Improve launch time for Apps & notifications page

In original design, we reload usage data at least thrice
for showing recent apps.

For now, we only reload usage data once in constuctor.
And we reload data again when we are calling updateState.

Test: Open App & notifications page, and then I compare the lauch time
with P platform device.
Fixes: 126013076

Change-Id: Ida769f28a4419125e1948e36658686ee55bf51a5

tests/robotests/src/com/android/settings/applications/RecentAppsPreferenceControllerTest.java

@@ -25,9 +25,9 @@ import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.anyLong;
 import static org.mockito.ArgumentMatchers.argThat;
-import static org.mockito.Mockito.doNothing;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -146,6 +146,7 @@ public class RecentAppsPreferenceControllerTest {
         when(mUsageStatsManager.queryUsageStats(anyInt(), anyLong(), anyLong()))
                 .thenReturn(stats);
         mAppEntry.info = mApplicationInfo;
+        mController.reloadData();
 
         assertThat(mController.getAvailabilityStatus()).isEqualTo(AVAILABLE);
     }
@@ -157,13 +158,17 @@ public class RecentAppsPreferenceControllerTest {
     }
 
     @Test
-    public void displayPreferenceAndUpdateState_shouldRefreshUi() {
-        doNothing().when(mController).refreshUi();
-
+    public void displayPreference_shouldNotReloadData() {
         mController.displayPreference(mScreen);
-        mController.updateState(mScreen);
 
-        verify(mController, times(2)).refreshUi();
+        verify(mController, never()).reloadData();
+    }
+
+    @Test
+    public void displayPreference_shouldRefreshUi() {
+        mController.displayPreference(mScreen);
+
+        verify(mController).refreshUi();
     }
 
     @Test
@@ -173,6 +178,25 @@ public class RecentAppsPreferenceControllerTest {
         assertThat(mController.mAppEntitiesController).isNotNull();
     }
 
+    @Test
+    public void updateState_firstLaunch_shouldNotReloadData() {
+        mController.mIsFirstLaunch = true;
+
+        mController.updateState(mRecentAppsPreference);
+
+        verify(mController, never()).reloadData();
+    }
+
+    @Test
+    public void updateState_afterFirstLaunch_shouldReloadDataAndRefreshUi() {
+        mController.mIsFirstLaunch = false;
+
+        mController.updateState(mRecentAppsPreference);
+
+        verify(mController).reloadData();
+        verify(mController).refreshUi();
+    }
+
     @Test
     public void updateState_threeValidRecentOpenAppsSet_setAppEntityThreeTime() {
         final List<UsageStats> stats = new ArrayList<>();
@@ -203,6 +227,7 @@ public class RecentAppsPreferenceControllerTest {
         when(mUsageStatsManager.queryUsageStats(anyInt(), anyLong(), anyLong()))
                 .thenReturn(stats);
         mAppEntry.info = mApplicationInfo;
+        mController.mIsFirstLaunch = false;
 
         mController.updateState(mRecentAppsPreference);
 
@@ -243,6 +268,7 @@ public class RecentAppsPreferenceControllerTest {
         when(mUsageStatsManager.queryUsageStats(anyInt(), anyLong(), anyLong()))
                 .thenReturn(stats);
         mAppEntry.info = mApplicationInfo;
+        mController.mIsFirstLaunch = false;
 
         mController.updateState(mRecentAppsPreference);
 
@@ -274,6 +300,7 @@ public class RecentAppsPreferenceControllerTest {
         when(mUsageStatsManager.queryUsageStats(anyInt(), anyLong(), anyLong()))
                 .thenReturn(stats);
         mAppEntry.info = mApplicationInfo;
+        mController.mIsFirstLaunch = false;
 
         mController.updateState(mRecentAppsPreference);
 
@@ -314,6 +341,7 @@ public class RecentAppsPreferenceControllerTest {
         // Make sure stat2 is considered an instant app.
         ReflectionHelpers.setStaticField(AppUtils.class, "sInstantAppDataProvider",
                 (InstantAppDataProvider) (ApplicationInfo info) -> info == stat2Entry.info);
+        mController.mIsFirstLaunch = false;
 
         mController.updateState(mRecentAppsPreference);
 
@@ -389,6 +417,7 @@ public class RecentAppsPreferenceControllerTest {
                 .thenReturn(new ResolveInfo());
         when(mUsageStatsManager.queryUsageStats(anyInt(), anyLong(), anyLong()))
                 .thenReturn(stats);
+        mController.mIsFirstLaunch = false;
 
         mController.updateState(mRecentAppsPreference);