Modify the privacy controller to be selectable in the next updateState()

Listen WifiEntry#onUpdated() to update preference states will be modify
in next CLs.

Bug: 170148009
Test: make RunSettingsRoboTests ROBOTEST_FILTER=WifiPrivacyPreferenceController2Test
Change-Id: I5acf096970431a0b093dd7e0968f30c1959e3b7f
diff --git a/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2.java b/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2.java
index 76a8c5f..db8bd67 100644
--- a/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2.java
+++ b/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2.java
@@ -255,6 +255,11 @@
      * API call for refreshing the preferences in this fragment.
      */
     public void refreshPreferences() {
+        updatePreferenceStates();
+        displayPreferenceControllers();
+    }
+
+    protected void displayPreferenceControllers() {
         final PreferenceScreen screen = getPreferenceScreen();
         for (AbstractPreferenceController controller : mControllers) {
             // WifiDetailPreferenceController2 gets the callback WifiEntryCallback#onUpdated,
diff --git a/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2.java b/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2.java
index a0d4b16..60c1d99 100644
--- a/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2.java
+++ b/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2.java
@@ -69,12 +69,12 @@
     public void updateState(Preference preference) {
         final DropDownPreference dropDownPreference = (DropDownPreference) preference;
         final int randomizationLevel = getRandomizationValue();
+        final boolean isSelectable = mWifiEntry.canSetPrivacy();
+        preference.setSelectable(isSelectable);
         dropDownPreference.setValue(Integer.toString(randomizationLevel));
-        updateSummary(dropDownPreference, randomizationLevel);
-
-        // Makes preference not selectable, when this is a ephemeral network.
-        if (!mWifiEntry.canSetPrivacy()) {
-            preference.setSelectable(false);
+        if (isSelectable) {
+            updateSummary(dropDownPreference, randomizationLevel);
+        } else {
             dropDownPreference.setSummary(R.string.wifi_privacy_settings_ephemeral_summary);
         }
     }
diff --git a/tests/robotests/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2Test.java b/tests/robotests/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2Test.java
index 4b1a8ca..7f03623 100644
--- a/tests/robotests/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2Test.java
+++ b/tests/robotests/src/com/android/settings/wifi/details2/WifiNetworkDetailsFragment2Test.java
@@ -73,4 +73,46 @@
 
         verify(menuItem).setIcon(com.android.internal.R.drawable.ic_mode_edit);
     }
+
+    @Test
+    public void refreshPreferences_shouldUpdatePreferenceStates() {
+        final FakeWifiNetworkDetailsFragment2 fakeFragment = new FakeWifiNetworkDetailsFragment2();
+
+        fakeFragment.refreshPreferences();
+
+        assertThat(fakeFragment.isUpdatePreferenceStatesCalled()).isTrue();
+    }
+
+    @Test
+    public void refreshPreferences_shouldDisplayPreferenceControllers() {
+        final FakeWifiNetworkDetailsFragment2 fakeFragment = new FakeWifiNetworkDetailsFragment2();
+
+        fakeFragment.refreshPreferences();
+
+        assertThat(fakeFragment.isDisplayPreferenceControllersCalled()).isTrue();
+    }
+
+    // Fake WifiNetworkDetailsFragment2 to verify the protected functions
+    public class FakeWifiNetworkDetailsFragment2 extends WifiNetworkDetailsFragment2 {
+
+        private boolean mUpdatePreferenceStatesCalled;
+        private boolean mDisplayPreferenceControllersCalled;
+
+        @Override
+        protected void updatePreferenceStates() {
+            mUpdatePreferenceStatesCalled = true;
+        }
+
+        @Override
+        protected void displayPreferenceControllers() {
+            mDisplayPreferenceControllersCalled = true;
+        }
+
+        public boolean isUpdatePreferenceStatesCalled() {
+            return mUpdatePreferenceStatesCalled;
+        }
+        public boolean isDisplayPreferenceControllersCalled() {
+            return mDisplayPreferenceControllersCalled;
+        }
+    }
 }
diff --git a/tests/robotests/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2Test.java b/tests/robotests/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2Test.java
index 0414b1c..adf3a07 100644
--- a/tests/robotests/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2Test.java
+++ b/tests/robotests/src/com/android/settings/wifi/details2/WifiPrivacyPreferenceController2Test.java
@@ -105,4 +105,38 @@
 
         assertThat(mDropDownPreference.isSelectable()).isFalse();
     }
+
+    @Test
+    public void testUpdateState_canSetPrivacyInNextUpdate_shouldBeSelectable() {
+        // Return false in WifiEntry#canSetPrivacy to make preference un-selectable first.
+        when(mMockWifiEntry.canSetPrivacy()).thenReturn(false);
+
+        mPreferenceController.updateState(mDropDownPreference);
+
+        assertThat(mDropDownPreference.isSelectable()).isFalse();
+
+        // Return true in WifiEntry#canSetPrivacy to verify preference back to selectable.
+        when(mMockWifiEntry.canSetPrivacy()).thenReturn(true);
+
+        mPreferenceController.updateState(mDropDownPreference);
+
+        assertThat(mDropDownPreference.isSelectable()).isTrue();
+    }
+
+    @Test
+    public void testUpdateState_canNotSetPrivacyInNextUpdate_shouldNotSelectable() {
+        // Return true in WifiEntry#canSetPrivacy to make preference selectable first.
+        when(mMockWifiEntry.canSetPrivacy()).thenReturn(true);
+
+        mPreferenceController.updateState(mDropDownPreference);
+
+        assertThat(mDropDownPreference.isSelectable()).isTrue();
+
+        // Return false in WifiEntry#canSetPrivacy to verify preference back to un-selectable.
+        when(mMockWifiEntry.canSetPrivacy()).thenReturn(false);
+
+        mPreferenceController.updateState(mDropDownPreference);
+
+        assertThat(mDropDownPreference.isSelectable()).isFalse();
+    }
 }