Show None default app in stylus preference if no Notes holder.

This also fixes the role holder not updating when the
default role holder has changed.

Test: StylusDevicesControllerTest
Bug: 254834764
Change-Id: Iec7ed7698f18279da9a04918dcdf3e20e73609d1

res/values/strings.xml

@@ -10778,6 +10778,9 @@
     <!-- Subtext of system default app for current setting [CHAR LIMIT=NONE] -->
     <string name="system_default_app_subtext">System default</string>
 
+    <!-- Summary of a default app when there is no app set [CHAR LIMIT=60] -->
+    <string name="default_app_none">None</string>
+
     <!-- Developer settings: text for the bug report handler selection toast shown if an invalid bug report handler was chosen. [CHAR LIMIT=NONE] -->
     <string name="select_invalid_bug_report_handler_toast_text">This choice is no longer valid. Try again.</string>
 

src/com/android/settings/connecteddevice/stylus/StylusDevicesController.java

@@ -85,16 +85,24 @@ public class StylusDevicesController extends AbstractPreferenceController implem
     }
 
     @Nullable
-    private Preference createDefaultNotesPreference() {
+    private Preference createOrUpdateDefaultNotesPreference(@Nullable Preference preference) {
         RoleManager rm = mContext.getSystemService(RoleManager.class);
-        if (rm == null) {
+        if (rm == null || !rm.isRoleAvailable(RoleManager.ROLE_NOTES)) {
             return null;
         }
 
+        Preference pref = preference == null ? new Preference(mContext) : preference;
+        pref.setKey(KEY_DEFAULT_NOTES);
+        pref.setTitle(mContext.getString(R.string.stylus_default_notes_app));
+        pref.setIcon(R.drawable.ic_article);
+        pref.setOnPreferenceClickListener(this);
+        pref.setEnabled(true);
+
         List<String> roleHolders = rm.getRoleHoldersAsUser(RoleManager.ROLE_NOTES,
                 mContext.getUser());
         if (roleHolders.isEmpty()) {
-            return null;
+            pref.setSummary(R.string.default_app_none);
+            return pref;
         }
 
         String packageName = roleHolders.get(0);
@@ -107,13 +115,6 @@ public class StylusDevicesController extends AbstractPreferenceController implem
         } catch (PackageManager.NameNotFoundException e) {
             Log.e(TAG, "Notes role package not found.");
         }
-
-        Preference pref = new Preference(mContext);
-        pref.setKey(KEY_DEFAULT_NOTES);
-        pref.setTitle(mContext.getString(R.string.stylus_default_notes_app));
-        pref.setIcon(R.drawable.ic_article);
-        pref.setOnPreferenceClickListener(this);
-        pref.setEnabled(true);
         pref.setSummary(appName);
         return pref;
     }
@@ -187,13 +188,11 @@ public class StylusDevicesController extends AbstractPreferenceController implem
     private void refresh() {
         if (!isAvailable()) return;
 
-        Preference notesPref = mPreferencesContainer.findPreference(KEY_DEFAULT_NOTES);
+        Preference currNotesPref = mPreferencesContainer.findPreference(KEY_DEFAULT_NOTES);
-        if (notesPref == null) {
+        Preference notesPref = createOrUpdateDefaultNotesPreference(currNotesPref);
-            notesPref = createDefaultNotesPreference();
+        if (currNotesPref == null && notesPref != null) {
-            if (notesPref != null) {
             mPreferencesContainer.addPreference(notesPref);
         }
-        }
 
         Preference handwritingPref = mPreferencesContainer.findPreference(KEY_HANDWRITING);
         // TODO(b/255732419): add proper InputMethodInfo conditional to show or hide

tests/robotests/src/com/android/settings/connecteddevice/stylus/StylusDevicesControllerTest.java

@@ -101,6 +101,7 @@ public class StylusDevicesControllerTest {
 
         when(mRm.getRoleHoldersAsUser(eq(RoleManager.ROLE_NOTES), any(UserHandle.class)))
                 .thenReturn(Collections.singletonList(NOTES_PACKAGE_NAME));
+        when(mRm.isRoleAvailable(RoleManager.ROLE_NOTES)).thenReturn(true);
         when(mContext.getPackageManager()).thenReturn(mPm);
         when(mPm.getApplicationInfo(eq(NOTES_PACKAGE_NAME),
                 any(PackageManager.ApplicationInfoFlags.class))).thenReturn(new ApplicationInfo());
@@ -235,16 +236,26 @@ public class StylusDevicesControllerTest {
     }
 
     @Test
-    public void defaultNotesPreference_noRoleHolder_hidesNotesRoleApp() {
+    public void defaultNotesPreference_roleHolderChanges_updatesPreference() {
+        showScreen(mController);
+        Preference defaultNotesPref = mPreferenceContainer.getPreference(0);
         when(mRm.getRoleHoldersAsUser(eq(RoleManager.ROLE_NOTES), any(UserHandle.class)))
                 .thenReturn(Collections.emptyList());
         showScreen(mController);
 
-        for (int i = 0; i < mPreferenceContainer.getPreferenceCount(); i++) {
+        assertThat(defaultNotesPref.getSummary().toString()).isEqualTo(
-            Preference pref = mPreferenceContainer.getPreference(i);
+                mContext.getString(R.string.default_app_none));
-            assertThat(pref.getTitle().toString()).isNotEqualTo(
-                    mContext.getString(R.string.stylus_default_notes_app));
     }
+
+    @Test
+    public void defaultNotesPreference_noRoleHolder_showNoneInSummary() {
+        when(mRm.getRoleHoldersAsUser(eq(RoleManager.ROLE_NOTES), any(UserHandle.class)))
+                .thenReturn(Collections.emptyList());
+        showScreen(mController);
+
+        Preference defaultNotesPref = mPreferenceContainer.getPreference(0);
+        assertThat(defaultNotesPref.getSummary().toString()).isEqualTo(
+                mContext.getString(R.string.default_app_none));
     }
 
     @Test