchIndexableResource;
 import android.provider.Settings;
 import android.widget.Switch;
 
+import androidx.appcompat.app.AlertDialog;
 import androidx.preference.Preference;
 import androidx.preference.Preference.OnPreferenceChangeListener;
 import androidx.preference.PreferenceScreen;
@@ -43,12 +45,13 @@ import com.android.settingslib.widget.FooterPreference;
 import java.util.Arrays;
 import java.util.List;
 
+
 /**
  * Screen pinning settings.
  */
 @SearchIndexable
 public class ScreenPinningSettings extends SettingsPreferenceFragment
-        implements SwitchBar.OnSwitchChangeListener {
+        implements SwitchBar.OnSwitchChangeListener, DialogInterface.OnClickListener {
 
     private static final String KEY_USE_SCREEN_LOCK = "use_screen_lock";
     private static final String KEY_FOOTER = "screen_pinning_settings_screen_footer";
@@ -78,9 +81,9 @@ public class ScreenPinningSettings extends SettingsPreferenceFragment
         mFooterPreference = root.findPreference(KEY_FOOTER);
 
         mSwitchBar = activity.getSwitchBar();
-        mSwitchBar.addOnSwitchChangeListener(this);
         mSwitchBar.show();
         mSwitchBar.setChecked(isLockToAppEnabled(getActivity()));
+        mSwitchBar.addOnSwitchChangeListener(this);
 
         updateDisplay();
     }
@@ -184,7 +187,26 @@ public class ScreenPinningSettings extends SettingsPreferenceFragment
      */
     @Override
     public void onSwitchChanged(Switch switchView, boolean isChecked) {
-        setLockToAppEnabled(isChecked);
+        if (isChecked) {
+            new AlertDialog.Builder(getContext())
+                    .setMessage(R.string.screen_pinning_dialog_message)
+                    .setPositiveButton(R.string.dlg_ok, this)
+                    .setNegativeButton(R.string.dlg_cancel, this)
+                    .setCancelable(false)
+                    .show();
+        } else {
+            setLockToAppEnabled(false);
+            updateDisplay();
+        }
+    }
+
+    @Override
+    public void onClick(DialogInterface dialogInterface, int which) {
+        if (which == DialogInterface.BUTTON_POSITIVE) {
+            setLockToAppEnabled(true);
+        } else {
+            mSwitchBar.setChecked(false);
+        }
         updateDisplay();
     }
 
@@ -210,14 +232,14 @@ public class ScreenPinningSettings extends SettingsPreferenceFragment
      * For search
      */
     public static final BaseSearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
-        new BaseSearchIndexProvider() {
+            new BaseSearchIndexProvider() {
 
-            @Override
+                @Override
-            public List<SearchIndexableResource> getXmlResourcesToIndex(Context context,
+                public List<SearchIndexableResource> getXmlResourcesToIndex(Context context,
-                    boolean enabled) {
+                        boolean enabled) {
-                final SearchIndexableResource sir = new SearchIndexableResource(context);
+                    final SearchIndexableResource sir = new SearchIndexableResource(context);
-                sir.xmlResId = R.xml.screen_pinning_settings;
+                    sir.xmlResId = R.xml.screen_pinning_settings;
-                return Arrays.asList(sir);
+                    return Arrays.asList(sir);
-            }
+                }
-        };
+            };
 }