[Contributions-Tab] Scroll to top on NavBar Button Pressed (#4668)

* [Contributions-Tab] Scroll to top on NavBar Button Pressed

On NavBar Contributions Button pressed, if already on the Contributions tab,
scroll to the top of the recyclerView in ContributionsListFragment.

* [UnitTest][Contributions-Tab] Scroll to Top on NavBar Button Pressed

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsFragment.java

@@ -204,6 +204,12 @@ public class ContributionsFragment
                 throwable -> Timber.e(throwable, "Error occurred while loading notifications")));
     }
 
+    public void scrollToTop( ){
+        if (contributionsListFragment != null) {
+            contributionsListFragment.scrollToTop();
+        }
+    }
+
     private void initNotificationViews(List<Notification> notificationList) {
         Timber.d("Number of notifications is %d", notificationList.size());
         if (notificationList.isEmpty()) {

app/src/main/java/fr/free/nrw/commons/contributions/ContributionsListFragment.java

@@ -312,6 +312,10 @@ public class ContributionsListFragment extends CommonsDaggerSupportFragment impl
         animateFAB(isFabOpen);
     }
 
+    public void scrollToTop() {
+        rvContributionsList.smoothScrollToPosition(0);
+    }
+
     private void animateFAB(final boolean isFabOpen) {
         this.isFabOpen = !isFabOpen;
         if (fabPlus.isShown()) {

app/src/main/java/fr/free/nrw/commons/contributions/MainActivity.java

@@ -163,7 +163,9 @@ public class MainActivity  extends BaseActivity
         //showBottom so that we do not show the bottom tray again when constructing
         //from the saved instance state.
         if (fragment instanceof ContributionsFragment) {
-            if (activeFragment == ActiveFragment.CONTRIBUTIONS) { // Do nothing if same tab
+            if (activeFragment == ActiveFragment.CONTRIBUTIONS) {
+                // scroll to top if already on the Contributions tab
+                contributionsFragment.scrollToTop();
                 return true;
             }
             contributionsFragment = (ContributionsFragment) fragment;

app/src/test/kotlin/fr/free/nrw/commons/contributions/ContributionsFragmentUnitTests.kt

@@ -29,6 +29,7 @@ import org.junit.runner.RunWith
 import org.mockito.ArgumentMatchers.*
 import org.mockito.Mock
 import org.mockito.Mockito.`when`
+import org.mockito.Mockito.verify
 import org.mockito.MockitoAnnotations
 import org.powermock.reflect.Whitebox
 import org.robolectric.Robolectric
@@ -217,6 +218,14 @@ class ContributionsFragmentUnitTests {
         fragment.updateLimitedConnectionToggle(menu)
     }
 
+    @Test
+    @Throws(Exception::class)
+    fun testScrollToTop(){
+        Shadows.shadowOf(Looper.getMainLooper()).idle()
+        fragment.scrollToTop()
+        verify(contributionsListFragment).scrollToTop()
+    }
+
     @Test
     @Throws(Exception::class)
     fun testOnAttach() {

app/src/test/kotlin/fr/free/nrw/commons/contributions/ContributionsListFragmentUnitTests.kt

@@ -24,6 +24,7 @@ import org.junit.runner.RunWith
 import org.mockito.ArgumentMatchers.anyInt
 import org.mockito.Mock
 import org.mockito.Mockito.`when`
+import org.mockito.Mockito.verify
 import org.mockito.MockitoAnnotations
 import org.powermock.reflect.Whitebox
 import org.robolectric.Robolectric
@@ -160,6 +161,14 @@ class ContributionsListFragmentUnitTests {
         fragment.getContributionStateAt(0)
     }
 
+    @Test
+    @Throws(Exception::class)
+    fun testOnScrollToTop() {
+        Shadows.shadowOf(Looper.getMainLooper()).idle()
+        fragment.scrollToTop()
+        verify(rvContributionsList).smoothScrollToPosition(0)
+    }
+
     @Test
     @Throws(Exception::class)
     fun testOnConfirmClicked() {

app/src/test/kotlin/fr/free/nrw/commons/contributions/MainActivityUnitTests.kt

@@ -24,6 +24,7 @@ import org.junit.Test
 import org.junit.runner.RunWith
 import org.mockito.Mock
 import org.mockito.Mockito.`when`
+import org.mockito.Mockito.verify
 import org.mockito.MockitoAnnotations
 import org.powermock.api.mockito.PowerMockito
 import org.robolectric.Robolectric
@@ -243,6 +244,21 @@ class MainActivityUnitTests {
         method.invoke(activity, contributionsFragment, false)
     }
 
+    @Test
+    @Throws(Exception::class)
+    fun testLoadFragmentCaseContributionsFragmentCaseTrue() {
+        activeFragment = ActiveFragment.CONTRIBUTIONS
+        activity.activeFragment = activeFragment
+        val method: Method = MainActivity::class.java.getDeclaredMethod(
+            "loadFragment",
+            Fragment::class.java,
+            Boolean::class.java
+        )
+        method.isAccessible = true
+        method.invoke(activity, contributionsFragment, false)
+        verify(contributionsFragment).scrollToTop();
+    }
+
     @Test
     @Throws(Exception::class)
     fun testLoadFragmentCaseNearbyParentFragmentCaseTrue() {