Refine battery settings layout

- Add loading text to progress bar to prevent UI flaky
 - Setup enable/disable state for battery saver switch
 - Remove battery saver page divider

Bug: 177964551
Bug: 177964753
Bug: 184626649
Test: make SettingsRoboTests, visually
Change-Id: I8e05c0c0f02710729e1f59eff23fb3f425770de9

res/xml/battery_saver_settings.xml

@@ -37,26 +37,14 @@
         android:key="battery_saver_sticky"
         android:title="@string/battery_saver_sticky_title_new"
         android:summary="@string/summary_placeholder"
-        settings:allowDividerBelow="true"
         settings:keywords="@string/keywords_battery_saver_sticky"
         settings:controller="com.android.settings.fuelgauge.batterysaver.BatterySaverStickyPreferenceController"/>
 
-<!--    <com.android.settings.widget.TwoStateButtonPreference-->
-<!--        android:key="battery_saver"-->
-<!--        android:title="@string/battery_saver"-->
-<!--        android:selectable="false"-->
-<!--        android:summary="@string/battery_saver_turn_on_summary"-->
-<!--        settings:allowDividerBelow="true"-->
-<!--        settings:textOn="@string/battery_saver_button_turn_on"-->
-<!--        settings:textOff="@string/battery_saver_button_turn_off"-->
-<!--        settings:controller="com.android.settings.fuelgauge.batterysaver.BatterySaverButtonPreferenceController"/>-->
-
     <com.android.settingslib.widget.FooterPreference
         android:order="100"
         android:key="battery_saver_footer_preference"
         android:selectable="true"
         android:title="@*android:string/battery_saver_description"
-        settings:allowDividerAbove="true"
         settings:searchable="false"/>
 
 </PreferenceScreen>

src/com/android/settings/fuelgauge/BatteryHeaderPreferenceController.java

@@ -50,7 +50,6 @@ public class BatteryHeaderPreferenceController extends BasePreferenceController
         BatteryPreferenceController {
     @VisibleForTesting
     static final String KEY_BATTERY_HEADER = "battery_header";
-    private static final String ANNOTATION_URL = "url";
     private static final int BATTERY_MAX_LEVEL = 100;
 
     @VisibleForTesting
@@ -87,6 +86,9 @@ public class BatteryHeaderPreferenceController extends BasePreferenceController
     public void displayPreference(PreferenceScreen screen) {
         super.displayPreference(screen);
         mBatteryUsageProgressBarPref = screen.findPreference(getPreferenceKey());
+        //Set up loading text first to prevent layout flaky before info loaded.
+        mBatteryUsageProgressBarPref.setBottomSummary(
+                mContext.getString(R.string.settings_license_activity_loading));
 
         if (com.android.settings.Utils.isBatteryPresent(mContext)) {
             quickUpdateHeaderPreference();

src/com/android/settings/fuelgauge/batterysaver/BatterySaverButtonPreferenceController.java

@@ -122,5 +122,8 @@ public class BatterySaverButtonPreferenceController extends
 
     @Override
     public void onBatteryChanged(boolean pluggedIn) {
+        if (mPreference != null) {
+            mPreference.setEnabled(!pluggedIn);
+        }
     }
 }

tests/robotests/src/com/android/settings/fuelgauge/BatteryHeaderPreferenceControllerTest.java

@@ -317,6 +317,14 @@ public class BatteryHeaderPreferenceControllerTest {
         assertThat(mBatteryUsageProgressBarPref.isVisible()).isFalse();
     }
 
+    @Test
+    public void displayPreference_init_showLoading() {
+        mController.displayPreference(mPreferenceScreen);
+
+        verify(mBatteryUsageProgressBarPref).setBottomSummary(
+                mContext.getString(R.string.settings_license_activity_loading));
+    }
+
     private CharSequence formatBatteryPercentageText() {
         return TextUtils.expandTemplate(mContext.getText(R.string.battery_header_title_alternate),
                 NumberFormat.getIntegerInstance().format(BATTERY_LEVEL));

tests/robotests/src/com/android/settings/fuelgauge/batterysaver/BatterySaverButtonPreferenceControllerTest.java

@@ -103,6 +103,20 @@ public class BatterySaverButtonPreferenceControllerTest {
         verify(mPowerManager).setPowerSaveModeEnabled(false);
     }
 
+    @Test
+    public void onBatteryChanged_pluggedIn_preferenceDisabled() {
+        mController.onBatteryChanged(/* pluggedIn */ true);
+
+        assertThat(mPreference.isEnabled()).isFalse();
+    }
+
+    @Test
+    public void onBatteryChanged_unplugged_preferenceEnabled() {
+        mController.onBatteryChanged(/* pluggedIn */ false);
+
+        assertThat(mPreference.isEnabled()).isTrue();
+    }
+
     @Test
     public void isPublicSlice_returnsTrue() {
         assertThat(mController.isPublicSlice()).isTrue();